Aristotle - Works
[Translated under the editorship of W. D. Ross]
Organon I - Categories
2
Organon II - On Interpretation
47
Organon III - Prior Analytics
81
Organon IV - Posterior Analytics
221
Organon V - Topics
326
Organon VI - On Sophistical Refutations
533
Physics
602
On the Heavens
852
On Generation and Corruption
952
Meteorology
1033
On the Soul
1159
Parva Naturalia
1256
History of Animals
1389
On the Parts of Animals
1791
On the Motion of Animals
1966
On the Gait of Animals
1984
On the Generation of Animals
2 009
Metaphysics
2 205
Nicomachean Ethics
2 536
Politics
2 788
Athenian Constitution
3 050
Rhetoric
3 132
Poetics
3 308
Aristotle - Categories
[Translated by E. M. Edghill]
Things are said to be named 'equivocally' when, though they
have a common name, the definition corresponding with the
name differs for each. Thus, a real man and a figure in a picture
can both lay claim to the name 'animal'; yet these are
equivocally so named, for, though they have a common name,
the definition corresponding with the name differs for each. For
should any one define in what sense each is an animal, his
definition in the one case will be appropriate to that case only.
On the other hand, things are said to be named 'univocally'
which have both the name and the definition answering to the
name in common. A man and an ox are both 'animal', and these
are univocally so named, inasmuch as not only the name, but
also the definition, is the same in both cases: for if a man
should state in what sense each is an animal, the statement in
the one case would be identical with that in the other.
Things are said to be named 'derivatively', which derive their
name from some other name, but differ from it in termination.
Thus the grammarian derives his name from the word
'grammar', and the courageous man from the word 'courage'.
Forms of speech are either simple or composite. Examples of
the latter are such expressions as 'the man runs', 'the man
wins'; of the former 'man', 'ox', 'runs', 'wins'.
Of things themselves some are predicable of a subject, and are
never present in a subject. Thus 'man' is predicable of the
individual man, and is never present in a subject.
By being 'present in a subject' I do not mean present as parts
are present in a whole, but being incapable of existence apart
from the said subject.
Some things, again, are present in a subject, but are never
predicable of a subject. For instance, a certain point of
grammatical knowledge is present in the mind, but is not
predicable of any subject; or again, a certain whiteness may be
present in the body (for colour requires a material basis), yet it
is never predicable of anything.
Other things, again, are both predicable of a subject and present
in a subject. Thus while knowledge is present in the human
mind, it is predicable of grammar.
There is, lastly, a class of things which are neither present in a
subject nor predicable of a subject, such as the individual man
or the individual horse. But, to speak more generally, that which
is individual and has the character of a unit is never predicable
of a subject. Yet in some cases there is nothing to prevent such
being present in a subject. Thus a certain point of grammatical
knowledge is present in a subject.
When one thing is predicated of another, all that which is
predicable of the predicate will be predicable also of the subject.
Thus, 'man' is predicated of the individual man; but 'animal' is
predicated of 'man'; it will, therefore, be predicable of the
individual man also: for the individual man is both 'man' and
'animal'.
If genera are different and co-ordinate, their differentiae are
themselves different in kind. Take as an instance the genus
'animal' and the genus 'knowledge'. 'With feet', 'two-footed',
'winged', 'aquatic', are differentiae of 'animal'; the species of
knowledge are not distinguished by the same differentiae. One
species of knowledge does not differ from another in being
'two-footed'.
But where one genus is subordinate to another, there is nothing
to prevent their having the same differentiae: for the greater
class is predicated of the lesser, so that all the differentiae of
the predicate will be differentiae also of the subject.
Expressions which are in no way composite signify substance,
quantity, quality, relation, place, time, position, state, action, or
affection. To sketch my meaning roughly, examples of substance
are 'man' or 'the horse', of quantity, such terms as 'two cubits
long' or 'three cubits long', of quality, such attributes as 'white',
'grammatical'. 'Double', 'half, 'greater', fall under the category
of relation; 'in a the market place', 'in the Lyceum', under that of
place; 'yesterday', 'last year', under that of time. 'Lying', 'sitting',
are terms indicating position, 'shod', 'armed', state; 'to lance', 'to
cauterize', action; 'to be lanced', 'to be cauterized', affection.
No one of these terms, in and by itself, involves an affirmation;
it is by the combination of such terms that positive or negative
statements arise. For every assertion must, as is admitted, be
either true or false, whereas expressions which are not in any
way composite such as 'man', 'white', 'runs', 'wins', cannot be
either true or false.
Substance, in the truest and primary and most definite sense of
the word, is that which is neither predicable of a subject nor
present in a subject; for instance, the individual man or horse.
But in a secondary sense those things are called substances
within which, as species, the primary substances are included;
also those which, as genera, include the species. For instance,
the individual man is included in the species 'man', and the
genus to which the species belongs is 'animal'; these, therefore
- that is to say, the species 'man' and the genus 'animal, - are
termed secondary substances.
It is plain from what has been said that both the name and the
definition of the predicate must be predicable of the subject. For
instance, 'man' is predicted of the individual man. Now in this
case the name of the species man' is applied to the individual,
for we use the term 'man' in describing the individual; and the
definition of 'man' will also be predicated of the individual man,
for the individual man is both man and animal. Thus, both the
name and the definition of the species are predicable of the
individual.
With regard, on the other hand, to those things which are
present in a subject, it is generally the case that neither their
name nor their definition is predicable of that in which they are
present. Though, however, the definition is never predicable,
there is nothing in certain cases to prevent the name being
used. For instance, 'white' being present in a body is predicated
of that in which it is present, for a body is called white: the
definition, however, of the colour white' is never predicable of
the body.
Everything except primary substances is either predicable of a
primary substance or present in a primary substance. This
becomes evident by reference to particular instances which
occur. 'Animal' is predicated of the species 'man', therefore of
the individual man, for if there were no individual man of
whom it could be predicated, it could not be predicated of the
species 'man' at all. Again, colour is present in body, therefore in
individual bodies, for if there were no individual body in which
it was present, it could not be present in body at all. Thus
everything except primary substances is either predicated of
primary substances, or is present in them, and if these last did
not exist, it would be impossible for anything else to exist.
Of secondary substances, the species is more truly substance
than the genus, being more nearly related to primary substance.
For if any one should render an account of what a primary
substance is, he would render a more instructive account, and
one more proper to the subject, by stating the species than by
stating the genus. Thus, he would give a more instructive
account of an individual man by stating that he was man than
by stating that he was animal, for the former description is
peculiar to the individual in a greater degree, while the latter is
too general. Again, the man who gives an account of the nature
of an individual tree will give a more instructive account by
mentioning the species 'tree' than by mentioning the genus
'plant'.
Moreover, primary substances are most properly called
substances in virtue of the fact that they are the entities which
underlie every, else, and that everything else is either predicated
of them or present in them. Now the same relation which
subsists between primary substance and everything else
subsists also between the species and the genus: for the species
is to the genus as subject is to predicate, since the genus is
predicated of the species, whereas the species cannot be
predicated of the genus. Thus we have a second ground for
asserting that the species is more truly substance than the
genus.
Of species themselves, except in the case of such as are genera,
no one is more truly substance than another. We should not
give a more appropriate account of the individual man by
stating the species to which he belonged, than we should of an
individual horse by adopting the same method of definition. In
the same way, of primary substances, no one is more truly
substance than another; an individual man is not more truly
substance than an individual ox.
It is, then, with good reason that of all that remains, when we
exclude primary substances, we concede to species and genera
alone the name 'secondary substance', for these alone of all the
predicates convey a knowledge of primary substance. For it is by
stating the species or the genus that we appropriately define
any individual man; and we shall make our definition more
exact by stating the former than by stating the latter. All other
things that we state, such as that he is white, that he runs, and
so on, are irrelevant to the definition. Thus it is just that these
alone, apart from primary substances, should be called
substances.
Further, primary substances are most properly so called,
because they underlie and are the subjects of everything else.
Now the same relation that subsists between primary substance
and everything else subsists also between the species and the
genus to which the primary substance belongs, on the one
hand, and every attribute which is not included within these, on
the other. For these are the subjects of all such. If we call an
individual man 'skilled in grammar', the predicate is applicable
also to the species and to the genus to which he belongs. This
law holds good in all cases.
It is a common characteristic of all sub. stance that it is never
present in a subject. For primary substance is neither present in
a subject nor predicated of a subject; while, with regard to
secondary substances, it is clear from the following arguments
(apart from others) that they are not present in a subject. For
'man' is predicated of the individual man, but is not present in
any subject: for manhood is not present in the individual man.
In the same way, 'animal' is also predicated of the individual
man, but is not present in him. Again, when a thing is present
in a subject, though the name may quite well be applied to that
in which it is present, the definition cannot be applied. Yet of
secondary substances, not only the name, but also the
definition, applies to the subject: we should use both the
definition of the species and that of the genus with reference to
the individual man. Thus substance cannot be present in a
subject.
Yet this is not peculiar to substance, for it is also the case that
differentiae cannot be present in subjects. The characteristics
'terrestrial' and 'two-footed' are predicated of the species 'man',
but not present in it. For they are not in man. Moreover, the
definition of the differentia may be predicated of that of which
the differentia itself is predicated. For instance, if the
characteristic 'terrestrial' is predicated of the species 'man', the
definition also of that characteristic may be used to form the
predicate of the species 'man': for 'man' is terrestrial.
The fact that the parts of substances appear to be present in the
whole, as in a subject, should not make us apprehensive lest we
should have to admit that such parts are not substances: for in
explaining the phrase 'being present in a subject', we stated'
that we meant 'otherwise than as parts in a whole'.
It is the mark of substances and of differentiae that, in all
propositions of which they form the predicate, they are
predicated univocally. For all such propositions have for their
subject either the individual or the species. It is true that,
inasmuch as primary substance is not predicable of anything, it
can never form the predicate of any proposition. But of
secondary substances, the species is predicated of the
individual, the genus both of the species and of the individual.
Similarly the differentiae are predicated of the species and of
the individuals. Moreover, the definition of the species and that
of the genus are applicable to the primary substance, and that
of the genus to the species. For all that is predicated of the
predicate will be predicated also of the subject. Similarly, the
definition of the differentiae will be applicable to the species
and to the individuals. But it was stated above that the word
'univocal' was applied to those things which had both name
and definition in common. It is, therefore, established that in
every proposition, of which either substance or a differentia
forms the predicate, these are predicated univocally.
All substance appears to signify that which is individual. In the
case of primary substance this is indisputably true, for the thing
is a unit. In the case of secondary substances, when we speak,
for instance, of 'man' or 'animal', our form of speech gives the
impression that we are here also indicating that which is
individual, but the impression is not strictly true; for a
secondary substance is not an individual, but a class with a
certain qualification; for it is not one and single as a primary
substance is; the words 'man', 'animal', are predicable of more
than one subject.
Yet species and genus do not merely indicate quality, like the
term 'white'; 'white' indicates quality and nothing further, but
species and genus determine the quality with reference to a
substance: they signify substance qualitatively differentiated.
The determinate qualification covers a larger field in the case of
the genus that in that of the species: he who uses the word
'animal' is herein using a word of wider extension than he who
uses the word 'man'.
Another mark of substance is that it has no contrary. What
could be the contrary of any primary substance, such as the
individual man or animal? It has none. Nor can the species or
the genus have a contrary. Yet this characteristic is not peculiar
to substance, but is true of many other things, such as quantity.
There is nothing that forms the contrary of 'two cubits long' or
of 'three cubits long', or of 'ten', or of any such term. A man may
contend that 'much' is the contrary of 'little', or 'great' of 'small',
but of definite quantitative terms no contrary exists.
Substance, again, does not appear to admit of variation of
degree. I do not mean by this that one substance cannot be
more or less truly substance than another, for it has already
been stated' that this is the case; but that no single substance
admits of varying degrees within itself. For instance, one
particular substance, 'man', cannot be more or less man either
than himself at some other time or than some other man. One
man cannot be more man than another, as that which is white
may be more or less white than some other white object, or as
that which is beautiful may be more or less beautiful than some
other beautiful object. The same quality, moreover, is said to
10
subsist in a thing in varying degrees at different times. A body,
being white, is said to be whiter at one time than it was before,
or, being warm, is said to be warmer or less warm than at some
other time. But substance is not said to be more or less that
which it is: a man is not more truly a man at one time than he
was before, nor is anything, if it is substance, more or less what
it is. Substance, then, does not admit of variation of degree.
The most distinctive mark of substance appears to be that,
while remaining numerically one and the same, it is capable of
admitting contrary qualities. From among things other than
substance, we should find ourselves unable to bring forward any
which possessed this mark. Thus, one and the same colour
cannot be white and black. Nor can the same one action be
good and bad: this law holds good with everything that is not
substance. But one and the selfsame substance, while retaining
its identity, is yet capable of admitting contrary qualities. The
same individual person is at one time white, at another black, at
one time warm, at another cold, at one time good, at another
bad. This capacity is found nowhere else, though it might be
maintained that a statement or opinion was an exception to the
rule. The same statement, it is agreed, can be both true and
false. For if the statement 'he is sitting' is true, yet, when the
person in question has risen, the same statement will be false.
The same applies to opinions. For if any one thinks truly that a
person is sitting, yet, when that person has risen, this same
opinion, if still held, will be false. Yet although this exception
may be allowed, there is, nevertheless, a difference in the
manner in which the thing takes place. It is by themselves
changing that substances admit contrary qualities. It is thus
that that which was hot becomes cold, for it has entered into a
different state. Similarly that which was white becomes black,
and that which was bad good, by a process of change; and in the
same way in all other cases it is by changing that substances
are capable of admitting contrary qualities. But statements and
11
opinions themselves remain unaltered in all respects: it is by
the alteration in the facts of the case that the contrary quality
comes to be theirs. The statement 'he is sitting' remains
unaltered, but it is at one time true, at another false, according
to circumstances. What has been said of statements applies
also to opinions. Thus, in respect of the manner in which the
thing takes place, it is the peculiar mark of substance that it
should be capable of admitting contrary qualities; for it is by
itself changing that it does so.
If, then, a man should make this exception and contend that
statements and opinions are capable of admitting contrary
qualities, his contention is unsound. For statements and
opinions are said to have this capacity, not because they
themselves undergo modification, but because this modification
occurs in the case of something else. The truth or falsity of a
statement depends on facts, and not on any power on the part
of the statement itself of admitting contrary qualities. In short,
there is nothing which can alter the nature of statements and
opinions. As, then, no change takes place in themselves, these
cannot be said to be capable of admitting contrary qualities.
But it is by reason of the modification which takes place within
the substance itself that a substance is said to be capable of
admitting contrary qualities; for a substance admits within
itself either disease or health, whiteness or blackness. It is in
this sense that it is said to be capable of admitting contrary
qualities.
To sum up, it is a distinctive mark of substance, that, while
remaining numerically one and the same, it is capable of
admitting contrary qualities, the modification taking place
through a change in the substance itself.
Let these remarks suffice on the subject of substance.
12
Quantity is either discrete or continuous. Moreover, some
quantities are such that each part of the whole has a relative
position to the other parts: others have within them no such
relation of part to part.
Instances of discrete quantities are number and speech; of
continuous, lines, surfaces, solids, and, besides these, time and
place.
In the case of the parts of a number, there is no common
boundary at which they join. For example: two fives make ten,
but the two fives have no common boundary, but are separate;
the parts three and seven also do not join at any boundary. Nor,
to generalize, would it ever be possible in the case of number
that there should be a common boundary among the parts; they
are always separate. Number, therefore, is a discrete quantity.
The same is true of speech. That speech is a quantity is evident:
for it is measured in long and short syllables. I mean here that
speech which is vocal. Moreover, it is a discrete quantity for its
parts have no common boundary. There is no common
boundary at which the syllables join, but each is separate and
distinct from the rest.
A line, on the other hand, is a continuous quantity, for it is
possible to find a common boundary at which its parts join. In
the case of the line, this common boundary is the point; in the
case of the plane, it is the line: for the parts of the plane have
also a common boundary. Similarly you can find a common
boundary in the case of the parts of a solid, namely either a line
or a plane.
13
Space and time also belong to this class of quantities. Time,
past, present, and future, forms a continuous whole. Space,
likewise, is a continuous quantity; for the parts of a solid occupy
a certain space, and these have a common boundary; it follows
that the parts of space also, which are occupied by the parts of
the solid, have the same common boundary as the parts of the
solid. Thus, not only time, but space also, is a continuous
quantity, for its parts have a common boundary.
Quantities consist either of parts which bear a relative position
each to each, or of parts which do not. The parts of a line bear a
relative position to each other, for each lies somewhere, and it
would be possible to distinguish each, and to state the position
of each on the plane and to explain to what sort of part among
the rest each was contiguous. Similarly the parts of a plane
have position, for it could similarly be stated what was the
position of each and what sort of parts were contiguous. The
same is true with regard to the solid and to space. But it would
be impossible to show that the arts of a number had a relative
position each to each, or a particular position, or to state what
parts were contiguous. Nor could this be done in the case of
time, for none of the parts of time has an abiding existence, and
that which does not abide can hardly have position. It would be
better to say that such parts had a relative order, in virtue of one
being prior to another. Similarly with number: in counting, 'one'
is prior to 'two', and 'two' to 'three', and thus the parts of
number may be said to possess a relative order, though it would
be impossible to discover any distinct position for each. This
holds good also in the case of speech. None of its parts has an
abiding existence: when once a syllable is pronounced, it is not
possible to retain it, so that, naturally, as the parts do not abide,
they cannot have position. Thus, some quantities consist of
parts which have position, and some of those which have not.
14
Strictly speaking, only the things which I have mentioned
belong to the category of quantity: everything else that is called
quantitative is a quantity in a secondary sense. It is because we
have in mind some one of these quantities, properly so called,
that we apply quantitative terms to other things. We speak of
what is white as large, because the surface over which the
white extends is large; we speak of an action or a process as
lengthy, because the time covered is long; these things cannot
in their own right claim the quantitative epithet. For instance,
should any one explain how long an action was, his statement
would be made in terms of the time taken, to the effect that it
lasted a year, or something of that sort. In the same way, he
would explain the size of a white object in terms of surface, for
he would state the area which it covered. Thus the things
already mentioned, and these alone, are in their intrinsic nature
quantities; nothing else can claim the name in its own right,
but, if at all, only in a secondary sense.
Quantities have no contraries. In the case of definite quantities
this is obvious; thus, there is nothing that is the contrary of 'two
cubits long' or of 'three cubits long', or of a surface, or of any
such quantities. A man might, indeed, argue that 'much' was
the contrary of 'little', and 'great' of 'small'. But these are not
quantitative, but relative; things are not great or small
absolutely, they are so called rather as the result of an act of
comparison. For instance, a mountain is called small, a grain
large, in virtue of the fact that the latter is greater than others of
its kind, the former less. Thus there is a reference here to an
external standard, for if the terms 'great' and 'small' were used
absolutely, a mountain would never be called small or a grain
large. Again, we say that there are many people in a village, and
few in Athens, although those in the city are many times as
numerous as those in the village: or we say that a house has
many in it, and a theatre few, though those in the theatre far
outnumber those in the house. The terms 'two cubits long,
15
"three cubits long,' and so on indicate quantity, the terms 'great'
and 'small' indicate relation, for they have reference to an
external standard. It is, therefore, plain that these are to be
classed as relative.
Again, whether we define them as quantitative or not, they
have no contraries: for how can there be a contrary of an
attribute which is not to be apprehended in or by itself, but only
by reference to something external? Again, if 'great' and 'small'
are contraries, it will come about that the same subject can
admit contrary qualities at one and the same time, and that
things will themselves be contrary to themselves. For it
happens at times that the same thing is both small and great.
For the same thing may be small in comparison with one thing,
and great in comparison with another, so that the same thing
comes to be both small and great at one and the same time, and
is of such a nature as to admit contrary qualities at one and the
same moment. Yet it was agreed, when substance was being
discussed, that nothing admits contrary qualities at one and the
same moment. For though substance is capable of admitting
contrary qualities, yet no one is at the same time both sick and
healthy, nothing is at the same time both white and black. Nor
is there anything which is qualified in contrary ways at one and
the same time.
Moreover, if these were contraries, they would themselves be
contrary to themselves. For if 'great' is the contrary of 'small',
and the same thing is both great and small at the same time,
then 'small' or 'great' is the contrary of itself. But this is
impossible. The term 'great', therefore, is not the contrary of the
term 'small', nor 'much' of 'little'. And even though a man
should call these terms not relative but quantitative, they would
not have contraries.
16
It is in the case of space that quantity most plausibly appears to
admit of a contrary. For men define the term 'above' as the
contrary of 'below', when it is the region at the centre they
mean by 'below'; and this is so, because nothing is farther from
the extremities of the universe than the region at the centre.
Indeed, it seems that in defining contraries of every kind men
have recourse to a spatial metaphor, for they say that those
things are contraries which, within the same class, are
separated by the greatest possible distance.
Quantity does not, it appears, admit of variation of degree. One
thing cannot be two cubits long in a greater degree than
another. Similarly with regard to number: what is 'three' is not
more truly three than what is 'five' is five; nor is one set of three
more truly three than another set. Again, one period of time is
not said to be more truly time than another. Nor is there any
other kind of quantity, of all that have been mentioned, with
regard to which variation of degree can be predicated. The
category of quantity, therefore, does not admit of variation of
degree.
The most distinctive mark of quantity is that equality and
inequality are predicated of it. Each of the aforesaid quantities
is said to be equal or unequal. For instance, one solid is said to
be equal or unequal to another; number, too, and time can have
these terms applied to them, indeed can all those kinds of
quantity that have been mentioned.
That which is not a quantity can by no means, it would seem,
be termed equal or unequal to anything else. One particular
disposition or one particular quality, such as whiteness, is by no
means compared with another in terms of equality and
inequality but rather in terms of similarity. Thus it is the
distinctive mark of quantity that it can be called equal and
unequal.
17
Those things are called relative, which, being either said to be of
something else or related to something else, are explained by
reference to that other thing. For instance, the word 'superior' is
explained by reference to something else, for it is superiority
over something else that is meant. Similarly, the expression
'double' has this external reference, for it is the double of
something else that is meant. So it is with everything else of
this kind. There are, moreover, other relatives, e.g. habit,
disposition, perception, knowledge, and attitude. The
significance of all these is explained by a reference to
something else and in no other way. Thus, a habit is a habit of
something, knowledge is knowledge of something, attitude is
the attitude of something. So it is with all other relatives that
have been mentioned. Those terms, then, are called relative, the
nature of which is explained by reference to something else, the
preposition 'of or some other preposition being used to indicate
the relation. Thus, one mountain is called great in comparison
with son with another; for the mountain claims this attribute by
comparison with something. Again, that which is called similar
must be similar to something else, and all other such attributes
have this external reference. It is to be noted that lying and
standing and sitting are particular attitudes, but attitude is itself
a relative term. To lie, to stand, to be seated, are not themselves
attitudes, but take their name from the aforesaid attitudes.
It is possible for relatives to have contraries. Thus virtue has a
contrary, vice, these both being relatives; knowledge, too, has a
contrary, ignorance. But this is not the mark of all relatives;
'double' and 'triple' have no contrary, nor indeed has any such
term.
18
It also appears that relatives can admit of variation of degree.
For 'like' and 'unlike', 'equal' and 'unequal', have the
modifications 'more' and 'less' applied to them, and each of
these is relative in character: for the terms 'like' and 'unequal'
bear 'unequal' bear a reference to something external. Yet,
again, it is not every relative term that admits of variation of
degree. No term such as 'double' admits of this modification. All
relatives have correlatives: by the term 'slave' we mean the
slave of a master, by the term 'master', the master of a slave; by
'double', the double of its hall; by 'half, the half of its double; by
'greater', greater than that which is less; by 'less,' less than that
which is greater.
So it is with every other relative term; but the case we use to
express the correlation differs in some instances. Thus, by
knowledge we mean knowledge the knowable; by the knowable,
that which is to be apprehended by knowledge; by perception,
perception of the perceptible; by the perceptible, that which is
apprehended by perception.
Sometimes, however, reciprocity of correlation does not appear
to exist. This comes about when a blunder is made, and that to
which the relative is related is not accurately stated. If a man
states that a wing is necessarily relative to a bird, the connexion
between these two will not be reciprocal, for it will not be
possible to say that a bird is a bird by reason of its wings. The
reason is that the original statement was inaccurate, for the
wing is not said to be relative to the bird qua bird, since many
creatures besides birds have wings, but qua winged creature. If,
then, the statement is made accurate, the connexion will be
reciprocal, for we can speak of a wing, having reference
necessarily to a winged creature, and of a winged creature as
being such because of its wings.
19
Occasionally, perhaps, it is necessary to coin words, if no word
exists by which a correlation can adequately be explained. If we
define a rudder as necessarily having reference to a boat, our
definition will not be appropriate, for the rudder does not have
this reference to a boat qua boat, as there are boats which have
no rudders. Thus we cannot use the terms reciprocally, for the
word 'boat' cannot be said to find its explanation in the word
'rudder'. As there is no existing word, our definition would
perhaps be more accurate if we coined some word like
'ruddered' as the correlative of 'rudder'. If we express ourselves
thus accurately, at any rate the terms are reciprocally
connected, for the 'ruddered' thing is 'ruddered' in virtue of its
rudder. So it is in all other cases. A head will be more accurately
defined as the correlative of that which is 'headed', than as that
of an animal, for the animal does not have a head qua animal,
since many animals have no head.
Thus we may perhaps most easily comprehend that to which a
thing is related, when a name does not exist, if, from that which
has a name, we derive a new name, and apply it to that with
which the first is reciprocally connected, as in the aforesaid
instances, when we derived the word 'winged' from 'wing' and
from 'rudder'.
All relatives, then, if properly defined, have a correlative. I add
this condition because, if that to which they are related is stated
as haphazard and not accurately, the two are not found to be
interdependent. Let me state what I mean more clearly. Even in
the case of acknowledged correlatives, and where names exist
for each, there will be no interdependence if one of the two is
denoted, not by that name which expresses the correlative
notion, but by one of irrelevant significance. The term 'slave,' if
defined as related, not to a master, but to a man, or a biped, or
anything of that sort, is not reciprocally connected with that in
relation to which it is defined, for the statement is not exact.
20
Further, if one thing is said to be correlative with another, and
the terminology used is correct, then, though all irrelevant
attributes should be removed, and only that one attribute left in
virtue of which it was correctly stated to be correlative with that
other, the stated correlation will still exist. If the correlative of
'the slave' is said to be 'the master', then, though all irrelevant
attributes of the said 'master', such as 'biped', 'receptive of
knowledge', 'human', should be removed, and the attribute
'master' alone left, the stated correlation existing between him
and the slave will remain the same, for it is of a master that a
slave is said to be the slave. On the other hand, if, of two
correlatives, one is not correctly termed, then, when all other
attributes are removed and that alone is left in virtue of which it
was stated to be correlative, the stated correlation will be found
to have disappeared.
For suppose the correlative of 'the slave' should be said to be
'the man', or the correlative of 'the wing"the bird'; if the
attribute 'master' be withdrawn from' the man', the correlation
between 'the man' and 'the slave' will cease to exist, for if the
man is not a master, the slave is not a slave. Similarly, if the
attribute 'winged' be withdrawn from 'the bird', 'the wing' will
no longer be relative; for if the so-called correlative is not
winged, it follows that 'the wing' has no correlative.
Thus it is essential that the correlated terms should be exactly
designated; if there is a name existing, the statement will be
easy; if not, it is doubtless our duty to construct names. When
the terminology is thus correct, it is evident that all correlatives
are interdependent.
Correlatives are thought to come into existence simultaneously.
This is for the most part true, as in the case of the double and
the half. The existence of the half necessitates the existence of
that of which it is a half. Similarly the existence of a master
21
necessitates the existence of a slave, and that of a slave implies
that of a master; these are merely instances of a general rule.
Moreover, they cancel one another; for if there is no double it
follows that there is no half, and vice versa; this rule also
applies to all such correlatives. Yet it does not appear to be true
in all cases that correlatives come into existence
simultaneously. The object of knowledge would appear to exist
before knowledge itself, for it is usually the case that we acquire
knowledge of objects already existing; it would be difficult, if
not impossible, to find a branch of knowledge the beginning of
the existence of which was contemporaneous with that of its
object.
Again, while the object of knowledge, if it ceases to exist,
cancels at the same time the knowledge which was its
correlative, the converse of this is not true. It is true that if the
object of knowledge does not exist there can be no knowledge:
for there will no longer be anything to know. Yet it is equally
true that, if knowledge of a certain object does not exist, the
object may nevertheless quite well exist. Thus, in the case of the
squaring of the circle, if indeed that process is an object of
knowledge, though it itself exists as an object of knowledge, yet
the knowledge of it has not yet come into existence. Again, if all
animals ceased to exist, there would be no knowledge, but there
might yet be many objects of knowledge.
This is likewise the case with regard to perception: for the
object of perception is, it appears, prior to the act of perception.
If the perceptible is annihilated, perception also will cease to
exist; but the annihilation of perception does not cancel the
existence of the perceptible. For perception implies a body
perceived and a body in which perception takes place. Now if
that which is perceptible is annihilated, it follows that the body
is annihilated, for the body is a perceptible thing; and if the
body does not exist, it follows that perception also ceases to
22
exist. Thus the annihilation of the perceptible involves that of
perception.
But the annihilation of perception does not involve that of the
perceptible. For if the animal is annihilated, it follows that
perception also is annihilated, but perceptibles such as body,
heat, sweetness, bitterness, and so on, will remain.
Again, perception is generated at the same time as the
perceiving subject, for it comes into existence at the same time
as the animal. But the perceptible surely exists before
perception; for fire and water and such elements, out of which
the animal is itself composed, exist before the animal is an
animal at all, and before perception. Thus it would seem that
the perceptible exists before perception.
It may be questioned whether it is true that no substance is
relative, as seems to be the case, or whether exception is to be
made in the case of certain secondary substances. With regard
to primary substances, it is quite true that there is no such
possibility, for neither wholes nor parts of primary substances
are relative. The individual man or ox is not defined with
reference to something external. Similarly with the parts: a
particular hand or head is not defined as a particular hand or
head of a particular person, but as the hand or head of a
particular person. It is true also, for the most part at least, in the
case of secondary substances; the species 'man' and the species
'ox' are not defined with reference to anything outside
themselves. Wood, again, is only relative in so far as it is some
one's property, not in so far as it is wood. It is plain, then, that in
the cases mentioned substance is not relative. But with regard
to some secondary substances there is a difference of opinion;
thus, such terms as 'head' and 'hand' are defined with reference
to that of which the things indicated are a part, and so it comes
about that these appear to have a relative character. Indeed, if
23
our definition of that which is relative was complete, it is very
difficult, if not impossible, to prove that no substance is relative.
If, however, our definition was not complete, if those things only
are properly called relative in the case of which relation to an
external object is a necessary condition of existence, perhaps
some explanation of the dilemma may be found.
The former definition does indeed apply to all relatives, but the
fact that a thing is explained with reference to something else
does not make it essentially relative.
From this it is plain that, if a man definitely apprehends a
relative thing, he will also definitely apprehend that to which it
is relative. Indeed this is self-evident: for if a man knows that
some particular thing is relative, assuming that we call that a
relative in the case of which relation to something is a
necessary condition of existence, he knows that also to which it
is related. For if he does not know at all that to which it is
related, he will not know whether or not it is relative. This is
clear, moreover, in particular instances. If a man knows
definitely that such and such a thing is 'double', he will also
forthwith know definitely that of which it is the double. For if
there is nothing definite of which he knows it to be the double,
he does not know at all that it is double. Again, if he knows that
a thing is more beautiful, it follows necessarily that he will
forthwith definitely know that also than which it is more
beautiful. He will not merely know indefinitely that it is more
beautiful than something which is less beautiful, for this would
be supposition, not knowledge. For if he does not know
definitely that than which it is more beautiful, he can no longer
claim to know definitely that it is more beautiful than
something else which is less beautiful: for it might be that
nothing was less beautiful. It is, therefore, evident that if a man
apprehends some relative thing definitely, he necessarily knows
that also definitely to which it is related.
24
Now the head, the hand, and such things are substances, and it
is possible to know their essential character definitely, but it
does not necessarily follow that we should know that to which
they are related. It is not possible to know forthwith whose
head or hand is meant. Thus these are not relatives, and, this
being the case, it would be true to say that no substance is
relative in character. It is perhaps a difficult matter, in such
cases, to make a positive statement without more exhaustive
examination, but to have raised questions with regard to details
is not without advantage.
8
By 'quality' I mean that in virtue of which people are said to be
such and such.
Quality is a term that is used in many senses. One sort of
quality let us call 'habit' or 'disposition'. Habit differs from
disposition in being more lasting and more firmly established.
The various kinds of knowledge and of virtue are habits, for
knowledge, even when acquired only in a moderate degree, is, it
is agreed, abiding in its character and difficult to displace,
unless some great mental upheaval takes place, through disease
or any such cause. The virtues, also, such as justice, self-
restraint, and so on, are not easily dislodged or dismissed, so as
to give place to vice.
By a disposition, on the other hand, we mean a condition that is
easily changed and quickly gives place to its opposite. Thus,
heat, cold, disease, health, and so on are dispositions. For a man
is disposed in one way or another with reference to these, but
quickly changes, becoming cold instead of warm, ill instead of
well. So it is with all other dispositions also, unless through
25
lapse of time a disposition has itself become inveterate and
almost impossible to dislodge: in which case we should perhaps
go so far as to call it a habit.
It is evident that men incline to call those conditions habits
which are of a more or less permanent type and difficult to
displace; for those who are not retentive of knowledge, but
volatile, are not said to have such and such a 'habit' as regards
knowledge, yet they are disposed, we may say, either better or
worse, towards knowledge. Thus habit differs from disposition
in this, that while the latter in ephemeral, the former is
permanent and difficult to alter.
Habits are at the same time dispositions, but dispositions are
not necessarily habits. For those who have some specific habit
may be said also, in virtue of that habit, to be thus or thus
disposed; but those who are disposed in some specific way have
not in all cases the corresponding habit.
Another sort of quality is that in virtue of which, for example,
we call men good boxers or runners, or healthy or sickly: in fact
it includes all those terms which refer to inborn capacity or
incapacity. Such things are not predicated of a person in virtue
of his disposition, but in virtue of his inborn capacity or
incapacity to do something with ease or to avoid defeat of any
kind. Persons are called good boxers or good runners, not in
virtue of such and such a disposition, but in virtue of an inborn
capacity to accomplish something with ease. Men are called
healthy in virtue of the inborn capacity of easy resistance to
those unhealthy influences that may ordinarily arise; unhealthy,
in virtue of the lack of this capacity. Similarly with regard to
softness and hardness. Hardness is predicated of a thing
because it has that capacity of resistance which enables it to
withstand disintegration; softness, again, is predicated of a
thing by reason of the lack of that capacity.
26
A third class within this category is that of affective qualities
and affections. Sweetness, bitterness, sourness, are examples of
this sort of quality, together with all that is akin to these; heat,
moreover, and cold, whiteness, and blackness are affective
qualities. It is evident that these are qualities, for those things
that possess them are themselves said to be such and such by
reason of their presence. Honey is called sweet because it
contains sweetness; the body is called white because it contains
whiteness; and so in all other cases.
The term 'affective quality' is not used as indicating that those
things which admit these qualities are affected in any way.
Honey is not called sweet because it is affected in a specific way,
nor is this what is meant in any other instance. Similarly heat
and cold are called affective qualities, not because those things
which admit them are affected. What is meant is that these said
qualities are capable of producing an 'affection' in the way of
perception. For sweetness has the power of affecting the sense
of taste; heat, that of touch; and so it is with the rest of these
qualities.
Whiteness and blackness, however, and the other colours, are
not said to be affective qualities in this sense, but - because
they themselves are the results of an affection. It is plain that
many changes of colour take place because of affections. When
a man is ashamed, he blushes; when he is afraid, he becomes
pale, and so on. So true is this, that when a man is by nature
liable to such affections, arising from some concomitance of
elements in his constitution, it is a probable inference that he
has the corresponding complexion of skin. For the same
disposition of bodily elements, which in the former instance
was momentarily present in the case of an access of shame,
might be a result of a man's natural temperament, so as to
produce the corresponding colouring also as a natural
characteristic. All conditions, therefore, of this kind, if caused by
27
certain permanent and lasting affections, are called affective
qualities. For pallor and duskiness of complexion are called
qualities, inasmuch as we are said to be such and such in virtue
of them, not only if they originate in natural constitution, but
also if they come about through long disease or sunburn, and
are difficult to remove, or indeed remain throughout life. For in
the same way we are said to be such and such because of these.
Those conditions, however, which arise from causes which may
easily be rendered ineffective or speedily removed, are called,
not qualities, but affections: for we are not said to be such
virtue of them. The man who blushes through shame is not said
to be a constitutional blusher, nor is the man who becomes pale
through fear said to be constitutionally pale. He is said rather to
have been affected.
Thus such conditions are called affections, not qualities.
In like manner there are affective qualities and affections of the
soul. That temper with which a man is born and which has its
origin in certain deep-seated affections is called a quality. I
mean such conditions as insanity, irascibility, and so on: for
people are said to be mad or irascible in virtue of these.
Similarly those abnormal psychic states which are not inborn,
but arise from the concomitance of certain other elements, and
are difficult to remove, or altogether permanent, are called
qualities, for in virtue of them men are said to be such and
such.
Those, however, which arise from causes easily rendered
ineffective are called affections, not qualities. Suppose that a
man is irritable when vexed: he is not even spoken of as a bad-
tempered man, when in such circumstances he loses his
temper somewhat, but rather is said to be affected. Such
conditions are therefore termed, not qualities, but affections.
28
The fourth sort of quality is figure and the shape that belongs to
a thing; and besides this, straightness and curvedness and any
other qualities of this type; each of these defines a thing as
being such and such. Because it is triangular or quadrangular a
thing is said to have a specific character, or again because it is
straight or curved; in fact a thing's shape in every case gives rise
to a qualification of it.
Rarity and density, roughness and smoothness, seem to be
terms indicating quality: yet these, it would appear, really
belong to a class different from that of quality. For it is rather a
certain relative position of the parts composing the thing thus
qualified which, it appears, is indicated by each of these terms.
A thing is dense, owing to the fact that its parts are closely
combined with one another; rare, because there are interstices
between the parts; smooth, because its parts lie, so to speak,
evenly; rough, because some parts project beyond others.
There may be other sorts of quality, but those that are most
properly so called have, we may safely say, been enumerated.
These, then, are qualities, and the things that take their name
from them as derivatives, or are in some other way dependent
on them, are said to be qualified in some specific way. In most,
indeed in almost all cases, the name of that which is qualified is
derived from that of the quality. Thus the terms 'whiteness',
'grammar', 'justice', give us the adjectives 'white', 'grammatical',
'just', and so on.
There are some cases, however, in which, as the quality under
consideration has no name, it is impossible that those
possessed of it should have a name that is derivative. For
instance, the name given to the runner or boxer, who is so
called in virtue of an inborn capacity, is not derived from that of
any quality; for lob those capacities have no name assigned to
them. In this, the inborn capacity is distinct from the science,
29
with reference to which men are called, e.g. boxers or wrestlers.
Such a science is classed as a disposition; it has a name, and is
called 'boxing' or 'wrestling' as the case may be, and the name
given to those disposed in this way is derived from that of the
science. Sometimes, even though a name exists for the quality,
that which takes its character from the quality has a name that
is not a derivative. For instance, the upright man takes his
character from the possession of the quality of integrity, but the
name given him is not derived from the word 'integrity'. Yet this
does not occur often.
We may therefore state that those things are said to be
possessed of some specific quality which have a name derived
from that of the aforesaid quality, or which are in some other
way dependent on it.
One quality may be the contrary of another; thus justice is the
contrary of injustice, whiteness of blackness, and so on. The
things, also, which are said to be such and such in virtue of
these qualities, may be contrary the one to the other; for that
which is unjust is contrary to that which is just, that which is
white to that which is black. This, however, is not always the
case. Red, yellow, and such colours, though qualities, have no
contraries.
If one of two contraries is a quality, the other will also be a
quality. This will be evident from particular instances, if we
apply the names used to denote the other categories; for
instance, granted that justice is the contrary of injustice and
justice is a quality, injustice will also be a quality: neither
quantity, nor relation, nor place, nor indeed any other category
but that of quality, will be applicable properly to injustice. So it
is with all other contraries falling under the category of quality.
Qualities admit of variation of degree. Whiteness is predicated
of one thing in a greater or less degree than of another. This is
30
also the case with reference to justice. Moreover, one and the
same thing may exhibit a quality in a greater degree than it did
before: if a thing is white, it may become whiter.
Though this is generally the case, there are exceptions. For if we
should say that justice admitted of variation of degree,
difficulties might ensue, and this is true with regard to all those
qualities which are dispositions. There are some, indeed, who
dispute the possibility of variation here. They maintain that
justice and health cannot very well admit of variation of degree
themselves, but that people vary in the degree in which they
possess these qualities, and that this is the case with
grammatical learning and all those qualities which are classed
as dispositions. However that may be, it is an incontrovertible
fact that the things which in virtue of these qualities are said to
be what they are vary in the degree in which they possess them;
for one man is said to be better versed in grammar, or more
healthy or just, than another, and so on.
The qualities expressed by the terms 'triangular' and
'quadrangular' do not appear to admit of variation of degree,
nor indeed do any that have to do with figure. For those things
to which the definition of the triangle or circle is applicable are
all equally triangular or circular. Those, on the other hand, to
which the same definition is not applicable, cannot be said to
differ from one another in degree; the square is no more a circle
than the rectangle, for to neither is the definition of the circle
appropriate. In short, if the definition of the term proposed is
not applicable to both objects, they cannot be compared. Thus it
is not all qualities which admit of variation of degree.
Whereas none of the characteristics I have mentioned are
peculiar to quality, the fact that likeness and unlikeness can be
predicated with reference to quality only, gives to that category
its distinctive feature. One thing is like another only with
31
reference to that in virtue of which it is such and such; thus this
forms the peculiar mark of quality.
We must not be disturbed because it may be argued that,
though proposing to discuss the category of quality, we have
included in it many relative terms. We did say that habits and
dispositions were relative. In practically all such cases the genus
is relative, the individual not. Thus knowledge, as a genus, is
explained by reference to something else, for we mean a
knowledge of something. But particular branches of knowledge
are not thus explained. The knowledge of grammar is not
relative to anything external, nor is the knowledge of music, but
these, if relative at all, are relative only in virtue of their genera;
thus grammar is said be the knowledge of something, not the
grammar of something; similarly music is the knowledge of
something, not the music of something.
Thus individual branches of knowledge are not relative. And it
is because we possess these individual branches of knowledge
that we are said to be such and such. It is these that we actually
possess: we are called experts because we possess knowledge in
some particular branch. Those particular branches, therefore, of
knowledge, in virtue of which we are sometimes said to be such
and such, are themselves qualities, and are not relative. Further,
if anything should happen to fall within both the category of
quality and that of relation, there would be nothing
extraordinary in classing it under both these heads.
Action and affection both admit of contraries and also of
variation of degree. Heating is the contrary of cooling, being
heated of being cooled, being glad of being vexed. Thus they
32
admit of contraries. They also admit of variation of degree: for it
is possible to heat in a greater or less degree; also to be heated
in a greater or less degree. Thus action and affection also admit
of variation of degree. So much, then, is stated with regard to
these categories.
We spoke, moreover, of the category of position when we were
dealing with that of relation, and stated that such terms derived
their names from those of the corresponding attitudes.
As for the rest, time, place, state, since they are easily
intelligible, I say no more about them than was said at the
beginning, that in the category of state are included such states
as 'shod', 'armed', in that of place 'in the Lyceum' and so on, as
was explained before.
10
The proposed categories have, then, been adequately dealt with.
We must next explain the various senses in which the term
'opposite' is used. Things are said to be opposed in four senses:
(i) as correlatives to one another, (ii) as contraries to one
another, (iii) as privatives to positives, (iv) as affirmatives to
negatives.
Let me sketch my meaning in outline. An instance of the use of
the word 'opposite' with reference to correlatives is afforded by
the expressions 'double' and 'half; with reference to contraries
by 'bad' and 'good'. Opposites in the sense of 'privatives' and
'positives' are' blindness' and 'sight'; in the sense of
affirmatives and negatives, the propositions 'he sits', 'he does
not sit'.
33
(i) Pairs of opposites which fall under the category of relation
are explained by a reference of the one to the other, the
reference being indicated by the preposition 'of or by some
other preposition. Thus, double is a relative term, for that which
is double is explained as the double of something. Knowledge,
again, is the opposite of the thing known, in the same sense;
and the thing known also is explained by its relation to its
opposite, knowledge. For the thing known is explained as that
which is known by something, that is, by knowledge. Such
things, then, as are opposite the one to the other in the sense of
being correlatives are explained by a reference of the one to the
other.
(ii) Pairs of opposites which are contraries are not in any way
interdependent, but are contrary the one to the other. The good
is not spoken of as the good of the had, but as the contrary of
the bad, nor is white spoken of as the white of the black, but as
the contrary of the black. These two types of opposition are
therefore distinct. Those contraries which are such that the
subjects in which they are naturally present, or of which they
are predicated, must necessarily contain either the one or the
other of them, have no intermediate, but those in the case of
which no such necessity obtains, always have an intermediate.
Thus disease and health are naturally present in the body of an
animal, and it is necessary that either the one or the other
should be present in the body of an animal. Odd and even,
again, are predicated of number, and it is necessary that the one
or the other should be present in numbers. Now there is no
intermediate between the terms of either of these two pairs. On
the other hand, in those contraries with regard to which no
such necessity obtains, we find an intermediate. Blackness and
whiteness are naturally present in the body, but it is not
necessary that either the one or the other should be present in
the body, inasmuch as it is not true to say that everybody must
be white or black. Badness and goodness, again, are predicated
34
of man, and of many other things, but it is not necessary that
either the one quality or the other should be present in that of
which they are predicated: it is not true to say that everything
that may be good or bad must be either good or bad. These pairs
of contraries have intermediates: the intermediates between
white and black are grey, sallow, and all the other colours that
come between; the intermediate between good and bad is that
which is neither the one nor the other.
Some intermediate qualities have names, such as grey and
sallow and all the other colours that come between white and
black; in other cases, however, it is not easy to name the
intermediate, but we must define it as that which is not either
extreme, as in the case of that which is neither good nor bad,
neither just nor unjust.
(iii) 'privatives' and 'Positives' have reference to the same
subject. Thus, sight and blindness have reference to the eye. It is
a universal rule that each of a pair of opposites of this type has
reference to that to which the particular 'positive' is natural. We
say that that is capable of some particular faculty or possession
has suffered privation when the faculty or possession in
question is in no way present in that in which, and at the time
at which, it should naturally be present. We do not call that
toothless which has not teeth, or that blind which has not sight,
but rather that which has not teeth or sight at the time when by
nature it should. For there are some creatures which from birth
are without sight, or without teeth, but these are not called
toothless or blind.
To be without some faculty or to possess it is not the same as
the corresponding 'privative' or 'positive'. 'Sight' is a 'positive',
'blindness' a 'privative', but 'to possess sight' is not equivalent
to 'sight', 'to be blind' is not equivalent to 'blindness'. Blindness
is a 'privative', to be blind is to be in a state of privation, but is
35
not a 'privative'. Moreover, if 'blindness' were equivalent to
'being blind', both would be predicated of the same subject; but
though a man is said to be blind, he is by no means said to be
blindness.
To be in a state of 'possession' is, it appears, the opposite of
being in a state of 'privation', just as 'positives' and 'privatives'
themselves are opposite. There is the same type of antithesis in
both cases; for just as blindness is opposed to sight, so is being
blind opposed to having sight.
That which is affirmed or denied is not itself affirmation or
denial. By 'affirmation' we mean an affirmative proposition, by
'denial' a negative. Now, those facts which form the matter of
the affirmation or denial are not propositions; yet these two are
said to be opposed in the same sense as the affirmation and
denial, for in this case also the type of antithesis is the same.
For as the affirmation is opposed to the denial, as in the two
propositions 'he sits', 'he does not sit', so also the fact which
constitutes the matter of the proposition in one case is opposed
to that in the other, his sitting, that is to say, to his not sitting.
It is evident that 'positives' and 'privatives' are not opposed
each to each in the same sense as relatives. The one is not
explained by reference to the other; sight is not sight of
blindness, nor is any other preposition used to indicate the
relation. Similarly blindness is not said to be blindness of sight,
but rather, privation of sight. Relatives, moreover, reciprocate; if
blindness, therefore, were a relative, there would be a
reciprocity of relation between it and that with which it was
correlative. But this is not the case. Sight is not called the sight
of blindness.
That those terms which fall under the heads of 'positives' and
'privatives' are not opposed each to each as contraries, either, is
plain from the following facts: Of a pair of contraries such that
36
they have no intermediate, one or the other must needs be
present in the subject in which they naturally subsist, or of
which they are predicated; for it is those, as we proved,' in the
case of which this necessity obtains, that have no intermediate.
Moreover, we cited health and disease, odd and even, as
instances. But those contraries which have an intermediate are
not subject to any such necessity. It is not necessary that every
substance, receptive of such qualities, should be either black or
white, cold or hot, for something intermediate between these
contraries may very well be present in the subject. We proved,
moreover, that those contraries have an intermediate in the
case of which the said necessity does not obtain. Yet when one
of the two contraries is a constitutive property of the subject, as
it is a constitutive property of fire to be hot, of snow to be white,
it is necessary determinately that one of the two contraries, not
one or the other, should be present in the subject; for fire
cannot be cold, or snow black. Thus, it is not the case here that
one of the two must needs be present in every subject receptive
of these qualities, but only in that subject of which the one
forms a constitutive property. Moreover, in such cases it is one
member of the pair determinately, and not either the one or the
other, which must be present.
In the case of 'positives' and 'privatives', on the other hand,
neither of the aforesaid statements holds good. For it is not
necessary that a subject receptive of the qualities should always
have either the one or the other; that which has not yet
advanced to the state when sight is natural is not said either to
be blind or to see. Thus 'positives' and 'privatives' do not belong
to that class of contraries which consists of those which have
no intermediate. On the other hand, they do not belong either to
that class which consists of contraries which have an
intermediate. For under certain conditions it is necessary that
either the one or the other should form part of the constitution
of every appropriate subject. For when a thing has reached the
37
stage when it is by nature capable of sight, it will be said either
to see or to be blind, and that in an indeterminate sense,
signifying that the capacity may be either present or absent; for
it is not necessary either that it should see or that it should be
blind, but that it should be either in the one state or in the
other. Yet in the case of those contraries which have an
intermediate we found that it was never necessary that either
the one or the other should be present in every appropriate
subject, but only that in certain subjects one of the pair should
be present, and that in a determinate sense. It is, therefore,
plain that 'positives' and 'privatives' are not opposed each to
each in either of the senses in which contraries are opposed.
Again, in the case of contraries, it is possible that there should
be changes from either into the other, while the subject retains
its identity, unless indeed one of the contraries is a constitutive
property of that subject, as heat is of fire. For it is possible that
that that which is healthy should become diseased, that which
is white, black, that which is cold, hot, that which is good, bad,
that which is bad, good. The bad man, if he is being brought into
a better way of life and thought, may make some advance,
however slight, and if he should once improve, even ever so
little, it is plain that he might change completely, or at any rate
make very great progress; for a man becomes more and more
easily moved to virtue, however small the improvement was at
first. It is, therefore, natural to suppose that he will make yet
greater progress than he has made in the past; and as this
process goes on, it will change him completely and establish
him in the contrary state, provided he is not hindered by lack of
time. In the case of 'positives' and 'privatives', however, change
in both directions is impossible. There may be a change from
possession to privation, but not from privation to possession.
The man who has become blind does not regain his sight; the
man who has become bald does not regain his hair; the man
who has lost his teeth does not grow his grow a new set.
38
(iv) Statements opposed as affirmation and negation belong
manifestly to a class which is distinct, for in this case, and in
this case only, it is necessary for the one opposite to be true and
the other false.
Neither in the case of contraries, nor in the case of correlatives,
nor in the case of 'positives' and 'privatives', is it necessary for
one to be true and the other false. Health and disease are
contraries: neither of them is true or false. 'Double' and 'half
are opposed to each other as correlatives: neither of them is
true or false. The case is the same, of course, with regard to
'positives' and 'privatives' such as 'sight' and 'blindness'. In
short, where there is no sort of combination of words, truth and
falsity have no place, and all the opposites we have mentioned
so far consist of simple words.
At the same time, when the words which enter into opposed
statements are contraries, these, more than any other set of
opposites, would seem to claim this characteristic. 'Socrates is
ill' is the contrary of 'Socrates is well', but not even of such
composite expressions is it true to say that one of the pair must
always be true and the other false. For if Socrates exists, one
will be true and the other false, but if he does not exist, both
will be false; for neither 'Socrates is ill' nor 'Socrates is well' is
true, if Socrates does not exist at all.
In the case of 'positives' and 'privatives', if the subject does not
exist at all, neither proposition is true, but even if the subject
exists, it is not always the fact that one is true and the other
false. For 'Socrates has sight' is the opposite of 'Socrates is blind'
in the sense of the word 'opposite' which applies to possession
and privation. Now if Socrates exists, it is not necessary that
one should be true and the other false, for when he is not yet
able to acquire the power of vision, both are false, as also if
Socrates is altogether non-existent.
39
But in the case of affirmation and negation, whether the subject
exists or not, one is always false and the other true. For
manifestly, if Socrates exists, one of the two propositions
'Socrates is ill', 'Socrates is not ill', is true, and the other false.
This is likewise the case if he does not exist; for if he does not
exist, to say that he is ill is false, to say that he is not ill is true.
Thus it is in the case of those opposites only, which are opposite
in the sense in which the term is used with reference to
affirmation and negation, that the rule holds good, that one of
the pair must be true and the other false.
11
That the contrary of a good is an evil is shown by induction: the
contrary of health is disease, of courage, cowardice, and so on.
But the contrary of an evil is sometimes a good, sometimes an
evil. For defect, which is an evil, has excess for its contrary, this
also being an evil, and the mean, which is a good, is equally the
contrary of the one and of the other. It is only in a few cases,
however, that we see instances of this: in most, the contrary of
an evil is a good.
In the case of contraries, it is not always necessary that if one
exists the other should also exist: for if all become healthy there
will be health and no disease, and again, if everything turns
white, there will be white, but no black. Again, since the fact
that Socrates is ill is the contrary of the fact that Socrates is
well, and two contrary conditions cannot both obtain in one and
the same individual at the same time, both these contraries
could not exist at once: for if that Socrates was well was a fact,
then that Socrates was ill could not possibly be one.
40
It is plain that contrary attributes must needs be present in
subjects which belong to the same species or genus. Disease
and health require as their subject the body of an animal; white
and black require a body, without further qualification; justice
and injustice require as their subject the human soul.
Moreover, it is necessary that pairs of contraries should in all
cases either belong to the same genus or belong to contrary
genera or be themselves genera. White and black belong to the
same genus, colour; justice and injustice, to contrary genera,
virtue and vice; while good and evil do not belong to genera, but
are themselves actual genera, with terms under them.
12
There are four senses in which one thing can be said to be
'prior' to another. Primarily and most properly the term has
reference to time: in this sense the word is used to indicate that
one thing is older or more ancient than another, for the
expressions 'older' and 'more ancient' imply greater length of
time.
Secondly, one thing is said to be 'prior' to another when the
sequence of their being cannot be reversed. In this sense 'one' is
'prior' to 'two'. For if 'two' exists, it follows directly that 'one'
must exist, but if 'one' exists, it does not follow necessarily that
'two' exists: thus the sequence subsisting cannot be reversed. It
is agreed, then, that when the sequence of two things cannot be
reversed, then that one on which the other depends is called
'prior' to that other.
In the third place, the term 'prior' is used with reference to any
order, as in the case of science and of oratory. For in sciences
41
which use demonstration there is that which is prior and that
which is posterior in order; in geometry, the elements are prior
to the propositions; in reading and writing, the letters of the
alphabet are prior to the syllables. Similarly, in the case of
speeches, the exordium is prior in order to the narrative.
Besides these senses of the word, there is a fourth. That which
is better and more honourable is said to have a natural priority.
In common parlance men speak of those whom they honour
and love as 'coming first' with them. This sense of the word is
perhaps the most far-fetched.
Such, then, are the different senses in which the term 'prior' is
used.
Yet it would seem that besides those mentioned there is yet
another. For in those things, the being of each of which implies
that of the other, that which is in any way the cause may
reasonably be said to be by nature 'prior' to the effect. It is plain
that there are instances of this. The fact of the being of a man
carries with it the truth of the proposition that he is, and the
implication is reciprocal: for if a man is, the proposition
wherein we allege that he is true, and conversely, if the
proposition wherein we allege that he is true, then he is. The
true proposition, however, is in no way the cause of the being of
the man, but the fact of the man's being does seem somehow to
be the cause of the truth of the proposition, for the truth or
falsity of the proposition depends on the fact of the man's being
or not being.
Thus the word 'prior' may be used in five senses.
42
13
The term 'simultaneous' is primarily and most appropriately
applied to those things the genesis of the one of which is
simultaneous with that of the other; for in such cases neither is
prior or posterior to the other. Such things are said to be
simultaneous in point of time. Those things, again, are
'simultaneous' in point of nature, the being of each of which
involves that of the other, while at the same time neither is the
cause of the other's being. This is the case with regard to the
double and the half, for these are reciprocally dependent, since,
if there is a double, there is also a half, and if there is a half,
there is also a double, while at the same time neither is the
cause of the being of the other.
Again, those species which are distinguished one from another
and opposed one to another within the same genus are said to
be 'simultaneous' in nature. I mean those species which are
distinguished each from each by one and the same method of
division. Thus the 'winged' species is simultaneous with the
'terrestrial' and the 'water' species. These are distinguished
within the same genus, and are opposed each to each, for the
genus 'animal' has the 'winged', the 'terrestrial', and the 'water'
species, and no one of these is prior or posterior to another; on
the contrary, all such things appear to be 'simultaneous' in
nature. Each of these also, the terrestrial, the winged, and the
water species, can be divided again into subspecies. Those
species, then, also will be 'simultaneous' point of nature, which,
belonging to the same genus, are distinguished each from each
by one and the same method of differentiation.
But genera are prior to species, for the sequence of their being
cannot be reversed. If there is the species 'water-animal', there
will be the genus 'animal', but granted the being of the genus
43
'animal', it does not follow necessarily that there will be the
species 'water-animal'.
Those things, therefore, are said to be 'simultaneous' in nature,
the being of each of which involves that of the other, while at
the same time neither is in any way the cause of the other's
being; those species, also, which are distinguished each from
each and opposed within the same genus. Those things,
moreover, are 'simultaneous' in the unqualified sense of the
word which come into being at the same time.
14
There are six sorts of movement: generation, destruction,
increase, diminution, alteration, and change of place.
It is evident in all but one case that all these sorts of movement
are distinct each from each. Generation is distinct from
destruction, increase and change of place from diminution, and
so on. But in the case of alteration it may be argued that the
process necessarily implies one or other of the other five sorts
of motion. This is not true, for we may say that all affections, or
nearly all, produce in us an alteration which is distinct from all
other sorts of motion, for that which is affected need not suffer
either increase or diminution or any of the other sorts of
motion. Thus alteration is a distinct sort of motion; for, if it were
not, the thing altered would not only be altered, but would
forthwith necessarily suffer increase or diminution or some one
of the other sorts of motion in addition; which as a matter of
fact is not the case. Similarly that which was undergoing the
process of increase or was subject to some other sort of motion
would, if alteration were not a distinct form of motion,
necessarily be subject to alteration also. But there are some
44
things which undergo increase but yet not alteration. The
square, for instance, if a gnomon is applied to it, undergoes
increase but not alteration, and so it is with all other figures of
this sort. Alteration and increase, therefore, are distinct.
Speaking generally, rest is the contrary of motion. But the
different forms of motion have their own contraries in other
forms; thus destruction is the contrary of generation,
diminution of increase, rest in a place, of change of place. As for
this last, change in the reverse direction would seem to be most
truly its contrary; thus motion upwards is the contrary of
motion downwards and vice versa.
In the case of that sort of motion which yet remains, of those
that have been enumerated, it is not easy to state what is its
contrary. It appears to have no contrary, unless one should
define the contrary here also either as 'rest in its quality' or as
'change in the direction of the contrary quality', just as we
defined the contrary of change of place either as rest in a place
or as change in the reverse direction. For a thing is altered when
change of quality takes place; therefore either rest in its quality
or change in the direction of the contrary may be called the
contrary of this qualitative form of motion. In this way
becoming white is the contrary of becoming black; there is
alteration in the contrary direction, since a change of a
qualitative nature takes place.
15
The term 'to have' is used in various senses. In the first place it
is used with reference to habit or disposition or any other
quality, for we are said to 'have' a piece of knowledge or a virtue.
Then, again, it has reference to quantity, as, for instance, in the
45
case of a man's height; for he is said to 'have' a height of three
or four cubits. It is used, moreover, with regard to apparel, a
man being said to 'have' a coat or tunic; or in respect of
something which we have on a part of ourselves, as a ring on
the hand: or in respect of something which is a part of us, as
hand or foot. The term refers also to content, as in the case of a
vessel and wheat, or of a jar and wine; a jar is said to 'have'
wine, and a corn-measure wheat. The expression in such cases
has reference to content. Or it refers to that which has been
acquired; we are said to 'have' a house or a field. A man is also
said to 'have' a wife, and a wife a husband, and this appears to
be the most remote meaning of the term, for by the use of it we
mean simply that the husband lives with the wife.
Other senses of the word might perhaps be found, but the most
ordinary ones have all been enumerated.
46
Aristotle - On Interpretation
[Translated by E. M. Edghill]
First we must define the terms 'noun' and 'verb', then the terms
'denial' and 'affirmation', then 'proposition' and 'sentence.'
Spoken words are the symbols of mental experience and
written words are the symbols of spoken words. Just as all men
have not the same writing, so all men have not the same
speech sounds, but the mental experiences, which these
directly symbolize, are the same for all, as also are those things
of which our experiences are the images. This matter has,
however, been discussed in my treatise about the soul, for it
belongs to an investigation distinct from that which lies before
us.
As there are in the mind thoughts which do not involve truth or
falsity, and also those which must be either true or false, so it is
in speech. For truth and falsity imply combination and
separation. Nouns and verbs, provided nothing is added, are
like thoughts without combination or separation; 'man' and
'white', as isolated terms, are not yet either true or false. In
proof of this, consider the word 'goat-stag.' It has significance,
but there is no truth or falsity about it, unless 'is' or 'is not' is
added, either in the present or in some other tense.
47
By a noun we mean a sound significant by convention, which
has no reference to time, and of which no part is significant
apart from the rest. In the noun 'Fairsteed,' the part 'steed' has
no significance in and by itself, as in the phrase 'fair steed.' Yet
there is a difference between simple and composite nouns; for
in the former the part is in no way significant, in the latter it
contributes to the meaning of the whole, although it has not an
independent meaning. Thus in the word 'pirate-boat' the word
'boat' has no meaning except as part of the whole word.
The limitation 'by convention' was introduced because nothing
is by nature a noun or name - it is only so when it becomes a
symbol; inarticulate sounds, such as those which brutes
produce, are significant, yet none of these constitutes a noun.
The expression 'not-man' is not a noun. There is indeed no
recognized term by which we may denote such an expression,
for it is not a sentence or a denial. Let it then be called an
indefinite noun.
The expressions 'of Philo', 'to Philo', and so on, constitute not
nouns, but cases of a noun. The definition of these cases of a
noun is in other respects the same as that of the noun proper,
but, when coupled with 'is', 'was', or will be', they do not, as
they are, form a proposition either true or false, and this the
noun proper always does, under these conditions. Take the
words 'of Philo is' or 'of or 'of Philo is not'; these words do not,
as they stand, form either a true or a false proposition.
48
A verb is that which, in addition to its proper meaning, carries
with it the notion of time. No part of it has any independent
meaning, and it is a sign of something said of something else.
I will explain what I mean by saying that it carries with it the
notion of time. 'Health' is a noun, but 'is healthy' is a verb; for
besides its proper meaning it indicates the present existence of
the state in question.
Moreover, a verb is always a sign of something said of
something else, i.e. of something either predicable of or present
in some other thing.
Such expressions as 'is not-healthy', 'is not, ill', I do not
describe as verbs; for though they carry the additional note of
time, and always form a predicate, there is no specified name
for this variety; but let them be called indefinite verbs, since
they apply equally well to that which exists and to that which
does not.
Similarly 'he was healthy', 'he will be healthy', are not verbs,
but tenses of a verb; the difference lies in the fact that the verb
indicates present time, while the tenses of the verb indicate
those times which lie outside the present.
Verbs in and by themselves are substantival and have
significance, for he who uses such expressions arrests the
hearer's mind, and fixes his attention; but they do not, as they
stand, express any judgement, either positive or negative. For
neither are 'to be' and 'not to be' the participle 'being'
significant of any fact, unless something is added; for they do
not themselves indicate anything, but imply a copulation, of
which we cannot form a conception apart from the things
coupled.
49
A sentence is a significant portion of speech, some parts of
which have an independent meaning, that is to say, as an
utterance, though not as the expression of any positive
judgement. Let me explain. The word 'human' has meaning,
but does not constitute a proposition, either positive or
negative. It is only when other words are added that the whole
will form an affirmation or denial. But if we separate one
syllable of the word 'human' from the other, it has no meaning;
similarly in the word 'mouse', the part 'ouse' has no meaning in
itself, but is merely a sound. In composite words, indeed, the
parts contribute to the meaning of the whole; yet, as has been
pointed out, they have not an independent meaning.
Every sentence has meaning, not as being the natural means by
which a physical faculty is realized, but, as we have said, by
convention. Yet every sentence is not a proposition; only such
are propositions as have in them either truth or falsity. Thus a
prayer is a sentence, but is neither true nor false.
Let us therefore dismiss all other types of sentence but the
proposition, for this last concerns our present inquiry, whereas
the investigation of the others belongs rather to the study of
rhetoric or of poetry.
50
The first class of simple propositions is the simple affirmation,
the next, the simple denial; all others are only one by
conjunction.
Every proposition must contain a verb or the tense of a verb.
The phrase which defines the species 'man', if no verb in
present, past, or future time be added, is not a proposition. It
may be asked how the expression 'a footed animal with two
feet' can be called single; for it is not the circumstance that the
words follow in unbroken succession that effects the unity. This
inquiry, however, finds its place in an investigation foreign to
that before us.
We call those propositions single which indicate a single fact, or
the conjunction of the parts of which results in unity: those
propositions, on the other hand, are separate and many in
number, which indicate many facts, or whose parts have no
conjunction.
Let us, moreover, consent to call a noun or a verb an expression
only, and not a proposition, since it is not possible for a man to
speak in this way when he is expressing something, in such a
way as to make a statement, whether his utterance is an
answer to a question or an act of his own initiation.
To return: of propositions one kind is simple, i.e. that which
asserts or denies something of something, the other composite,
i.e. that which is compounded of simple propositions. A simple
proposition is a statement, with meaning, as to the presence of
something in a subject or its absence, in the present, past, or
future, according to the divisions of time.
51
An affirmation is a positive assertion of something about
something, a denial a negative assertion.
Now it is possible both to affirm and to deny the presence of
something which is present or of something which is not, and
since these same affirmations and denials are possible with
reference to those times which lie outside the present, it would
be possible to contradict any affirmation or denial. Thus it is
plain that every affirmation has an opposite denial, and
similarly every denial an opposite affirmation.
We will call such a pair of propositions a pair of contradictories.
Those positive and negative propositions are said to be
contradictory which have the same subject and predicate. The
identity of subject and of predicate must not be 'equivocal'.
Indeed there are definitive qualifications besides this, which we
make to meet the casuistries of sophists.
Some things are universal, others individual. By the term
'universal' I mean that which is of such a nature as to be
predicated of many subjects, by 'individual' that which is not
thus predicated. Thus 'man' is a universal, 'Callias' an
individual.
Our propositions necessarily sometimes concern a universal
subject, sometimes an individual.
If, then, a man states a positive and a negative proposition of
universal character with regard to a universal, these two
propositions are 'contrary'. By the expression 'a proposition of
52
universal character with regard to a universal', such
propositions as 'every man is white', 'no man is white' are
meant. When, on the other hand, the positive and negative
propositions, though they have regard to a universal, are yet
not of universal character, they will not be contrary, albeit the
meaning intended is sometimes contrary. As instances of
propositions made with regard to a universal, but not of
universal character, we may take the 'propositions 'man is
white', 'man is not white'. 'Man' is a universal, but the
proposition is not made as of universal character; for the word
'every' does not make the subject a universal, but rather gives
the proposition a universal character. If, however, both
predicate and subject are distributed, the proposition thus
constituted is contrary to truth; no affirmation will, under such
circumstances, be true. The proposition 'every man is every
animal' is an example of this type.
An affirmation is opposed to a denial in the sense which I
denote by the term 'contradictory', when, while the subject
remains the same, the affirmation is of universal character and
the denial is not. The affirmation 'every man is white' is the
contradictory of the denial 'not every man is white', or again,
the proposition 'no man is white' is the contradictory of the
proposition 'some men are white'. But propositions are opposed
as contraries when both the affirmation and the denial are
universal, as in the sentences 'every man is white', 'no man is
white', 'every man is just', 'no man is just'.
We see that in a pair of this sort both propositions cannot be
true, but the contradictories of a pair of contraries can
sometimes both be true with reference to the same subject; for
instance 'not every man is white' and some men are white' are
both true. Of such corresponding positive and negative
propositions as refer to universals and have a universal
character, one must be true and the other false. This is the case
53
also when the reference is to individuals, as in the propositions
'Socrates is white', 'Socrates is not white'.
When, on the other hand, the reference is to universals, but the
propositions are not universal, it is not always the case that one
is true and the other false, for it is possible to state truly that
man is white and that man is not white and that man is
beautiful and that man is not beautiful; for if a man is deformed
he is the reverse of beautiful, also if he is progressing towards
beauty he is not yet beautiful.
This statement might seem at first sight to carry with it a
contradiction, owing to the fact that the proposition 'man is not
white' appears to be equivalent to the proposition 'no man is
white'. This, however, is not the case, nor are they necessarily
at the same time true or false.
It is evident also that the denial corresponding to a single
affirmation is itself single; for the denial must deny just that
which the affirmation affirms concerning the same subject, and
must correspond with the affirmation both in the universal or
particular character of the subject and in the distributed or
undistributed sense in which it is understood.
For instance, the affirmation 'Socrates is white' has its proper
denial in the proposition 'Socrates is not white'. If anything else
be negatively predicated of the subject or if anything else be the
subject though the predicate remain the same, the denial will
not be the denial proper to that affirmation, but on that is
distinct.
The denial proper to the affirmation 'every man is white' is 'not
every man is white'; that proper to the affirmation 'some men
are white' is 'no man is white', while that proper to the
affirmation 'man is white' is 'man is not white'.
54
We have shown further that a single denial is contradictorily
opposite to a single affirmation and we have explained which
these are; we have also stated that contrary are distinct from
contradictory propositions and which the contrary are; also that
with regard to a pair of opposite propositions it is not always
the case that one is true and the other false. We have pointed
out, moreover, what the reason of this is and under what
circumstances the truth of the one involves the falsity of the
other.
8
An affirmation or denial is single, if it indicates some one fact
about some one subject; it matters not whether the subject is
universal and whether the statement has a universal character,
or whether this is not so. Such single propositions are: 'every
man is white', 'not every man is white';'man is white', 'man is
not white'; 'no man is white', 'some men are white'; provided
the word 'white' has one meaning. If, on the other hand, one
word has two meanings which do not combine to form one, the
affirmation is not single. For instance, if a man should establish
the symbol 'garment' as significant both of a horse and of a
man, the proposition 'garment is white' would not be a single
affirmation, nor its opposite a single denial. For it is equivalent
to the proposition 'horse and man are white', which, again, is
equivalent to the two propositions 'horse is white', 'man is
white'. If, then, these two propositions have more than a single
significance, and do not form a single proposition, it is plain
that the first proposition either has more than one significance
or else has none; for a particular man is not a horse.
55
This, then, is another instance of those propositions of which
both the positive and the negative forms may be true or false
simultaneously.
In the case of that which is or which has taken place,
propositions, whether positive or negative, must be true or
false. Again, in the case of a pair of contradictories, either when
the subject is universal and the propositions are of a universal
character, or when it is individual, as has been said,' one of the
two must be true and the other false; whereas when the subject
is universal, but the propositions are not of a universal
character, there is no such necessity. We have discussed this
type also in a previous chapter.
When the subject, however, is individual, and that which is
predicated of it relates to the future, the case is altered. For if all
propositions whether positive or negative are either true or
false, then any given predicate must either belong to the subject
or not, so that if one man affirms that an event of a given
character will take place and another denies it, it is plain that
the statement of the one will correspond with reality and that
of the other will not. For the predicate cannot both belong and
not belong to the subject at one and the same time with regard
to the future.
Thus, if it is true to say that a thing is white, it must necessarily
be white; if the reverse proposition is true, it will of necessity
not be white. Again, if it is white, the proposition stating that it
is white was true; if it is not white, the proposition to the
opposite effect was true. And if it is not white, the man who
states that it is making a false statement; and if the man who
56
states that it is white is making a false statement, it follows that
it is not white. It may therefore be argued that it is necessary
that affirmations or denials must be either true or false.
Now if this be so, nothing is or takes place fortuitously, either in
the present or in the future, and there are no real alternatives;
everything takes place of necessity and is fixed. For either he
that affirms that it will take place or he that denies this is in
correspondence with fact, whereas if things did not take place
of necessity, an event might just as easily not happen as
happen; for the meaning of the word 'fortuitous' with regard to
present or future events is that reality is so constituted that it
may issue in either of two opposite directions. Again, if a thing
is white now, it was true before to say that it would be white, so
that of anything that has taken place it was always true to say
'it is' or 'it will be'. But if it was always true to say that a thing is
or will be, it is not possible that it should not be or not be about
to be, and when a thing cannot not come to be, it is impossible
that it should not come to be, and when it is impossible that it
should not come to be, it must come to be. All, then, that is
about to be must of necessity take place. It results from this
that nothing is uncertain or fortuitous, for if it were fortuitous it
would not be necessary.
Again, to say that neither the affirmation nor the denial is true,
maintaining, let us say, that an event neither will take place nor
will not take place, is to take up a position impossible to defend.
In the first place, though facts should prove the one proposition
false, the opposite would still be untrue. Secondly, if it was true
to say that a thing was both white and large, both these
qualities must necessarily belong to it; and if they will belong to
it the next day, they must necessarily belong to it the next day.
But if an event is neither to take place nor not to take place the
next day, the element of chance will be eliminated. For
57
example, it would be necessary that a sea-fight should neither
take place nor fail to take place on the next day.
These awkward results and others of the same kind follow, if it
is an irrefragable law that of every pair of contradictory
propositions, whether they have regard to universals and are
stated as universally applicable, or whether they have regard to
individuals, one must be true and the other false, and that there
are no real alternatives, but that all that is or takes place is the
outcome of necessity. There would be no need to deliberate or
to take trouble, on the supposition that if we should adopt a
certain course, a certain result would follow, while, if we did
not, the result would not follow. For a man may predict an
event ten thousand years beforehand, and another may predict
the reverse; that which was truly predicted at the moment in
the past will of necessity take place in the fullness of time.
Further, it makes no difference whether people have or have
not actually made the contradictory statements. For it is
manifest that the circumstances are not influenced by the fact
of an affirmation or denial on the part of anyone. For events
will not take place or fail to take place because it was stated
that they would or would not take place, nor is this any more
the case if the prediction dates back ten thousand years or any
other space of time. Wherefore, if through all time the nature of
things was so constituted that a prediction about an event was
true, then through all time it was necessary that that should
find fulfillment; and with regard to all events, circumstances
have always been such that their occurrence is a matter of
necessity. For that of which someone has said truly that it will
be, cannot fail to take place; and of that which takes place, it
was always true to say that it would be.
Yet this view leads to an impossible conclusion; for we see that
both deliberation and action are causative with regard to the
58
future, and that, to speak more generally, in those things which
are not continuously actual there is potentiality in either
direction. Such things may either be or not be; events also
therefore may either take place or not take place. There are
many obvious instances of this. It is possible that this coat may
be cut in half, and yet it may not be cut in half, but wear out
first. In the same way, it is possible that it should not be cut in
half; unless this were so, it would not be possible that it should
wear out first. So it is therefore with all other events which
possess this kind of potentiality. It is therefore plain that it is
not of necessity that everything is or takes place; but in some
instances there are real alternatives, in which case the
affirmation is no more true and no more false than the denial;
while some exhibit a predisposition and general tendency in
one direction or the other, and yet can issue in the opposite
direction by exception.
Now that which is must needs be when it is, and that which is
not must needs not be when it is not. Yet it cannot be said
without qualification that all existence and non-existence is the
outcome of necessity. For there is a difference between saying
that that which is, when it is, must needs be, and simply saying
that all that is must needs be, and similarly in the case of that
which is not. In the case, also, of two contradictory propositions
this holds good. Everything must either be or not be, whether in
the present or in the future, but it is not always possible to
distinguish and state determinately which of these alternatives
must necessarily come about.
Let me illustrate. A sea-fight must either take place to-morrow
or not, but it is not necessary that it should take place to-
morrow, neither is it necessary that it should not take place, yet
it is necessary that it either should or should not take place to-
morrow. Since propositions correspond with facts, it is evident
that when in future events there is a real alternative, and a
59
potentiality in contrary directions, the corresponding
affirmation and denial have the same character.
This is the case with regard to that which is not always existent
or not always nonexistent. One of the two propositions in such
instances must be true and the other false, but we cannot say
determinately that this or that is false, but must leave the
alternative undecided. One may indeed be more likely to be true
than the other, but it cannot be either actually true or actually
false. It is therefore plain that it is not necessary that of an
affirmation and a denial one should be true and the other false.
For in the case of that which exists potentially, but not actually,
the rule which applies to that which exists actually does not
hold good. The case is rather as we have indicated.
10
An affirmation is the statement of a fact with regard to a
subject, and this subject is either a noun or that which has no
name; the subject and predicate in an affirmation must each
denote a single thing. I have already explained' what is meant
by a noun and by that which has no name; for I stated that the
expression 'not-man' was not a noun, in the proper sense of the
word, but an indefinite noun, denoting as it does in a certain
sense a single thing. Similarly the expression 'does not enjoy
health' is not a verb proper, but an indefinite verb. Every
affirmation, then, and every denial, will consist of a noun and a
verb, either definite or indefinite.
There can be no affirmation or denial without a verb; for the
expressions 'is', 'will be', 'was', 'is coming to be', and the like
are verbs according to our definition, since besides their specific
meaning they convey the notion of time. Thus the primary
60
affirmation and denial are 'as follows: 'man is', 'man is not'.
Next to these, there are the propositions: 'not-man is', 'not-man
is not'. Again we have the propositions: 'every man is, 'every
man is not', 'all that is not-man is', 'all that is not-man is not'.
The same classification holds good with regard to such periods
of time as lie outside the present.
When the verb 'is' is used as a third element in the sentence,
there can be positive and negative propositions of two sorts.
Thus in the sentence 'man is just' the verb 'is' is used as a third
element, call it verb or noun, which you will. Four propositions,
therefore, instead of two can be formed with these materials.
Two of the four, as regards their affirmation and denial,
correspond in their logical sequence with the propositions
which deal with a condition of privation; the other two do not
correspond with these.
I mean that the verb 'is' is added either to the term 'just' or to
the term 'not-just', and two negative propositions are formed in
the same way. Thus we have the four propositions. Reference to
the subjoined table will make matters clear:
A. Affirmation
B. Denial
Man is just
Man is not just
D. Denial
C. Affirmation
Man is not not-just Man is not-just
Here 'is' and 'is not' are added either to 'just' or to 'not-just'
61
This then is the proper scheme for these propositions, as has
been said in the Analytics. The same rule holds good, if the
subject is distributed. Thus we have the table:
A'. Affirmation
Every man is just
B\ Denial
Not every man
is just
D\ Denial
Not every man is
not-just
C. Affirmation
Every man is
not-just
Yet here it is not possible, in the same way as in the former
case, that the propositions joined in the table by a diagonal line
should both be true; though under certain circumstances this is
the case.
We have thus set out two pairs of opposite propositions; there
are moreover two other pairs, if a term be conjoined with 'not-
man', the latter forming a kind of subject. Thus:
A". Not-man is just
B". Not-man is not
just
D". Not-man is not
not-just
C". Not-man is not-
just
62
This is an exhaustive enumeration of all the pairs of opposite
propositions that can possibly be framed. This last group should
remain distinct from those which preceded it, since it employs
as its subject the expression 'not-man'.
When the verb 'is' does not fit the structure of the sentence (for
instance, when the verbs 'walks', 'enjoys health' are used), that
scheme applies, which applied when the word 'is' was added.
Thus we have the propositions: 'every man enjoys health',
'every man does-not-enjoy-health', 'all that is not-man enjoys
health', 'all that is not-man does-not-enjoy-health'. We must
not in these propositions use the expression 'not every man'.
The negative must be attached to the word 'man', for the word
'every' does not give to the subject a universal significance, but
implies that, as a subject, it is distributed. This is plain from the
following pairs: 'man enjoys health', 'man does not enjoy
health'; 'not-man enjoys health', 'not man does not enjoy
health'. These propositions differ from the former in being
indefinite and not universal in character. Thus the adjectives
'every' and no additional significance except that the subject,
whether in a positive or in a negative sentence, is distributed.
The rest of the sentence, therefore, will in each case be the
same.
Since the contrary of the proposition 'every animal is just' is 'no
animal is just', it is plain that these two propositions will never
both be true at the same time or with reference to the same
subject. Sometimes, however, the contradictories of these
contraries will both be true, as in the instance before us: the
propositions 'not every animal is just' and 'some animals are
just' are both true.
63
Further, the proposition 'no man is just' follows from the
proposition 'every man is not just' and the proposition 'not
every man is not just', which is the opposite of 'every man is
not-just', follows from the proposition 'some men are just'; for
if this be true, there must be some just men.
It is evident, also, that when the subject is individual, if a
question is asked and the negative answer is the true one, a
certain positive proposition is also true. Thus, if the question
were asked Socrates wise?' and the negative answer were the
true one, the positive inference 'Then Socrates is unwise' is
correct. But no such inference is correct in the case of
universals, but rather a negative proposition. For instance, if to
the question 'Is every man wise?' the answer is 'no', the
inference 'Then every man is unwise' is false. But under these
circumstances the inference 'Not every man is wise' is correct.
This last is the contradictory, the former the contrary. Negative
expressions, which consist of an indefinite noun or predicate,
such as 'not-man' or 'not-just', may seem to be denials
containing neither noun nor verb in the proper sense of the
words. But they are not. For a denial must always be either true
or false, and he that uses the expression 'not man', if nothing
more be added, is not nearer but rather further from making a
true or a false statement than he who uses the expression
'man'.
The propositions 'everything that is not man is just', and the
contradictory of this, are not equivalent to any of the other
propositions; on the other hand, the proposition 'everything
that is not man is not just' is equivalent to the proposition
'nothing that is not man is just'.
The conversion of the position of subject and predicate in a
sentence involves no difference in its meaning. Thus we say
'man is white' and 'white is man'. If these were not equivalent,
64
there would be more than one contradictory to the same
proposition, whereas it has been demonstrated' that each
proposition has one proper contradictory and one only. For of
the proposition 'man is white' the appropriate contradictory is
'man is not white', and of the proposition 'white is man', if its
meaning be different, the contradictory will either be 'white is
not not-man' or 'white is not man'. Now the former of these is
the contradictory of the proposition 'white is not-man', and the
latter of these is the contradictory of the proposition 'man is
white'; thus there will be two contradictories to one
proposition.
It is evident, therefore, that the inversion of the relative
position of subject and predicate does not affect the sense of
affirmations and denials.
11
There is no unity about an affirmation or denial which, either
positively or negatively, predicates one thing of many subjects,
or many things of the same subject, unless that which is
indicated by the many is really some one thing, do not apply
this word 'one' to those things which, though they have a single
recognized name, yet do not combine to form a unity. Thus,
man may be an animal, and biped, and domesticated, but these
three predicates combine to form a unity. On the other hand,
the predicates 'white', 'man', and 'walking' do not thus
combine. Neither, therefore, if these three form the subject of
an affirmation, nor if they form its predicate, is there any unity
about that affirmation. In both cases the unity is linguistic, but
not real.
65
If therefore the dialectical question is a request for an answer,
i.e. either for the admission of a premiss or for the admission of
one of two contradictories - and the premiss is itself always one
of two contradictories - the answer to such a question as
contains the above predicates cannot be a single proposition.
For as I have explained in the Topics, question is not a single
one, even if the answer asked for is true.
At the same time it is plain that a question of the form 'what is
it?' is not a dialectical question, for a dialectical questioner
must by the form of his question give his opponent the chance
of announcing one of two alternatives, whichever he wishes. He
must therefore put the question into a more definite form, and
inquire, e.g.. whether man has such and such a characteristic or
not.
Some combinations of predicates are such that the separate
predicates unite to form a single predicate. Let us consider
under what conditions this is and is not possible. We may
either state in two separate propositions that man is an animal
and that man is a biped, or we may combine the two, and state
that man is an animal with two feet. Similarly we may use
'man' and 'white' as separate predicates, or unite them into
one. Yet if a man is a shoemaker and is also good, we cannot
construct a composite proposition and say that he is a good
shoemaker. For if, whenever two separate predicates truly
belong to a subject, it follows that the predicate resulting from
their combination also truly belongs to the subject, many
absurd results ensue. For instance, a man is man and white.
Therefore, if predicates may always be combined, he is a white
man. Again, if the predicate 'white' belongs to him, then the
combination of that predicate with the former composite
predicate will be permissible. Thus it will be right to say that he
is a white man so on indefinitely. Or, again, we may combine
the predicates 'musical', 'white', and 'walking', and these may
66
be combined many times. Similarly we may say that Socrates is
Socrates and a man, and that therefore he is the man Socrates,
or that Socrates is a man and a biped, and that therefore he is a
two-footed man. Thus it is manifest that if man states
unconditionally that predicates can always be combined, many
absurd consequences ensue.
We will now explain what ought to be laid down.
Those predicates, and terms forming the subject of predication,
which are accidental either to the same subject or to one
another, do not combine to form a unity. Take the proposition
'man is white of complexion and musical'. Whiteness and being
musical do not coalesce to form a unity, for they belong only
accidentally to the same subject. Nor yet, if it were true to say
that that which is white is musical, would the terms 'musical'
and 'white' form a unity, for it is only incidentally that that
which is musical is white; the combination of the two will,
therefore, not form a unity.
Thus, again, whereas, if a man is both good and a shoemaker,
we cannot combine the two propositions and say simply that he
is a good shoemaker, we are, at the same time, able to combine
the predicates 'animal' and 'biped' and say that a man is an
animal with two feet, for these predicates are not accidental.
Those predicates, again, cannot form a unity, of which the one
is implicit in the other: thus we cannot combine the predicate
'white' again and again with that which already contains the
notion 'white', nor is it right to call a man an animal-man or a
two-footed man; for the notions 'animal' and 'biped' are
implicit in the word 'man'. On the other hand, it is possible to
predicate a term simply of any one instance, and to say that
some one particular man is a man or that some one white man
is a white man.
67
Yet this is not always possible: indeed, when in the adjunct
there is some opposite which involves a contradiction, the
predication of the simple term is impossible. Thus it is not right
to call a dead man a man. When, however, this is not the case,
it is not impossible.
Yet the facts of the case might rather be stated thus: when
some such opposite elements are present, resolution is never
possible, but when they are not present, resolution is
nevertheless not always possible. Take the proposition 'Homer
is so-and-so', say 'a poet'; does it follow that Homer is, or does
it not? The verb 'is' is here used of Homer only incidentally, the
proposition being that Homer is a poet, not that he is, in the
independent sense of the word.
Thus, in the case of those predications which have within them
no contradiction when the nouns are expanded into definitions,
and wherein the predicates belong to the subject in their own
proper sense and not in any indirect way, the individual may be
the subject of the simple propositions as well as of the
composite. But in the case of that which is not, it is not true to
say that because it is the object of opinion, it is; for the opinion
held about it is that it is not, not that it is.
12
As these distinctions have been made, we must consider the
mutual relation of those affirmations and denials which assert
or deny possibility or contingency, impossibility or necessity:
for the subject is not without difficulty.
We admit that of composite expressions those are contradictory
each to each which have the verb 'to be' its positive and
68
negative form respectively. Thus the contradictory of the
proposition 'man is' is 'man is not', not 'not-man is', and the
contradictory of 'man is white' is 'man is not white', not 'man is
not-white'. For otherwise, since either the positive or the
negative proposition is true of any subject, it will turn out true
to say that a piece of wood is a man that is not white.
Now if this is the case, in those propositions which do not
contain the verb 'to be' the verb which takes its place will
exercise the same function. Thus the contradictory of 'man
walks' is 'man does not walk', not 'not-man walks'; for to say
'man walks' merely equivalent to saying 'man is walking'.
If then this rule is universal, the contradictory of 'it may be' is
may not be', not 'it cannot be'.
Now it appears that the same thing both may and may not be;
for instance, everything that may be cut or may walk may also
escape cutting and refrain from walking; and the reason is that
those things that have potentiality in this sense are not always
actual. In such cases, both the positive and the negative
propositions will be true; for that which is capable of walking or
of being seen has also a potentiality in the opposite direction.
But since it is impossible that contradictory propositions should
both be true of the same subject, it follows that' it may not be'
is not the contradictory of 'it may be'. For it is a logical
consequence of what we have said, either that the same
predicate can be both applicable and inapplicable to one and
the same subject at the same time, or that it is not by the
addition of the verbs 'be' and 'not be', respectively, that positive
and negative propositions are formed. If the former of these
alternatives must be rejected, we must choose the latter.
The contradictory, then, of 'it may be' is 'it cannot be'. The
same rule applies to the proposition 'it is contingent that it
69
should be'; the contradictory of this is 'it is not contingent that
it should be'. The similar propositions, such as 'it is necessary'
and 'it is impossible', may be dealt with in the same manner.
For it comes about that just as in the former instances the verbs
'is' and 'is not' were added to the subject-matter of the
sentence 'white' and 'man', so here 'that it should be' and 'that
it should not be' are the subject-matter and 'is possible', 'is
contingent', are added. These indicate that a certain thing is or
is not possible, just as in the former instances 'is' and 'is not'
indicated that certain things were or were not the case.
The contradictory, then, of 'it may not be' is not 'it cannot be',
but 'it cannot not be', and the contradictory of 'it may be' is not
'it may not be', but cannot be'. Thus the propositions 'it may be'
and 'it may not be' appear each to imply the other: for, since
these two propositions are not contradictory, the same thing
both may and may not be. But the propositions 'it may be' and
'it cannot be' can never be true of the same subject at the same
time, for they are contradictory. Nor can the propositions 'it
may not be' and 'it cannot not be' be at once true of the same
subject.
The propositions which have to do with necessity are governed
by the same principle. The contradictory of 'it is necessary that
it should be', is not 'it is necessary that it should not be,' but 'it
is not necessary that it should be', and the contradictory of 'it is
necessary that it should not be' is 'it is not necessary that it
should not be'.
Again, the contradictory of 'it is impossible that it should be' is
not 'it is impossible that it should not be' but 'it is not
impossible that it should be', and the contradictory of 'it is
impossible that it should not be' is 'it is not impossible that it
should not be'.
70
To generalize, we must, as has been stated, define the clauses
'that it should be' and 'that it should not be' as the subject-
matter of the propositions, and in making these terms into
affirmations and denials we must combine them with 'that it
should be' and 'that it should not be' respectively.
We must consider the following pairs as contradictory
propositions:
It may be. It cannot be.
It is contingent.lt is not contingent.
It is impossible.lt is not impossible.
It is necessary.lt is not necessary.
It is true. It is not true.
13
Logical sequences follow in due course when we have arranged
the propositions thus. From the proposition 'it may be' it
follows that it is contingent, and the relation is reciprocal. It
follows also that it is not impossible and not necessary.
From the proposition 'it may not be' or 'it is contingent that it
should not be' it follows that it is not necessary that it should
not be and that it is not impossible that it should not be. From
the proposition 'it cannot be' or 'it is not contingent' it follows
that it is necessary that it should not be and that it is
impossible that it should be. From the proposition 'it cannot not
be' or 'it is not contingent that it should not be' it follows that it
71
is necessary that it should be and that it is impossible that it
should not be.
Let us consider these statements by the help of a table:
A. B.
It may be. It cannot be.
It is contingent. It is not contingent.
It is not impossible that it It is impossible that it should
should be. be.
It is not necessary that it It is necessary that it should
should be. not be.
C. D.
It may not be. It cannot not be.
It is contingent that it should It is not contingent that it
not be. should not be.
It is not impossible that it It is impossible that it should
should not be. not be.
It is not necessary that it It is necessary that it should
should not be. be.
Now the propositions 'it is impossible that it should be' and 'it
is not impossible that it should be' are consequent upon the
propositions 'it may be', 'it is contingent', and 'it cannot be', 'it
is not contingent', the contradictories upon the contradictories.
72
But there is inversion. The negative of the proposition 'it is
impossible' is consequent upon the proposition 'it may be' and
the corresponding positive in the first case upon the negative in
the second. For 'it is impossible' is a positive proposition and 'it
is not impossible' is negative.
We must investigate the relation subsisting between these
propositions and those which predicate necessity. That there is
a distinction is clear. In this case, contrary propositions follow
respectively from contradictory propositions, and the
contradictory propositions belong to separate sequences. For
the proposition 'it is not necessary that it should be' is not the
negative of 'it is necessary that it should not be', for both these
propositions may be true of the same subject; for when it is
necessary that a thing should not be, it is not necessary that it
should be. The reason why the propositions predicating
necessity do not follow in the same kind of sequence as the
rest, lies in the fact that the proposition 'it is impossible' is
equivalent, when used with a contrary subject, to the
proposition 'it is necessary'. For when it is impossible that a
thing should be, it is necessary, not that it should be, but that it
should not be, and when it is impossible that a thing should not
be, it is necessary that it should be. Thus, if the propositions
predicating impossibility or non-impossibility follow without
change of subject from those predicating possibility or non-
possibility, those predicating necessity must follow with the
contrary subject; for the propositions 'it is impossible' and 'it is
necessary' are not equivalent, but, as has been said, inversely
connected.
Yet perhaps it is impossible that the contradictory propositions
predicating necessity should be thus arranged. For when it is
necessary that a thing should be, it is possible that it should be.
(For if not, the opposite follows, since one or the other must
follow; so, if it is not possible, it is impossible, and it is thus
73
impossible that a thing should be, which must necessarily be;
which is absurd.)
Yet from the proposition 'it may be' it follows that it is not
impossible, and from that it follows that it is not necessary; it
comes about therefore that the thing which must necessarily be
need not be; which is absurd. But again, the proposition 'it is
necessary that it should be' does not follow from the
proposition 'it may be', nor does the proposition 'it is necessary
that it should not be'. For the proposition 'it may be' implies a
twofold possibility, while, if either of the two former
propositions is true, the twofold possibility vanishes. For if a
thing may be, it may also not be, but if it is necessary that it
should be or that it should not be, one of the two alternatives
will be excluded. It remains, therefore, that the proposition 'it is
not necessary that it should not be' follows from the
proposition 'it may be'. For this is true also of that which must
necessarily be.
Moreover the proposition 'it is not necessary that it should not
be' is the contradictory of that which follows from the
proposition 'it cannot be'; for 'it cannot be' is followed by 'it is
impossible that it should be' and by 'it is necessary that it
should not be', and the contradictory of this is the proposition
'it is not necessary that it should not be'. Thus in this case also
contradictory propositions follow contradictory in the way
indicated, and no logical impossibilities occur when they are
thus arranged.
It may be questioned whether the proposition 'it may be'
follows from the proposition 'it is necessary that it should be'. If
not, the contradictory must follow, namely that it cannot be, or,
if a man should maintain that this is not the contradictory, then
the proposition 'it may not be'.
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Now both of these are false of that which necessarily is. At the
same time, it is thought that if a thing may be cut it may also
not be cut, if a thing may be it may also not be, and thus it
would follow that a thing which must necessarily be may
possibly not be; which is false. It is evident, then, that it is not
always the case that that which may be or may walk possesses
also a potentiality in the other direction. There are exceptions.
In the first place we must except those things which possess a
potentiality not in accordance with a rational principle, as fire
possesses the potentiality of giving out heat, that is, an
irrational capacity. Those potentialities which involve a rational
principle are potentialities of more than one result, that is, of
contrary results; those that are irrational are not always thus
constituted. As I have said, fire cannot both heat and not heat,
neither has anything that is always actual any twofold
potentiality. Yet some even of those potentialities which are
irrational admit of opposite results. However, thus much has
been said to emphasize the truth that it is not every potentiality
which admits of opposite results, even where the word is used
always in the same sense.
But in some cases the word is used equivocally. For the term
'possible' is ambiguous, being used in the one case with
reference to facts, to that which is actualized, as when a man is
said to find walking possible because he is actually walking,
and generally when a capacity is predicated because it is
actually realized; in the other case, with reference to a state in
which realization is conditionally practicable, as when a man is
said to find walking possible because under certain conditions
he would walk. This last sort of potentiality belongs only to that
which can be in motion, the former can exist also in the case of
that which has not this power. Both of that which is walking
and is actual, and of that which has the capacity though not
necessarily realized, it is true to say that it is not impossible
that it should walk (or, in the other case, that it should be), but
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while we cannot predicate this latter kind of potentiality of that
which is necessary in the unqualified sense of the word, we can
predicate the former.
Our conclusion, then, is this: that since the universal is
consequent upon the particular, that which is necessary is also
possible, though not in every sense in which the word may be
used.
We may perhaps state that necessity and its absence are the
initial principles of existence and non-existence, and that all
else must be regarded as posterior to these.
It is plain from what has been said that that which is of
necessity is actual. Thus, if that which is eternal is prior,
actuality also is prior to potentiality. Some things are actualities
without potentiality, namely, the primary substances; a second
class consists of those things which are actual but also
potential, whose actuality is in nature prior to their potentiality,
though posterior in time; a third class comprises those things
which are never actualized, but are pure potentialities.
14
The question arises whether an affirmation finds its contrary in
a denial or in another affirmation; whether the proposition
'every man is just' finds its contrary in the proposition 'no man
is just', or in the proposition 'every man is unjust'. Take the
propositions 'Callias is just', 'Callias is not just', 'Callias is
unjust'; we have to discover which of these form contraries.
Now if the spoken word corresponds with the judgement of the
mind, and if, in thought, that judgement is the contrary of
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another, which pronounces a contrary fact, in the way, for
instance, in which the judgement 'every man is just'
pronounces a contrary to that pronounced by the judgement
'every man is unjust', the same must needs hold good with
regard to spoken affirmations.
But if, in thought, it is not the judgement which pronounces a
contrary fact that is the contrary of another, then one
affirmation will not find its contrary in another, but rather in
the corresponding denial. We must therefore consider which
true judgement is the contrary of the false, that which forms
the denial of the false judgement or that which affirms the
contrary fact.
Let me illustrate. There is a true judgement concerning that
which is good, that it is good; another, a false judgement, that it
is not good; and a third, which is distinct, that it is bad. Which
of these two is contrary to the true? And if they are one and the
same, which mode of expression forms the contrary?
It is an error to suppose that judgements are to be defined as
contrary in virtue of the fact that they have contrary subjects;
for the judgement concerning a good thing, that it is good, and
that concerning a bad thing, that it is bad, may be one and the
same, and whether they are so or not, they both represent the
truth. Yet the subjects here are contrary. But judgements are
not contrary because they have contrary subjects, but because
they are to the contrary effect.
Now if we take the judgement that that which is good is good,
and another that it is not good, and if there are at the same
time other attributes, which do not and cannot belong to the
good, we must nevertheless refuse to treat as the contraries of
the true judgement those which opine that some other attribute
subsists which does not subsist, as also those that opine that
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some other attribute does not subsist which does subsist, for
both these classes of judgement are of unlimited content.
Those judgements must rather be termed contrary to the true
judgements, in which error is present. Now these judgements
are those which are concerned with the starting points of
generation, and generation is the passing from one extreme to
its opposite; therefore error is a like transition.
Now that which is good is both good and not bad. The first
quality is part of its essence, the second accidental; for it is by
accident that it is not bad. But if that true judgement is most
really true, which concerns the subject's intrinsic nature, then
that false judgement likewise is most really false, which
concerns its intrinsic nature. Now the judgement that that is
good is not good is a false judgement concerning its intrinsic
nature, the judgement that it is bad is one concerning that
which is accidental. Thus the judgement which denies the true
judgement is more really false than that which positively
asserts the presence of the contrary quality. But it is the man
who forms that judgement which is contrary to the true who is
most thoroughly deceived, for contraries are among the things
which differ most widely within the same class. If then of the
two judgements one is contrary to the true judgement, but that
which is contradictory is the more truly contrary, then the
latter, it seems, is the real contrary. The judgement that that
which is good is bad is composite. For presumably the man who
forms that judgement must at the same time understand that
that which is good is not good.
Further, the contradictory is either always the contrary or
never; therefore, if it must necessarily be so in all other cases,
our conclusion in the case just dealt with would seem to be
correct. Now where terms have no contrary, that judgement is
false, which forms the negative of the true; for instance, he who
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thinks a man is not a man forms a false judgement. If then in
these cases the negative is the contrary, then the principle is
universal in its application.
Again, the judgement that that which is not good is not good is
parallel with the judgement that that which is good is good.
Besides these there is the judgement that that which is good is
not good, parallel with the judgement that that that is not good
is good. Let us consider, therefore, what would form the
contrary of the true judgement that that which is not good is
not good. The judgement that it is bad would, of course, fail to
meet the case, since two true judgements are never contrary
and this judgement might be true at the same time as that with
which it is connected. For since some things which are not good
are bad, both judgements may be true. Nor is the judgement
that it is not bad the contrary, for this too might be true, since
both qualities might be predicated of the same subject. It
remains, therefore, that of the judgement concerning that
which is not good, that it is not good, the contrary judgement is
that it is good; for this is false. In the same way, moreover, the
judgement concerning that which is good, that it is not good, is
the contrary of the judgement that it is good.
It is evident that it will make no difference if we universalize
the positive judgement, for the universal negative judgement
will form the contrary. For instance, the contrary of the
judgement that everything that is good is good is that nothing
that is good is good. For the judgement that that which is good
is good, if the subject be understood in a universal sense, is
equivalent to the judgement that whatever is good is good, and
this is identical with the judgement that everything that is good
is good. We may deal similarly with judgements concerning
that which is not good.
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If therefore this is the rule with judgements, and if spoken
affirmations and denials are judgements expressed in words, it
is plain that the universal denial is the contrary of the
affirmation about the same subject. Thus the propositions
'everything good is good', 'every man is good', have for their
contraries the propositions 'nothing good is good', 'no man is
good'. The contradictory propositions, on the other hand, are
'not everything good is good', 'not every man is good'.
It is evident, also, that neither true judgements nor true
propositions can be contrary the one to the other. For whereas,
when two propositions are true, a man may state both at the
same time without inconsistency, contrary propositions are
those which state contrary conditions, and contrary conditions
cannot subsist at one and the same time in the same subject.
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Aristotle - Prior Analytics
[Translated by A. J. Jenkinson]
Book I
We must first state the subject of our inquiry and the faculty to
which it belongs: its subject is demonstration and the faculty
that carries it out demonstrative science. We must next define a
premiss, a term, and a syllogism, and the nature of a perfect
and of an imperfect syllogism; and after that, the inclusion or
noninclusion of one term in another as in a whole, and what we
mean by predicating one term of all, or none, of another.
A premiss then is a sentence affirming or denying one thing of
another. This is either universal or particular or indefinite. By
universal I mean the statement that something belongs to all or
none of something else; by particular that it belongs to some or
not to some or not to all; by indefinite that it does or does not
belong, without any mark to show whether it is universal or
particular, e.g. 'contraries are subjects of the same science', or
'pleasure is not good'. The demonstrative premiss differs from
the dialectical, because the demonstrative premiss is the
assertion of one of two contradictory statements (the
demonstrator does not ask for his premiss, but lays it down),
whereas the dialectical premiss depends on the adversary's
choice between two contradictories. But this will make no
difference to the production of a syllogism in either case; for
both the demonstrator and the dialectician argue syllogistically
after stating that something does or does not belong to
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something else. Therefore a syllogistic premiss without
qualification will be an affirmation or denial of something
concerning something else in the way we have described; it will
be demonstrative, if it is true and obtained through the first
principles of its science; while a dialectical premiss is the giving
of a choice between two contradictories, when a man is
proceeding by question, but when he is syllogizing it is the
assertion of that which is apparent and generally admitted, as
has been said in the Topics. The nature then of a premiss and
the difference between syllogistic, demonstrative, and
dialectical premisses, may be taken as sufficiently defined by us
in relation to our present need, but will be stated accurately in
the sequel.
I call that a term into which the premiss is resolved, i.e. both the
predicate and that of which it is predicated, 'being' being added
and 'not being' removed, or vice versa.
A syllogism is discourse in which, certain things being stated,
something other than what is stated follows of necessity from
their being so. I mean by the last phrase that they produce the
consequence, and by this, that no further term is required from
without in order to make the consequence necessary.
I call that a perfect syllogism which needs nothing other than
what has been stated to make plain what necessarily follows; a
syllogism is imperfect, if it needs either one or more
propositions, which are indeed the necessary consequences of
the terms set down, but have not been expressly stated as
premisses.
That one term should be included in another as in a whole is
the same as for the other to be predicated of all of the first. And
we say that one term is predicated of all of another, whenever
no instance of the subject can be found of which the other term
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cannot be asserted: 'to be predicated of none' must be
understood in the same way.
Every premiss states that something either is or must be or may
be the attribute of something else; of premisses of these three
kinds some are affirmative, others negative, in respect of each
of the three modes of attribution; again some affirmative and
negative premisses are universal, others particular, others
indefinite. It is necessary then that in universal attribution the
terms of the negative premiss should be convertible, e.g. if no
pleasure is good, then no good will be pleasure; the terms of the
affirmative must be convertible, not however, universally, but in
part, e.g. if every pleasure, is good, some good must be pleasure;
the particular affirmative must convert in part (for if some
pleasure is good, then some good will be pleasure); but the
particular negative need not convert, for if some animal is not
man, it does not follow that some man is not animal.
First then take a universal negative with the terms A and B. If no
B is A, neither can any A be B. For if some A (say C) were B, it
would not be true that no B is A; for C is a B. But if every B is A
then some A is B. For if no A were B, then no B could be A. But
we assumed that every B is A. Similarly too, if the premiss is
particular. For if some B is A, then some of the As must be B. For
if none were, then no B would be A. But if some B is not A, there
is no necessity that some of the As should not be B; e.g. let B
stand for animal and A for man. Not every animal is a man; but
every man is an animal.
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The same manner of conversion will hold good also in respect
of necessary premisses. The universal negative converts
universally; each of the affirmatives converts into a particular. If
it is necessary that no B is A, it is necessary also that no A is B.
For if it is possible that some A is B, it would be possible also
that some B is A. If all or some B is A of necessity, it is necessary
also that some A is B: for if there were no necessity, neither
would some of the Bs be A necessarily. But the particular
negative does not convert, for the same reason which we have
already stated.
In respect of possible premisses, since possibility is used in
several senses (for we say that what is necessary and what is
not necessary and what is potential is possible), affirmative
statements will all convert in a manner similar to those
described. For if it is possible that all or some B is A, it will be
possible that some A is B. For if that were not possible, then no
B could possibly be A. This has been already proved. But in
negative statements the case is different. Whatever is said to be
possible, either because B necessarily is A, or because B is not
necessarily A, admits of conversion like other negative
statements, e.g. if one should say, it is possible that man is not
horse, or that no garment is white. For in the former case the
one term necessarily does not belong to the other; in the latter
there is no necessity that it should: and the premiss converts
like other negative statements. For if it is possible for no man to
be a horse, it is also admissible for no horse to be a man; and if
it is admissible for no garment to be white, it is also admissible
for nothing white to be a garment. For if any white thing must
be a garment, then some garment will necessarily be white. This
has been already proved. The particular negative also must be
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treated like those dealt with above. But if anything is said to be
possible because it is the general rule and natural (and it is in
this way we define the possible), the negative premisses can no
longer be converted like the simple negatives; the universal
negative premiss does not convert, and the particular does. This
will be plain when we speak about the possible. At present we
may take this much as clear in addition to what has been said:
the statement that it is possible that no B is A or some B is not A
is affirmative in form: for the expression 'is possible' ranks
along with 'is', and 'is' makes an affirmation always and in
every case, whatever the terms to which it is added, in
predication, e.g. 'it is not-good' or 'it is not-white' or in a word 'it
is not-this'. But this also will be proved in the sequel. In
conversion these premisses will behave like the other
affirmative propositions.
After these distinctions we now state by what means, when,
and how every syllogism is produced; subsequently we must
speak of demonstration. Syllogism should be discussed before
demonstration because syllogism is the general: the
demonstration is a sort of syllogism, but not every syllogism is a
demonstration.
Whenever three terms are so related to one another that the
last is contained in the middle as in a whole, and the middle is
either contained in, or excluded from, the first as in or from a
whole, the extremes must be related by a perfect syllogism. I
call that term middle which is itself contained in another and
contains another in itself: in position also this comes in the
middle. By extremes I mean both that term which is itself
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contained in another and that in which another is contained. If
A is predicated of all B, and B of all C, A must be predicated of
all C: we have already explained what we mean by 'predicated
of all'. Similarly also, if A is predicated of no B, and B of all C, it
is necessary that no C will be A.
But if the first term belongs to all the middle, but the middle to
none of the last term, there will be no syllogism in respect of
the extremes; for nothing necessary follows from the terms
being so related; for it is possible that the first should belong
either to all or to none of the last, so that neither a particular
nor a universal conclusion is necessary. But if there is no
necessary consequence, there cannot be a syllogism by means
of these premisses. As an example of a universal affirmative
relation between the extremes we may take the terms animal,
man, horse; of a universal negative relation, the terms animal,
man, stone. Nor again can syllogism be formed when neither
the first term belongs to any of the middle, nor the middle to
any of the last. As an example of a positive relation between the
extremes take the terms science, line, medicine: of a negative
relation science, line, unit.
If then the terms are universally related, it is clear in this figure
when a syllogism will be possible and when not, and that if a
syllogism is possible the terms must be related as described,
and if they are so related there will be a syllogism.
But if one term is related universally, the other in part only, to
its subject, there must be a perfect syllogism whenever
universality is posited with reference to the major term either
affirmatively or negatively, and particularity with reference to
the minor term affirmatively: but whenever the universality is
posited in relation to the minor term, or the terms are related in
any other way, a syllogism is impossible. I call that term the
major in which the middle is contained and that term the
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minor which comes under the middle. Let all B be A and some C
be B. Then if 'predicated of all' means what was said above, it is
necessary that some C is A. And if no B is A but some C is B, it is
necessary that some C is not A. The meaning of 'predicated of
none' has also been defined. So there will be a perfect syllogism.
This holds good also if the premiss BC should be indefinite,
provided that it is affirmative: for we shall have the same
syllogism whether the premiss is indefinite or particular.
But if the universality is posited with respect to the minor term
either affirmatively or negatively, a syllogism will not be
possible, whether the major premiss is positive or negative,
indefinite or particular: e.g. if some B is or is not A, and all C is
B. As an example of a positive relation between the extremes
take the terms good, state, wisdom: of a negative relation, good,
state, ignorance. Again if no C is B, but some B is or is not A or
not every B is A, there cannot be a syllogism. Take the terms
white, horse, swan: white, horse, raven. The same terms may be
taken also if the premiss BA is indefinite.
Nor when the major premiss is universal, whether affirmative
or negative, and the minor premiss is negative and particular,
can there be a syllogism, whether the minor premiss be
indefinite or particular: e.g. if all B is A and some C is not B, or if
not all C is B. For the major term may be predicable both of all
and of none of the minor, to some of which the middle term
cannot be attributed. Suppose the terms are animal, man,
white: next take some of the white things of which man is not
predicated - swan and snow: animal is predicated of all of the
one, but of none of the other. Consequently there cannot be a
syllogism. Again let no B be A, but let some C not be B. Take the
terms inanimate, man, white: then take some white things of
which man is not predicated - swan and snow: the term
inanimate is predicated of all of the one, of none of the other.
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Further since it is indefinite to say some C is not B, and it is true
that some C is not B, whether no C is B, or not all C is B, and
since if terms are assumed such that no C is B, no syllogism
follows (this has already been stated) it is clear that this
arrangement of terms will not afford a syllogism: otherwise one
would have been possible with a universal negative minor
premiss. A similar proof may also be given if the universal
premiss is negative.
Nor can there in any way be a syllogism if both the relations of
subject and predicate are particular, either positively or
negatively, or the one negative and the other affirmative, or one
indefinite and the other definite, or both indefinite. Terms
common to all the above are animal, white, horse: animal,
white, stone.
It is clear then from what has been said that if there is a
syllogism in this figure with a particular conclusion, the terms
must be related as we have stated: if they are related otherwise,
no syllogism is possible anyhow. It is evident also that all the
syllogisms in this figure are perfect (for they are all completed
by means of the premisses originally taken) and that all
conclusions are proved by this figure, viz. universal and
particular, affirmative and negative. Such a figure I call the first.
Whenever the same thing belongs to all of one subject, and to
none of another, or to all of each subject or to none of either, I
call such a figure the second; by middle term in it I mean that
which is predicated of both subjects, by extremes the terms of
which this is said, by major extreme that which lies near the
middle, by minor that which is further away from the middle.
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The middle term stands outside the extremes, and is first in
position. A syllogism cannot be perfect anyhow in this figure,
but it may be valid whether the terms are related universally or
not.
If then the terms are related universally a syllogism will be
possible, whenever the middle belongs to all of one subject and
to none of another (it does not matter which has the negative
relation), but in no other way. Let M be predicated of no N, but of
all 0. Since, then, the negative relation is convertible, N will
belong to no M: but M was assumed to belong to all 0:
consequently N will belong to no 0. This has already been
proved. Again if M belongs to all N, but to no 0, then N will
belong to no 0. For if M belongs to no 0, belongs to no M: but
M (as was said) belongs to all N: then will belong to no N: for
the first figure has again been formed. But since the negative
relation is convertible, N will belong to no 0. Thus it will be the
same syllogism that proves both conclusions.
It is possible to prove these results also by reductio ad
impossibile.
It is clear then that a syllogism is formed when the terms are so
related, but not a perfect syllogism; for necessity is not perfectly
established merely from the original premisses; others also are
needed.
But if M is predicated of every N and 0, there cannot be a
syllogism. Terms to illustrate a positive relation between the
extremes are substance, animal, man; a negative relation,
substance, animal, number - substance being the middle term.
Nor is a syllogism possible when M is predicated neither of any
N nor of any 0. Terms to illustrate a positive relation are line,
animal, man: a negative relation, line, animal, stone.
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It is clear then that if a syllogism is formed when the terms are
universally related, the terms must be related as we stated at
the outset: for if they are otherwise related no necessary
consequence follows.
If the middle term is related universally to one of the extremes,
a particular negative syllogism must result whenever the
middle term is related universally to the major whether
positively or negatively, and particularly to the minor and in a
manner opposite to that of the universal statement: by 'an
opposite manner' I mean, if the universal statement is negative,
the particular is affirmative: if the universal is affirmative, the
particular is negative. For if M belongs to no N, but to some 0, it
is necessary that N does not belong to some 0. For since the
negative statement is convertible, N will belong to no M: but M
was admitted to belong to some 0: therefore N will not belong
to some 0: for the result is reached by means of the first figure.
Again if M belongs to all N, but not to some 0, it is necessary
that N does not belong to some 0: for if N belongs to all 0, and
M is predicated also of all N, M must belong to all 0: but we
assumed that M does not belong to some 0. And if M belongs to
all N but not to all 0, we shall conclude that N does not belong
to all 0: the proof is the same as the above. But if M is
predicated of all 0, but not of all N, there will be no syllogism.
Take the terms animal, substance, raven; animal, white, raven.
Nor will there be a conclusion when M is predicated of no 0, but
of some N. Terms to illustrate a positive relation between the
extremes are animal, substance, unit: a negative relation,
animal, substance, science.
If then the universal statement is opposed to the particular, we
have stated when a syllogism will be possible and when not:
but if the premisses are similar in form, I mean both negative or
both affirmative, a syllogism will not be possible anyhow. First
let them be negative, and let the major premiss be universal, e.g.
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let M belong to no N, and not to some 0. It is possible then for N
to belong either to all or to no 0. Terms to illustrate the
negative relation are black, snow, animal. But it is not possible
to find terms of which the extremes are related positively and
universally, if M belongs to some 0, and does not belong to
some 0. For if N belonged to all 0, but M to no N, then M would
belong to no 0: but we assumed that it belongs to some 0. In
this way then it is not admissible to take terms: our point must
be proved from the indefinite nature of the particular
statement. For since it is true that M does not belong to some 0,
even if it belongs to no 0, and since if it belongs to no a
syllogism is (as we have seen) not possible, clearly it will not be
possible now either.
Again let the premisses be affirmative, and let the major
premiss as before be universal, e.g. let M belong to all N and to
some 0. It is possible then for N to belong to all or to no 0.
Terms to illustrate the negative relation are white, swan, stone.
But it is not possible to take terms to illustrate the universal
affirmative relation, for the reason already stated: the point
must be proved from the indefinite nature of the particular
statement. But if the minor premiss is universal, and M belongs
to no 0, and not to some N, it is possible for N to belong either
to all or to no 0. Terms for the positive relation are white,
animal, raven: for the negative relation, white, stone, raven. If
the premisses are affirmative, terms for the negative relation
are white, animal, snow; for the positive relation, white, animal,
swan. Evidently then, whenever the premisses are similar in
form, and one is universal, the other particular, a syllogism can,
not be formed anyhow. Nor is one possible if the middle term
belongs to some of each of the extremes, or does not belong to
some of either, or belongs to some of the one, not to some of the
other, or belongs to neither universally, or is related to them
indefinitely. Common terms for all the above are white, animal,
man: white, animal, inanimate. It is clear then from what has
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been said that if the terms are related to one another in the way
stated, a syllogism results of necessity; and if there is a
syllogism, the terms must be so related. But it is evident also
that all the syllogisms in this figure are imperfect: for all are
made perfect by certain supplementary statements, which
either are contained in the terms of necessity or are assumed as
hypotheses, i.e. when we prove per impossibile. And it is evident
that an affirmative conclusion is not attained by means of this
figure, but all are negative, whether universal or particular.
But if one term belongs to all, and another to none, of a third, or
if both belong to all, or to none, of it, I call such a figure the
third; by middle term in it I mean that of which both the
predicates are predicated, by extremes I mean the predicates, by
the major extreme that which is further from the middle, by the
minor that which is nearer to it. The middle term stands outside
the extremes, and is last in position. A syllogism cannot be
perfect in this figure either, but it may be valid whether the
terms are related universally or not to the middle term.
If they are universal, whenever both P and R belong to S, it
follows that P will necessarily belong to some R. For, since the
affirmative statement is convertible, S will belong to some R:
consequently since P belongs to all S, and S to some R, P must
belong to some R: for a syllogism in the first figure is produced.
It is possible to demonstrate this also per impossibile and by
exposition. For if both P and R belong to all S, should one of the
Ss, e.g. N, be taken, both P and R will belong to this, and thus P
will belong to some R.
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If R belongs to all S, and P to no S, there will be a syllogism to
prove that P will necessarily not belong to some R. This may be
demonstrated in the same way as before by converting the
premiss RS. It might be proved also per impossibile, as in the
former cases. But if R belongs to no S, P to all S, there will be no
syllogism. Terms for the positive relation are animal, horse,
man: for the negative relation animal, inanimate, man.
Nor can there be a syllogism when both terms are asserted of
no S. Terms for the positive relation are animal, horse,
inanimate; for the negative relation man, horse, inanimate -
inanimate being the middle term.
It is clear then in this figure also when a syllogism will be
possible and when not, if the terms are related universally. For
whenever both the terms are affirmative, there will be a
syllogism to prove that one extreme belongs to some of the
other; but when they are negative, no syllogism will be possible.
But when one is negative, the other affirmative, if the major is
negative, the minor affirmative, there will be a syllogism to
prove that the one extreme does not belong to some of the
other: but if the relation is reversed, no syllogism will be
possible. If one term is related universally to the middle, the
other in part only, when both are affirmative there must be a
syllogism, no matter which of the premisses is universal. For if
R belongs to all S, P to some S, P must belong to some R. For
since the affirmative statement is convertible S will belong to
some P: consequently since R belongs to all S, and S to some P, R
must also belong to some P: therefore P must belong to some R.
Again if R belongs to some S, and P to all S, P must belong to
some R. This may be demonstrated in the same way as the
preceding. And it is possible to demonstrate it also per
impossibile and by exposition, as in the former cases. But if one
term is affirmative, the other negative, and if the affirmative is
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universal, a syllogism will be possible whenever the minor term
is affirmative. For if R belongs to all S, but P does not belong to
some S, it is necessary that P does not belong to some R. For if P
belongs to all R, and R belongs to all S, then P will belong to all
S: but we assumed that it did not. Proof is possible also without
reduction ad impossibile, if one of the Ss be taken to which P
does not belong.
But whenever the major is affirmative, no syllogism will be
possible, e.g. if P belongs to all S and R does not belong to some
S. Terms for the universal affirmative relation are animate, man,
animal. For the universal negative relation it is not possible to
get terms, if R belongs to some S, and does not belong to some
S. For if P belongs to all S, and R to some S, then P will belong to
some R: but we assumed that it belongs to no R. We must put
the matter as before.' Since the expression 'it does not belong to
some' is indefinite, it may be used truly of that also which
belongs to none. But if R belongs to no S, no syllogism is
possible, as has been shown. Clearly then no syllogism will be
possible here.
But if the negative term is universal, whenever the major is
negative and the minor affirmative there will be a syllogism. For
if P belongs to no S, and R belongs to some S, P will not belong
to some R: for we shall have the first figure again, if the premiss
RS is converted.
But when the minor is negative, there will be no syllogism.
Terms for the positive relation are animal, man, wild: for the
negative relation, animal, science, wild - the middle in both
being the term wild.
Nor is a syllogism possible when both are stated in the negative,
but one is universal, the other particular. When the minor is
related universally to the middle, take the terms animal,
science, wild; animal, man, wild. When the major is related
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universally to the middle, take as terms for a negative relation
raven, snow, white. For a positive relation terms cannot be
found, if R belongs to some S, and does not belong to some S.
For if P belongs to all R, and R to some S, then P belongs to some
S: but we assumed that it belongs to no S. Our point, then, must
be proved from the indefinite nature of the particular
statement.
Nor is a syllogism possible anyhow, if each of the extremes
belongs to some of the middle or does not belong, or one
belongs and the other does not to some of the middle, or one
belongs to some of the middle, the other not to all, or if the
premisses are indefinite. Common terms for all are animal,
man, white: animal, inanimate, white.
It is clear then in this figure also when a syllogism will be
possible, and when not; and that if the terms are as stated, a
syllogism results of necessity, and if there is a syllogism, the
terms must be so related. It is clear also that all the syllogisms
in this figure are imperfect (for all are made perfect by certain
supplementary assumptions), and that it will not be possible to
reach a universal conclusion by means of this figure, whether
negative or affirmative.
It is evident also that in all the figures, whenever a proper
syllogism does not result, if both the terms are affirmative or
negative nothing necessary follows at all, but if one is
affirmative, the other negative, and if the negative is stated
universally, a syllogism always results relating the minor to the
major term, e.g. if A belongs to all or some B, and B belongs to
no C: for if the premisses are converted it is necessary that C
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does not belong to some A. Similarly also in the other figures: a
syllogism always results by means of conversion. It is evident
also that the substitution of an indefinite for a particular
affirmative will effect the same syllogism in all the figures.
It is clear too that all the imperfect syllogisms are made perfect
by means of the first figure. For all are brought to a conclusion
either ostensively or per impossibile. In both ways the first
figure is formed: if they are made perfect ostensively, because
(as we saw) all are brought to a conclusion by means of
conversion, and conversion produces the first figure: if they are
proved per impossibile, because on the assumption of the false
statement the syllogism comes about by means of the first
figure, e.g. in the last figure, if A and B belong to all C, it follows
that A belongs to some B: for if A belonged to no B, and B
belongs to all C, A would belong to no C: but (as we stated) it
belongs to all C. Similarly also with the rest.
It is possible also to reduce all syllogisms to the universal
syllogisms in the first figure. Those in the second figure are
clearly made perfect by these, though not all in the same way;
the universal syllogisms are made perfect by converting the
negative premiss, each of the particular syllogisms by reductio
ad impossibile. In the first figure particular syllogisms are
indeed made perfect by themselves, but it is possible also to
prove them by means of the second figure, reducing them ad
impossibile, e.g. if A belongs to all B, and B to some C, it follows
that A belongs to some C. For if it belonged to no C, and belongs
to all B, then B will belong to no C: this we know by means of
the second figure. Similarly also demonstration will be possible
in the case of the negative. For if A belongs to no B, and B
belongs to some C, A will not belong to some C: for if it belonged
to all C, and belongs to no B, then B will belong to no C: and this
(as we saw) is the middle figure. Consequently, since all
syllogisms in the middle figure can be reduced to universal
96
syllogisms in the first figure, and since particular syllogisms in
the first figure can be reduced to syllogisms in the middle
figure, it is clear that particular syllogisms can be reduced to
universal syllogisms in the first figure. Syllogisms in the third
figure, if the terms are universal, are directly made perfect by
means of those syllogisms; but, when one of the premisses is
particular, by means of the particular syllogisms in the first
figure: and these (we have seen) may be reduced to the
universal syllogisms in the first figure: consequently also the
particular syllogisms in the third figure may be so reduced. It is
clear then that all syllogisms may be reduced to the universal
syllogisms in the first figure.
We have stated then how syllogisms which prove that
something belongs or does not belong to something else are
constituted, both how syllogisms of the same figure are
constituted in themselves, and how syllogisms of different
figures are related to one another.
8
Since there is a difference according as something belongs,
necessarily belongs, or may belong to something else (for many
things belong indeed, but not necessarily, others neither
necessarily nor indeed at all, but it is possible for them to
belong), it is clear that there will be different syllogisms to prove
each of these relations, and syllogisms with differently related
terms, one syllogism concluding from what is necessary,
another from what is, a third from what is possible.
There is hardly any difference between syllogisms from
necessary premisses and syllogisms from premisses which
merely assert. When the terms are put in the same way, then,
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whether something belongs or necessarily belongs (or does not
belong) to something else, a syllogism will or will not result
alike in both cases, the only difference being the addition of the
expression 'necessarily' to the terms. For the negative statement
is convertible alike in both cases, and we should give the same
account of the expressions 'to be contained in something as in a
whole' and 'to be predicated of all of something'. With the
exceptions to be made below, the conclusion will be proved to
be necessary by means of conversion, in the same manner as in
the case of simple predication. But in the middle figure when
the universal statement is affirmative, and the particular
negative, and again in the third figure when the universal is
affirmative and the particular negative, the demonstration will
not take the same form, but it is necessary by the 'exposition' of
a part of the subject of the particular negative proposition, to
which the predicate does not belong, to make the syllogism in
reference to this: with terms so chosen the conclusion will
necessarily follow. But if the relation is necessary in respect of
the part taken, it must hold of some of that term in which this
part is included: for the part taken is just some of that. And
each of the resulting syllogisms is in the appropriate figure.
It happens sometimes also that when one premiss is necessary
the conclusion is necessary, not however when either premiss is
necessary, but only when the major is, e.g. if A is taken as
necessarily belonging or not belonging to B, but B is taken as
simply belonging to C: for if the premisses are taken in this way,
A will necessarily belong or not belong to C. For since
necessarily belongs, or does not belong, to every B, and since C
is one of the Bs, it is clear that for C also the positive or the
98
negative relation to A will hold necessarily. But if the major
premiss is not necessary, but the minor is necessary, the
conclusion will not be necessary. For if it were, it would result
both through the first figure and through the third that A
belongs necessarily to some B. But this is false; for B may be
such that it is possible that A should belong to none of it.
Further, an example also makes it clear that the conclusion not
be necessary, e.g. if A were movement, B animal, C man: man is
an animal necessarily, but an animal does not move necessarily,
nor does man. Similarly also if the major premiss is negative;
for the proof is the same.
In particular syllogisms, if the universal premiss is necessary,
then the conclusion will be necessary; but if the particular, the
conclusion will not be necessary, whether the universal premiss
is negative or affirmative. First let the universal be necessary,
and let A belong to all B necessarily, but let B simply belong to
some C: it is necessary then that A belongs to some C
necessarily: for C falls under B, and A was assumed to belong
necessarily to all B. Similarly also if the syllogism should be
negative: for the proof will be the same. But if the particular
premiss is necessary, the conclusion will not be necessary: for
from the denial of such a conclusion nothing impossible results,
just as it does not in the universal syllogisms. The same is true
of negative syllogisms. Try the terms movement, animal, white.
10
In the second figure, if the negative premiss is necessary, then
the conclusion will be necessary, but if the affirmative, not
necessary. First let the negative be necessary; let A be possible
of no B, and simply belong to C. Since then the negative
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statement is convertible, B is possible of no A. But A belongs to
all C; consequently B is possible of no C. For C falls under A. The
same result would be obtained if the minor premiss were
negative: for if A is possible be of no C, C is possible of no A: but
A belongs to all B, consequently C is possible of none of the Bs:
for again we have obtained the first figure. Neither then is B
possible of C: for conversion is possible without modifying the
relation.
But if the affirmative premiss is necessary, the conclusion will
not be necessary. Let A belong to all B necessarily, but to no C
simply. If then the negative premiss is converted, the first figure
results. But it has been proved in the case of the first figure that
if the negative major premiss is not necessary the conclusion
will not be necessary either. Therefore the same result will
obtain here. Further, if the conclusion is necessary, it follows
that C necessarily does not belong to some A. For if B
necessarily belongs to no C, C will necessarily belong to no B.
But B at any rate must belong to some A, if it is true (as was
assumed) that A necessarily belongs to all B. Consequently it is
necessary that C does not belong to some A. But nothing
prevents such an A being taken that it is possible for C to belong
to all of it. Further one might show by an exposition of terms
that the conclusion is not necessary without qualification,
though it is a necessary conclusion from the premisses. For
example let A be animal, B man, C white, and let the premisses
be assumed to correspond to what we had before: it is possible
that animal should belong to nothing white. Man then will not
belong to anything white, but not necessarily: for it is possible
for man to be born white, not however so long as animal
belongs to nothing white. Consequently under these conditions
the conclusion will be necessary, but it is not necessary without
qualification.
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Similar results will obtain also in particular syllogisms. For
whenever the negative premiss is both universal and necessary,
then the conclusion will be necessary: but whenever the
affirmative premiss is universal, the negative particular, the
conclusion will not be necessary. First then let the negative
premiss be both universal and necessary: let it be possible for
no B that A should belong to it, and let A simply belong to some
C. Since the negative statement is convertible, it will be possible
for no A that B should belong to it: but A belongs to some C;
consequently B necessarily does not belong to some of the Cs.
Again let the affirmative premiss be both universal and
necessary, and let the major premiss be affirmative. If then A
necessarily belongs to all B, but does not belong to some C, it is
clear that B will not belong to some C, but not necessarily. For
the same terms can be used to demonstrate the point, which
were used in the universal syllogisms. Nor again, if the negative
statement is necessary but particular, will the conclusion be
necessary. The point can be demonstrated by means of the
same terms.
11
In the last figure when the terms are related universally to the
middle, and both premisses are affirmative, if one of the two is
necessary, then the conclusion will be necessary. But if one is
negative, the other affirmative, whenever the negative is
necessary the conclusion also will be necessary, but whenever
the affirmative is necessary the conclusion will not be
necessary. First let both the premisses be affirmative, and let A
and B belong to all C, and let AC be necessary. Since then B
belongs to all C, C also will belong to some B, because the
universal is convertible into the particular: consequently if A
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belongs necessarily to all C, and C belongs to some B, it is
necessary that A should belong to some B also. For B is under C.
The first figure then is formed. A similar proof will be given also
if BC is necessary. For C is convertible with some A:
consequently if B belongs necessarily to all C, it will belong
necessarily also to some A.
Again let AC be negative, BC affirmative, and let the negative
premiss be necessary. Since then C is convertible with some B,
but A necessarily belongs to no C, A will necessarily not belong
to some B either: for B is under C. But if the affirmative is
necessary, the conclusion will not be necessary. For suppose BC
is affirmative and necessary, while AC is negative and not
necessary. Since then the affirmative is convertible, C also will
belong to some B necessarily: consequently if A belongs to none
of the Cs, while C belongs to some of the Bs, A will not belong to
some of the Bs - but not of necessity; for it has been proved, in
the case of the first figure, that if the negative premiss is not
necessary, neither will the conclusion be necessary. Further, the
point may be made clear by considering the terms. Let the term
A be 'good', let that which B signifies be 'animal', let the term C
be 'horse'. It is possible then that the term good should belong
to no horse, and it is necessary that the term animal should
belong to every horse: but it is not necessary that some animal
should not be good, since it is possible for every animal to be
good. Or if that is not possible, take as the term 'awake' or
'asleep': for every animal can accept these.
If, then, the premisses are universal, we have stated when the
conclusion will be necessary. But if one premiss is universal, the
other particular, and if both are affirmative, whenever the
universal is necessary the conclusion also must be necessary.
The demonstration is the same as before; for the particular
affirmative also is convertible. If then it is necessary that B
should belong to all C, and A falls under C, it is necessary that B
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should belong to some A. But if B must belong to some A, then A
must belong to some B: for conversion is possible. Similarly also
if AC should be necessary and universal: for B falls under C. But
if the particular premiss is necessary, the conclusion will not be
necessary. Let the premiss BC be both particular and necessary,
and let A belong to all C, not however necessarily. If the
proposition BC is converted the first figure is formed, and the
universal premiss is not necessary, but the particular is
necessary. But when the premisses were thus, the conclusion
(as we proved was not necessary: consequently it is not here
either. Further, the point is clear if we look at the terms. Let A be
waking, B biped, and C animal. It is necessary that B should
belong to some C, but it is possible for A to belong to C, and that
A should belong to B is not necessary. For there is no necessity
that some biped should be asleep or awake. Similarly and by
means of the same terms proof can be made, should the
proposition AC be both particular and necessary.
But if one premiss is affirmative, the other negative, whenever
the universal is both negative and necessary the conclusion also
will be necessary. For if it is not possible that A should belong to
any C, but B belongs to some C, it is necessary that A should not
belong to some B. But whenever the affirmative proposition is
necessary, whether universal or particular, or the negative is
particular, the conclusion will not be necessary. The proof of
this by reduction will be the same as before; but if terms are
wanted, when the universal affirmative is necessary, take the
terms 'waking' - 'animal' - 'man', 'man' being middle, and when
the affirmative is particular and necessary, take the terms
'waking' - 'animal' - 'white': for it is necessary that animal
should belong to some white thing, but it is possible that
waking should belong to none, and it is not necessary that
waking should not belong to some animal. But when the
negative proposition being particular is necessary, take the
terms 'biped', 'moving', 'animal', 'animal' being middle.
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12
It is clear then that a simple conclusion is not reached unless
both premisses are simple assertions, but a necessary-
conclusion is possible although one only of the premisses is
necessary. But in both cases, whether the syllogisms are
affirmative or negative, it is necessary that one premiss should
be similar to the conclusion. I mean by 'similar', if the
conclusion is a simple assertion, the premiss must be simple; if
the conclusion is necessary, the premiss must be necessary.
Consequently this also is clear, that the conclusion will be
neither necessary nor simple unless a necessary or simple
premiss is assumed.
13
Perhaps enough has been said about the proof of necessity, how
it comes about and how it differs from the proof of a simple
statement. We proceed to discuss that which is possible, when
and how and by what means it can be proved. I use the terms
'to be possible' and 'the possible' of that which is not necessary
but, being assumed, results in nothing impossible. We say
indeed ambiguously of the necessary that it is possible. But that
my definition of the possible is correct is clear from the phrases
by which we deny or on the contrary affirm possibility. For the
expressions 'it is not possible to belong', 'it is impossible to
belong', and 'it is necessary not to belong' are either identical or
follow from one another; consequently their opposites also, 'it is
possible to belong', 'it is not impossible to belong', and 'it is not
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necessary not to belong', will either be identical or follow from
one another. For of everything the affirmation or the denial
holds good. That which is possible then will be not necessary
and that which is not necessary will be possible. It results that
all premisses in the mode of possibility are convertible into one
another. I mean not that the affirmative are convertible into the
negative, but that those which are affirmative in form admit of
conversion by opposition, e.g. 'it is possible to belong' may be
converted into 'it is possible not to belong', and 'it is possible for
A to belong to all B' into 'it is possible for A to belong to no B' or
'not to all B', and 'it is possible for A to belong to some B' into 'it
is possible for A not to belong to some B'. And similarly the
other propositions in this mode can be converted. For since that
which is possible is not necessary, and that which is not
necessary may possibly not belong, it is clear that if it is
possible that A should belong to B, it is possible also that it
should not belong to B: and if it is possible that it should belong
to all, it is also possible that it should not belong to all. The
same holds good in the case of particular affirmations: for the
proof is identical. And such premisses are affirmative and not
negative; for 'to be possible' is in the same rank as 'to be', as
was said above.
Having made these distinctions we next point out that the
expression 'to be possible' is used in two ways. In one it means
to happen generally and fall short of necessity, e.g. man's
turning grey or growing or decaying, or generally what naturally
belongs to a thing (for this has not its necessity unbroken, since
man's existence is not continuous for ever, although if a man
does exist, it comes about either necessarily or generally). In
another sense the expression means the indefinite, which can
be both thus and not thus, e.g. an animal's walking or an
earthquake's taking place while it is walking, or generally what
happens by chance: for none of these inclines by nature in the
one way more than in the opposite.
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That which is possible in each of its two senses is convertible
into its opposite, not however in the same way: but what is
natural is convertible because it does not necessarily belong (for
in this sense it is possible that a man should not grow grey) and
what is indefinite is convertible because it inclines this way no
more than that. Science and demonstrative syllogism are not
concerned with things which are indefinite, because the middle
term is uncertain; but they are concerned with things that are
natural, and as a rule arguments and inquiries are made about
things which are possible in this sense. Syllogisms indeed can
be made about the former, but it is unusual at any rate to
inquire about them.
These matters will be treated more definitely in the sequel; our
business at present is to state the moods and nature of the
syllogism made from possible premisses. The expression 'it is
possible for this to belong to that' may be understood in two
senses: 'that' may mean either that to which 'that' belongs or
that to which it may belong; for the expression 'A is possible of
the subject of B' means that it is possible either of that of which
B is stated or of that of which B may possibly be stated. It makes
no difference whether we say, A is possible of the subject of B, or
all B admits of A. It is clear then that the expression 'A may
possibly belong to all B' might be used in two senses. First then
we must state the nature and characteristics of the syllogism
which arises if B is possible of the subject of C, and A is possible
of the subject of B. For thus both premisses are assumed in the
mode of possibility; but whenever A is possible of that of which
B is true, one premiss is a simple assertion, the other a
problematic. Consequently we must start from premisses which
are similar in form, as in the other cases.
106
14
Whenever A may possibly belong to all B, and B to all C, there
will be a perfect syllogism to prove that A may possibly belong
to all C. This is clear from the definition: for it was in this way
that we explained 'to be possible for one term to belong to all of
another'. Similarly if it is possible for A to belong no B, and for B
to belong to all C, then it is possible for A to belong to no C. For
the statement that it is possible for A not to belong to that of
which B may be true means (as we saw) that none of those
things which can possibly fall under the term B is left out of
account. But whenever A may belong to all B, and B may belong
to no C, then indeed no syllogism results from the premisses
assumed, but if the premiss BC is converted after the manner of
problematic propositions, the same syllogism results as before.
For since it is possible that B should belong to no C, it is possible
also that it should belong to all C. This has been stated above.
Consequently if B is possible for all C, and A is possible for all B,
the same syllogism again results. Similarly if in both the
premisses the negative is joined with 'it is possible': e.g. if A
may belong to none of the Bs, and B to none of the Cs. No
syllogism results from the assumed premisses, but if they are
converted we shall have the same syllogism as before. It is clear
then that if the minor premiss is negative, or if both premisses
are negative, either no syllogism results, or if one it is not
perfect. For the necessity results from the conversion.
But if one of the premisses is universal, the other particular,
when the major premiss is universal there will be a perfect
syllogism. For if A is possible for all B, and B for some C, then A
is possible for some C. This is clear from the definition of being
possible. Again if A may belong to no B, and B may belong to
some of the Cs, it is necessary that A may possibly not belong to
some of the Cs. The proof is the same as above. But if the
particular premiss is negative, and the universal is affirmative,
107
the major still being universal and the minor particular, e.g. A is
possible for all B, B may possibly not belong to some C, then a
clear syllogism does not result from the assumed premisses, but
if the particular premiss is converted and it is laid down that B
possibly may belong to some C, we shall have the same
conclusion as before, as in the cases given at the beginning.
But if the major premiss is the minor universal, whether both
are affirmative, or negative, or different in quality, or if both are
indefinite or particular, in no way will a syllogism be possible.
For nothing prevents B from reaching beyond A, so that as
predicates cover unequal areas. Let C be that by which B
extends beyond A. To C it is not possible that A should belong -
either to all or to none or to some or not to some, since
premisses in the mode of possibility are convertible and it is
possible for B to belong to more things than A can. Further, this
is obvious if we take terms; for if the premisses are as assumed,
the major term is both possible for none of the minor and must
belong to all of it. Take as terms common to all the cases under
consideration 'animal' - 'white' - 'man', where the major
belongs necessarily to the minor; 'animal' - 'white' - 'garment',
where it is not possible that the major should belong to the
minor. It is clear then that if the terms are related in this
manner, no syllogism results. For every syllogism proves that
something belongs either simply or necessarily or possibly. It is
clear that there is no proof of the first or of the second. For the
affirmative is destroyed by the negative, and the negative by the
affirmative. There remains the proof of possibility. But this is
impossible. For it has been proved that if the terms are related
in this manner it is both necessary that the major should
belong to all the minor and not possible that it should belong to
any. Consequently there cannot be a syllogism to prove the
possibility; for the necessary (as we stated) is not possible.
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It is clear that if the terms are universal in possible premisses a
syllogism always results in the first figure, whether they are
affirmative or negative, only a perfect syllogism results in the
first case, an imperfect in the second. But possibility must be
understood according to the definition laid down, not as
covering necessity. This is sometimes forgotten.
15
If one premiss is a simple proposition, the other a problematic,
whenever the major premiss indicates possibility all the
syllogisms will be perfect and establish possibility in the sense
defined; but whenever the minor premiss indicates possibility
all the syllogisms will be imperfect, and those which are
negative will establish not possibility according to the
definition, but that the major does not necessarily belong to
any, or to all, of the minor. For if this is so, we say it is possible
that it should belong to none or not to all. Let A be possible for
all B, and let B belong to all C. Since C falls under B, and A is
possible for all B, clearly it is possible for all C also. So a perfect
syllogism results. Likewise if the premiss AB is negative, and the
premiss BC is affirmative, the former stating possible, the latter
simple attribution, a perfect syllogism results proving that A
possibly belongs to no C.
It is clear that perfect syllogisms result if the minor premiss
states simple belonging: but that syllogisms will result if the
modality of the premisses is reversed, must be proved per
impossibile. At the same time it will be evident that they are
imperfect: for the proof proceeds not from the premisses
assumed. First we must state that if B's being follows
necessarily from As being, B's possibility will follow necessarily
109
from A's possibility. Suppose, the terms being so related, that A
is possible, and B is impossible. If then that which is possible,
when it is possible for it to be, might happen, and if that which
is impossible, when it is impossible, could not happen, and if at
the same time A is possible and B impossible, it would be
possible for A to happen without B, and if to happen, then to be.
For that which has happened, when it has happened, is. But we
must take the impossible and the possible not only in the
sphere of becoming, but also in the spheres of truth and
predicability, and the various other spheres in which we speak
of the possible: for it will be alike in all. Further we must
understand the statement that B's being depends on A's being,
not as meaning that if some single thing A is, B will be: for
nothing follows of necessity from the being of some one thing,
but from two at least, i.e. when the premisses are related in the
manner stated to be that of the syllogism. For if C is predicated
of D, and D of F, then G is necessarily predicated of F. And if each
is possible, the conclusion also is possible. If then, for example,
one should indicate the premisses by A, and the conclusion by
B, it would not only result that if A is necessary B is necessary,
but also that if A is possible, B is possible.
Since this is proved it is evident that if a false and not
impossible assumption is made, the consequence of the
assumption will also be false and not impossible: e.g. if A is
false, but not impossible, and if B is the consequence of A, B also
will be false but not impossible. For since it has been proved
that if B's being is the consequence of A's being, then B's
possibility will follow from A's possibility (and A is assumed to
be possible), consequently B will be possible: for if it were
impossible, the same thing would at the same time be possible
and impossible.
Since we have defined these points, let A belong to all B, and B
be possible for all C: it is necessary then that should be a
no
possible attribute for all C. Suppose that it is not possible, but
assume that B belongs to all C: this is false but not impossible. If
then A is not possible for C but B belongs to all C, then A is not
possible for all B: for a syllogism is formed in the third degree.
But it was assumed that A is a possible attribute for all B. It is
necessary then that A is possible for all C. For though the
assumption we made is false and not impossible, the
conclusion is impossible. It is possible also in the first figure to
bring about the impossibility, by assuming that B belongs to C.
For if B belongs to all C, and A is possible for all B, then A would
be possible for all C. But the assumption was made that A is not
possible for all C.
We must understand 'that which belongs to all' with no
limitation in respect of time, e.g. to the present or to a particular
period, but simply without qualification. For it is by the help of
such premisses that we make syllogisms, since if the premiss is
understood with reference to the present moment, there cannot
be a syllogism. For nothing perhaps prevents 'man' belonging at
a particular time to everything that is moving, i.e. if nothing else
were moving: but 'moving' is possible for every horse; yet 'man'
is possible for no horse. Further let the major term be 'animal',
the middle 'moving', the the minor 'man'. The premisses then
will be as before, but the conclusion necessary, not possible. For
man is necessarily animal. It is clear then that the universal
must be understood simply, without limitation in respect of
time.
Again let the premiss AB be universal and negative, and assume
that A belongs to no B, but B possibly belongs to all C. These
propositions being laid down, it is necessary that A possibly
belongs to no C. Suppose that it cannot belong, and that B
belongs to C, as above. It is necessary then that A belongs to
some B: for we have a syllogism in the third figure: but this is
impossible. Thus it will be possible for A to belong to no C; for if
111
at is supposed false, the consequence is an impossible one. This
syllogism then does not establish that which is possible
according to the definition, but that which does not necessarily
belong to any part of the subject (for this is the contradictory of
the assumption which was made: for it was supposed that A
necessarily belongs to some C, but the syllogism per impossibile
establishes the contradictory which is opposed to this). Further,
it is clear also from an example that the conclusion will not
establish possibility. Let A be 'raven', B 'intelligent', and C 'man'.
A then belongs to no B: for no intelligent thing is a raven. But B
is possible for all C: for every man may possibly be intelligent.
But A necessarily belongs to no C: so the conclusion does not
establish possibility. But neither is it always necessary. Let A be
'moving', B 'science', C 'man'. A then will belong to no B; but B is
possible for all C. And the conclusion will not be necessary. For
it is not necessary that no man should move; rather it is not
necessary that any man should move. Clearly then the
conclusion establishes that one term does not necessarily
belong to any instance of another term. But we must take our
terms better.
If the minor premiss is negative and indicates possibility, from
the actual premisses taken there can be no syllogism, but if the
problematic premiss is converted, a syllogism will be possible,
as before. Let A belong to all B, and let B possibly belong to no C.
If the terms are arranged thus, nothing necessarily follows: but
if the proposition BC is converted and it is assumed that B is
possible for all C, a syllogism results as before: for the terms are
in the same relative positions. Likewise if both the relations are
negative, if the major premiss states that A does not belong to B,
and the minor premiss indicates that B may possibly belong to
no C. Through the premisses actually taken nothing necessary
results in any way; but if the problematic premiss is converted,
we shall have a syllogism. Suppose that A belongs to no B, and B
may possibly belong to no C. Through these comes nothing
112
necessary. But if B is assumed to be possible for all C (and this is
true) and if the premiss AB remains as before, we shall again
have the same syllogism. But if it be assumed that B does not
belong to any C, instead of possibly not belonging, there cannot
be a syllogism anyhow, whether the premiss AB is negative or
affirmative. As common instances of a necessary and positive
relation we may take the terms white - animal - snow: of a
necessary and negative relation, white - animal - pitch. Clearly
then if the terms are universal, and one of the premisses is
assertoric, the other problematic, whenever the minor premiss
is problematic a syllogism always results, only sometimes it
results from the premisses that are taken, sometimes it requires
the conversion of one premiss. We have stated when each of
these happens and the reason why. But if one of the relations is
universal, the other particular, then whenever the major
premiss is universal and problematic, whether affirmative or
negative, and the particular is affirmative and assertoric, there
will be a perfect syllogism, just as when the terms are universal.
The demonstration is the same as before. But whenever the
major premiss is universal, but assertoric, not problematic, and
the minor is particular and problematic, whether both
premisses are negative or affirmative, or one is negative, the
other affirmative, in all cases there will be an imperfect
syllogism. Only some of them will be proved per impossibile,
others by the conversion of the problematic premiss, as has
been shown above. And a syllogism will be possible by means of
conversion when the major premiss is universal and assertoric,
whether positive or negative, and the minor particular, negative,
and problematic, e.g. if A belongs to all B or to no B, and B may
possibly not belong to some C. For if the premiss BC is
converted in respect of possibility, a syllogism results. But
whenever the particular premiss is assertoric and negative,
there cannot be a syllogism. As instances of the positive relation
we may take the terms white - animal - snow; of the negative,
113
white - animal - pitch. For the demonstration must be made
through the indefinite nature of the particular premiss. But if
the minor premiss is universal, and the major particular,
whether either premiss is negative or affirmative, problematic
or assertoric, nohow is a syllogism possible. Nor is a syllogism
possible when the premisses are particular or indefinite,
whether problematic or assertoric, or the one problematic, the
other assertoric. The demonstration is the same as above. As
instances of the necessary and positive relation we may take
the terms animal - white - man; of the necessary and negative
relation, animal - white - garment. It is evident then that if the
major premiss is universal, a syllogism always results, but if the
minor is universal nothing at all can ever be proved.
16
Whenever one premiss is necessary, the other problematic,
there will be a syllogism when the terms are related as before;
and a perfect syllogism when the minor premiss is necessary. If
the premisses are affirmative the conclusion will be
problematic, not assertoric, whether the premisses are universal
or not: but if one is affirmative, the other negative, when the
affirmative is necessary the conclusion will be problematic, not
negative assertoric; but when the negative is necessary the
conclusion will be problematic negative, and assertoric negative,
whether the premisses are universal or not. Possibility in the
conclusion must be understood in the same manner as before.
There cannot be an inference to the necessary negative
proposition: for 'not necessarily to belong' is different from
'necessarily not to belong'.
114
If the premisses are affirmative, clearly the conclusion which
follows is not necessary. Suppose A necessarily belongs to all B,
and let B be possible for all C. We shall have an imperfect
syllogism to prove that A may belong to all C. That it is
imperfect is clear from the proof: for it will be proved in the
same manner as above. Again, let A be possible for all B, and let
B necessarily belong to all C. We shall then have a syllogism to
prove that A may belong to all C, not that A does belong to all C:
and it is perfect, not imperfect: for it is completed directly
through the original premisses.
But if the premisses are not similar in quality, suppose first that
the negative premiss is necessary, and let necessarily A not be
possible for any B, but let B be possible for all C. It is necessary
then that A belongs to no C. For suppose A to belong to all C or
to some C. Now we assumed that A is not possible for any B.
Since then the negative proposition is convertible, B is not
possible for any A. But A is supposed to belong to all C or to
some C. Consequently B will not be possible for any C or for all
C. But it was originally laid down that B is possible for all C. And
it is clear that the possibility of belonging can be inferred, since
the fact of not belonging is inferred. Again, let the affirmative
premiss be necessary, and let A possibly not belong to any B,
and let B necessarily belong to all C. The syllogism will be
perfect, but it will establish a problematic negative, not an
assertoric negative. For the major premiss was problematic, and
further it is not possible to prove the assertoric conclusion per
impossibile. For if it were supposed that A belongs to some C,
and it is laid down that A possibly does not belong to any B, no
impossible relation between B and C follows from these
premisses. But if the minor premiss is negative, when it is
problematic a syllogism is possible by conversion, as above; but
when it is necessary no syllogism can be formed. Nor again
when both premisses are negative, and the minor is necessary.
The same terms as before serve both for the positive relation -
115
white-animal-snow, and for the negative relation - white-
animal-pitch.
The same relation will obtain in particular syllogisms.
Whenever the negative proposition is necessary, the conclusion
will be negative assertoric: e.g. if it is not possible that A should
belong to any B, but B may belong to some of the Cs, it is
necessary that A should not belong to some of the Cs. For if A
belongs to all C, but cannot belong to any B, neither can B
belong to any A. So if A belongs to all C, to none of the Cs can B
belong. But it was laid down that B may belong to some C. But
when the particular affirmative in the negative syllogism, e.g.
BC the minor premiss, or the universal proposition in the
affirmative syllogism, e.g. AB the major premiss, is necessary,
there will not be an assertoric conclusion. The demonstration is
the same as before. But if the minor premiss is universal, and
problematic, whether affirmative or negative, and the major
premiss is particular and necessary, there cannot be a syllogism.
Premisses of this kind are possible both where the relation is
positive and necessary, e.g. animal-white-man, and where it is
necessary and negative, e.g. animal-white-garment. But when
the universal is necessary, the particular problematic, if the
universal is negative we may take the terms animal-white-
raven to illustrate the positive relation, or animal-white-pitch to
illustrate the negative; and if the universal is affirmative we
may take the terms animal-white-swan to illustrate the positive
relation, and animal-white-snow to illustrate the negative and
necessary relation. Nor again is a syllogism possible when the
premisses are indefinite, or both particular. Terms applicable in
either case to illustrate the positive relation are animal-white-
man: to illustrate the negative, animal-white-inanimate. For the
relation of animal to some white, and of white to some
inanimate, is both necessary and positive and necessary and
negative. Similarly if the relation is problematic: so the terms
may be used for all cases.
116
Clearly then from what has been said a syllogism results or not
from similar relations of the terms whether we are dealing with
simple existence or necessity, with this exception, that if the
negative premiss is assertoric the conclusion is problematic, but
if the negative premiss is necessary the conclusion is both
problematic and negative assertoric. [It is clear also that all the
syllogisms are imperfect and are perfected by means of the
figures above mentioned.]
17
In the second figure whenever both premisses are problematic,
no syllogism is possible, whether the premisses are affirmative
or negative, universal or particular. But when one premiss is
assertoric, the other problematic, if the affirmative is assertoric
no syllogism is possible, but if the universal negative is
assertoric a conclusion can always be drawn. Similarly when
one premiss is necessary, the other problematic. Here also we
must understand the term 'possible' in the conclusion, in the
same sense as before.
First we must point out that the negative problematic
proposition is not convertible, e.g. if A may belong to no B, it
does not follow that B may belong to no A. For suppose it to
follow and assume that B may belong to no A. Since then
problematic affirmations are convertible with negations,
whether they are contraries or contradictories, and since B may
belong to no A, it is clear that B may belong to all A. But this is
false: for if all this can be that, it does not follow that all that
can be this: consequently the negative proposition is not
convertible. Further, these propositions are not incompatible, 'A
may belong to no B', 'B necessarily does not belong to some of
117
the As'; e.g. it is possible that no man should be white (for it is
also possible that every man should be white), but it is not true
to say that it is possible that no white thing should be a man:
for many white things are necessarily not men, and the
necessary (as we saw) other than the possible.
Moreover it is not possible to prove the convertibility of these
propositions by a reductio ad absurdum, i.e. by claiming assent
to the following argument: 'since it is false that B may belong to
no A, it is true that it cannot belong to no A, for the one
statement is the contradictory of the other. But if this is so, it is
true that B necessarily belongs to some of the As: consequently
A necessarily belongs to some of the Bs. But this is impossible.'
The argument cannot be admitted, for it does not follow that
some A is necessarily B, if it is not possible that no A should be
B. For the latter expression is used in two senses, one if A some
is necessarily B, another if some A is necessarily not B. For it is
not true to say that that which necessarily does not belong to
some of the As may possibly not belong to any A, just as it is not
true to say that what necessarily belongs to some A may
possibly belong to all A. If any one then should claim that
because it is not possible for C to belong to all D, it necessarily
does not belong to some D, he would make a false assumption:
for it does belong to all D, but because in some cases it belongs
necessarily, therefore we say that it is not possible for it to
belong to all. Hence both the propositions 'A necessarily belongs
to some B' and A necessarily does not belong to some B' are
opposed to the proposition A belongs to all B'. Similarly also
they are opposed to the proposition A may belong to no B'. It is
clear then that in relation to what is possible and not possible,
in the sense originally defined, we must assume, not that A
necessarily belongs to some B, but that A necessarily does not
belong to some B. But if this is assumed, no absurdity results:
consequently no syllogism. It is clear from what has been said
that the negative proposition is not convertible.
118
This being proved, suppose it possible that A may belong to no B
and to all C. By means of conversion no syllogism will result: for
the major premiss, as has been said, is not convertible. Nor can
a proof be obtained by a reductio ad absurdum: for if it is
assumed that B can belong to all C, no false consequence
results: for A may belong both to all C and to no C. In general, if
there is a syllogism, it is clear that its conclusion will be
problematic because neither of the premisses is assertoric; and
this must be either affirmative or negative. But neither is
possible. Suppose the conclusion is affirmative: it will be proved
by an example that the predicate cannot belong to the subject.
Suppose the conclusion is negative: it will be proved that it is
not problematic but necessary. Let A be white, B man, C horse. It
is possible then for A to belong to all of the one and to none of
the other. But it is not possible for B to belong nor not to belong
to C. That it is not possible for it to belong, is clear. For no horse
is a man. Neither is it possible for it not to belong. For it is
necessary that no horse should be a man, but the necessary we
found to be different from the possible. No syllogism then
results. A similar proof can be given if the major premiss is
negative, the minor affirmative, or if both are affirmative or
negative. The demonstration can be made by means of the same
terms. And whenever one premiss is universal, the other
particular, or both are particular or indefinite, or in whatever
other way the premisses can be altered, the proof will always
proceed through the same terms. Clearly then, if both the
premisses are problematic, no syllogism results.
18
But if one premiss is assertoric, the other problematic, if the
affirmative is assertoric and the negative problematic no
119
syllogism will be possible, whether the premisses are universal
or particular. The proof is the same as above, and by means of
the same terms. But when the affirmative premiss is
problematic, and the negative assertoric, we shall have a
syllogism. Suppose A belongs to no B, but can belong to all C. If
the negative proposition is converted, B will belong to no A. But
ex hypothesi can belong to all C: so a syllogism is made, proving
by means of the first figure that B may belong to no C. Similarly
also if the minor premiss is negative. But if both premisses are
negative, one being assertoric, the other problematic, nothing
follows necessarily from these premisses as they stand, but if
the problematic premiss is converted into its complementary
affirmative a syllogism is formed to prove that B may belong to
no C, as before: for we shall again have the first figure. But if
both premisses are affirmative, no syllogism will be possible.
This arrangement of terms is possible both when the relation is
positive, e.g. health, animal, man, and when it is negative, e.g.
health, horse, man.
The same will hold good if the syllogisms are particular.
Whenever the affirmative proposition is assertoric, whether
universal or particular, no syllogism is possible (this is proved
similarly and by the same examples as above), but when the
negative proposition is assertoric, a conclusion can be drawn by
means of conversion, as before. Again if both the relations are
negative, and the assertoric proposition is universal, although
no conclusion follows from the actual premisses, a syllogism
can be obtained by converting the problematic premiss into its
complementary affirmative as before. But if the negative
proposition is assertoric, but particular, no syllogism is possible,
whether the other premiss is affirmative or negative. Nor can a
conclusion be drawn when both premisses are indefinite,
whether affirmative or negative, or particular. The proof is the
same and by the same terms.
120
19
If one of the premisses is necessary, the other problematic, then
if the negative is necessary a syllogistic conclusion can be
drawn, not merely a negative problematic but also a negative
assertoric conclusion; but if the affirmative premiss is
necessary, no conclusion is possible. Suppose that A necessarily
belongs to no B, but may belong to all C. If the negative premiss
is converted B will belong to no A: but A ex hypothesi is capable
of belonging to all C: so once more a conclusion is drawn by the
first figure that B may belong to no C. But at the same time it is
clear that B will not belong to any C. For assume that it does:
then if A cannot belong to any B, and B belongs to some of the
Cs, A cannot belong to some of the Cs: but ex hypothesi it may
belong to all. A similar proof can be given if the minor premiss
is negative. Again let the affirmative proposition be necessary,
and the other problematic; i.e. suppose that A may belong to no
B, but necessarily belongs to all C. When the terms are arranged
in this way, no syllogism is possible. For (1) it sometimes turns
out that B necessarily does not belong to C. Let A be white, B
man, C swan. White then necessarily belongs to swan, but may
belong to no man; and man necessarily belongs to no swan;
Clearly then we cannot draw a problematic conclusion; for that
which is necessary is admittedly distinct from that which is
possible. (2) Nor again can we draw a necessary conclusion: for
that presupposes that both premisses are necessary, or at any
rate the negative premiss. (3) Further it is possible also, when
the terms are so arranged, that B should belong to C: for
nothing prevents C falling under B, A being possible for all B,
and necessarily belonging to C; e.g. if C stands for 'awake', B for
'animal', A for 'motion'. For motion necessarily belongs to what
121
is awake, and is possible for every animal: and everything that is
awake is animal. Clearly then the conclusion cannot be the
negative assertion, if the relation must be positive when the
terms are related as above. Nor can the opposite affirmations be
established: consequently no syllogism is possible. A similar
proof is possible if the major premiss is affirmative.
But if the premisses are similar in quality, when they are
negative a syllogism can always be formed by converting the
problematic premiss into its complementary affirmative as
before. Suppose A necessarily does not belong to B, and possibly
may not belong to C: if the premisses are converted B belongs to
no A, and A may possibly belong to all C: thus we have the first
figure. Similarly if the minor premiss is negative. But if the
premisses are affirmative there cannot be a syllogism. Clearly
the conclusion cannot be a negative assertoric or a negative
necessary proposition because no negative premiss has been
laid down either in the assertoric or in the necessary mode. Nor
can the conclusion be a problematic negative proposition. For if
the terms are so related, there are cases in which B necessarily
will not belong to C; e.g. suppose that A is white, B swan, C man.
Nor can the opposite affirmations be established, since we have
shown a case in which B necessarily does not belong to C. A
syllogism then is not possible at all.
Similar relations will obtain in particular syllogisms. For
whenever the negative proposition is universal and necessary, a
syllogism will always be possible to prove both a problematic
and a negative assertoric proposition (the proof proceeds by
conversion); but when the affirmative proposition is universal
and necessary, no syllogistic conclusion can be drawn. This can
be proved in the same way as for universal propositions, and by
the same terms. Nor is a syllogistic conclusion possible when
both premisses are affirmative: this also may be proved as
above. But when both premisses are negative, and the premiss
122
that definitely disconnects two terms is universal and
necessary, though nothing follows necessarily from the
premisses as they are stated, a conclusion can be drawn as
above if the problematic premiss is converted into its
complementary affirmative. But if both are indefinite or
particular, no syllogism can be formed. The same proof will
serve, and the same terms.
It is clear then from what has been said that if the universal and
negative premiss is necessary, a syllogism is always possible,
proving not merely a negative problematic, but also a negative
assertoric proposition; but if the affirmative premiss is
necessary no conclusion can be drawn. It is clear too that a
syllogism is possible or not under the same conditions whether
the mode of the premisses is assertoric or necessary. And it is
clear that all the syllogisms are imperfect, and are completed by
means of the figures mentioned.
20
In the last figure a syllogism is possible whether both or only
one of the premisses is problematic. When the premisses are
problematic the conclusion will be problematic; and also when
one premiss is problematic, the other assertoric. But when the
other premiss is necessary, if it is affirmative the conclusion will
be neither necessary or assertoric; but if it is negative the
syllogism will result in a negative assertoric proposition, as
above. In these also we must understand the expression
'possible' in the conclusion in the same way as before.
First let the premisses be problematic and suppose that both A
and B may possibly belong to every C. Since then the affirmative
proposition is convertible into a particular, and B may possibly
123
belong to every C, it follows that C may possibly belong to some
B. So, if A is possible for every C, and C is possible for some of
the Bs, then A is possible for some of the Bs. For we have got the
first figure. And A if may possibly belong to no C, but B may
possibly belong to all C, it follows that A may possibly not
belong to some B: for we shall have the first figure again by
conversion. But if both premisses should be negative no
necessary consequence will follow from them as they are
stated, but if the premisses are converted into their
corresponding affirmatives there will be a syllogism as before.
For if A and B may possibly not belong to C, if 'may possibly
belong' is substituted we shall again have the first figure by
means of conversion. But if one of the premisses is universal,
the other particular, a syllogism will be possible, or not, under
the arrangement of the terms as in the case of assertoric
propositions. Suppose that A may possibly belong to all C, and B
to some C. We shall have the first figure again if the particular
premiss is converted. For if A is possible for all C, and C for
some of the Bs, then A is possible for some of the Bs. Similarly if
the proposition BC is universal. Likewise also if the proposition
AC is negative, and the proposition BC affirmative: for we shall
again have the first figure by conversion. But if both premisses
should be negative - the one universal and the other particular
- although no syllogistic conclusion will follow from the
premisses as they are put, it will follow if they are converted, as
above. But when both premisses are indefinite or particular, no
syllogism can be formed: for A must belong sometimes to all B
and sometimes to no B. To illustrate the affirmative relation
take the terms animal-man-white; to illustrate the negative,
take the terms horse-man-white - white being the middle term.
124
21
If one premiss is pure, the other problematic, the conclusion
will be problematic, not pure; and a syllogism will be possible
under the same arrangement of the terms as before. First let the
premisses be affirmative: suppose that A belongs to all C, and B
may possibly belong to all C. If the proposition BC is converted,
we shall have the first figure, and the conclusion that A may
possibly belong to some of the Bs. For when one of the
premisses in the first figure is problematic, the conclusion also
(as we saw) is problematic. Similarly if the proposition BC is
pure, AC problematic; or if AC is negative, BC affirmative, no
matter which of the two is pure; in both cases the conclusion
will be problematic: for the first figure is obtained once more,
and it has been proved that if one premiss is problematic in that
figure the conclusion also will be problematic. But if the minor
premiss BC is negative, or if both premisses are negative, no
syllogistic conclusion can be drawn from the premisses as they
stand, but if they are converted a syllogism is obtained as
before.
If one of the premisses is universal, the other particular, then
when both are affirmative, or when the universal is negative,
the particular affirmative, we shall have the same sort of
syllogisms: for all are completed by means of the first figure. So
it is clear that we shall have not a pure but a problematic
syllogistic conclusion. But if the affirmative premiss is
universal, the negative particular, the proof will proceed by a
reductio ad impossibile. Suppose that B belongs to all C, and A
may possibly not belong to some C: it follows that may possibly
not belong to some B. For if A necessarily belongs to all B, and B
(as has been assumed) belongs to all C, A will necessarily belong
to all C: for this has been proved before. But it was assumed at
the outset that A may possibly not belong to some C.
125
Whenever both premisses are indefinite or particular, no
syllogism will be possible. The demonstration is the same as
was given in the case of universal premisses, and proceeds by
means of the same terms.
22
If one of the premisses is necessary, the other problematic,
when the premisses are affirmative a problematic affirmative
conclusion can always be drawn; when one proposition is
affirmative, the other negative, if the affirmative is necessary a
problematic negative can be inferred; but if the negative
proposition is necessary both a problematic and a pure negative
conclusion are possible. But a necessary negative conclusion
will not be possible, any more than in the other figures. Suppose
first that the premisses are affirmative, i.e. that A necessarily
belongs to all C, and B may possibly belong to all C. Since then A
must belong to all C, and C may belong to some B, it follows that
A may (not does) belong to some B: for so it resulted in the first
figure. A similar proof may be given if the proposition BC is
necessary, and AC is problematic. Again suppose one
proposition is affirmative, the other negative, the affirmative
being necessary: i.e. suppose A may possibly belong to no C, but
B necessarily belongs to all C. We shall have the first figure once
more: and - since the negative premiss is problematic - it is
clear that the conclusion will be problematic: for when the
premisses stand thus in the first figure, the conclusion (as we
found) is problematic. But if the negative premiss is necessary,
the conclusion will be not only that A may possibly not belong
to some B but also that it does not belong to some B. For
suppose that A necessarily does not belong to C, but B may
belong to all C. If the affirmative proposition BC is converted, we
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shall have the first figure, and the negative premiss is necessary.
But when the premisses stood thus, it resulted that A might
possibly not belong to some C, and that it did not belong to
some C; consequently here it follows that A does not belong to
some B. But when the minor premiss is negative, if it is
problematic we shall have a syllogism by altering the premiss
into its complementary affirmative, as before; but if it is
necessary no syllogism can be formed. For A sometimes
necessarily belongs to all B, and sometimes cannot possibly
belong to any B. To illustrate the former take the terms sleep-
sleeping horse-man; to illustrate the latter take the terms sleep-
waking horse-man.
Similar results will obtain if one of the terms is related
universally to the middle, the other in part. If both premisses
are affirmative, the conclusion will be problematic, not pure;
and also when one premiss is negative, the other affirmative,
the latter being necessary. But when the negative premiss is
necessary, the conclusion also will be a pure negative
proposition; for the same kind of proof can be given whether
the terms are universal or not. For the syllogisms must be made
perfect by means of the first figure, so that a result which
follows in the first figure follows also in the third. But when the
minor premiss is negative and universal, if it is problematic a
syllogism can be formed by means of conversion; but if it is
necessary a syllogism is not possible. The proof will follow the
same course as where the premisses are universal; and the
same terms may be used.
It is clear then in this figure also when and how a syllogism can
be formed, and when the conclusion is problematic, and when
it is pure. It is evident also that all syllogisms in this figure are
imperfect, and that they are made perfect by means of the first
figure.
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23
It is clear from what has been said that the syllogisms in these
figures are made perfect by means of universal syllogisms in
the first figure and are reduced to them. That every syllogism
without qualification can be so treated, will be clear presently,
when it has been proved that every syllogism is formed through
one or other of these figures.
It is necessary that every demonstration and every syllogism
should prove either that something belongs or that it does not,
and this either universally or in part, and further either
ostensively or hypothetically. One sort of hypothetical proof is
the reductio ad impossibile. Let us speak first of ostensive
syllogisms: for after these have been pointed out the truth of
our contention will be clear with regard to those which are
proved per impossibile, and in general hypothetically.
If then one wants to prove syllogistically A of B, either as an
attribute of it or as not an attribute of it, one must assert
something of something else. If now A should be asserted of B,
the proposition originally in question will have been assumed.
But if A should be asserted of C, but C should not be asserted of
anything, nor anything of it, nor anything else of A, no syllogism
will be possible. For nothing necessarily follows from the
assertion of some one thing concerning some other single thing.
Thus we must take another premiss as well. If then A be
asserted of something else, or something else of A, or
something different of C, nothing prevents a syllogism being
formed, but it will not be in relation to B through the premisses
taken. Nor when C belongs to something else, and that to
something else and so on, no connexion however being made
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with B, will a syllogism be possible concerning A in its relation
to B. For in general we stated that no syllogism can establish the
attribution of one thing to another, unless some middle term is
taken, which is somehow related to each by way of predication.
For the syllogism in general is made out of premisses, and a
syllogism referring to this out of premisses with the same
reference, and a syllogism relating this to that proceeds through
premisses which relate this to that. But it is impossible to take a
premiss in reference to B, if we neither affirm nor deny
anything of it; or again to take a premiss relating A to B, if we
take nothing common, but affirm or deny peculiar attributes of
each. So we must take something midway between the two,
which will connect the predications, if we are to have a
syllogism relating this to that. If then we must take something
common in relation to both, and this is possible in three ways
(either by predicating A of C, and C of B, or C of both, or both of
C), and these are the figures of which we have spoken, it is clear
that every syllogism must be made in one or other of these
figures. The argument is the same if several middle terms
should be necessary to establish the relation to B; for the figure
will be the same whether there is one middle term or many.
It is clear then that the ostensive syllogisms are effected by
means of the aforesaid figures; these considerations will show
that reductiones ad also are effected in the same way. For all
who effect an argument per impossibile infer syllogistically
what is false, and prove the original conclusion hypothetically
when something impossible results from the assumption of its
contradictory; e.g. that the diagonal of the square is
incommensurate with the side, because odd numbers are equal
to evens if it is supposed to be commensurate. One infers
syllogistically that odd numbers come out equal to evens, and
one proves hypothetically the incommensurability of the
diagonal, since a falsehood results through contradicting this.
For this we found to be reasoning per impossibile, viz. proving
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something impossible by means of an hypothesis conceded at
the beginning. Consequently, since the falsehood is established
in reductions ad impossibile by an ostensive syllogism, and the
original conclusion is proved hypothetically, and we have
already stated that ostensive syllogisms are effected by means
of these figures, it is evident that syllogisms per impossibile
also will be made through these figures. Likewise all the other
hypothetical syllogisms: for in every case the syllogism leads up
to the proposition that is substituted for the original thesis; but
the original thesis is reached by means of a concession or some
other hypothesis. But if this is true, every demonstration and
every syllogism must be formed by means of the three figures
mentioned above. But when this has been shown it is clear that
every syllogism is perfected by means of the first figure and is
reducible to the universal syllogisms in this figure.
24
Further in every syllogism one of the premisses must be
affirmative, and universality must be present: unless one of the
premisses is universal either a syllogism will not be possible, or
it will not refer to the subject proposed, or the original position
will be begged. Suppose we have to prove that pleasure in music
is good. If one should claim as a premiss that pleasure is good
without adding 'all', no syllogism will be possible; if one should
claim that some pleasure is good, then if it is different from
pleasure in music, it is not relevant to the subject proposed; if it
is this very pleasure, one is assuming that which was proposed
at the outset to be proved. This is more obvious in geometrical
proofs, e.g. that the angles at the base of an isosceles triangle
are equal. Suppose the lines A and B have been drawn to the
centre. If then one should assume that the angle AC is equal to
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the angle BD, without claiming generally that angles of
semicircles are equal; and again if one should assume that the
angle C is equal to the angle D, without the additional
assumption that every angle of a segment is equal to every
other angle of the same segment; and further if one should
assume that when equal angles are taken from the whole
angles, which are themselves equal, the remainders E and F are
equal, he will beg the thing to be proved, unless he also states
that when equals are taken from equals the remainders are
equal.
It is clear then that in every syllogism there must be a universal
premiss, and that a universal statement is proved only when all
the premisses are universal, while a particular statement is
proved both from two universal premisses and from one only:
consequently if the conclusion is universal, the premisses also
must be universal, but if the premisses are universal it is
possible that the conclusion may not be universal. And it is
clear also that in every syllogism either both or one of the
premisses must be like the conclusion. I mean not only in being
affirmative or negative, but also in being necessary, pure,
problematic. We must consider also the other forms of
predication.
It is clear also when a syllogism in general can be made and
when it cannot; and when a valid, when a perfect syllogism can
be formed; and that if a syllogism is formed the terms must be
arranged in one of the ways that have been mentioned.
25
It is clear too that every demonstration will proceed through
three terms and no more, unless the same conclusion is
131
established by different pairs of propositions; e.g. the
conclusion E may be established through the propositions A and
B, and through the propositions C and D, or through the
propositions A and B, or A and C, or B and C. For nothing
prevents there being several middles for the same terms. But in
that case there is not one but several syllogisms. Or again when
each of the propositions A and B is obtained by syllogistic
inference, e.g. by means of D and E, and again B by means of F
and G. Or one may be obtained by syllogistic, the other by
inductive inference. But thus also the syllogisms are many; for
the conclusions are many, e.g. A and B and C. But if this can be
called one syllogism, not many, the same conclusion may be
reached by more than three terms in this way, but it cannot be
reached as C is established by means of A and B. Suppose that
the proposition E is inferred from the premisses A, B, C, and D. It
is necessary then that of these one should be related to another
as whole to part: for it has already been proved that if a
syllogism is formed some of its terms must be related in this
way. Suppose then that A stands in this relation to B. Some
conclusion then follows from them. It must either be E or one or
other of C and D, or something other than these.
(1) If it is E the syllogism will have A and B for its sole premisses.
But if C and D are so related that one is whole, the other part,
some conclusion will follow from them also; and it must be
either E, or one or other of the propositions A and B, or
something other than these. And if it is (i) E, or (ii) A or B, either
(i) the syllogisms will be more than one, or (ii) the same thing
happens to be inferred by means of several terms only in the
sense which we saw to be possible. But if (iii) the conclusion is
other than E or A or B, the syllogisms will be many, and
unconnected with one another. But if C is not so related to D as
to make a syllogism, the propositions will have been assumed
to no purpose, unless for the sake of induction or of obscuring
the argument or something of the sort.
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(2) But if from the propositions A and B there follows not E but
some other conclusion, and if from C and D either A or B follows
or something else, then there are several syllogisms, and they
do not establish the conclusion proposed: for we assumed that
the syllogism proved E. And if no conclusion follows from C and
D, it turns out that these propositions have been assumed to no
purpose, and the syllogism does not prove the original
proposition.
So it is clear that every demonstration and every syllogism will
proceed through three terms only.
This being evident, it is clear that a syllogistic conclusion
follows from two premisses and not from more than two. For
the three terms make two premisses, unless a new premiss is
assumed, as was said at the beginning, to perfect the
syllogisms. It is clear therefore that in whatever syllogistic
argument the premisses through which the main conclusion
follows (for some of the preceding conclusions must be
premisses) are not even in number, this argument either has
not been drawn syllogistically or it has assumed more than was
necessary to establish its thesis.
If then syllogisms are taken with respect to their main
premisses, every syllogism will consist of an even number of
premisses and an odd number of terms (for the terms exceed
the premisses by one), and the conclusions will be half the
number of the premisses. But whenever a conclusion is reached
by means of prosyllogisms or by means of several continuous
middle terms, e.g. the proposition AB by means of the middle
terms C and D, the number of the terms will similarly exceed
that of the premisses by one (for the extra term must either be
added outside or inserted: but in either case it follows that the
relations of predication are one fewer than the terms related),
and the premisses will be equal in number to the relations of
133
predication. The premisses however will not always be even, the
terms odd; but they will alternate - when the premisses are
even, the terms must be odd; when the terms are even, the
premisses must be odd: for along with one term one premiss is
added, if a term is added from any quarter. Consequently since
the premisses were (as we saw) even, and the terms odd, we
must make them alternately even and odd at each addition. But
the conclusions will not follow the same arrangement either in
respect to the terms or to the premisses. For if one term is
added, conclusions will be added less by one than the pre-
existing terms: for the conclusion is drawn not in relation to the
single term last added, but in relation to all the rest, e.g. if to
ABC the term D is added, two conclusions are thereby added,
one in relation to A, the other in relation to B. Similarly with any
further additions. And similarly too if the term is inserted in the
middle: for in relation to one term only, a syllogism will not be
constructed. Consequently the conclusions will be much more
numerous than the terms or the premisses.
26
Since we understand the subjects with which syllogisms are
concerned, what sort of conclusion is established in each figure,
and in how many moods this is done, it is evident to us both
what sort of problem is difficult and what sort is easy to prove.
For that which is concluded in many figures and through many
moods is easier; that which is concluded in few figures and
through few moods is more difficult to attempt. The universal
affirmative is proved by means of the first figure only and by
this in only one mood; the universal negative is proved both
through the first figure and through the second, through the
first in one mood, through the second in two. The particular
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affirmative is proved through the first and through the last
figure, in one mood through the first, in three moods through
the last. The particular negative is proved in all the figures, but
once in the first, in two moods in the second, in three moods in
the third. It is clear then that the universal affirmative is most
difficult to establish, most easy to overthrow. In general,
universals are easier game for the destroyer than particulars:
for whether the predicate belongs to none or not to some, they
are destroyed: and the particular negative is proved in all the
figures, the universal negative in two. Similarly with universal
negatives: the original statement is destroyed, whether the
predicate belongs to all or to some: and this we found possible
in two figures. But particular statements can be refuted in one
way only - by proving that the predicate belongs either to all or
to none. But particular statements are easier to establish: for
proof is possible in more figures and through more moods. And
in general we must not forget that it is possible to refute
statements by means of one another, I mean, universal
statements by means of particular, and particular statements by
means of universal: but it is not possible to establish universal
statements by means of particular, though it is possible to
establish particular statements by means of universal. At the
same time it is evident that it is easier to refute than to
establish.
The manner in which every syllogism is produced, the number
of the terms and premisses through which it proceeds, the
relation of the premisses to one another, the character of the
problem proved in each figure, and the number of the figures
appropriate to each problem, all these matters are clear from
what has been said.
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27
We must now state how we may ourselves always have a supply
of syllogisms in reference to the problem proposed and by what
road we may reach the principles relative to the problem: for
perhaps we ought not only to investigate the construction of
syllogisms, but also to have the power of making them.
Of all the things which exist some are such that they cannot be
predicated of anything else truly and universally, e.g. Cleon and
Callias, i.e. the individual and sensible, but other things may be
predicated of them (for each of these is both man and animal);
and some things are themselves predicated of others, but
nothing prior is predicated of them; and some are predicated of
others, and yet others of them, e.g. man of Callias and animal of
man. It is clear then that some things are naturally not stated of
anything: for as a rule each sensible thing is such that it cannot
be predicated of anything, save incidentally: for we sometimes
say that that white object is Socrates, or that that which
approaches is Callias. We shall explain in another place that
there is an upward limit also to the process of predicating: for
the present we must assume this. Of these ultimate predicates
it is not possible to demonstrate another predicate, save as a
matter of opinion, but these may be predicated of other things.
Neither can individuals be predicated of other things, though
other things can be predicated of them. Whatever lies between
these limits can be spoken of in both ways: they may be stated
of others, and others stated of them. And as a rule arguments
and inquiries are concerned with these things. We must select
the premisses suitable to each problem in this manner: first we
must lay down the subject and the definitions and the
properties of the thing; next we must lay down those attributes
which follow the thing, and again those which the thing follows,
and those which cannot belong to it. But those to which it
cannot belong need not be selected, because the negative
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statement implied above is convertible. Of the attributes which
follow we must distinguish those which fall within the
definition, those which are predicated as properties, and those
which are predicated as accidents, and of the latter those which
apparently and those which really belong. The larger the supply
a man has of these, the more quickly will he reach a conclusion;
and in proportion as he apprehends those which are truer, the
more cogently will he demonstrate. But he must select not
those which follow some particular but those which follow the
thing as a whole, e.g. not what follows a particular man but
what follows every man: for the syllogism proceeds through
universal premisses. If the statement is indefinite, it is
uncertain whether the premiss is universal, but if the statement
is definite, the matter is clear. Similarly one must select those
attributes which the subject follows as wholes, for the reason
given. But that which follows one must not suppose to follow as
a whole, e.g. that every animal follows man or every science
music, but only that it follows, without qualification, and indeed
we state it in a proposition: for the other statement is useless
and impossible, e.g. that every man is every animal or justice is
all good. But that which something follows receives the mark
'every'. Whenever the subject, for which we must obtain the
attributes that follow, is contained by something else, what
follows or does not follow the highest term universally must not
be selected in dealing with the subordinate term (for these
attributes have been taken in dealing with the superior term; for
what follows animal also follows man, and what does not
belong to animal does not belong to man); but we must choose
those attributes which are peculiar to each subject. For some
things are peculiar to the species as distinct from the genus; for
species being distinct there must be attributes peculiar to each.
Nor must we take as things which the superior term follows,
those things which the inferior term follows, e.g. take as
subjects of the predicate 'animal' what are really subjects of the
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predicate 'man'. It is necessary indeed, if animal follows man,
that it should follow all these also. But these belong more
properly to the choice of what concerns man. One must
apprehend also normal consequents and normal antecedents -
for propositions which obtain normally are established
syllogistically from premisses which obtain normally, some if
not all of them having this character of normality. For the
conclusion of each syllogism resembles its principles. We must
not however choose attributes which are consequent upon all
the terms: for no syllogism can be made out of such premisses.
The reason why this is so will be clear in the sequel.
28
If men wish to establish something about some whole, they
must look to the subjects of that which is being established (the
subjects of which it happens to be asserted), and the attributes
which follow that of which it is to be predicated. For if any of
these subjects is the same as any of these attributes, the
attribute originally in question must belong to the subject
originally in question. But if the purpose is to establish not a
universal but a particular proposition, they must look for the
terms of which the terms in question are predicable: for if any
of these are identical, the attribute in question must belong to
some of the subject in question. Whenever the one term has to
belong to none of the other, one must look to the consequents
of the subject, and to those attributes which cannot possibly be
present in the predicate in question: or conversely to the
attributes which cannot possibly be present in the subject, and
to the consequents of the predicate. If any members of these
groups are identical, one of the terms in question cannot
possibly belong to any of the other. For sometimes a syllogism
138
in the first figure results, sometimes a syllogism in the second.
But if the object is to establish a particular negative proposition,
we must find antecedents of the subject in question and
attributes which cannot possibly belong to the predicate in
question. If any members of these two groups are identical, it
follows that one of the terms in question does not belong to
some of the other. Perhaps each of these statements will
become clearer in the following way. Suppose the consequents
of A are designated by B, the antecedents of A by C, attributes
which cannot possibly belong to A by D. Suppose again that the
attributes of E are designated by F, the antecedents of E by G,
and attributes which cannot belong to E by H. If then one of the
Cs should be identical with one of the Fs, A must belong to all E:
for F belongs to all E, and A to all C, consequently A belongs to
all E. If C and G are identical, A must belong to some of the Es:
for A follows C, and E follows all G. If F and D are identical, A
will belong to none of the Es by a prosyllogism: for since the
negative proposition is convertible, and F is identical with D, A
will belong to none of the Fs, but F belongs to all E. Again, if B
and H are identical, A will belong to none of the Es: for B will
belong to all A, but to no E: for it was assumed to be identical
with H, and H belonged to none of the Es. If D and G are
identical, A will not belong to some of the Es: for it will not
belong to G, because it does not belong to D: but G falls under E:
consequently A will not belong to some of the Es. If B is
identical with G, there will be a converted syllogism: for E will
belong to all A since B belongs to A and E to B (for B was found
to be identical with G): but that A should belong to all E is not
necessary, but it must belong to some E because it is possible to
convert the universal statement into a particular.
It is clear then that in every proposition which requires proof
we must look to the aforesaid relations of the subject and
predicate in question: for all syllogisms proceed through these.
But if we are seeking consequents and antecedents we must
139
look for those which are primary and most universal, e.g. in
reference to E we must look to KF rather than to F alone, and in
reference to A we must look to KC rather than to C alone. For if
A belongs to KF, it belongs both to F and to E: but if it does not
follow KF, it may yet follow F. Similarly we must consider the
antecedents of A itself: for if a term follows the primary
antecedents, it will follow those also which are subordinate, but
if it does not follow the former, it may yet follow the latter.
It is clear too that the inquiry proceeds through the three terms
and the two premisses, and that all the syllogisms proceed
through the aforesaid figures. For it is proved that A belongs to
all E, whenever an identical term is found among the Cs and Fs.
This will be the middle term; A and E will be the extremes. So
the first figure is formed. And A will belong to some E, whenever
C and G are apprehended to be the same. This is the last figure:
for G becomes the middle term. And A will belong to no E, when
D and F are identical. Thus we have both the first figure and the
middle figure; the first, because A belongs to no F, since the
negative statement is convertible, and F belongs to all E: the
middle figure because D belongs to no A, and to all E. And A will
not belong to some E, whenever D and G are identical. This is
the last figure: for A will belong to no G, and E will belong to all
G. Clearly then all syllogisms proceed through the aforesaid
figures, and we must not select consequents of all the terms,
because no syllogism is produced from them. For (as we saw) it
is not possible at all to establish a proposition from
consequents, and it is not possible to refute by means of a
consequent of both the terms in question: for the middle term
must belong to the one, and not belong to the other.
It is clear too that other methods of inquiry by selection of
middle terms are useless to produce a syllogism, e.g. if the
consequents of the terms in question are identical, or if the
antecedents of A are identical with those attributes which
140
cannot possibly belong to E, or if those attributes are identical
which cannot belong to either term: for no syllogism is
produced by means of these. For if the consequents are
identical, e.g. B and F, we have the middle figure with both
premisses affirmative: if the antecedents of A are identical with
attributes which cannot belong to E, e.g. C with H, we have the
first figure with its minor premiss negative. If attributes which
cannot belong to either term are identical, e.g. C and H, both
premisses are negative, either in the first or in the middle
figure. But no syllogism is possible in this way.
It is evident too that we must find out which terms in this
inquiry are identical, not which are different or contrary, first
because the object of our investigation is the middle term, and
the middle term must be not diverse but identical. Secondly,
wherever it happens that a syllogism results from taking
contraries or terms which cannot belong to the same thing, all
arguments can be reduced to the aforesaid moods, e.g. if B and F
are contraries or cannot belong to the same thing. For if these
are taken, a syllogism will be formed to prove that A belongs to
none of the Es, not however from the premisses taken but in the
aforesaid mood. For B will belong to all A and to no E.
Consequently B must be identical with one of the Hs. Again, if B
and G cannot belong to the same thing, it follows that A will not
belong to some of the Es: for then too we shall have the middle
figure: for B will belong to all A and to no G. Consequently B
must be identical with some of the Hs. For the fact that B and G
cannot belong to the same thing differs in no way from the fact
that B is identical with some of the Hs: for that includes
everything which cannot belong to E.
It is clear then that from the inquiries taken by themselves no
syllogism results; but if B and F are contraries B must be
identical with one of the Hs, and the syllogism results through
these terms. It turns out then that those who inquire in this
141
manner are looking gratuitously for some other way than the
necessary way because they have failed to observe the identity
of the Bs with the Hs.
29
Syllogisms which lead to impossible conclusions are similar to
ostensive syllogisms; they also are formed by means of the
consequents and antecedents of the terms in question. In both
cases the same inquiry is involved. For what is proved
ostensively may also be concluded syllogistically per
impossibile by means of the same terms; and what is proved
per impossibile may also be proved ostensively, e.g. that A
belongs to none of the Es. For suppose A to belong to some E:
then since B belongs to all A and A to some of the Es, B will
belong to some of the Es: but it was assumed that it belongs to
none. Again we may prove that A belongs to some E: for if A
belonged to none of the Es, and E belongs to all G, A will belong
to none of the Gs: but it was assumed to belong to all. Similarly
with the other propositions requiring proof. The proof per
impossibile will always and in all cases be from the
consequents and antecedents of the terms in question.
Whatever the problem the same inquiry is necessary whether
one wishes to use an ostensive syllogism or a reduction to
impossibility. For both the demonstrations start from the same
terms, e.g. suppose it has been proved that A belongs to no E,
because it turns out that otherwise B belongs to some of the Es
and this is impossible - if now it is assumed that B belongs to
no E and to all A, it is clear that A will belong to no E. Again if it
has been proved by an ostensive syllogism that A belongs to no
E, assume that A belongs to some E and it will be proved per
impossibile to belong to no E. Similarly with the rest. In all cases
142
it is necessary to find some common term other than the
subjects of inquiry, to which the syllogism establishing the false
conclusion may relate, so that if this premiss is converted, and
the other remains as it is, the syllogism will be ostensive by
means of the same terms. For the ostensive syllogism differs
from the reductio ad impossibile in this: in the ostensive
syllogism both remisses are laid down in accordance with the
truth, in the reductio ad impossibile one of the premisses is
assumed falsely
These points will be made clearer by the sequel, when we
discuss the reduction to impossibility: at present this much
must be clear, that we must look to terms of the kinds
mentioned whether we wish to use an ostensive syllogism or a
reduction to impossibility In the other hypothetical syllogisms,
I mean those which proceed by substitution, or by positing a
certain quality, the inquiry will be directed to the terms of the
problem to be proved - not the terms of the original problem,
but the new terms introduced; and the method of the inquiry
will be the same as before. But we must consider and determine
in how many ways hypothetical syllogisms are possible.
Each of the problems then can be proved in the manner
described; but it is possible to establish some of them
syllogistically in another way, e.g. universal problems by the
inquiry which leads up to a particular conclusion, with the
addition of an hypothesis. For if the Cs and the Gs should be
identical, but E should be assumed to belong to the Gs only,
then A would belong to every E: and again if the Ds and the Gs
should be identical, but E should be predicated of the Gs only, it
follows that A will belong to none of the Es. Clearly then we
must consider the matter in this way also. The method is the
same whether the relation is necessary or possible. For the
inquiry will be the same, and the syllogism will proceed through
terms arranged in the same order whether a possible or a pure
143
proposition is proved. We must find in the case of possible
relations, as well as terms that belong, terms which can belong
though they actually do not: for we have proved that the
syllogism which establishes a possible relation proceeds
through these terms as well. Similarly also with the other
modes of predication.
It is clear then from what has been said not only that all
syllogisms can be formed in this way, but also that they cannot
be formed in any other. For every syllogism has been proved to
be formed through one of the aforementioned figures, and
these cannot be composed through other terms than the
consequents and antecedents of the terms in question: for from
these we obtain the premisses and find the middle term.
Consequently a syllogism cannot be formed by means of other
terms.
30
The method is the same in all cases, in philosophy, in any art or
study. We must look for the attributes and the subjects of both
our terms, and we must supply ourselves with as many of these
as possible, and consider them by means of the three terms,
refuting statements in one way, confirming them in another, in
the pursuit of truth starting from premisses in which the
arrangement of the terms is in accordance with truth, while if
we look for dialectical syllogisms we must start from probable
premisses. The principles of syllogisms have been stated in
general terms, both how they are characterized and how we
must hunt for them, so as not to look to everything that is said
about the terms of the problem or to the same points whether
we are confirming or refuting, or again whether we are
144
confirming of all or of some, and whether we are refuting of all
or some, we must look to fewer points and they must be
definite. We have also stated how we must select with reference
to everything that is, e.g. about good or knowledge. But in each
science the principles which are peculiar are the most
numerous. Consequently it is the business of experience to give
the principles which belong to each subject. I mean for example
that astronomical experience supplies the principles of
astronomical science: for once the phenomena were adequately
apprehended, the demonstrations of astronomy were
discovered. Similarly with any other art or science.
Consequently, if the attributes of the thing are apprehended,
our business will then be to exhibit readily the demonstrations.
For if none of the true attributes of things had been omitted in
the historical survey, we should be able to discover the proof
and demonstrate everything which admitted of proof, and to
make that clear, whose nature does not admit of proof.
In general then we have explained fairly well how we must
select premisses: we have discussed the matter accurately in
the treatise concerning dialectic.
31
It is easy to see that division into classes is a small part of the
method we have described: for division is, so to speak, a weak
syllogism; for what it ought to prove, it begs, and it always
establishes something more general than the attribute in
question. First, this very point had escaped all those who used
the method of division; and they attempted to persuade men
that it was possible to make a demonstration of substance and
essence. Consequently they did not understand what it is
145
possible to prove syllogistically by division, nor did they
understand that it was possible to prove syllogistically in the
manner we have described. In demonstrations, when there is a
need to prove a positive statement, the middle term through
which the syllogism is formed must always be inferior to and
not comprehend the first of the extremes. But division has a
contrary intention: for it takes the universal as middle. Let
animal be the term signified by A, mortal by B, and immortal by
C, and let man, whose definition is to be got, be signified by D.
The man who divides assumes that every animal is either
mortal or immortal: i.e. whatever is A is all either B or C. Again,
always dividing, he lays it down that man is an animal, so he
assumes A of D as belonging to it. Now the true conclusion is
that every D is either B or C, consequently man must be either
mortal or immortal, but it is not necessary that man should be a
mortal animal - this is begged: and this is what ought to have
been proved syllogistically. And again, taking A as mortal
animal, B as footed, C as footless, and D as man, he assumes in
the same way that A inheres either in B or in C (for every mortal
animal is either footed or footless), and he assumes A of D (for
he assumed man, as we saw, to be a mortal animal);
consequently it is necessary that man should be either a footed
or a footless animal; but it is not necessary that man should be
footed: this he assumes: and it is just this again which he ought
to have demonstrated. Always dividing then in this way it turns
out that these logicians assume as middle the universal term,
and as extremes that which ought to have been the subject of
demonstration and the differentiae. In conclusion, they do not
make it clear, and show it to be necessary, that this is man or
whatever the subject of inquiry may be: for they pursue the
other method altogether, never even suspecting the presence of
the rich supply of evidence which might be used. It is clear that
it is neither possible to refute a statement by this method of
division, nor to draw a conclusion about an accident or property
146
of a thing, nor about its genus, nor in cases in which it is
unknown whether it is thus or thus, e.g. whether the diagonal is
incommensurate. For if he assumes that every length is either
commensurate or incommensurate, and the diagonal is a
length, he has proved that the diagonal is either
incommensurate or commensurate. But if he should assume
that it is incommensurate, he will have assumed what he ought
to have proved. He cannot then prove it: for this is his method,
but proof is not possible by this method. Let A stand for
'incommensurate or commensurate', B for 'length', C for
'diagonal'. It is clear then that this method of investigation is
not suitable for every inquiry, nor is it useful in those cases in
which it is thought to be most suitable.
From what has been said it is clear from what elements
demonstrations are formed and in what manner, and to what
points we must look in each problem.
32
Our next business is to state how we can reduce syllogisms to
the aforementioned figures: for this part of the inquiry still
remains. If we should investigate the production of the
syllogisms and had the power of discovering them, and further
if we could resolve the syllogisms produced into the
aforementioned figures, our original problem would be brought
to a conclusion. It will happen at the same time that what has
been already said will be confirmed and its truth made clearer
by what we are about to say. For everything that is true must in
every respect agree with itself First then we must attempt to
select the two premisses of the syllogism (for it is easier to
divide into large parts than into small, and the composite parts
147
are larger than the elements out of which they are made); next
we must inquire which are universal and which particular, and
if both premisses have not been stated, we must ourselves
assume the one which is missing. For sometimes men put
forward the universal premiss, but do not posit the premiss
which is contained in it, either in writing or in discussion: or
men put forward the premisses of the principal syllogism, but
omit those through which they are inferred, and invite the
concession of others to no purpose. We must inquire then
whether anything unnecessary has been assumed, or anything
necessary has been omitted, and we must posit the one and
take away the other, until we have reached the two premisses:
for unless we have these, we cannot reduce arguments put
forward in the way described. In some arguments it is easy to
see what is wanting, but some escape us, and appear to be
syllogisms, because something necessary results from what has
been laid down, e.g. if the assumptions were made that
substance is not annihilated by the annihilation of what is not
substance, and that if the elements out of which a thing is
made are annihilated, then that which is made out of them is
destroyed: these propositions being laid down, it is necessary
that any part of substance is substance; this has not however
been drawn by syllogism from the propositions assumed, but
premisses are wanting. Again if it is necessary that animal
should exist, if man does, and that substance should exist, if
animal does, it is necessary that substance should exist if man
does: but as yet the conclusion has not been drawn
syllogistically: for the premisses are not in the shape we
required. We are deceived in such cases because something
necessary results from what is assumed, since the syllogism
also is necessary. But that which is necessary is wider than the
syllogism: for every syllogism is necessary, but not everything
which is necessary is a syllogism. Consequently, though
something results when certain propositions are assumed, we
148
must not try to reduce it directly, but must first state the two
premisses, then divide them into their terms. We must take that
term as middle which is stated in both the remisses: for it is
necessary that the middle should be found in both premisses in
all the figures.
If then the middle term is a predicate and a subject of
predication, or if it is a predicate, and something else is denied
of it, we shall have the first figure: if it both is a predicate and is
denied of something, the middle figure: if other things are
predicated of it, or one is denied, the other predicated, the last
figure. For it was thus that we found the middle term placed in
each figure. It is placed similarly too if the premisses are not
universal: for the middle term is determined in the same way.
Clearly then, if the same term is not stated more than once in
the course of an argument, a syllogism cannot be made: for a
middle term has not been taken. Since we know what sort of
thesis is established in each figure, and in which the universal,
in what sort the particular is described, clearly we must not
look for all the figures, but for that which is appropriate to the
thesis in hand. If the thesis is established in more figures than
one, we shall recognize the figure by the position of the middle
term.
33
Men are frequently deceived about syllogisms because the
inference is necessary, as has been said above; sometimes they
are deceived by the similarity in the positing of the terms; and
this ought not to escape our notice. E.g. if A is stated of B, and B
of C: it would seem that a syllogism is possible since the terms
stand thus: but nothing necessary results, nor does a syllogism.
149
Let A represent the term 'being eternal', B 'Aristomenes as an
object of thought', C Aristomenes'. It is true then that A belongs
to B. For Aristomenes as an object of thought is eternal. But B
also belongs to C: for Aristomenes is Aristomenes as an object
of thought. But A does not belong to C: for Aristomenes is
perishable. For no syllogism was made although the terms
stood thus: that required that the premiss AB should be stated
universally. But this is false, that every Aristomenes who is an
object of thought is eternal, since Aristomenes is perishable.
Again let C stand for 'Miccalus', B for 'musical Miccalus', A for
'perishing to-morrow'. It is true to predicate B of C: for Miccalus
is musical Miccalus. Also A can be predicated of B: for musical
Miccalus might perish to-morrow. But to state A of C is false at
any rate. This argument then is identical with the former; for it
is not true universally that musical Miccalus perishes to-
morrow: but unless this is assumed, no syllogism (as we have
shown) is possible.
This deception then arises through ignoring a small distinction.
For if we accept the conclusion as though it made no difference
whether we said 'This belong to that' or 'This belongs to all of
that'.
34
Men will frequently fall into fallacies through not setting out
the terms of the premiss well, e.g. suppose A to be health, B
disease, C man. It is true to say that A cannot belong to any B
(for health belongs to no disease) and again that B belongs to
every C (for every man is capable of disease). It would seem to
follow that health cannot belong to any man. The reason for
this is that the terms are not set out well in the statement, since
150
if the things which are in the conditions are substituted, no
syllogism can be made, e.g. if 'healthy' is substituted for 'health'
and 'diseased' for 'disease'. For it is not true to say that being
healthy cannot belong to one who is diseased. But unless this is
assumed no conclusion results, save in respect of possibility:
but such a conclusion is not impossible: for it is possible that
health should belong to no man. Again the fallacy may occur in
a similar way in the middle figure: 'it is not possible that health
should belong to any disease, but it is possible that health
should belong to every man, consequently it is not possible that
disease should belong to any man'. In the third figure the fallacy
results in reference to possibility. For health and diseae and
knowledge and ignorance, and in general contraries, may
possibly belong to the same thing, but cannot belong to one
another. This is not in agreement with what was said before: for
we stated that when several things could belong to the same
thing, they could belong to one another.
It is evident then that in all these cases the fallacy arises from
the setting out of the terms: for if the things that are in the
conditions are substituted, no fallacy arises. It is clear then that
in such premisses what possesses the condition ought always
to be substituted for the condition and taken as the term.
35
We must not always seek to set out the terms a single word: for
we shall often have complexes of words to which a single name
is not given. Hence it is difficult to reduce syllogisms with such
terms. Sometimes too fallacies will result from such a search,
e.g. the belief that syllogism can establish that which has no
mean. Let A stand for two right angles, B for triangle, C for
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isosceles triangle. A then belongs to C because of B: but A
belongs to B without the mediation of another term: for the
triangle in virtue of its own nature contains two right angles,
consequently there will be no middle term for the proposition
AB, although it is demonstrable. For it is clear that the middle
must not always be assumed to be an individual thing, but
sometimes a complex of words, as happens in the case
mentioned.
36
That the first term belongs to the middle, and the middle to the
extreme, must not be understood in the sense that they can
always be predicated of one another or that the first term will
be predicated of the middle in the same way as the middle is
predicated of the last term. The same holds if the premisses are
negative. But we must suppose the verb 'to belong' to have as
many meanings as the senses in which the verb 'to be' is used,
and in which the assertion that a thing 'is' may be said to be
true. Take for example the statement that there is a single
science of contraries. Let A stand for 'there being a single
science', and B for things which are contrary to one another.
Then A belongs to B, not in the sense that contraries are the fact
of there being a single science of them, but in the sense that it
is true to say of the contraries that there is a single science of
them.
It happens sometimes that the first term is stated of the middle,
but the middle is not stated of the third term, e.g. if wisdom is
knowledge, and wisdom is of the good, the conclusion is that
there is knowledge of the good. The good then is not knowledge,
though wisdom is knowledge. Sometimes the middle term is
152
stated of the third, but the first is not stated of the middle, e.g. if
there is a science of everything that has a quality, or is a
contrary, and the good both is a contrary and has a quality, the
conclusion is that there is a science of the good, but the good is
not science, nor is that which has a quality or is a contrary,
though the good is both of these. Sometimes neither the first
term is stated of the middle, nor the middle of the third, while
the first is sometimes stated of the third, and sometimes not:
e.g. if there is a genus of that of which there is a science, and if
there is a science of the good, we conclude that there is a genus
of the good. But nothing is predicated of anything. And if that of
which there is a science is a genus, and if there is a science of
the good, we conclude that the good is a genus. The first term
then is predicated of the extreme, but in the premisses one
thing is not stated of another.
The same holds good where the relation is negative. For 'that
does not belong to this' does not always mean that 'this is not
that', but sometimes that 'this is not of that' or 'for that', e.g.
'there is not a motion of a motion or a becoming of a becoming,
but there is a becoming of pleasure: so pleasure is not a
becoming.' Or again it may be said that there is a sign of
laughter, but there is not a sign of a sign, consequently laughter
is not a sign. This holds in the other cases too, in which the
thesis is refuted because the genus is asserted in a particular
way, in relation to the terms of the thesis. Again take the
inference 'opportunity is not the right time: for opportunity
belongs to God, but the right time does not, since nothing is
useful to God'. We must take as terms opportunity-right time-
God: but the premiss must be understood according to the case
of the noun. For we state this universally without qualification,
that the terms ought always to be stated in the nominative, e.g.
man, good, contraries, not in oblique cases, e.g. of man, of a
good, of contraries, but the premisses ought to be understood
with reference to the cases of each term -either the dative, e.g.
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'equal to this', or the genitive, e.g. 'double of this', or the
accusative, e.g. 'that which strikes or sees this', or the
nominative, e.g. 'man is an animal', or in whatever other way
the word falls in the premiss.
37
The expressions 'this belongs to that' and 'this holds true of
that' must be understood in as many ways as there are different
categories, and these categories must be taken either with or
without qualification, and further as simple or compound: the
same holds good of the corresponding negative expressions. We
must consider these points and define them better.
38
A term which is repeated in the premisses ought to be joined to
the first extreme, not to the middle. I mean for example that if a
syllogism should be made proving that there is knowledge of
justice, that it is good, the expression 'that it is good' (or 'qua
good') should be joined to the first term. Let A stand for
'knowledge that it is good', B for good, G for justice. It is true to
predicate A of B. For of the good there is knowledge that it is
good. Also it is true to predicate B of C. For justice is identical
with a good. In this way an analysis of the argument can be
made. But if the expression 'that it is good' were added to B, the
conclusion will not follow: for A will be true of B, but B will not
be true of C. For to predicate of justice the term 'good that it is
good' is false and not intelligible. Similarly if it should be proved
154
that the healthy is an object of knowledge qua good, of goat-
stag an object of knowledge qua not existing, or man perishable
qua an object of sense: in every case in which an addition is
made to the predicate, the addition must be joined to the
extreme.
The position of the terms is not the same when something is
established without qualification and when it is qualified by
some attribute or condition, e.g. when the good is proved to be
an object of knowledge and when it is proved to be an object of
knowledge that it is good. If it has been proved to be an object of
knowledge without qualification, we must put as middle term
'that which is', but if we add the qualification 'that it is good',
the middle term must be 'that which is something'. Let A stand
for 'knowledge that it is something', B stand for 'something',
and C stand for 'good'. It is true to predicate A of B: for ex
hypothesi there is a science of that which is something, that it
is something. B too is true of C: for that which C represents is
something. Consequently A is true of C: there will then be
knowledge of the good, that it is good: for ex hypothesi the term
'something' indicates the thing's special nature. But if 'being'
were taken as middle and 'being' simply were joined to the
extreme, not 'being something', we should not have had a
syllogism proving that there is knowledge of the good, that it is
good, but that it is; e.g. let A stand for knowledge that it is, B for
being, C for good. Clearly then in syllogisms which are thus
limited we must take the terms in the way stated.
39
We ought also to exchange terms which have the same value,
word for word, and phrase for phrase, and word and phrase, and
155
always take a word in preference to a phrase: for thus the
setting out of the terms will be easier. For example if it makes
no difference whether we say that the supposable is not the
genus of the opinable or that the opinable is not identical with a
particular kind of supposable (for what is meant is the same in
both statements), it is better to take as the terms the
supposable and the opinable in preference to the phrase
suggested.
40
Since the expressions 'pleasure is good' and 'pleasure is the
good' are not identical, we must not set out the terms in the
same way; but if the syllogism is to prove that pleasure is the
good, the term must be 'the good', but if the object is to prove
that pleasure is good, the term will be 'good'. Similarly in all
other cases.
41
It is not the same, either in fact or in speech, that A belongs to
all of that to which B belongs, and that A belongs to all of that to
all of which B belongs: for nothing prevents B from belonging to
C, though not to all C: e.g. let B stand for beautiful, and C for
white. If beauty belongs to something white, it is true to say
that beauty belongs to that which is white; but not perhaps to
everything that is white. If then A belongs to B, but not to
everything of which B is predicated, then whether B belongs to
all C or merely belongs to C, it is not necessary that A should
156
belong, I do not say to all C, but even to C at all. But if A belongs
to everything of which B is truly stated, it will follow that A can
be said of all of that of all of which B is said. If however A is said
of that of all of which B may be said, nothing prevents B
belonging to C, and yet A not belonging to all C or to any C at all.
If then we take three terms it is clear that the expression A is
said of all of which B is said' means this, A is said of all the
things of which B is said'. And if B is said of all of a third term,
so also is A: but if B is not said of all of the third term, there is
no necessity that A should be said of all of it.
We must not suppose that something absurd results through
setting out the terms: for we do not use the existence of this
particular thing, but imitate the geometrician who says that
'this line a foot long' or 'this straight line' or 'this line without
breadth' exists although it does not, but does not use the
diagrams in the sense that he reasons from them. For in
general, if two things are not related as whole to part and part
to whole, the prover does not prove from them, and so no
syllogism a is formed. We (I mean the learner) use the process
of setting out terms like perception by sense, not as though it
were impossible to demonstrate without these illustrative
terms, as it is to demonstrate without the premisses of the
syllogism.
42
We should not forget that in the same syllogism not all
conclusions are reached through one figure, but one through
one figure, another through another. Clearly then we must
analyse arguments in accordance with this. Since not every
problem is proved in every figure, but certain problems in each
157
figure, it is clear from the conclusion in what figure the
premisses should be sought.
43
In reference to those arguments aiming at a definition which
have been directed to prove some part of the definition, we
must take as a term the point to which the argument has been
directed, not the whole definition: for so we shall be less likely
to be disturbed by the length of the term: e.g. if a man proves
that water is a drinkable liquid, we must take as terms
drinkable and water.
44
Further we must not try to reduce hypothetical syllogisms; for
with the given premisses it is not possible to reduce them. For
they have not been proved by syllogism, but assented to by
agreement. For instance if a man should suppose that unless
there is one faculty of contraries, there cannot be one science,
and should then argue that not every faculty is of contraries, e.g.
of what is healthy and what is sickly: for the same thing will
then be at the same time healthy and sickly. He has shown that
there is not one faculty of all contraries, but he has not proved
that there is not a science. And yet one must agree. But the
agreement does not come from a syllogism, but from an
hypothesis. This argument cannot be reduced: but the proof
that there is not a single faculty can. The latter argument
perhaps was a syllogism: but the former was an hypothesis.
158
The same holds good of arguments which are brought to a
conclusion per impossibile. These cannot be analysed either;
but the reduction to what is impossible can be analysed since it
is proved by syllogism, though the rest of the argument cannot,
because the conclusion is reached from an hypothesis. But
these differ from the previous arguments: for in the former a
preliminary agreement must be reached if one is to accept the
conclusion; e.g. an agreement that if there is proved to be one
faculty of contraries, then contraries fall under the same
science; whereas in the latter, even if no preliminary agreement
has been made, men still accept the reasoning, because the
falsity is patent, e.g. the falsity of what follows from the
assumption that the diagonal is commensurate, viz. that then
odd numbers are equal to evens.
Many other arguments are brought to a conclusion by the help
of an hypothesis; these we ought to consider and mark out
clearly. We shall describe in the sequel their differences, and the
various ways in which hypothetical arguments are formed: but
at present this much must be clear, that it is not possible to
resolve such arguments into the figures. And we have explained
the reason.
45
Whatever problems are proved in more than one figure, if they
have been established in one figure by syllogism, can be
reduced to another figure, e.g. a negative syllogism in the first
figure can be reduced to the second, and a syllogism in the
middle figure to the first, not all however but some only. The
point will be clear in the sequel. If A belongs to no B, and B to all
C, then A belongs to no C. Thus the first figure; but if the
159
negative statement is converted, we shall have the middle
figure. For B belongs to no A, and to all C. Similarly if the
syllogism is not universal but particular, e.g. if A belongs to no B,
and B to some C. Convert the negative statement and you will
have the middle figure.
The universal syllogisms in the second figure can be reduced to
the first, but only one of the two particular syllogisms. Let A
belong to no B and to all C. Convert the negative statement, and
you will have the first figure. For B will belong to no A and A to
all C. But if the affirmative statement concerns B, and the
negative C, C must be made first term. For C belongs to no A,
and A to all B: therefore C belongs to no B. B then belongs to no
C: for the negative statement is convertible.
But if the syllogism is particular, whenever the negative
statement concerns the major extreme, reduction to the first
figure will be possible, e.g. if A belongs to no B and to some C:
convert the negative statement and you will have the first
figure. For B will belong to no A and A to some C. But when the
affirmative statement concerns the major extreme, no
resolution will be possible, e.g. if A belongs to all B, but not to all
C: for the statement AB does not admit of conversion, nor would
there be a syllogism if it did.
Again syllogisms in the third figure cannot all be resolved into
the first, though all syllogisms in the first figure can be resolved
into the third. Let A belong to all B and B to some C. Since the
particular affirmative is convertible, C will belong to some B: but
A belonged to all B: so that the third figure is formed. Similarly
if the syllogism is negative: for the particular affirmative is
convertible: therefore A will belong to no B, and to some C.
Of the syllogisms in the last figure one only cannot be resolved
into the first, viz. when the negative statement is not universal:
all the rest can be resolved. Let A and B be affirmed of all C:
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then C can be converted partially with either A or B: C then
belongs to some B. Consequently we shall get the first figure, if
A belongs to all C, and C to some of the Bs. If A belongs to all C
and B to some C, the argument is the same: for B is convertible
in reference to C. But if B belongs to all C and A to some C, the
first term must be B: for B belongs to all C, and C to some A,
therefore B belongs to some A. But since the particular
statement is convertible, A will belong to some B. If the
syllogism is negative, when the terms are universal we must
take them in a similar way. Let B belong to all C, and A to no C:
then C will belong to some B, and A to no C; and so C will be
middle term. Similarly if the negative statement is universal,
the affirmative particular: for A will belong to no C, and C to
some of the Bs. But if the negative statement is particular, no
resolution will be possible, e.g. if B belongs to all C, and A not
belong to some C: convert the statement BC and both premisses
will be particular.
It is clear that in order to resolve the figures into one another
the premiss which concerns the minor extreme must be
converted in both the figures: for when this premiss is altered,
the transition to the other figure is made.
One of the syllogisms in the middle figure can, the other
cannot, be resolved into the third figure. Whenever the
universal statement is negative, resolution is possible. For if A
belongs to no B and to some C, both B and C alike are
convertible in relation to A, so that B belongs to no A and C to
some A. A therefore is middle term. But when A belongs to all B,
and not to some C, resolution will not be possible: for neither of
the premisses is universal after conversion.
Syllogisms in the third figure can be resolved into the middle
figure, whenever the negative statement is universal, e.g. if A
belongs to no C, and B to some or all C. For C then will belong to
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no A and to some B. But if the negative statement is particular,
no resolution will be possible: for the particular negative does
not admit of conversion.
It is clear then that the same syllogisms cannot be resolved in
these figures which could not be resolved into the first figure,
and that when syllogisms are reduced to the first figure these
alone are confirmed by reduction to what is impossible.
It is clear from what we have said how we ought to reduce
syllogisms, and that the figures may be resolved into one
another.
46
In establishing or refuting, it makes some difference whether
we suppose the expressions 'not to be this' and 'to be not-this'
are identical or different in meaning, e.g. 'not to be white' and
'to be not-white'. For they do not mean the same thing, nor is
'to be not-white' the negation of 'to be white', but 'not to be
white'. The reason for this is as follows. The relation of 'he can
walk' to 'he can not-walk' is similar to the relation of 'it is
white' to 'it is not-white'; so is that of 'he knows what is good'
to 'he knows what is not-good'. For there is no difference
between the expressions 'he knows what is good' and 'he is
knowing what is good', or 'he can walk' and 'he is able to walk':
therefore there is no difference between their contraries 'he
cannot walk'-'he is not able to walk'. If then 'he is not able to
walk' means the same as 'he is able not to walk', capacity to
walk and incapacity to walk will belong at the same time to the
same person (for the same man can both walk and not-walk,
and is possessed of knowledge of what is good and of what is
not-good), but an affirmation and a denial which are opposed to
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one another do not belong at the same time to the same thing.
As then 'not to know what is good' is not the same as 'to know
what is not good', so 'to be not-good' is not the same as 'not to
be good'. For when two pairs correspond, if the one pair are
different from one another, the other pair also must be
different. Nor is 'to be not-equal' the same as 'not to be equal':
for there is something underlying the one, viz. that which is
not-equal, and this is the unequal, but there is nothing
underlying the other. Wherefore not everything is either equal
or unequal, but everything is equal or is not equal. Further the
expressions 'it is a not-white log' and 'it is not a white log' do
not imply one another's truth. For if 'it is a not-white log', it
must be a log: but that which is not a white log need not be a
log at all. Therefore it is clear that 'it is not-good' is not the
denial of 'it is good'. If then every single statement may truly be
said to be either an affirmation or a negation, if it is not a
negation clearly it must in a sense be an affirmation. But every
affirmation has a corresponding negation. The negation then of
'it is not-good' is 'it is not not-good'. The relation of these
statements to one another is as follows. Let A stand for 'to be
good', B for 'not to be good', let C stand for 'to be not-good' and
be placed under B, and let D stand for not to be not-good' and
be placed under A. Then either A or B will belong to everything,
but they will never belong to the same thing; and either C or D
will belong to everything, but they will never belong to the same
thing. And B must belong to everything to which C belongs. For
if it is true to say 'it is a not-white', it is true also to say 'it is not
white': for it is impossible that a thing should simultaneously
be white and be not-white, or be a not-white log and be a white
log; consequently if the affirmation does not belong, the denial
must belong. But C does not always belong to B: for what is not
a log at all, cannot be a not-white log either. On the other hand
D belongs to everything to which A belongs. For either C or D
belongs to everything to which A belongs. But since a thing
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cannot be simultaneously not-white and white, D must belong
to everything to which A belongs. For of that which is white it is
true to say that it is not not-white. But A is not true of all D. For
of that which is not a log at all it is not true to say A, viz. that it
is a white log. Consequently D is true, but A is not true, i.e. that
it is a white log. It is clear also that A and C cannot together
belong to the same thing, and that B and D may possibly belong
to the same thing.
Privative terms are similarly related positive ter terms respect of
this arrangement. Let A stand for 'equal', B for 'not equal', C for
'unequal', D for 'not unequal'.
In many things also, to some of which something belongs which
does not belong to others, the negation may be true in a similar
way, viz. that all are not white or that each is not white, while
that each is not-white or all are not-white is false. Similarly also
'every animal is not-white' is not the negation of 'every animal
is white' (for both are false): the proper negation is 'every
animal is not white'. Since it is clear that 'it is not-white' and 'it
is not white' mean different things, and one is an affirmation,
the other a denial, it is evident that the method of proving each
cannot be the same, e.g. that whatever is an animal is not white
or may not be white, and that it is true to call it not-white; for
this means that it is not-white. But we may prove that it is true
to call it white or not-white in the same way for both are proved
constructively by means of the first figure. For the expression 'it
is true' stands on a similar footing to 'it is'. For the negation of
'it is true to call it white' is not 'it is true to call it not-white' but
'it is not true to call it white'. If then it is to be true to say that
whatever is a man is musical or is not-musical, we must
assume that whatever is an animal either is musical or is not-
musical; and the proof has been made. That whatever is a man
is not musical is proved destructively in the three ways
mentioned.
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In general whenever A and B are such that they cannot belong
at the same time to the same thing, and one of the two
necessarily belongs to everything, and again C and D are related
in the same way, and A follows C but the relation cannot be
reversed, then D must follow B and the relation cannot be
reversed. And A and D may belong to the same thing, but B and
C cannot. First it is clear from the following consideration that D
follows B. For since either C or D necessarily belongs to
everything; and since C cannot belong to that to which B
belongs, because it carries A along with it and A and B cannot
belong to the same thing; it is clear that D must follow B. Again
since C does not reciprocate with but A, but C or D belongs to
everything, it is possible that A and D should belong to the same
thing. But B and C cannot belong to the same thing, because A
follows C; and so something impossible results. It is clear then
that B does not reciprocate with D either, since it is possible that
D and A should belong at the same time to the same thing.
It results sometimes even in such an arrangement of terms that
one is deceived through not apprehending the opposites rightly,
one of which must belong to everything, e.g. we may reason
that 'if A and B cannot belong at the same time to the same
thing, but it is necessary that one of them should belong to
whatever the other does not belong to: and again C and D are
related in the same way, and follows everything which C
follows: it will result that B belongs necessarily to everything to
which D belongs': but this is false. Assume that F stands for the
negation of A and B, and again that H stands for the negation of
C and D. It is necessary then that either A or F should belong to
everything: for either the affirmation or the denial must belong.
And again either C or H must belong to everything: for they are
related as affirmation and denial. And ex hypothesi A belongs to
everything ever thing to which C belongs. Therefore H belongs
to everything to which F belongs. Again since either F or B
belongs to everything, and similarly either H or D, and since H
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follows F, B must follow D: for we know this. If then A follows C,
B must follow D'. But this is false: for as we proved the sequence
is reversed in terms so constituted. The fallacy arises because
perhaps it is not necessary that A or F should belong to
everything, or that F or B should belong to everything: for F is
not the denial of A. For not good is the negation of good: and
not-good is not identical with 'neither good nor not-good'.
Similarly also with C and D. For two negations have been
assumed in respect to one term.
Book II
We have already explained the number of the figures, the
character and number of the premisses, when and how a
syllogism is formed; further what we must look for when a
refuting and establishing propositions, and how we should
investigate a given problem in any branch of inquiry, also by
what means we shall obtain principles appropriate to each
subject. Since some syllogisms are universal, others particular,
all the universal syllogisms give more than one result, and of
particular syllogisms the affirmative yield more than one, the
negative yield only the stated conclusion. For all propositions
are convertible save only the particular negative: and the
conclusion states one definite thing about another definite
thing. Consequently all syllogisms save the particular negative
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yield more than one conclusion, e.g. if A has been proved to to
all or to some B, then B must belong to some A: and if A has
been proved to belong to no B, then B belongs to no A. This is a
different conclusion from the former. But if A does not belong to
some B, it is not necessary that B should not belong to some A:
for it may possibly belong to all A.
This then is the reason common to all syllogisms whether
universal or particular. But it is possible to give another reason
concerning those which are universal. For all the things that are
subordinate to the middle term or to the conclusion may be
proved by the same syllogism, if the former are placed in the
middle, the latter in the conclusion; e.g. if the conclusion AB is
proved through C, whatever is subordinate to B or C must accept
the predicate A: for if D is included in B as in a whole, and B is
included in A, then D will be included in A. Again if E is included
in C as in a whole, and C is included in A, then E will be
included in A. Similarly if the syllogism is negative. In the
second figure it will be possible to infer only that which is
subordinate to the conclusion, e.g. if A belongs to no B and to all
C; we conclude that B belongs to no C. If then D is subordinate
to C, clearly B does not belong to it. But that B does not belong
to what is subordinate to A is not clear by means of the
syllogism. And yet B does not belong to E, if E is subordinate to
A. But while it has been proved through the syllogism that B
belongs to no C, it has been assumed without proof that B does
not belong to A, consequently it does not result through the
syllogism that B does not belong to E.
But in particular syllogisms there will be no necessity of
inferring what is subordinate to the conclusion (for a syllogism
does not result when this premiss is particular), but whatever is
subordinate to the middle term may be inferred, not however
through the syllogism, e.g. if A belongs to all B and B to some C.
Nothing can be inferred about that which is subordinate to C;
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something can be inferred about that which is subordinate to B,
but not through the preceding syllogism. Similarly in the other
figures. That which is subordinate to the conclusion cannot be
proved; the other subordinate can be proved, only not through
the syllogism, just as in the universal syllogisms what is
subordinate to the middle term is proved (as we saw) from a
premiss which is not demonstrated: consequently either a
conclusion is not possible in the case of universal syllogisms or
else it is possible also in the case of particular syllogisms.
It is possible for the premisses of the syllogism to be true, or to
be false, or to be the one true, the other false. The conclusion is
either true or false necessarily. From true premisses it is not
possible to draw a false conclusion, but a true conclusion may
be drawn from false premisses, true however only in respect to
the fact, not to the reason. The reason cannot be established
from false premisses: why this is so will be explained in the
sequel.
First then that it is not possible to draw a false conclusion from
true premisses, is made clear by this consideration. If it is
necessary that B should be when A is, it is necessary that A
should not be when B is not. If then A is true, B must be true:
otherwise it will turn out that the same thing both is and is not
at the same time. But this is impossible. Let it not, because A is
laid down as a single term, be supposed that it is possible, when
a single fact is given, that something should necessarily result.
For that is not possible. For what results necessarily is the
conclusion, and the means by which this comes about are at the
least three terms, and two relations of subject and predicate or
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premisses. If then it is true that A belongs to all that to which B
belongs, and that B belongs to all that to which C belongs, it is
necessary that A should belong to all that to which C belongs,
and this cannot be false: for then the same thing will belong
and not belong at the same time. So A is posited as one thing,
being two premisses taken together. The same holds good of
negative syllogisms: it is not possible to prove a false conclusion
from true premisses.
But from what is false a true conclusion may be drawn, whether
both the premisses are false or only one, provided that this is
not either of the premisses indifferently, if it is taken as wholly
false: but if the premiss is not taken as wholly false, it does not
matter which of the two is false. (1) Let A belong to the whole of
C, but to none of the Bs, neither let B belong to C. This is
possible, e.g. animal belongs to no stone, nor stone to any man.
If then A is taken to belong to all B and B to all C, A will belong
to all C; consequently though both the premisses are false the
conclusion is true: for every man is an animal. Similarly with
the negative. For it is possible that neither A nor B should
belong to any C, although A belongs to all B, e.g. if the same
terms are taken and man is put as middle: for neither animal
nor man belongs to any stone, but animal belongs to every man.
Consequently if one term is taken to belong to none of that to
which it does belong, and the other term is taken to belong to
all of that to which it does not belong, though both the
premisses are false the conclusion will be true. (2) A similar
proof may be given if each premiss is partially false.
(3) But if one only of the premisses is false, when the first
premiss is wholly false, e.g. AB, the conclusion will not be true,
but if the premiss BC is wholly false, a true conclusion will be
possible. I mean by 'wholly false' the contrary of the truth, e.g. if
what belongs to none is assumed to belong to all, or if what
belongs to all is assumed to belong to none. Let A belong to no
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B, and B to all C. If then the premiss BC which I take is true, and
the premiss AB is wholly false, viz. that A belongs to all B, it is
impossible that the conclusion should be true: for A belonged to
none of the Cs, since A belonged to nothing to which B
belonged, and B belonged to all C. Similarly there cannot be a
true conclusion if A belongs to all B, and B to all C, but while the
true premiss BC is assumed, the wholly false premiss AB is also
assumed, viz. that A belongs to nothing to which B belongs:
here the conclusion must be false. For A will belong to all C,
since A belongs to everything to which B belongs, and B to all C.
It is clear then that when the first premiss is wholly false,
whether affirmative or negative, and the other premiss is true,
the conclusion cannot be true.
(4) But if the premiss is not wholly false, a true conclusion is
possible. For if A belongs to all C and to some B, and if B belongs
to all C, e.g. animal to every swan and to some white thing, and
white to every swan, then if we take as premisses that A
belongs to all B, and B to all C, A will belong to all C truly: for
every swan is an animal. Similarly if the statement AB is
negative. For it is possible that A should belong to some B and to
no C, and that B should belong to all C, e.g. animal to some
white thing, but to no snow, and white to all snow. If then one
should assume that A belongs to no B, and B to all C, then will
belong to no C.
(5) But if the premiss AB, which is assumed, is wholly true, and
the premiss BC is wholly false, a true syllogism will be possible:
for nothing prevents A belonging to all B and to all C, though B
belongs to no C, e.g. these being species of the same genus
which are not subordinate one to the other: for animal belongs
both to horse and to man, but horse to no man. If then it is
assumed that A belongs to all B and B to all C, the conclusion
will be true, although the premiss BC is wholly false. Similarly if
the premiss AB is negative. For it is possible that A should
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belong neither to any B nor to any C, and that B should not
belong to any C, e.g. a genus to species of another genus: for
animal belongs neither to music nor to the art of healing, nor
does music belong to the art of healing. If then it is assumed
that A belongs to no B, and B to all C, the conclusion will be true.
(6) And if the premiss BC is not wholly false but in part only,
even so the conclusion may be true. For nothing prevents A
belonging to the whole of B and of C, while B belongs to some C,
e.g. a genus to its species and difference: for animal belongs to
every man and to every footed thing, and man to some footed
things though not to all. If then it is assumed that A belongs to
all B, and B to all C, A will belong to all C: and this ex hypothesi
is true. Similarly if the premiss AB is negative. For it is possible
that A should neither belong to any B nor to any C, though B
belongs to some C, e.g. a genus to the species of another genus
and its difference: for animal neither belongs to any wisdom
nor to any instance of 'speculative', but wisdom belongs to
some instance of 'speculative'. If then it should be assumed that
A belongs to no B, and B to all C, will belong to no C: and this ex
hypothesi is true.
In particular syllogisms it is possible when the first premiss is
wholly false, and the other true, that the conclusion should be
true; also when the first premiss is false in part, and the other
true; and when the first is true, and the particular is false; and
when both are false. (7) For nothing prevents A belonging to no
B, but to some C, and B to some C, e.g. animal belongs to no
snow, but to some white thing, and snow to some white thing. If
then snow is taken as middle, and animal as first term, and it is
assumed that A belongs to the whole of B, and B to some C, then
the premiss BC is wholly false, the premiss BC true, and the
conclusion true. Similarly if the premiss AB is negative: for it is
possible that A should belong to the whole of B, but not to some
C, although B belongs to some C, e.g. animal belongs to every
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man, but does not follow some white, but man belongs to some
white; consequently if man be taken as middle term and it is
assumed that A belongs to no B but B belongs to some C, the
conclusion will be true although the premiss AB is wholly false.
(If the premiss AB is false in part, the conclusion may be true.
For nothing prevents A belonging both to B and to some C, and
B belonging to some C, e.g. animal to something beautiful and
to something great, and beautiful belonging to something great.
If then A is assumed to belong to all B, and B to some C, the a
premiss AB will be partially false, the premiss BC will be true,
and the conclusion true. Similarly if the premiss AB is negative.
For the same terms will serve, and in the same positions, to
prove the point.
(9) Again if the premiss AB is true, and the premiss BC is false,
the conclusion may be true. For nothing prevents A belonging to
the whole of B and to some C, while B belongs to no C, e.g.
animal to every swan and to some black things, though swan
belongs to no black thing. Consequently if it should be assumed
that A belongs to all B, and B to some C, the conclusion will be
true, although the statement BC is false. Similarly if the premiss
AB is negative. For it is possible that A should belong to no B,
and not to some C, while B belongs to no C, e.g. a genus to the
species of another genus and to the accident of its own species:
for animal belongs to no number and not to some white things,
and number belongs to nothing white. If then number is taken
as middle, and it is assumed that A belongs to no B, and B to
some C, then A will not belong to some C, which ex hypothesi is
true. And the premiss AB is true, the premiss BC false.
(10) Also if the premiss AB is partially false, and the premiss BC
is false too, the conclusion may be true. For nothing prevents A
belonging to some B and to some C, though B belongs to no C,
e.g. if B is the contrary of C, and both are accidents of the same
genus: for animal belongs to some white things and to some
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black things, but white belongs to no black thing. If then it is
assumed that A belongs to all B, and B to some C, the conclusion
will be true. Similarly if the premiss AB is negative: for the same
terms arranged in the same way will serve for the proof.
(11) Also though both premisses are false the conclusion may be
true. For it is possible that A may belong to no B and to some C,
while B belongs to no C, e.g. a genus in relation to the species of
another genus, and to the accident of its own species: for
animal belongs to no number, but to some white things, and
number to nothing white. If then it is assumed that A belongs to
all B and B to some C, the conclusion will be true, though both
premisses are false. Similarly also if the premiss AB is negative.
For nothing prevents A belonging to the whole of B, and not to
some C, while B belongs to no C, e.g. animal belongs to every
swan, and not to some black things, and swan belongs to
nothing black. Consequently if it is assumed that A belongs to
no B, and B to some C, then A does not belong to some C. The
conclusion then is true, but the premisses arc false.
In the middle figure it is possible in every way to reach a true
conclusion through false premisses, whether the syllogisms are
universal or particular, viz. when both premisses are wholly
false; when each is partially false; when one is true, the other
wholly false (it does not matter which of the two premisses is
false); if both premisses are partially false; if one is quite true,
the other partially false; if one is wholly false, the other partially
true. For (1) if A belongs to no B and to all C, e.g. animal to no
stone and to every horse, then if the premisses are stated
contrariwise and it is assumed that A belongs to all B and to no
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C, though the premisses are wholly false they will yield a true
conclusion. Similarly if A belongs to all B and to no C: for we
shall have the same syllogism.
(2) Again if one premiss is wholly false, the other wholly true:
for nothing prevents A belonging to all B and to all C, though B
belongs to no C, e.g. a genus to its co-ordinate species. For
animal belongs to every horse and man, and no man is a horse.
If then it is assumed that animal belongs to all of the one, and
none of the other, the one premiss will be wholly false, the
other wholly true, and the conclusion will be true whichever
term the negative statement concerns.
(3) Also if one premiss is partially false, the other wholly true.
For it is possible that A should belong to some B and to all C,
though B belongs to no C, e.g. animal to some white things and
to every raven, though white belongs to no raven. If then it is
assumed that A belongs to no B, but to the whole of C, the
premiss AB is partially false, the premiss AC wholly true, and
the conclusion true. Similarly if the negative statement is
transposed: the proof can be made by means of the same terms.
Also if the affirmative premiss is partially false, the negative
wholly true, a true conclusion is possible. For nothing prevents
A belonging to some B, but not to C as a whole, while B belongs
to no C, e.g. animal belongs to some white things, but to no
pitch, and white belongs to no pitch. Consequently if it is
assumed that A belongs to the whole of B, but to no C, the
premiss AB is partially false, the premiss AC is wholly true, and
the conclusion is true.
(4) And if both the premisses are partially false, the conclusion
may be true. For it is possible that A should belong to some B
and to some C, and B to no C, e.g. animal to some white things
and to some black things, though white belongs to nothing
black. If then it is assumed that A belongs to all B and to no C,
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both premisses are partially false, but the conclusion is true.
Similarly, if the negative premiss is transposed, the proof can be
made by means of the same terms.
It is clear also that our thesis holds in particular syllogisms. For
(5) nothing prevents A belonging to all B and to some C, though
B does not belong to some C, e.g. animal to every man and to
some white things, though man will not belong to some white
things. If then it is stated that A belongs to no B and to some C,
the universal premiss is wholly false, the particular premiss is
true, and the conclusion is true. Similarly if the premiss AB is
affirmative: for it is possible that A should belong to no B, and
not to some C, though B does not belong to some C, e.g. animal
belongs to nothing lifeless, and does not belong to some white
things, and lifeless will not belong to some white things. If then
it is stated that A belongs to all B and not to some C, the
premiss AB which is universal is wholly false, the premiss AC is
true, and the conclusion is true. Also a true conclusion is
possible when the universal premiss is true, and the particular
is false. For nothing prevents A following neither B nor C at all,
while B does not belong to some C, e.g. animal belongs to no
number nor to anything lifeless, and number does not follow
some lifeless things. If then it is stated that A belongs to no B
and to some C, the conclusion will be true, and the universal
premiss true, but the particular false. Similarly if the premiss
which is stated universally is affirmative. For it is possible that
should A belong both to B and to G as wholes, though B does not
follow some C, e.g. a genus in relation to its species and
difference: for animal follows every man and footed things as a
whole, but man does not follow every footed thing.
Consequently if it is assumed that A belongs to the whole of B,
but does not belong to some C, the universal premiss is true, the
particular false, and the conclusion true.
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(6) It is clear too that though both premisses are false they may
yield a true conclusion, since it is possible that A should belong
both to B and to C as wholes, though B does not follow some C.
For if it is assumed that A belongs to no B and to some C, the
premisses are both false, but the conclusion is true. Similarly if
the universal premiss is affirmative and the particular negative.
For it is possible that A should follow no B and all C, though B
does not belong to some C, e.g. animal follows no science but
every man, though science does not follow every man. If then A
is assumed to belong to the whole of B, and not to follow some
C, the premisses are false but the conclusion is true.
In the last figure a true conclusion may come through what is
false, alike when both premisses are wholly false, when each is
partly false, when one premiss is wholly true, the other false,
when one premiss is partly false, the other wholly true, and vice
versa, and in every other way in which it is possible to alter the
premisses. For (1) nothing prevents neither A nor B from
belonging to any C, while A belongs to some B, e.g. neither man
nor footed follows anything lifeless, though man belongs to
some footed things. If then it is assumed that A and B belong to
all C, the premisses will be wholly false, but the conclusion true.
Similarly if one premiss is negative, the other affirmative. For it
is possible that B should belong to no C, but A to all C, and that
should not belong to some B, e.g. black belongs to no swan,
animal to every swan, and animal not to everything black.
Consequently if it is assumed that B belongs to all C, and A to
no C, A will not belong to some B: and the conclusion is true,
though the premisses are false.
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(2) Also if each premiss is partly false, the conclusion may be
true. For nothing prevents both A and B from belonging to some
C while A belongs to some B, e.g. white and beautiful belong to
some animals, and white to some beautiful things. If then it is
stated that A and B belong to all C, the premisses are partially
false, but the conclusion is true. Similarly if the premiss AC is
stated as negative. For nothing prevents A from not belonging,
and B from belonging, to some C, while A does not belong to all
B, e.g. white does not belong to some animals, beautiful belongs
to some animals, and white does not belong to everything
beautiful. Consequently if it is assumed that A belongs to no C,
and B to all C, both premisses are partly false, but the
conclusion is true.
(3) Similarly if one of the premisses assumed is wholly false, the
other wholly true. For it is possible that both A and B should
follow all C, though A does not belong to some B, e.g. animal
and white follow every swan, though animal does not belong to
everything white. Taking these then as terms, if one assumes
that B belongs to the whole of C, but A does not belong to C at
all, the premiss BC will be wholly true, the premiss AC wholly
false, and the conclusion true. Similarly if the statement BC is
false, the statement AC true, the conclusion may be true. The
same terms will serve for the proof. Also if both the premisses
assumed are affirmative, the conclusion may be true. For
nothing prevents B from following all C, and A from not
belonging to C at all, though A belongs to some B, e.g. animal
belongs to every swan, black to no swan, and black to some
animals. Consequently if it is assumed that A and B belong to
every C, the premiss BC is wholly true, the premiss AC is wholly
false, and the conclusion is true. Similarly if the premiss AC
which is assumed is true: the proof can be made through the
same terms.
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(4) Again if one premiss is wholly true, the other partly false, the
conclusion may be true. For it is possible that B should belong to
all C, and A to some C, while A belongs to some B, e.g. biped
belongs to every man, beautiful not to every man, and beautiful
to some bipeds. If then it is assumed that both A and B belong
to the whole of C, the premiss BC is wholly true, the premiss AC
partly false, the conclusion true. Similarly if of the premisses
assumed AC is true and BC partly false, a true conclusion is
possible: this can be proved, if the same terms as before are
transposed. Also the conclusion may be true if one premiss is
negative, the other affirmative. For since it is possible that B
should belong to the whole of C, and A to some C, and, when
they are so, that A should not belong to all B, therefore it is
assumed that B belongs to the whole of C, and A to no C, the
negative premiss is partly false, the other premiss wholly true,
and the conclusion is true. Again since it has been proved that if
A belongs to no C and B to some C, it is possible that A should
not belong to some C, it is clear that if the premiss AC is wholly
true, and the premiss BC partly false, it is possible that the
conclusion should be true. For if it is assumed that A belongs to
no C, and B to all C, the premiss AC is wholly true, and the
premiss BC is partly false.
(5) It is clear also in the case of particular syllogisms that a true
conclusion may come through what is false, in every possible
way. For the same terms must be taken as have been taken
when the premisses are universal, positive terms in positive
syllogisms, negative terms in negative. For it makes no
difference to the setting out of the terms, whether one assumes
that what belongs to none belongs to all or that what belongs to
some belongs to all. The same applies to negative statements.
It is clear then that if the conclusion is false, the premisses of
the argument must be false, either all or some of them; but
when the conclusion is true, it is not necessary that the
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premisses should be true, either one or all, yet it is possible,
though no part of the syllogism is true, that the conclusion may
none the less be true; but it is not necessitated. The reason is
that when two things are so related to one another, that if the
one is, the other necessarily is, then if the latter is not, the
former will not be either, but if the latter is, it is not necessary
that the former should be. But it is impossible that the same
thing should be necessitated by the being and by the not-being
of the same thing. I mean, for example, that it is impossible that
B should necessarily be great since A is white and that B should
necessarily be great since A is not white. For whenever since
this, A, is white it is necessary that that, B, should be great, and
since B is great that C should not be white, then it is necessary
if is white that C should not be white. And whenever it is
necessary, since one of two things is, that the other should be, it
is necessary, if the latter is not, that the former (viz. A) should
not be. If then B is not great A cannot be white. But if, when A is
not white, it is necessary that B should be great, it necessarily
results that if B is not great, B itself is great. (But this is
impossible.) For if B is not great, A will necessarily not be white.
If then when this is not white B must be great, it results that if B
is not great, it is great, just as if it were proved through three
terms.
Circular and reciprocal proof means proof by means of the
conclusion, i.e. by converting one of the premisses simply and
inferring the premiss which was assumed in the original
syllogism: e.g. suppose it has been necessary to prove that A
belongs to all C, and it has been proved through B; suppose that
A should now be proved to belong to B by assuming that A
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belongs to C, and C to B - so A belongs to B: but in the first
syllogism the converse was assumed, viz. that B belongs to C. Or
suppose it is necessary to prove that B belongs to C, and A is
assumed to belong to C, which was the conclusion of the first
syllogism, and B to belong to A but the converse was assumed
in the earlier syllogism, viz. that A belongs to B. In no other way
is reciprocal proof possible. If another term is taken as middle,
the proof is not circular: for neither of the propositions assumed
is the same as before: if one of the accepted terms is taken as
middle, only one of the premisses of the first syllogism can be
assumed in the second: for if both of them are taken the same
conclusion as before will result: but it must be different. If the
terms are not convertible, one of the premisses from which the
syllogism results must be undemonstrated: for it is not possible
to demonstrate through these terms that the third belongs to
the middle or the middle to the first. If the terms are
convertible, it is possible to demonstrate everything reciprocally,
e.g. if A and B and C are convertible with one another. Suppose
the proposition AC has been demonstrated through B as middle
term, and again the proposition AB through the conclusion and
the premiss BC converted, and similarly the proposition BC
through the conclusion and the premiss AB converted. But it is
necessary to prove both the premiss CB, and the premiss BA: for
we have used these alone without demonstrating them. If then
it is assumed that B belongs to all C, and C to all A, we shall
have a syllogism relating B to A. Again if it is assumed that C
belongs to all A, and A to all B, C must belong to all B. In both
these syllogisms the premiss CA has been assumed without
being demonstrated: the other premisses had ex hypothesi been
proved. Consequently if we succeed in demonstrating this
premiss, all the premisses will have been proved reciprocally. If
then it is assumed that C belongs to all B, and B to all A, both
the premisses assumed have been proved, and C must belong to
A. It is clear then that only if the terms are convertible is
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circular and reciprocal demonstration possible (if the terms are
not convertible, the matter stands as we said above). But it turns
out in these also that we use for the demonstration the very
thing that is being proved: for C is proved of B, and B of by
assuming that C is said of and C is proved of A through these
premisses, so that we use the conclusion for the demonstration.
In negative syllogisms reciprocal proof is as follows. Let B
belong to all C, and A to none of the Bs: we conclude that A
belongs to none of the Cs. If again it is necessary to prove that A
belongs to none of the Bs (which was previously assumed) A
must belong to no C, and C to all B: thus the previous premiss is
reversed. If it is necessary to prove that B belongs to C, the
proposition AB must no longer be converted as before: for the
premiss 'B belongs to no A' is identical with the premiss 'A
belongs to no B'. But we must assume that B belongs to all of
that to none of which longs. Let A belong to none of the Cs
(which was the previous conclusion) and assume that B belongs
to all of that to none of which A belongs. It is necessary then
that B should belong to all C. Consequently each of the three
propositions has been made a conclusion, and this is circular
demonstration, to assume the conclusion and the converse of
one of the premisses, and deduce the remaining premiss.
In particular syllogisms it is not possible to demonstrate the
universal premiss through the other propositions, but the
particular premiss can be demonstrated. Clearly it is impossible
to demonstrate the universal premiss: for what is universal is
proved through propositions which are universal, but the
conclusion is not universal, and the proof must start from the
conclusion and the other premiss. Further a syllogism cannot
be made at all if the other premiss is converted: for the result is
that both premisses are particular. But the particular premiss
may be proved. Suppose that A has been proved of some C
through B. If then it is assumed that B belongs to all A and the
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conclusion is retained, B will belong to some C: for we obtain
the first figure and A is middle. But if the syllogism is negative,
it is not possible to prove the universal premiss, for the reason
given above. But it is possible to prove the particular premiss, if
the proposition AB is converted as in the universal syllogism, i.e
'B belongs to some of that to some of which A does not belong':
otherwise no syllogism results because the particular premiss is
negative.
In the second figure it is not possible to prove an affirmative
proposition in this way, but a negative proposition may be
proved. An affirmative proposition is not proved because both
premisses of the new syllogism are not affirmative (for the
conclusion is negative) but an affirmative proposition is (as we
saw) proved from premisses which are both affirmative. The
negative is proved as follows. Let A belong to all B, and to no C:
we conclude that B belongs to no C. If then it is assumed that B
belongs to all A, it is necessary that A should belong to no C: for
we get the second figure, with B as middle. But if the premiss AB
was negative, and the other affirmative, we shall have the first
figure. For C belongs to all A and B to no C, consequently B
belongs to no A: neither then does A belong to B. Through the
conclusion, therefore, and one premiss, we get no syllogism, but
if another premiss is assumed in addition, a syllogism will be
possible. But if the syllogism not universal, the universal
premiss cannot be proved, for the same reason as we gave
above, but the particular premiss can be proved whenever the
universal statement is affirmative. Let A belong to all B, and not
to all C: the conclusion is BC. If then it is assumed that B
belongs to all A, but not to all C, A will not belong to some C, B
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being middle. But if the universal premiss is negative, the
premiss AC will not be demonstrated by the conversion of AB:
for it turns out that either both or one of the premisses is
negative; consequently a syllogism will not be possible. But the
proof will proceed as in the universal syllogisms, if it is
assumed that A belongs to some of that to some of which B
does not belong.
In the third figure, when both premisses are taken universally, it
is not possible to prove them reciprocally: for that which is
universal is proved through statements which are universal, but
the conclusion in this figure is always particular, so that it is
clear that it is not possible at all to prove through this figure the
universal premiss. But if one premiss is universal, the other
particular, proof of the latter will sometimes be possible,
sometimes not. When both the premisses assumed are
affirmative, and the universal concerns the minor extreme,
proof will be possible, but when it concerns the other extreme,
impossible. Let A belong to all C and B to some C: the conclusion
is the statement AB. If then it is assumed that C belongs to all A,
it has been proved that C belongs to some B, but that B belongs
to some C has not been proved. And yet it is necessary, if C
belongs to some B, that B should belong to some C. But it is not
the same that this should belong to that, and that to this: but
we must assume besides that if this belongs to some of that,
that belongs to some of this. But if this is assumed the
syllogism no longer results from the conclusion and the other
premiss. But if B belongs to all C, and A to some C, it will be
possible to prove the proposition AC, when it is assumed that C
belongs to all B, and A to some B. For if C belongs to all B and A
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to some B, it is necessary that A should belong to some C, B
being middle. And whenever one premiss is affirmative the
other negative, and the affirmative is universal, the other
premiss can be proved. Let B belong to all C, and A not to some
C: the conclusion is that A does not belong to some B. If then it
is assumed further that C belongs to all B, it is necessary that A
should not belong to some C, B being middle. But when the
negative premiss is universal, the other premiss is not except as
before, viz. if it is assumed that that belongs to some of that, to
some of which this does not belong, e.g. if A belongs to no C,
and B to some C: the conclusion is that A does not belong to
some B. If then it is assumed that C belongs to some of that to
some of which does not belong, it is necessary that C should
belong to some of the Bs. In no other way is it possible by
converting the universal premiss to prove the other: for in no
other way can a syllogism be formed.
It is clear then that in the first figure reciprocal proof is made
both through the third and through the first figure - if the
conclusion is affirmative through the first; if the conclusion is
negative through the last. For it is assumed that that belongs to
all of that to none of which this belongs. In the middle figure,
when the syllogism is universal, proof is possible through the
second figure and through the first, but when particular
through the second and the last. In the third figure all proofs
are made through itself. It is clear also that in the third figure
and in the middle figure those syllogisms which are not made
through those figures themselves either are not of the nature of
circular proof or are imperfect.
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8
To convert a syllogism means to alter the conclusion and make
another syllogism to prove that either the extreme cannot
belong to the middle or the middle to the last term. For it is
necessary, if the conclusion has been changed into its opposite
and one of the premisses stands, that the other premiss should
be destroyed. For if it should stand, the conclusion also must
stand. It makes a difference whether the conclusion is
converted into its contradictory or into its contrary. For the
same syllogism does not result whichever form the conversion
takes. This will be made clear by the sequel. By contradictory
opposition I mean the opposition of 'to all' to 'not to all', and of
'to some' to 'to none'; by contrary opposition I mean the
opposition of 'to all' to 'to none', and of 'to some' to 'not to
some'. Suppose that A been proved of C, through B as middle
term. If then it should be assumed that A belongs to no C, but to
all B, B will belong to no C. And if A belongs to no C, and B to all
C, A will belong, not to no B at all, but not to all B. For (as we
saw) the universal is not proved through the last figure. In a
word it is not possible to refute universally by conversion the
premiss which concerns the major extreme: for the refutation
always proceeds through the third since it is necessary to take
both premisses in reference to the minor extreme. Similarly if
the syllogism is negative. Suppose it has been proved that A
belongs to no C through B. Then if it is assumed that A belongs
to all C, and to no B, B will belong to none of the Cs. And if A and
B belong to all C, A will belong to some B: but in the original
premiss it belonged to no B.
If the conclusion is converted into its contradictory, the
syllogisms will be contradictory and not universal. For one
premiss is particular, so that the conclusion also will be
particular. Let the syllogism be affirmative, and let it be
converted as stated. Then if A belongs not to all C, but to all B, B
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will belong not to all C. And if A belongs not to all C, but B
belongs to all C, A will belong not to all B. Similarly if the
syllogism is negative. For if A belongs to some C, and to no B, B
will belong, not to no C at all, but - not to some C. And if A
belongs to some C, and B to all C, as was originally assumed, A
will belong to some B.
In particular syllogisms when the conclusion is converted into
its contradictory, both premisses may be refuted, but when it is
converted into its contrary, neither. For the result is no longer,
as in the universal syllogisms, refutation in which the
conclusion reached by 0, conversion lacks universality, but no
refutation at all. Suppose that A has been proved of some C. If
then it is assumed that A belongs to no C, and B to some C, A
will not belong to some B: and if A belongs to no C, but to all B, B
will belong to no C.Thus both premisses are refuted. But neither
can be refuted if the conclusion is converted into its contrary.
For if A does not belong to some C, but to all B, then B will not
belong to some C. But the original premiss is not yet refuted: for
it is possible that B should belong to some C, and should not
belong to some C. The universal premiss AB cannot be affected
by a syllogism at all: for if A does not belong to some of the Cs,
but B belongs to some of the Cs, neither of the premisses is
universal. Similarly if the syllogism is negative: for if it should
be assumed that A belongs to all C, both premisses are refuted:
but if the assumption is that A belongs to some C, neither
premiss is refuted. The proof is the same as before.
In the second figure it is not possible to refute the premiss
which concerns the major extreme by establishing something
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contrary to it, whichever form the conversion of the conclusion
may take. For the conclusion of the refutation will always be in
the third figure, and in this figure (as we saw) there is no
universal syllogism. The other premiss can be refuted in a
manner similar to the conversion: I mean, if the conclusion of
the first syllogism is converted into its contrary, the conclusion
of the refutation will be the contrary of the minor premiss of
the first, if into its contradictory, the contradictory. Let A belong
to all B and to no C: conclusion BC. If then it is assumed that B
belongs to all C, and the proposition AB stands, A will belong to
all C, since the first figure is produced. If B belongs to all C, and
A to no C, then A belongs not to all B: the figure is the last. But if
the conclusion BC is converted into its contradictory, the
premiss AB will be refuted as before, the premiss, AC by its
contradictory. For if B belongs to some C, and A to no C, then A
will not belong to some B. Again if B belongs to some C, and A to
all B, A will belong to some C, so that the syllogism results in
the contradictory of the minor premiss. A similar proof can be
given if the premisses are transposed in respect of their quality.
If the syllogism is particular, when the conclusion is converted
into its contrary neither premiss can be refuted, as also
happened in the first figure,' if the conclusion is converted into
its contradictory, both premisses can be refuted. Suppose that A
belongs to no B, and to some C: the conclusion is BC. If then it is
assumed that B belongs to some C, and the statement AB
stands, the conclusion will be that A does not belong to some C.
But the original statement has not been refuted: for it is
possible that A should belong to some C and also not to some C.
Again if B belongs to some C and A to some C, no syllogism will
be possible: for neither of the premisses taken is universal.
Consequently the proposition AB is not refuted. But if the
conclusion is converted into its contradictory, both premisses
can be refuted. For if B belongs to all C, and A to no B, A will
belong to no C: but it was assumed to belong to some C. Again if
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B belongs to all C and A to some C, A will belong to some B. The
same proof can be given if the universal statement is
affirmative.
10
In the third figure when the conclusion is converted into its
contrary, neither of the premisses can be refuted in any of the
syllogisms, but when the conclusion is converted into its
contradictory, both premisses may be refuted and in all the
moods. Suppose it has been proved that A belongs to some B, C
being taken as middle, and the premisses being universal. If
then it is assumed that A does not belong to some B, but B
belongs to all C, no syllogism is formed about A and C. Nor if A
does not belong to some B, but belongs to all C, will a syllogism
be possible about B and C. A similar proof can be given if the
premisses are not universal. For either both premisses arrived at
by the conversion must be particular, or the universal premiss
must refer to the minor extreme. But we found that no
syllogism is possible thus either in the first or in the middle
figure. But if the conclusion is converted into its contradictory,
both the premisses can be refuted. For if A belongs to no B, and
B to all C, then A belongs to no C: again if A belongs to no B, and
to all C, B belongs to no C. And similarly if one of the premisses
is not universal. For if A belongs to no B, and B to some C, A will
not belong to some C: if A belongs to no B, and to C, B will
belong to no C.
Similarly if the original syllogism is negative. Suppose it has
been proved that A does not belong to some B, BC being
affirmative, AC being negative: for it was thus that, as we saw, a
syllogism could be made. Whenever then the contrary of the
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conclusion is assumed a syllogism will not be possible. For if A
belongs to some B, and B to all C, no syllogism is possible (as we
saw) about A and C. Nor, if A belongs to some B, and to no C,
was a syllogism possible concerning B and C. Therefore the
premisses are not refuted. But when the contradictory of the
conclusion is assumed, they are refuted. For if A belongs to all B,
and B to C, A belongs to all C: but A was supposed originally to
belong to no C. Again if A belongs to all B, and to no C, then B
belongs to no C: but it was supposed to belong to all C. A similar
proof is possible if the premisses are not universal. For AC
becomes universal and negative, the other premiss particular
and affirmative. If then A belongs to all B, and B to some C, it
results that A belongs to some C: but it was supposed to belong
to no C. Again if A belongs to all B, and to no C, then B belongs
to no C: but it was assumed to belong to some C. If A belongs to
some B and B to some C, no syllogism results: nor yet if A
belongs to some B, and to no C. Thus in one way the premisses
are refuted, in the other way they are not.
From what has been said it is clear how a syllogism results in
each figure when the conclusion is converted; when a result
contrary to the premiss, and when a result contradictory to the
premiss, is obtained. It is clear that in the first figure the
syllogisms are formed through the middle and the last figures,
and the premiss which concerns the minor extreme is alway
refuted through the middle figure, the premiss which concerns
the major through the last figure. In the second figure
syllogisms proceed through the first and the last figures, and
the premiss which concerns the minor extreme is always
refuted through the first figure, the premiss which concerns the
major extreme through the last. In the third figure the
refutation proceeds through the first and the middle figures; the
premiss which concerns the major is always refuted through
the first figure, the premiss which concerns the minor through
the middle figure.
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11
It is clear then what conversion is, how it is effected in each
figure, and what syllogism results. The syllogism per
impossibile is proved when the contradictory of the conclusion
stated and another premiss is assumed; it can be made in all
the figures. For it resembles conversion, differing only in this:
conversion takes place after a syllogism has been formed and
both the premisses have been taken, but a reduction to the
impossible takes place not because the contradictory has been
agreed to already, but because it is clear that it is true. The
terms are alike in both, and the premisses of both are taken in
the same way. For example if A belongs to all B, C being middle,
then if it is supposed that A does not belong to all B or belongs
to no B, but to all C (which was admitted to be true), it follows
that C belongs to no B or not to all B. But this is impossible:
consequently the supposition is false: its contradictory then is
true. Similarly in the other figures: for whatever moods admit of
conversion admit also of the reduction per impossibile.
All the problems can be proved per impossibile in all the figures,
excepting the universal affirmative, which is proved in the
middle and third figures, but not in the first. Suppose that A
belongs not to all B, or to no B, and take besides another
premiss concerning either of the terms, viz. that C belongs to all
A, or that B belongs to all D; thus we get the first figure. If then
it is supposed that A does not belong to all B, no syllogism
results whichever term the assumed premiss concerns; but if it
is supposed that A belongs to no B, when the premiss BD is
assumed as well we shall prove syllogistically what is false, but
not the problem proposed. For if A belongs to no B, and B
belongs to all D, A belongs to no D. Let this be impossible: it is
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false then A belongs to no B. But the universal affirmative is not
necessarily true if the universal negative is false. But if the
premiss CA is assumed as well, no syllogism results, nor does it
do so when it is supposed that A does not belong to all B.
Consequently it is clear that the universal affirmative cannot be
proved in the first figure per impossibile.
But the particular affirmative and the universal and particular
negatives can all be proved. Suppose that A belongs to no B, and
let it have been assumed that B belongs to all or to some C.
Then it is necessary that A should belong to no C or not to all C.
But this is impossible (for let it be true and clear that A belongs
to all C): consequently if this is false, it is necessary that A
should belong to some B. But if the other premiss assumed
relates to A, no syllogism will be possible. Nor can a conclusion
be drawn when the contrary of the conclusion is supposed, e.g.
that A does not belong to some B. Clearly then we must suppose
the contradictory.
Again suppose that A belongs to some B, and let it have been
assumed that C belongs to all A. It is necessary then that C
should belong to some B. But let this be impossible, so that the
supposition is false: in that case it is true that A belongs to no B.
We may proceed in the same way if the proposition CA has been
taken as negative. But if the premiss assumed concerns B, no
syllogism will be possible. If the contrary is supposed, we shall
have a syllogism and an impossible conclusion, but the problem
in hand is not proved. Suppose that A belongs to all B, and let it
have been assumed that C belongs to all A. It is necessary then
that C should belong to all B. But this is impossible, so that it is
false that A belongs to all B. But we have not yet shown it to be
necessary that A belongs to no B, if it does not belong to all B.
Similarly if the other premiss taken concerns B; we shall have a
syllogism and a conclusion which is impossible, but the
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hypothesis is not refuted. Therefore it is the contradictory that
we must suppose.
To prove that A does not belong to all B, we must suppose that it
belongs to all B: for if A belongs to all B, and C to all A, then C
belongs to all B; so that if this is impossible, the hypothesis is
false. Similarly if the other premiss assumed concerns B. The
same results if the original proposition CA was negative: for
thus also we get a syllogism. But if the negative proposition
concerns B, nothing is proved. If the hypothesis is that A
belongs not to all but to some B, it is not proved that A belongs
not to all B, but that it belongs to no B. For if A belongs to some
B, and C to all A, then C will belong to some B. If then this is
impossible, it is false that A belongs to some B; consequently it
is true that A belongs to no B. But if this is proved, the truth is
refuted as well; for the original conclusion was that A belongs to
some B, and does not belong to some B. Further the impossible
does not result from the hypothesis: for then the hypothesis
would be false, since it is impossible to draw a false conclusion
from true premisses: but in fact it is true: for A belongs to some
B. Consequently we must not suppose that A belongs to some B,
but that it belongs to all B. Similarly if we should be proving that
A does not belong to some B: for if 'not to belong to some' and
'to belong not to all' have the same meaning, the demonstration
of both will be identical.
It is clear then that not the contrary but the contradictory ought
to be supposed in all the syllogisms. For thus we shall have
necessity of inference, and the claim we make is one that will
be generally accepted. For if of everything one or other of two
contradictory statements holds good, then if it is proved that
the negation does not hold, the affirmation must be true. Again
if it is not admitted that the affirmation is true, the claim that
the negation is true will be generally accepted. But in neither
way does it suit to maintain the contrary: for it is not necessary
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that if the universal negative is false, the universal affirmative
should be true, nor is it generally accepted that if the one is
false the other is true.
12
It is clear then that in the first figure all problems except the
universal affirmative are proved per impossibile. But in the
middle and the last figures this also is proved. Suppose that A
does not belong to all B, and let it have been assumed that A
belongs to all C. If then A belongs not to all B, but to all C, C will
not belong to all B. But this is impossible (for suppose it to be
clear that C belongs to all B): consequently the hypothesis is
false. It is true then that A belongs to all B. But if the contrary is
supposed, we shall have a syllogism and a result which is
impossible: but the problem in hand is not proved. For if A
belongs to no B, and to all C, C will belong to no B. This is
impossible; so that it is false that A belongs to no B. But though
this is false, it does not follow that it is true that A belongs to all
B.
When A belongs to some B, suppose that A belongs to no B, and
let A belong to all C. It is necessary then that C should belong to
no B. Consequently, if this is impossible, A must belong to some
B. But if it is supposed that A does not belong to some B, we
shall have the same results as in the first figure.
Again suppose that A belongs to some B, and let A belong to no
C. It is necessary then that C should not belong to some B. But
originally it belonged to all B, consequently the hypothesis is
false: A then will belong to no B.
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When A does not belong to an B, suppose it does belong to all B,
and to no C. It is necessary then that C should belong to no B.
But this is impossible: so that it is true that A does not belong to
all B. It is clear then that all the syllogisms can be formed in the
middle figure.
13
Similarly they can all be formed in the last figure. Suppose that
A does not belong to some B, but C belongs to all B: then A does
not belong to some C. If then this is impossible, it is false that A
does not belong to some B; so that it is true that A belongs to all
B. But if it is supposed that A belongs to no B, we shall have a
syllogism and a conclusion which is impossible: but the
problem in hand is not proved: for if the contrary is supposed,
we shall have the same results as before.
But to prove that A belongs to some B, this hypothesis must be
made. If A belongs to no B, and C to some B, A will belong not to
all C. If then this is false, it is true that A belongs to some B.
When A belongs to no B, suppose A belongs to some B, and let it
have been assumed that C belongs to all B. Then it is necessary
that A should belong to some C. But ex hypothesi it belongs to
no C, so that it is false that A belongs to some B. But if it is
supposed that A belongs to all B, the problem is not proved.
But this hypothesis must be made if we are prove that A belongs
not to all B. For if A belongs to all B and C to some B, then A
belongs to some C. But this we assumed not to be so, so it is
false that A belongs to all B. But in that case it is true that A
belongs not to all B. If however it is assumed that A belongs to
some B, we shall have the same result as before.
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It is clear then that in all the syllogisms which proceed per
impossibile the contradictory must be assumed. And it is plain
that in the middle figure an affirmative conclusion, and in the
last figure a universal conclusion, are proved in a way.
14
Demonstration per impossibile differs from ostensive proof in
that it posits what it wishes to refute by reduction to a
statement admitted to be false; whereas ostensive proof starts
from admitted positions. Both, indeed, take two premisses that
are admitted, but the latter takes the premisses from which the
syllogism starts, the former takes one of these, along with the
contradictory of the original conclusion. Also in the ostensive
proof it is not necessary that the conclusion should be known,
nor that one should suppose beforehand that it is true or not: in
the other it is necessary to suppose beforehand that it is not
true. It makes no difference whether the conclusion is
affirmative or negative; the method is the same in both cases.
Everything which is concluded ostensively can be proved per
impossibile, and that which is proved per impossibile can be
proved ostensively, through the same terms. Whenever the
syllogism is formed in the first figure, the truth will be found in
the middle or the last figure, if negative in the middle, if
affirmative in the last. Whenever the syllogism is formed in the
middle figure, the truth will be found in the first, whatever the
problem may be. Whenever the syllogism is formed in the last
figure, the truth will be found in the first and middle figures, if
affirmative in first, if negative in the middle. Suppose that A has
been proved to belong to no B, or not to all B, through the first
figure. Then the hypothesis must have been that A belongs to
some B, and the original premisses that C belongs to all A and to
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no B. For thus the syllogism was made and the impossible
conclusion reached. But this is the middle figure, if C belongs to
all A and to no B. And it is clear from these premisses that A
belongs to no B. Similarly if has been proved not to belong to all
B. For the hypothesis is that A belongs to all B; and the original
premisses are that C belongs to all A but not to all B. Similarly
too, if the premiss CA should be negative: for thus also we have
the middle figure. Again suppose it has been proved that A
belongs to some B. The hypothesis here is that is that A belongs
to no B; and the original premisses that B belongs to all C, and A
either to all or to some C: for in this way we shall get what is
impossible. But if A and B belong to all C, we have the last
figure. And it is clear from these premisses that A must belong
to some B. Similarly if B or A should be assumed to belong to
some C.
Again suppose it has been proved in the middle figure that A
belongs to all B. Then the hypothesis must have been that A
belongs not to all B, and the original premisses that A belongs to
all C, and C to all B: for thus we shall get what is impossible. But
if A belongs to all C, and C to all B, we have the first figure.
Similarly if it has been proved that A belongs to some B: for the
hypothesis then must have been that A belongs to no B, and the
original premisses that A belongs to all C, and C to some B. If
the syllogism is negative, the hypothesis must have been that A
belongs to some B, and the original premisses that A belongs to
no C, and C to all B, so that the first figure results. If the
syllogism is not universal, but proof has been given that A does
not belong to some B, we may infer in the same way. The
hypothesis is that A belongs to all B, the original premisses that
A belongs to no C, and C belongs to some B: for thus we get the
first figure.
Again suppose it has been proved in the third figure that A
belongs to all B. Then the hypothesis must have been that A
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belongs not to all B, and the original premisses that C belongs to
all B, and A belongs to all C; for thus we shall get what is
impossible. And the original premisses form the first figure.
Similarly if the demonstration establishes a particular
proposition: the hypothesis then must have been that A belongs
to no B, and the original premisses that C belongs to some B,
and A to all C. If the syllogism is negative, the hypothesis must
have been that A belongs to some B, and the original premisses
that C belongs to no A and to all B, and this is the middle figure.
Similarly if the demonstration is not universal. The hypothesis
will then be that A belongs to all B, the premisses that C belongs
to no A and to some B: and this is the middle figure.
It is clear then that it is possible through the same terms to
prove each of the problems ostensively as well. Similarly it will
be possible if the syllogisms are ostensive to reduce them ad
impossibile in the terms which have been taken, whenever the
contradictory of the conclusion of the ostensive syllogism is
taken as a premiss. For the syllogisms become identical with
those which are obtained by means of conversion, so that we
obtain immediately the figures through which each problem
will be solved. It is clear then that every thesis can be proved in
both ways, i.e. per impossibile and ostensively, and it is not
possible to separate one method from the other.
15
In what figure it is possible to draw a conclusion from
premisses which are opposed, and in what figure this is not
possible, will be made clear in this way. Verbally four kinds of
opposition are possible, viz. universal affirmative to universal
negative, universal affirmative to particular negative, particular
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affirmative to universal negative, and particular affirmative to
particular negative: but really there are only three: for the
particular affirmative is only verbally opposed to the particular
negative. Of the genuine opposites I call those which are
universal contraries, the universal affirmative and the universal
negative, e.g. 'every science is good', 'no science is good'; the
others I call contradictories.
In the first figure no syllogism whether affirmative or negative
can be made out of opposed premisses: no affirmative syllogism
is possible because both premisses must be affirmative, but
opposites are, the one affirmative, the other negative: no
negative syllogism is possible because opposites affirm and
deny the same predicate of the same subject, and the middle
term in the first figure is not predicated of both extremes, but
one thing is denied of it, and it is affirmed of something else:
but such premisses are not opposed.
In the middle figure a syllogism can be made both
oLcontradictories and of contraries. Let A stand for good, let B
and C stand for science. If then one assumes that every science
is good, and no science is good, A belongs to all B and to no C, so
that B belongs to no C: no science then is a science. Similarly if
after taking 'every science is good' one took 'the science of
medicine is not good'; for A belongs to all B but to no C, so that
a particular science will not be a science. Again, a particular
science will not be a science if A belongs to all C but to no B, and
B is science, C medicine, and A supposition: for after taking 'no
science is supposition', one has assumed that a particular
science is supposition. This syllogism differs from the preceding
because the relations between the terms are reversed: before,
the affirmative statement concerned B, now it concerns C.
Similarly if one premiss is not universal: for the middle term is
always that which is stated negatively of one extreme, and
affirmatively of the other. Consequently it is possible that
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contradictories may lead to a conclusion, though not always or
in every mood, but only if the terms subordinate to the middle
are such that they are either identical or related as whole to
part. Otherwise it is impossible: for the premisses cannot
anyhow be either contraries or contradictories.
In the third figure an affirmative syllogism can never be made
out of opposite premisses, for the reason given in reference to
the first figure; but a negative syllogism is possible whether the
terms are universal or not. Let B and C stand for science, A for
medicine. If then one should assume that all medicine is
science and that no medicine is science, he has assumed that B
belongs to all A and C to no A, so that a particular science will
not be a science. Similarly if the premiss BA is not assumed
universally. For if some medicine is science and again no
medicine is science, it results that some science is not science,
The premisses are contrary if the terms are taken universally; if
one is particular, they are contradictory.
We must recognize that it is possible to take opposites in the
way we said, viz. 'all science is good' and 'no science is good' or
'some science is not good'. This does not usually escape notice.
But it is possible to establish one part of a contradiction through
other premisses, or to assume it in the way suggested in the
Topics. Since there are three oppositions to affirmative
statements, it follows that opposite statements may be
assumed as premisses in six ways; we may have either
universal affirmative and negative, or universal affirmative and
particular negative, or particular affirmative and universal
negative, and the relations between the terms may be reversed;
e.g. A may belong to all B and to no C, or to all C and to no B, or
to all of the one, not to all of the other; here too the relation
between the terms may be reversed. Similarly in the third
figure. So it is clear in how many ways and in what figures a
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syllogism can be made by means of premisses which are
opposed.
It is clear too that from false premisses it is possible to draw a
true conclusion, as has been said before, but it is not possible if
the premisses are opposed. For the syllogism is always contrary
to the fact, e.g. if a thing is good, it is proved that it is not good,
if an animal, that it is not an animal because the syllogism
springs out of a contradiction and the terms presupposed are
either identical or related as whole and part. It is evident also
that in fallacious reasonings nothing prevents a contradiction to
the hypothesis from resulting, e.g. if something is odd, it is not
odd. For the syllogism owed its contrariety to its contradictory
premisses; if we assume such premisses we shall get a result
that contradicts our hypothesis. But we must recognize that
contraries cannot be inferred from a single syllogism in such a
way that we conclude that what is not good is good, or anything
of that sort unless a self-contradictory premiss is at once
assumed, e.g. 'every animal is white and not white', and we
proceed 'man is an animal'. Either we must introduce the
contradiction by an additional assumption, assuming, e.g., that
every science is supposition, and then assuming 'Medicine is a
science, but none of it is supposition' (which is the mode in
which refutations are made), or we must argue from two
syllogisms. In no other way than this, as was said before, is it
possible that the premisses should be really contrary.
16
To beg and assume the original question is a species of failure
to demonstrate the problem proposed; but this happens in
many ways. A man may not reason syllogistically at all, or he
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may argue from premisses which are less known or equally
unknown, or he may establish the antecedent by means of its
consequents; for demonstration proceeds from what is more
certain and is prior. Now begging the question is none of these:
but since we get to know some things naturally through
themselves, and other things by means of something else (the
first principles through themselves, what is subordinate to
them through something else), whenever a man tries to prove
what is not self-evident by means of itself, then he begs the
original question. This may be done by assuming what is in
question at once; it is also possible to make a transition to other
things which would naturally be proved through the thesis
proposed, and demonstrate it through them, e.g. if A should be
proved through B, and B through C, though it was natural that C
should be proved through A: for it turns out that those who
reason thus are proving A by means of itself. This is what those
persons do who suppose that they are constructing parallel
straight lines: for they fail to see that they are assuming facts
which it is impossible to demonstrate unless the parallels exist.
So it turns out that those who reason thus merely say a
particular thing is, if it is: in this way everything will be self-
evident. But that is impossible.
If then it is uncertain whether A belongs to C, and also whether
A belongs to B, and if one should assume that A does belong to
B, it is not yet clear whether he begs the original question, but it
is evident that he is not demonstrating: for what is as uncertain
as the question to be answered cannot be a principle of a
demonstration. If however B is so related to C that they are
identical, or if they are plainly convertible, or the one belongs to
the other, the original question is begged. For one might equally
well prove that A belongs to B through those terms if they are
convertible. But if they are not convertible, it is the fact that they
are not that prevents such a demonstration, not the method of
demonstrating. But if one were to make the conversion, then he
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would be doing what we have described and effecting a
reciprocal proof with three propositions.
Similarly if he should assume that B belongs to C, this being as
uncertain as the question whether A belongs to C, the question
is not yet begged, but no demonstration is made. If however A
and B are identical either because they are convertible or
because A follows B, then the question is begged for the same
reason as before. For we have explained the meaning of begging
the question, viz. proving that which is not self-evident by
means of itself.
If then begging the question is proving what is not self-evident
by means of itself, in other words failing to prove when the
failure is due to the thesis to be proved and the premiss through
which it is proved being equally uncertain, either because
predicates which are identical belong to the same subject, or
because the same predicate belongs to subjects which are
identical, the question may be begged in the middle and third
figures in both ways, though, if the syllogism is affirmative, only
in the third and first figures. If the syllogism is negative, the
question is begged when identical predicates are denied of the
same subject; and both premisses do not beg the question
indifferently (in a similar way the question may be begged in
the middle figure), because the terms in negative syllogisms are
not convertible. In scientific demonstrations the question is
begged when the terms are really related in the manner
described, in dialectical arguments when they are according to
common opinion so related.
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17
The objection that 'this is not the reason why the result is false',
which we frequently make in argument, is made primarily in
the case of a reductio ad impossibile, to rebut the proposition
which was being proved by the reduction. For unless a man has
contradicted this proposition he will not say, 'False cause', but
urge that something false has been assumed in the earlier parts
of the argument; nor will he use the formula in the case of an
ostensive proof; for here what one denies is not assumed as a
premiss. Further when anything is refuted ostensively by the
terms ABC, it cannot be objected that the syllogism does not
depend on the assumption laid down. For we use the expression
'false cause', when the syllogism is concluded in spite of the
refutation of this position; but that is not possible in ostensive
proofs: since if an assumption is refuted, a syllogism can no
longer be drawn in reference to it. It is clear then that the
expression 'false cause' can only be used in the case of a
reductio ad impossibile, and when the original hypothesis is so
related to the impossible conclusion, that the conclusion results
indifferently whether the hypothesis is made or not. The most
obvious case of the irrelevance of an assumption to a
conclusion which is false is when a syllogism drawn from
middle terms to an impossible conclusion is independent of the
hypothesis, as we have explained in the Topics. For to put that
which is not the cause as the cause, is just this: e.g. if a man,
wishing to prove that the diagonal of the square is
incommensurate with the side, should try to prove Zeno's
theorem that motion is impossible, and so establish a reductio
ad impossibile: for Zeno's false theorem has no connexion at all
with the original assumption. Another case is where the
impossible conclusion is connected with the hypothesis, but
does not result from it. This may happen whether one traces the
connexion upwards or downwards, e.g. if it is laid down that A
belongs to B, B to C, and C to D, and it should be false that B
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belongs to D: for if we eliminated A and assumed all the same
that B belongs to C and C to D, the false conclusion would not
depend on the original hypothesis. Or again trace the connexion
upwards; e.g. suppose that A belongs to B, E to A and F to E, it
being false that F belongs to A. In this way too the impossible
conclusion would result, though the original hypothesis were
eliminated. But the impossible conclusion ought to be
connected with the original terms: in this way it will depend on
the hypothesis, e.g. when one traces the connexion downwards,
the impossible conclusion must be connected with that term
which is predicate in the hypothesis: for if it is impossible that
A should belong to D, the false conclusion will no longer result
after A has been eliminated. If one traces the connexion
upwards, the impossible conclusion must be connected with
that term which is subject in the hypothesis: for if it is
impossible that F should belong to B, the impossible conclusion
will disappear if B is eliminated. Similarly when the syllogisms
are negative.
It is clear then that when the impossibility is not related to the
original terms, the false conclusion does not result on account
of the assumption. Or perhaps even so it may sometimes be
independent. For if it were laid down that A belongs not to B but
to K, and that K belongs to C and C to D, the impossible
conclusion would still stand. Similarly if one takes the terms in
an ascending series. Consequently since the impossibility
results whether the first assumption is suppressed or not, it
would appear to be independent of that assumption. Or perhaps
we ought not to understand the statement that the false
conclusion results independently of the assumption, in the
sense that if something else were supposed the impossibility
would result; but rather we mean that when the first
assumption is eliminated, the same impossibility results
through the remaining premisses; since it is not perhaps absurd
that the same false result should follow from several
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hypotheses, e.g. that parallels meet, both on the assumption
that the interior angle is greater than the exterior and on the
assumption that a triangle contains more than two right angles.
18
A false argument depends on the first false statement in it.
Every syllogism is made out of two or more premisses. If then
the false conclusion is drawn from two premisses, one or both
of them must be false: for (as we proved) a false syllogism
cannot be drawn from two premisses. But if the premisses are
more than two, e.g. if C is established through A and B, and
these through D, E, F, and G, one of these higher propositions
must be false, and on this the argument depends: for A and B
are inferred by means of D, E, F, and G. Therefore the conclusion
and the error results from one of them.
19
In order to avoid having a syllogism drawn against us we must
take care, whenever an opponent asks us to admit the reason
without the conclusions, not to grant him the same term twice
over in his premisses, since we know that a syllogism cannot be
drawn without a middle term, and that term which is stated
more than once is the middle. How we ought to watch the
middle in reference to each conclusion, is evident from our
knowing what kind of thesis is proved in each figure. This will
not escape us since we know how we are maintaining the
argument.
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That which we urge men to beware of in their admissions, they
ought in attack to try to conceal. This will be possible first, if,
instead of drawing the conclusions of preliminary syllogisms,
they take the necessary premisses and leave the conclusions in
the dark; secondly if instead of inviting assent to propositions
which are closely connected they take as far as possible those
that are not connected by middle terms. For example suppose
that A is to be inferred to be true of F, B, C, D, and E being middle
terms. One ought then to ask whether A belongs to B, and next
whether D belongs to E, instead of asking whether B belongs to
C; after that he may ask whether B belongs to C, and so on. If
the syllogism is drawn through one middle term, he ought to
begin with that: in this way he will most likely deceive his
opponent.
20
Since we know when a syllogism can be formed and how its
terms must be related, it is clear when refutation will be
possible and when impossible. A refutation is possible whether
everything is conceded, or the answers alternate (one, I mean,
being affirmative, the other negative). For as has been shown a
syllogism is possible whether the terms are related in
affirmative propositions or one proposition is affirmative, the
other negative: consequently, if what is laid down is contrary to
the conclusion, a refutation must take place: for a refutation is a
syllogism which establishes the contradictory. But if nothing is
conceded, a refutation is impossible: for no syllogism is possible
(as we saw) when all the terms are negative: therefore no
refutation is possible. For if a refutation were possible, a
syllogism must be possible; although if a syllogism is possible it
does not follow that a refutation is possible. Similarly refutation
206
is not possible if nothing is conceded universally: since the
fields of refutation and syllogism are defined in the same way.
21
It sometimes happens that just as we are deceived in the
arrangement of the terms, so error may arise in our thought
about them, e.g. if it is possible that the same predicate should
belong to more than one subject immediately, but although
knowing the one, a man may forget the other and think the
opposite true. Suppose that A belongs to B and to C in virtue of
their nature, and that B and C belong to all D in the same way. If
then a man thinks that A belongs to all B, and B to D, but A to no
C, and C to all D, he will both know and not know the same
thing in respect of the same thing. Again if a man were to make
a mistake about the members of a single series; e.g. suppose A
belongs to B, B to C, and C to D, but some one thinks that A
belongs to all B, but to no C: he will both know that A belongs to
D, and think that it does not. Does he then maintain after this
simply that what he knows, he does not think? For he knows in
a way that A belongs to C through B, since the part is included
in the whole; so that what he knows in a way, this he maintains
he does not think at all: but that is impossible.
In the former case, where the middle term does not belong to
the same series, it is not possible to think both the premisses
with reference to each of the two middle terms: e.g. that A
belongs to all B, but to no C, and both B and C belong to all D.
For it turns out that the first premiss of the one syllogism is
either wholly or partially contrary to the first premiss of the
other. For if he thinks that A belongs to everything to which B
belongs, and he knows that B belongs to D, then he knows that
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A belongs to D. Consequently if again he thinks that A belongs
to nothing to which C belongs, he thinks that A does not belong
to some of that to which B belongs; but if he thinks that A
belongs to everything to which B belongs, and again thinks that
A does not belong to some of that to which B belongs, these
beliefs are wholly or partially contrary. In this way then it is not
possible to think; but nothing prevents a man thinking one
premiss of each syllogism of both premisses of one of the two
syllogisms: e.g. A belongs to all B, and B to D, and again A
belongs to no C. An error of this kind is similar to the error into
which we fall concerning particulars: e.g. if A belongs to all B,
and B to all C, A will belong to all C. If then a man knows that A
belongs to everything to which B belongs, he knows that A
belongs to C. But nothing prevents his being ignorant that C
exists; e.g. let A stand for two right angles, B for triangle, C for a
particular diagram of a triangle. A man might think that C did
not exist, though he knew that every triangle contains two right
angles; consequently he will know and not know the same
thing at the same time. For the expression 'to know that every
triangle has its angles equal to two right angles' is ambiguous,
meaning to have the knowledge either of the universal or of the
particulars. Thus then he knows that C contains two right
angles with a knowledge of the universal, but not with a
knowledge of the particulars; consequently his knowledge will
not be contrary to his ignorance. The argument in the Meno that
learning is recollection may be criticized in a similar way. For it
never happens that a man starts with a foreknowledge of the
particular, but along with the process of being led to see the
general principle he receives a knowledge of the particulars, by
an act (as it were) of recognition. For we know some things
directly; e.g. that the angles are equal to two right angles, if we
know that the figure is a triangle. Similarly in all other cases.
By a knowledge of the universal then we see the particulars, but
we do not know them by the kind of knowledge which is proper
208
to them; consequently it is possible that we may make mistakes
about them, but not that we should have the knowledge and
error that are contrary to one another: rather we have the
knowledge of the universal but make a mistake in
apprehending the particular. Similarly in the cases stated above.
The error in respect of the middle term is not contrary to the
knowledge obtained through the syllogism, nor is the thought
in respect of one middle term contrary to that in respect of the
other. Nothing prevents a man who knows both that A belongs
to the whole of B, and that B again belongs to C, thinking that A
does not belong to C, e.g. knowing that every mule is sterile and
that this is a mule, and thinking that this animal is with foal: for
he does not know that A belongs to C, unless he considers the
two propositions together. So it is evident that if he knows the
one and does not know the other, he will fall into error. And this
is the relation of knowledge of the universal to knowledge of
the particular. For we know no sensible thing, once it has
passed beyond the range of our senses, even if we happen to
have perceived it, except by means of the universal and the
possession of the knowledge which is proper to the particular,
but without the actual exercise of that knowledge. For to know
is used in three senses: it may mean either to have knowledge
of the universal or to have knowledge proper to the matter in
hand or to exercise such knowledge: consequently three kinds
of error also are possible. Nothing then prevents a man both
knowing and being mistaken about the same thing, provided
that his knowledge and his error are not contrary. And this
happens also to the man whose knowledge is limited to each of
the premisses and who has not previously considered the
particular question. For when he thinks that the mule is with
foal he has not the knowledge in the sense of its actual exercise,
nor on the other hand has his thought caused an error contrary
to his knowledge: for the error contrary to the knowledge of the
universal would be a syllogism.
209
But he who thinks the essence of good is the essence of bad will
think the same thing to be the essence of good and the essence
of bad. Let A stand for the essence of good and B for the essence
of bad, and again C for the essence of good. Since then he thinks
B and C identical, he will think that G is B, and similarly that B is
A, consequently that C is A. For just as we saw that if B is true of
all of which C is true, and A is true of all of which B is true, A is
true of C, similarly with the word 'think'. Similarly also with the
word 'is'; for we saw that if C is the same as B, and B as A, C is
the same as A. Similarly therefore with 'opine'. Perhaps then
this is necessary if a man will grant the first point. But
presumably that is false, that any one could suppose the
essence of good to be the essence of bad, save incidentally. For it
is possible to think this in many different ways. But we must
consider this matter better.
22
Whenever the extremes are convertible it is necessary that the
middle should be convertible with both. For if A belongs to C
through B, then if A and C are convertible and C belongs
everything to which A belongs, B is convertible with A, and B
belongs to everything to which A belongs, through C as middle,
and C is convertible with B through A as middle. Similarly if the
conclusion is negative, e.g. if B belongs to C, but A does not
belong to B, neither will A belong to C. If then B is convertible
with A, C will be convertible with A. Suppose B does not belong
to A; neither then will C: for ex hypothesi B belonged to all C.
And if C is convertible with B, B is convertible also with A, for C
is said of that of all of which B is said. And if C is convertible in
relation to A and to B, B also is convertible in relation to A. For C
belongs to that to which B belongs: but C does not belong to
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that to which A belongs. And this alone starts from the
conclusion; the preceding moods do not do so as in the
affirmative syllogism. Again if A and B are convertible, and
similarly C and D, and if A or C must belong to anything
whatever, then B and D will be such that one or other belongs to
anything whatever. For since B belongs to that to which A
belongs, and D belongs to that to which C belongs, and since A
or C belongs to everything, but not together, it is clear that B or
D belongs to everything, but not together. For example if that
which is uncreated is incorruptible and that which is
incorruptible is uncreated, it is necessary that what is created
should be corruptible and what is corruptible should have been
created. For two syllogisms have been put together. Again if A or
B belongs to everything and if C or D belongs to everything, but
they cannot belong together, then when A and C are convertible
B and D are convertible. For if B does not belong to something to
which D belongs, it is clear that A belongs to it. But if A then C:
for they are convertible. Therefore C and D belong together. But
this is impossible. When A belongs to the whole of B and to C
and is affirmed of nothing else, and B also belongs to all C, it is
necessary that A and B should be convertible: for since A is said
of B and C only, and B is affirmed both of itself and of C, it is
clear that B will be said of everything of which A is said, except
A itself. Again when A and B belong to the whole of C, and C is
convertible with B, it is necessary that A should belong to all B:
for since A belongs to all C, and C to B by conversion, A will
belong to all B.
When, of two opposites A and B, A is preferable to B, and
similarly D is preferable to C, then if A and C together are
preferable to B and D together, A must be preferable to D. For A
is an object of desire to the same extent as B is an object of
aversion, since they are opposites: and C is similarly related to
D, since they also are opposites. If then A is an object of desire
to the same extent as D, B is an object of aversion to the same
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extent as C (since each is to the same extent as each - the one
an object of aversion, the other an object of desire). Therefore
both A and C together, and B and D together, will be equally
objects of desire or aversion. But since A and C are preferable to
B and D, A cannot be equally desirable with D; for then B along
with D would be equally desirable with A along with C. But if D
is preferable to A, then B must be less an object of aversion than
C: for the less is opposed to the less. But the greater good and
lesser evil are preferable to the lesser good and greater evil: the
whole BD then is preferable to the whole AC. But ex hypothesi
this is not so. A then is preferable to D, and C consequently is
less an object of aversion than B. If then every lover in virtue of
his love would prefer A, viz. that the beloved should be such as
to grant a favour, and yet should not grant it (for which C
stands), to the beloved's granting the favour (represented by D)
without being such as to grant it (represented by B), it is clear
that A (being of such a nature) is preferable to granting the
favour. To receive affection then is preferable in love to sexual
intercourse. Love then is more dependent on friendship than on
intercourse. And if it is most dependent on receiving affection,
then this is its end. Intercourse then either is not an end at all
or is an end relative to the further end, the receiving of
affection. And indeed the same is true of the other desires and
arts.
23
It is clear then how the terms are related in conversion, and in
respect of being in a higher degree objects of aversion or of
desire. We must now state that not only dialectical and
demonstrative syllogisms are formed by means of the aforesaid
figures, but also rhetorical syllogisms and in general any form of
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persuasion, however it may be presented. For every belief comes
either through syllogism or from induction.
Now induction, or rather the syllogism which springs out of
induction, consists in establishing syllogistically a relation
between one extreme and the middle by means of the other
extreme, e.g. if B is the middle term between A and C, it consists
in proving through C that A belongs to B. For this is the manner
in which we make inductions. For example let A stand for long-
lived, B for bileless, and C for the particular long-lived animals,
e.g. man, horse, mule. A then belongs to the whole of C: for
whatever is bileless is long-lived. But B also ('not possessing
bile') belongs to all C. If then C is convertible with B, and the
middle term is not wider in extension, it is necessary that A
should belong to B. For it has already been proved that if two
things belong to the same thing, and the extreme is convertible
with one of them, then the other predicate will belong to the
predicate that is converted. But we must apprehend C as made
up of all the particulars. For induction proceeds through an
enumeration of all the cases.
Such is the syllogism which establishes the first and immediate
premiss: for where there is a middle term the syllogism
proceeds through the middle term; when there is no middle
term, through induction. And in a way induction is opposed to
syllogism: for the latter proves the major term to belong to the
third term by means of the middle, the former proves the major
to belong to the middle by means of the third. In the order of
nature, syllogism through the middle term is prior and better
known, but syllogism through induction is clearer to us.
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24
We have an 'example' when the major term is proved to belong
to the middle by means of a term which resembles the third. It
ought to be known both that the middle belongs to the third
term, and that the first belongs to that which resembles the
third. For example let A be evil, B making war against
neighbours, C Athenians against Thebans, D Thebans against
Phocians. If then we wish to prove that to fight with the
Thebans is an evil, we must assume that to fight against
neighbours is an evil. Evidence of this is obtained from similar
cases, e.g. that the war against the Phocians was an evil to the
Thebans. Since then to fight against neighbours is an evil, and
to fight against the Thebans is to fight against neighbours, it is
clear that to fight against the Thebans is an evil. Now it is clear
that B belongs to C and to D (for both are cases of making war
upon one's neighbours) and that A belongs to D (for the war
against the Phocians did not turn out well for the Thebans): but
that A belongs to B will be proved through D. Similarly if the
belief in the relation of the middle term to the extreme should
be produced by several similar cases. Clearly then to argue by
example is neither like reasoning from part to whole, nor like
reasoning from whole to part, but rather reasoning from part to
part, when both particulars are subordinate to the same term,
and one of them is known. It differs from induction, because
induction starting from all the particular cases proves (as we
saw) that the major term belongs to the middle, and does not
apply the syllogistic conclusion to the minor term, whereas
argument by example does make this application and does not
draw its proof from all the particular cases.
214
25
By reduction we mean an argument in which the first term
clearly belongs to the middle, but the relation of the middle to
the last term is uncertain though equally or more probable than
the conclusion; or again an argument in which the terms
intermediate between the last term and the middle are few. For
in any of these cases it turns out that we approach more nearly
to knowledge. For example let A stand for what can be taught, B
for knowledge, C for justice. Now it is clear that knowledge can
be taught: but it is uncertain whether virtue is knowledge. If
now the statement BC is equally or more probable than AC, we
have a reduction: for we are nearer to knowledge, since we have
taken a new term, being so far without knowledge that A
belongs to C. Or again suppose that the terms intermediate
between B and C are few: for thus too we are nearer knowledge.
For example let D stand for squaring, E for rectilinear figure, F
for circle. If there were only one term intermediate between E
and F (viz. that the circle is made equal to a rectilinear figure by
the help of lunules), we should be near to knowledge. But when
BC is not more probable than AC, and the intermediate terms
are not few, I do not call this reduction: nor again when the
statement BC is immediate: for such a statement is knowledge.
26
An objection is a premiss contrary to a premiss. It differs from a
premiss, because it may be particular, but a premiss either
cannot be particular at all or not in universal syllogisms. An
objection is brought in two ways and through two figures; in
two ways because every objection is either universal or
particular, by two figures because objections are brought in
215
opposition to the premiss, and opposites can be proved only in
the first and third figures. If a man maintains a universal
affirmative, we reply with a universal or a particular negative;
the former is proved from the first figure, the latter from the
third. For example let stand for there being a single science, B
for contraries. If a man premises that contraries are subjects of
a single science, the objection may be either that opposites are
never subjects of a single science, and contraries are opposites,
so that we get the first figure, or that the knowable and the
unknowable are not subjects of a single science: this proof is in
the third figure: for it is true of C (the knowable and the
unknowable) that they are contraries, and it is false that they
are the subjects of a single science.
Similarly if the premiss objected to is negative. For if a man
maintains that contraries are not subjects of a single science,
we reply either that all opposites or that certain contraries, e.g.
what is healthy and what is sickly, are subjects of the same
science: the former argument issues from the first, the latter
from the third figure.
In general if a man urges a universal objection he must frame
his contradiction with reference to the universal of the terms
taken by his opponent, e.g. if a man maintains that contraries
are not subjects of the same science, his opponent must reply
that there is a single science of all opposites. Thus we must
have the first figure: for the term which embraces the original
subject becomes the middle term.
If the objection is particular, the objector must frame his
contradiction with reference to a term relatively to which the
subject of his opponent's premiss is universal, e.g. he will point
out that the knowable and the unknowable are not subjects of
the same science: 'contraries' is universal relatively to these.
And we have the third figure: for the particular term assumed is
216
middle, e.g. the knowable and the unknowable. Premisses from
which it is possible to draw the contrary conclusion are what we
start from when we try to make objections. Consequently we
bring objections in these figures only: for in them only are
opposite syllogisms possible, since the second figure cannot
produce an affirmative conclusion.
Besides, an objection in the middle figure would require a fuller
argument, e.g. if it should not be granted that A belongs to B,
because C does not follow B. This can be made clear only by
other premisses. But an objection ought not to turn off into
other things, but have its new premiss quite clear immediately.
For this reason also this is the only figure from which proof by
signs cannot be obtained.
We must consider later the other kinds of objection, namely the
objection from contraries, from similars, and from common
opinion, and inquire whether a particular objection cannot be
elicited from the first figure or a negative objection from the
second.
27
A probability and a sign are not identical, but a probability is a
generally approved proposition: what men know to happen or
not to happen, to be or not to be, for the most part thus and
thus, is a probability, e.g. 'the envious hate', 'the beloved show
affection'. A sign means a demonstrative proposition necessary
or generally approved: for anything such that when it is another
thing is, or when it has come into being the other has come into
being before or after, is a sign of the other's being or having
come into being. Now an enthymeme is a syllogism starting
from probabilities or signs, and a sign may be taken in three
217
ways, corresponding to the position of the middle term in the
figures. For it may be taken as in the first figure or the second or
the third. For example the proof that a woman is with child
because she has milk is in the first figure: for to have milk is the
middle term. Let A represent to be with child, B to have milk, C
woman. The proof that wise men are good, since Pittacus is
good, comes through the last figure. Let A stand for good, B for
wise men, C for Pittacus. It is true then to affirm both A and B of
C: only men do not say the latter, because they know it, though
they state the former. The proof that a woman is with child
because she is pale is meant to come through the middle figure:
for since paleness follows women with child and is a
concomitant of this woman, people suppose it has been proved
that she is with child. Let A stand for paleness, B for being with
child, C for woman. Now if the one proposition is stated, we
have only a sign, but if the other is stated as well, a syllogism,
e.g. 'Pittacus is generous, since ambitious men are generous and
Pittacus is ambitious.' Or again 'Wise men are good, since
Pittacus is not only good but wise.' In this way then syllogisms
are formed, only that which proceeds through the first figure is
irrefutable if it is true (for it is universal), that which proceeds
through the last figure is refutable even if the conclusion is true,
since the syllogism is not universal nor correlative to the matter
in question: for though Pittacus is good, it is not therefore
necessary that all other wise men should be good. But the
syllogism which proceeds through the middle figure is always
refutable in any case: for a syllogism can never be formed when
the terms are related in this way: for though a woman with
child is pale, and this woman also is pale, it is not necessary
that she should be with child. Truth then may be found in signs
whatever their kind, but they have the differences we have
stated.
We must either divide signs in the way stated, and among them
designate the middle term as the index (for people call that the
218
index which makes us know, and the middle term above all has
this character), or else we must call the arguments derived from
the extremes signs, that derived from the middle term the
index: for that which is proved through the first figure is most
generally accepted and most true.
It is possible to infer character from features, if it is granted that
the body and the soul are changed together by the natural
affections: I say 'natural', for though perhaps by learning music
a man has made some change in his soul, this is not one of
those affections which are natural to us; rather I refer to
passions and desires when I speak of natural emotions. If then
this were granted and also that for each change there is a
corresponding sign, and we could state the affection and sign
proper to each kind of animal, we shall be able to infer
character from features. For if there is an affection which
belongs properly to an individual kind, e.g. courage to lions, it is
necessary that there should be a sign of it: for ex hypothesi
body and soul are affected together. Suppose this sign is the
possession of large extremities: this may belong to other kinds
also though not universally. For the sign is proper in the sense
stated, because the affection is proper to the whole kind,
though not proper to it alone, according to our usual manner of
speaking. The same thing then will be found in another kind,
and man may be brave, and some other kinds of animal as well.
They will then have the sign: for ex hypothesi there is one sign
corresponding to each affection. If then this is so, and we can
collect signs of this sort in these animals which have only one
affection proper to them - but each affection has its sign, since
it is necessary that it should have a single sign - we shall then
be able to infer character from features. But if the kind as a
whole has two properties, e.g. if the lion is both brave and
generous, how shall we know which of the signs which are its
proper concomitants is the sign of a particular affection?
Perhaps if both belong to some other kind though not to the
219
whole of it, and if, in those kinds in which each is found though
not in the whole of their members, some members possess one
of the affections and not the other: e.g. if a man is brave but not
generous, but possesses, of the two signs, large extremities, it is
clear that this is the sign of courage in the lion also. To judge
character from features, then, is possible in the first figure if the
middle term is convertible with the first extreme, but is wider
than the third term and not convertible with it: e.g. let A stand
for courage, B for large extremities, and C for lion. B then
belongs to everything to which C belongs, but also to others. But
A belongs to everything to which B belongs, and to nothing
besides, but is convertible with B: otherwise, there would not be
a single sign correlative with each affection.
220
Aristotle - Posterior Analytics
[Translated by G. R. G. Mure]
Book I
All instruction given or received by way of argument proceeds
from pre-existent knowledge. This becomes evident upon a
survey of all the species of such instruction. The mathematical
sciences and all other speculative disciplines are acquired in
this way, and so are the two forms of dialectical reasoning,
syllogistic and inductive; for each of these latter make use of
old knowledge to impart new, the syllogism assuming an
audience that accepts its premisses, induction exhibiting the
universal as implicit in the clearly known particular. Again, the
persuasion exerted by rhetorical arguments is in principle the
same, since they use either example, a kind of induction, or
enthymeme, a form of syllogism.
The pre-existent knowledge required is of two kinds. In some
cases admission of the fact must be assumed, in others
comprehension of the meaning of the term used, and
sometimes both assumptions are essential. Thus, we assume
that every predicate can be either truly affirmed or truly denied
of any subject, and that 'triangle' means so and so; as regards
'unit' we have to make the double assumption of the meaning
of the word and the existence of the thing. The reason is that
these several objects are not equally obvious to us. Recognition
of a truth may in some cases contain as factors both previous
knowledge and also knowledge acquired simultaneously with
221
that recognition - knowledge, this latter, of the particulars
actually falling under the universal and therein already virtually
known. For example, the student knew beforehand that the
angles of every triangle are equal to two right angles; but it was
only at the actual moment at which he was being led on to
recognize this as true in the instance before him that he came
to know 'this figure inscribed in the semicircle' to be a triangle.
For some things (viz. the singulars finally reached which are not
predicable of anything else as subject) are only learnt in this
way, i.e. there is here no recognition through a middle of a
minor term as subject to a major. Before he was led on to
recognition or before he actually drew a conclusion, we should
perhaps say that in a manner he knew, in a manner not.
If he did not in an unqualified sense of the term know the
existence of this triangle, how could he know without
qualification that its angles were equal to two right angles? No:
clearly he knows not without qualification but only in the sense
that he knows universally. If this distinction is not drawn, we
are faced with the dilemma in the Meno: either a man will learn
nothing or what he already knows; for we cannot accept the
solution which some people offer. A man is asked, 'Do you, or do
you not, know that every pair is even?' He says he does know it.
The questioner then produces a particular pair, of the existence,
and so a fortiori of the evenness, of which he was unaware. The
solution which some people offer is to assert that they do not
know that every pair is even, but only that everything which
they know to be a pair is even: yet what they know to be even is
that of which they have demonstrated evenness, i.e. what they
made the subject of their premiss, viz. not merely every triangle
or number which they know to be such, but any and every
number or triangle without reservation. For no premiss is ever
couched in the form 'every number which you know to be such',
or 'every rectilinear figure which you know to be such': the
predicate is always construed as applicable to any and every
222
instance of the thing. On the other hand, I imagine there is
nothing to prevent a man in one sense knowing what he is
learning, in another not knowing it. The strange thing would be,
not if in some sense he knew what he was learning, but if he
were to know it in that precise sense and manner in which he
was learning it.
We suppose ourselves to possess unqualified scientific
knowledge of a thing, as opposed to knowing it in the accidental
way in which the sophist knows, when we think that we know
the cause on which the fact depends, as the cause of that fact
and of no other, and, further, that the fact could not be other
than it is. Now that scientific knowing is something of this sort
is evident - witness both those who falsely claim it and those
who actually possess it, since the former merely imagine
themselves to be, while the latter are also actually, in the
condition described. Consequently the proper object of
unqualified scientific knowledge is something which cannot be
other than it is.
There may be another manner of knowing as well - that will be
discussed later. What I now assert is that at all events we do
know by demonstration. By demonstration I mean a syllogism
productive of scientific knowledge, a syllogism, that is, the grasp
of which is eo ipso such knowledge. Assuming then that my
thesis as to the nature of scientific knowing is correct, the
premisses of demonstrated knowledge must be true, primary,
immediate, better known than and prior to the conclusion,
which is further related to them as effect to cause. Unless these
conditions are satisfied, the basic truths will not be
223
'appropriate' to the conclusion. Syllogism there may indeed be
without these conditions, but such syllogism, not being
productive of scientific knowledge, will not be demonstration.
The premisses must be true: for that which is non-existent
cannot be known - we cannot know, e.g. that the diagonal of a
square is commensurate with its side. The premisses must be
primary and indemonstrable; otherwise they will require
demonstration in order to be known, since to have knowledge, if
it be not accidental knowledge, of things which are
demonstrable, means precisely to have a demonstration of
them. The premisses must be the causes of the conclusion,
better known than it, and prior to it; its causes, since we possess
scientific knowledge of a thing only when we know its cause;
prior, in order to be causes; antecedently known, this
antecedent knowledge being not our mere understanding of the
meaning, but knowledge of the fact as well. Now 'prior' and
'better known' are ambiguous terms, for there is a difference
between what is prior and better known in the order of being
and what is prior and better known to man. I mean that objects
nearer to sense are prior and better known to man; objects
without qualification prior and better known are those further
from sense. Now the most universal causes are furthest from
sense and particular causes are nearest to sense, and they are
thus exactly opposed to one another. In saying that the
premisses of demonstrated knowledge must be primary, I mean
that they must be the 'appropriate' basic truths, for I identify
primary premiss and basic truth. A 'basic truth' in a
demonstration is an immediate proposition. An immediate
proposition is one which has no other proposition prior to it. A
proposition is either part of an enunciation, i.e. it predicates a
single attribute of a single subject. If a proposition is dialectical,
it assumes either part indifferently; if it is demonstrative, it lays
down one part to the definite exclusion of the other because
that part is true. The term 'enunciation' denotes either part of a
224
contradiction indifferently. A contradiction is an opposition
which of its own nature excludes a middle. The part of a
contradiction which conjoins a predicate with a subject is an
affirmation; the part disjoining them is a negation. I call an
immediate basic truth of syllogism a 'thesis' when, though it is
not susceptible of proof by the teacher, yet ignorance of it does
not constitute a total bar to progress on the part of the pupil:
one which the pupil must know if he is to learn anything
whatever is an axiom. I call it an axiom because there are such
truths and we give them the name of axioms par excellence. If a
thesis assumes one part or the other of an enunciation, i.e.
asserts either the existence or the non-existence of a subject, it
is a hypothesis; if it does not so assert, it is a definition.
Definition is a 'thesis' or a 'laying something down', since the
arithmetician lays it down that to be a unit is to be
quantitatively indivisible; but it is not a hypothesis, for to define
what a unit is is not the same as to affirm its existence.
Now since the required ground of our knowledge - i.e. of our
conviction - of a fact is the possession of such a syllogism as we
call demonstration, and the ground of the syllogism is the facts
constituting its premisses, we must not only know the primary
premisses - some if not all of them - beforehand, but know
them better than the conclusion: for the cause of an attribute's
inherence in a subject always itself inheres in the subject more
firmly than that attribute; e.g. the cause of our loving anything
is dearer to us than the object of our love. So since the primary
premisses are the cause of our knowledge - i.e. of our conviction
- it follows that we know them better - that is, are more
convinced of them - than their consequences, precisely because
of our knowledge of the latter is the effect of our knowledge of
the premisses. Now a man cannot believe in anything more
than in the things he knows, unless he has either actual
knowledge of it or something better than actual knowledge. But
we are faced with this paradox if a student whose belief rests
225
on demonstration has not prior knowledge; a man must believe
in some, if not in all, of the basic truths more than in the
conclusion. Moreover, if a man sets out to acquire the scientific
knowledge that comes through demonstration, he must not
only have a better knowledge of the basic truths and a firmer
conviction of them than of the connexion which is being
demonstrated: more than this, nothing must be more certain or
better known to him than these basic truths in their character
as contradicting the fundamental premisses which lead to the
opposed and erroneous conclusion. For indeed the conviction of
pure science must be unshakable.
Some hold that, owing to the necessity of knowing the primary
premisses, there is no scientific knowledge. Others think there
is, but that all truths are demonstrable. Neither doctrine is
either true or a necessary deduction from the premisses. The
first school, assuming that there is no way of knowing other
than by demonstration, maintain that an infinite regress is
involved, on the ground that if behind the prior stands no
primary, we could not know the posterior through the prior
(wherein they are right, for one cannot traverse an infinite
series): if on the other hand - they say - the series terminates
and there are primary premisses, yet these are unknowable
because incapable of demonstration, which according to them
is the only form of knowledge. And since thus one cannot know
the primary premisses, knowledge of the conclusions which
follow from them is not pure scientific knowledge nor properly
knowing at all, but rests on the mere supposition that the
premisses are true. The other party agree with them as regards
knowing, holding that it is only possible by demonstration, but
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they see no difficulty in holding that all truths are
demonstrated, on the ground that demonstration may be
circular and reciprocal.
Our own doctrine is that not all knowledge is demonstrative: on
the contrary, knowledge of the immediate premisses is
independent of demonstration. (The necessity of this is obvious;
for since we must know the prior premisses from which the
demonstration is drawn, and since the regress must end in
immediate truths, those truths must be indemonstrable.) Such,
then, is our doctrine, and in addition we maintain that besides
scientific knowledge there is its originative source which
enables us to recognize the definitions.
Now demonstration must be based on premisses prior to and
better known than the conclusion; and the same things cannot
simultaneously be both prior and posterior to one another: so
circular demonstration is clearly not possible in the unqualified
sense of 'demonstration', but only possible if 'demonstration' be
extended to include that other method of argument which rests
on a distinction between truths prior to us and truths without
qualification prior, i.e. the method by which induction produces
knowledge. But if we accept this extension of its meaning, our
definition of unqualified knowledge will prove faulty; for there
seem to be two kinds of it. Perhaps, however, the second form of
demonstration, that which proceeds from truths better known
to us, is not demonstration in the unqualified sense of the term.
The advocates of circular demonstration are not only faced with
the difficulty we have just stated: in addition their theory
reduces to the mere statement that if a thing exists, then it does
exist - an easy way of proving anything. That this is so can be
clearly shown by taking three terms, for to constitute the circle
it makes no difference whether many terms or few or even only
two are taken. Thus by direct proof, if A is, B must be; if B is, C
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must be; therefore if A is, C must be. Since then - by the circular
proof - if A is, B must be, and if B is, A must be, A may be
substituted for C above. Then 'if B is, A must be'='if B is, C must
be', which above gave the conclusion 'if A is, C must be': but C
and A have been identified. Consequently the upholders of
circular demonstration are in the position of saying that if A is,
A must be - a simple way of proving anything. Moreover, even
such circular demonstration is impossible except in the case of
attributes that imply one another, viz. 'peculiar' properties.
Now, it has been shown that the positing of one thing - be it one
term or one premiss - never involves a necessary consequent:
two premisses constitute the first and smallest foundation for
drawing a conclusion at all and therefore a fortiori for the
demonstrative syllogism of science. If, then, A is implied in B
and C, and B and C are reciprocally implied in one another and
in A, it is possible, as has been shown in my writings on the
syllogism, to prove all the assumptions on which the original
conclusion rested, by circular demonstration in the first figure.
But it has also been shown that in the other figures either no
conclusion is possible, or at least none which proves both the
original premisses. Propositions the terms of which are not
convertible cannot be circularly demonstrated at all, and since
convertible terms occur rarely in actual demonstrations, it is
clearly frivolous and impossible to say that demonstration is
reciprocal and that therefore everything can be demonstrated.
Since the object of pure scientific knowledge cannot be other
than it is, the truth obtained by demonstrative knowledge will
be necessary. And since demonstrative knowledge is only
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present when we have a demonstration, it follows that
demonstration is an inference from necessary premisses. So we
must consider what are the premisses of demonstration - i.e.
what is their character: and as a preliminary, let us define what
we mean by an attribute 'true in every instance of its subject',
an 'essential' attribute, and a 'commensurate and universal'
attribute. I call 'true in every instance' what is truly predicable
of all instances - not of one to the exclusion of others - and at
all times, not at this or that time only; e.g. if animal is truly
predicable of every instance of man, then if it be true to say 'this
is a man', 'this is an animal' is also true, and if the one be true
now the other is true now. A corresponding account holds if
point is in every instance predicable as contained in line. There
is evidence for this in the fact that the objection we raise
against a proposition put to us as true in every instance is either
an instance in which, or an occasion on which, it is not true.
Essential attributes are (1) such as belong to their subject as
elements in its essential nature (e.g. line thus belongs to
triangle, point to line; for the very being or 'substance' of
triangle and line is composed of these elements, which are
contained in the formulae defining triangle and line): (2) such
that, while they belong to certain subjects, the subjects to which
they belong are contained in the attribute's own defining
formula. Thus straight and curved belong to line, odd and even,
prime and compound, square and oblong, to number; and also
the formula defining any one of these attributes contains its
subject - e.g. line or number as the case may be.
Extending this classification to all other attributes, I distinguish
those that answer the above description as belonging
essentially to their respective subjects; whereas attributes
related in neither of these two ways to their subjects I call
accidents or 'coincidents'; e.g. musical or white is a 'coincident'
of animal.
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Further (a) that is essential which is not predicated of a subject
other than itself: e.g. 'the walking [thing]' walks and is white in
virtue of being something else besides; whereas substance, in
the sense of whatever signifies a 'this somewhat', is not what it
is in virtue of being something else besides. Things, then, not
predicated of a subject I call essential; things predicated of a
subject I call accidental or 'coincidental'.
In another sense again (b) a thing consequentially connected
with anything is essential; one not so connected is
'coincidental'. An example of the latter is 'While he was walking
it lightened': the lightning was not due to his walking; it was,
we should say, a coincidence. If, on the other hand, there is a
consequential connexion, the predication is essential; e.g. if a
beast dies when its throat is being cut, then its death is also
essentially connected with the cutting, because the cutting was
the cause of death, not death a 'coincident' of the cutting.
So far then as concerns the sphere of connexions scientifically
known in the unqualified sense of that term, all attributes
which (within that sphere) are essential either in the sense that
their subjects are contained in them, or in the sense that they
are contained in their subjects, are necessary as well as
consequentially connected with their subjects. For it is
impossible for them not to inhere in their subjects either simply
or in the qualified sense that one or other of a pair of opposites
must inhere in the subject; e.g. in line must be either
straightness or curvature, in number either oddness or
evenness. For within a single identical genus the contrary of a
given attribute is either its privative or its contradictory; e.g.
within number what is not odd is even, inasmuch as within this
sphere even is a necessary consequent of not-odd. So, since any
given predicate must be either affirmed or denied of any
subject, essential attributes must inhere in their subjects of
necessity.
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Thus, then, we have established the distinction between the
attribute which is 'true in every instance' and the 'essential'
attribute.
I term 'commensurately universal' an attribute which belongs to
every instance of its subject, and to every instance essentially
and as such; from which it clearly follows that all
commensurate universals inhere necessarily in their subjects.
The essential attribute, and the attribute that belongs to its
subject as such, are identical. E.g. point and straight belong to
line essentially, for they belong to line as such; and triangle as
such has two right angles, for it is essentially equal to two right
angles.
An attribute belongs commensurately and universally to a
subject when it can be shown to belong to any random instance
of that subject and when the subject is the first thing to which
it can be shown to belong. Thus, e.g. (1) the equality of its angles
to two right angles is not a commensurately universal attribute
of figure. For though it is possible to show that a figure has its
angles equal to two right angles, this attribute cannot be
demonstrated of any figure selected at haphazard, nor in
demonstrating does one take a figure at random - a square is a
figure but its angles are not equal to two right angles. On the
other hand, any isosceles triangle has its angles equal to two
right angles, yet isosceles triangle is not the primary subject of
this attribute but triangle is prior. So whatever can be shown to
have its angles equal to two right angles, or to possess any other
attribute, in any random instance of itself and primarily - that is
the first subject to which the predicate in question belongs
commensurately and universally, and the demonstration, in the
essential sense, of any predicate is the proof of it as belonging
to this first subject commensurately and universally: while the
proof of it as belonging to the other subjects to which it
attaches is demonstration only in a secondary and unessential
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sense. Nor again (2) is equality to two right angles a
commensurately universal attribute of isosceles; it is of wider
application.
We must not fail to observe that we often fall into error because
our conclusion is not in fact primary and commensurately
universal in the sense in which we think we prove it so. We
make this mistake (1) when the subject is an individual or
individuals above which there is no universal to be found: (2)
when the subjects belong to different species and there is a
higher universal, but it has no name: (3) when the subject which
the demonstrator takes as a whole is really only a part of a
larger whole; for then the demonstration will be true of the
individual instances within the part and will hold in every
instance of it, yet the demonstration will not be true of this
subject primarily and commensurately and universally. When a
demonstration is true of a subject primarily and
commensurately and universally, that is to be taken to mean
that it is true of a given subject primarily and as such. Case (3)
may be thus exemplified. If a proof were given that
perpendiculars to the same line are parallel, it might be
supposed that lines thus perpendicular were the proper subject
of the demonstration because being parallel is true of every
instance of them. But it is not so, for the parallelism depends
not on these angles being equal to one another because each is
a right angle, but simply on their being equal to one another. An
example of (1) would be as follows: if isosceles were the only
triangle, it would be thought to have its angles equal to two
right angles qua isosceles. An instance of (2) would be the law
that proportionals alternate. Alternation used to be
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demonstrated separately of numbers, lines, solids, and
durations, though it could have been proved of them all by a
single demonstration. Because there was no single name to
denote that in which numbers, lengths, durations, and solids
are identical, and because they differed specifically from one
another, this property was proved of each of them separately.
To-day, however, the proof is commensurately universal, for
they do not possess this attribute qua lines or qua numbers, but
qua manifesting this generic character which they are
postulated as possessing universally. Hence, even if one prove of
each kind of triangle that its angles are equal to two right
angles, whether by means of the same or different proofs; still,
as long as one treats separately equilateral, scalene, and
isosceles, one does not yet know, except sophistically, that
triangle has its angles equal to two right angles, nor does one
yet know that triangle has this property commensurately and
universally, even if there is no other species of triangle but
these. For one does not know that triangle as such has this
property, nor even that 'all' triangles have it - unless 'all' means
'each taken singly': if 'all' means 'as a whole class', then, though
there be none in which one does not recognize this property,
one does not know it of 'all triangles'.
When, then, does our knowledge fail of commensurate
universality, and when it is unqualified knowledge? If triangle
be identical in essence with equilateral, i.e. with each or all
equilaterals, then clearly we have unqualified knowledge: if on
the other hand it be not, and the attribute belongs to equilateral
qua triangle; then our knowledge fails of commensurate
universality. 'But', it will be asked, 'does this attribute belong to
the subject of which it has been demonstrated qua triangle or
qua isosceles? What is the point at which the subject, to which
it belongs is primary? (i.e. to what subject can it be
demonstrated as belonging commensurately and universally?)'
Clearly this point is the first term in which it is found to inhere
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as the elimination of inferior differentiae proceeds. Thus the
angles of a brazen isosceles triangle are equal to two right
angles: but eliminate brazen and isosceles and the attribute
remains. 'But' - you may say - 'eliminate figure or limit, and the
attribute vanishes.' True, but figure and limit are not the first
differentiae whose elimination destroys the attribute. 'Then
what is the first?' If it is triangle, it will be in virtue of triangle
that the attribute belongs to all the other subjects of which it is
predicable, and triangle is the subject to which it can be
demonstrated as belonging commensurately and universally.
Demonstrative knowledge must rest on necessary basic truths;
for the object of scientific knowledge cannot be other than it is.
Now attributes attaching essentially to their subjects attach
necessarily to them: for essential attributes are either elements
in the essential nature of their subjects, or contain their
subjects as elements in their own essential nature. (The pairs of
opposites which the latter class includes are necessary because
one member or the other necessarily inheres.) It follows from
this that premisses of the demonstrative syllogism must be
connexions essential in the sense explained: for all attributes
must inhere essentially or else be accidental, and accidental
attributes are not necessary to their subjects.
We must either state the case thus, or else premise that the
conclusion of demonstration is necessary and that a
demonstrated conclusion cannot be other than it is, and then
infer that the conclusion must be developed from necessary
premisses. For though you may reason from true premisses
without demonstrating, yet if your premisses are necessary you
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will assuredly demonstrate - in such necessity you have at once
a distinctive character of demonstration. That demonstration
proceeds from necessary premisses is also indicated by the fact
that the objection we raise against a professed demonstration is
that a premiss of it is not a necessary truth - whether we think
it altogether devoid of necessity, or at any rate so far as our
opponent's previous argument goes. This shows how naive it is
to suppose one's basic truths rightly chosen if one starts with a
proposition which is (1) popularly accepted and (2) true, such as
the sophists' assumption that to know is the same as to possess
knowledge. For (1) popular acceptance or rejection is no
criterion of a basic truth, which can only be the primary law of
the genus constituting the subject matter of the demonstration;
and (2) not all truth is 'appropriate'.
A further proof that the conclusion must be the development of
necessary premisses is as follows. Where demonstration is
possible, one who can give no account which includes the cause
has no scientific knowledge. If, then, we suppose a syllogism in
which, though A necessarily inheres in G, yet B, the middle term
of the demonstration, is not necessarily connected with A and
C, then the man who argues thus has no reasoned knowledge of
the conclusion, since this conclusion does not owe its necessity
to the middle term; for though the conclusion is necessary, the
mediating link is a contingent fact. Or again, if a man is without
knowledge now, though he still retains the steps of the
argument, though there is no change in himself or in the fact
and no lapse of memory on his part; then neither had he
knowledge previously. But the mediating link, not being
necessary, may have perished in the interval; and if so, though
there be no change in him nor in the fact, and though he will
still retain the steps of the argument, yet he has not knowledge,
and therefore had not knowledge before. Even if the link has not
actually perished but is liable to perish, this situation is possible
and might occur. But such a condition cannot be knowledge.
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When the conclusion is necessary, the middle through which it
was proved may yet quite easily be non-necessary. You can in
fact infer the necessary even from a non-necessary premiss,
just as you can infer the true from the not true. On the other
hand, when the middle is necessary the conclusion must be
necessary; just as true premisses always give a true conclusion.
Thus, if A is necessarily predicated of B and B of C, then A is
necessarily predicated of C. But when the conclusion is
nonnecessary the middle cannot be necessary either. Thus: let A
be predicated non-necessarily of G but necessarily of B, and let B
be a necessary predicate of C; then A too will be a necessary
predicate of C, which by hypothesis it is not.
To sum up, then: demonstrative knowledge must be knowledge
of a necessary nexus, and therefore must clearly be obtained
through a necessary middle term; otherwise its possessor will
know neither the cause nor the fact that his conclusion is a
necessary connexion. Either he will mistake the non-necessary
for the necessary and believe the necessity of the conclusion
without knowing it, or else he will not even believe it - in which
case he will be equally ignorant, whether he actually infers the
mere fact through middle terms or the reasoned fact and from
immediate premisses.
Of accidents that are not essential according to our definition of
essential there is no demonstrative knowledge; for since an
accident, in the sense in which I here speak of it, may also not
inhere, it is impossible to prove its inherence as a necessary
conclusion. A difficulty, however, might be raised as to why in
dialectic, if the conclusion is not a necessary connexion, such
and such determinate premisses should be proposed in order to
deal with such and such determinate problems. Would not the
result be the same if one asked any questions whatever and
then merely stated one's conclusion? The solution is that
determinate questions have to be put, not because the replies to
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them affirm facts which necessitate facts affirmed by the
conclusion, but because these answers are propositions which if
the answerer affirm, he must affirm the conclusion and affirm
it with truth if they are true.
Since it is just those attributes within every genus which are
essential and possessed by their respective subjects as such
that are necessary it is clear that both the conclusions and the
premisses of demonstrations which produce scientific
knowledge are essential. For accidents are not necessary: and,
further, since accidents are not necessary one does not
necessarily have reasoned knowledge of a conclusion drawn
from them (this is so even if the accidental premisses are
invariable but not essential, as in proofs through signs; for
though the conclusion be actually essential, one will not know
it as essential nor know its reason); but to have reasoned
knowledge of a conclusion is to know it through its cause. We
may conclude that the middle must be consequentially
connected with the minor, and the major with the middle.
It follows that we cannot in demonstrating pass from one genus
to another. We cannot, for instance, prove geometrical truths by
arithmetic. For there are three elements in demonstration: (1)
what is proved, the conclusion - an attribute inhering
essentially in a genus; (2) the axioms, i.e. axioms which are
premisses of demonstration; (3) the subject - genus whose
attributes, i.e. essential properties, are revealed by the
demonstration. The axioms which are premisses of
demonstration may be identical in two or more sciences: but in
the case of two different genera such as arithmetic and
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geometry you cannot apply arithmetical demonstration to the
properties of magnitudes unless the magnitudes in question are
numbers. How in certain cases transference is possible I will
explain later.
Arithmetical demonstration and the other sciences likewise
possess, each of them, their own genera; so that if the
demonstration is to pass from one sphere to another, the genus
must be either absolutely or to some extent the same. If this is
not so, transference is clearly impossible, because the extreme
and the middle terms must be drawn from the same genus:
otherwise, as predicated, they will not be essential and will thus
be accidents. That is why it cannot be proved by geometry that
opposites fall under one science, nor even that the product of
two cubes is a cube. Nor can the theorem of any one science be
demonstrated by means of another science, unless these
theorems are related as subordinate to superior (e.g. as optical
theorems to geometry or harmonic theorems to arithmetic).
Geometry again cannot prove of lines any property which they
do not possess qua lines, i.e. in virtue of the fundamental truths
of their peculiar genus: it cannot show, for example, that the
straight line is the most beautiful of lines or the contrary of the
circle; for these qualities do not belong to lines in virtue of their
peculiar genus, but through some property which it shares with
other genera.
8
It is also clear that if the premisses from which the syllogism
proceeds are commensurately universal, the conclusion of such
i.e. in the unqualified sense - must also be eternal. Therefore no
attribute can be demonstrated nor known by strictly scientific
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knowledge to inhere in perishable things. The proof can only be
accidental, because the attribute's connexion with its perishable
subject is not commensurately universal but temporary and
special. If such a demonstration is made, one premiss must be
perishable and not commensurately universal (perishable
because only if it is perishable will the conclusion be perishable;
not commensurately universal, because the predicate will be
predicable of some instances of the subject and not of others);
so that the conclusion can only be that a fact is true at the
moment - not commensurately and universally. The same is
true of definitions, since a definition is either a primary premiss
or a conclusion of a demonstration, or else only differs from a
demonstration in the order of its terms. Demonstration and
science of merely frequent occurrences - e.g. of eclipse as
happening to the moon - are, as such, clearly eternal: whereas
so far as they are not eternal they are not fully commensurate.
Other subjects too have properties attaching to them in the
same way as eclipse attaches to the moon.
It is clear that if the conclusion is to show an attribute inhering
as such, nothing can be demonstrated except from its
'appropriate' basic truths. Consequently a proof even from true,
indemonstrable, and immediate premisses does not constitute
knowledge. Such proofs are like Bryson's method of squaring
the circle; for they operate by taking as their middle a common
character - a character, therefore, which the subject may share
with another - and consequently they apply equally to subjects
different in kind. They therefore afford knowledge of an
attribute only as inhering accidentally, not as belonging to its
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subject as such: otherwise they would not have been applicable
to another genus.
Our knowledge of any attribute's connexion with a subject is
accidental unless we know that connexion through the middle
term in virtue of which it inheres, and as an inference from
basic premisses essential and 'appropriate' to the subject -
unless we know, e.g. the property of possessing angles equal to
two right angles as belonging to that subject in which it inheres
essentially, and as inferred from basic premisses essential and
'appropriate' to that subject: so that if that middle term also
belongs essentially to the minor, the middle must belong to the
same kind as the major and minor terms. The only exceptions
to this rule are such cases as theorems in harmonics which are
demonstrable by arithmetic. Such theorems are proved by the
same middle terms as arithmetical properties, but with a
qualification - the fact falls under a separate science (for the
subject genus is separate), but the reasoned fact concerns the
superior science, to which the attributes essentially belong.
Thus, even these apparent exceptions show that no attribute is
strictly demonstrable except from its 'appropriate' basic truths,
which, however, in the case of these sciences have the requisite
identity of character.
It is no less evident that the peculiar basic truths of each
inhering attribute are indemonstrable; for basic truths from
which they might be deduced would be basic truths of all that
is, and the science to which they belonged would possess
universal sovereignty. This is so because he knows better whose
knowledge is deduced from higher causes, for his knowledge is
from prior premisses when it derives from causes themselves
uncaused: hence, if he knows better than others or best of all,
his knowledge would be science in a higher or the highest
degree. But, as things are, demonstration is not transferable to
another genus, with such exceptions as we have mentioned of
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the application of geometrical demonstrations to theorems in
mechanics or optics, or of arithmetical demonstrations to those
of harmonics.
It is hard to be sure whether one knows or not; for it is hard to
be sure whether one's knowledge is based on the basic truths
appropriate to each attribute - the differentia of true knowledge.
We think we have scientific knowledge if we have reasoned
from true and primary premisses. But that is not so: the
conclusion must be homogeneous with the basic facts of the
science.
10
I call the basic truths of every genus those elements in it the
existence of which cannot be proved. As regards both these
primary truths and the attributes dependent on them the
meaning of the name is assumed. The fact of their existence as
regards the primary truths must be assumed; but it has to be
proved of the remainder, the attributes. Thus we assume the
meaning alike of unity, straight, and triangular; but while as
regards unity and magnitude we assume also the fact of their
existence, in the case of the remainder proof is required.
Of the basic truths used in the demonstrative sciences some are
peculiar to each science, and some are common, but common
only in the sense of analogous, being of use only in so far as
they fall within the genus constituting the province of the
science in question.
Peculiar truths are, e.g. the definitions of line and straight;
common truths are such as 'take equals from equals and equals
remain'. Only so much of these common truths is required as
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falls within the genus in question: for a truth of this kind will
have the same force even if not used generally but applied by
the geometer only to magnitudes, or by the arithmetician only
to numbers. Also peculiar to a science are the subjects the
existence as well as the meaning of which it assumes, and the
essential attributes of which it investigates, e.g. in arithmetic
units, in geometry points and lines. Both the existence and the
meaning of the subjects are assumed by these sciences; but of
their essential attributes only the meaning is assumed. For
example arithmetic assumes the meaning of odd and even,
square and cube, geometry that of incommensurable, or of
deflection or verging of lines, whereas the existence of these
attributes is demonstrated by means of the axioms and from
previous conclusions as premisses. Astronomy too proceeds in
the same way. For indeed every demonstrative science has three
elements: (1) that which it posits, the subject genus whose
essential attributes it examines; (2) the so-called axioms, which
are primary premisses of its demonstration; (3) the attributes,
the meaning of which it assumes. Yet some sciences may very
well pass over some of these elements; e.g. we might not
expressly posit the existence of the genus if its existence were
obvious (for instance, the existence of hot and cold is more
evident than that of number); or we might omit to assume
expressly the meaning of the attributes if it were well
understood. In the way the meaning of axioms, such as 'Take
equals from equals and equals remain', is well known and so
not expressly assumed. Nevertheless in the nature of the case
the essential elements of demonstration are three: the subject,
the attributes, and the basic premisses.
That which expresses necessary self-grounded fact, and which
we must necessarily believe, is distinct both from the
hypotheses of a science and from illegitimate postulate - I say
'must believe', because all syllogism, and therefore a fortiori
demonstration, is addressed not to the spoken word, but to the
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discourse within the soul, and though we can always raise
objections to the spoken word, to the inward discourse we
cannot always object. That which is capable of proof but
assumed by the teacher without proof is, if the pupil believes
and accepts it, hypothesis, though only in a limited sense
hypothesis - that is, relatively to the pupil; if the pupil has no
opinion or a contrary opinion on the matter, the same
assumption is an illegitimate postulate. Therein lies the
distinction between hypothesis and illegitimate postulate: the
latter is the contrary of the pupil's opinion, demonstrable, but
assumed and used without demonstration.
The definition - viz. those which are not expressed as
statements that anything is or is not - are not hypotheses: but it
is in the premisses of a science that its hypotheses are
contained. Definitions require only to be understood, and this is
not hypothesis - unless it be contended that the pupil's hearing
is also an hypothesis required by the teacher. Hypotheses, on
the contrary, postulate facts on the being of which depends the
being of the fact inferred. Nor are the geometer's hypotheses
false, as some have held, urging that one must not employ
falsehood and that the geometer is uttering falsehood in stating
that the line which he draws is a foot long or straight, when it is
actually neither. The truth is that the geometer does not draw
any conclusion from the being of the particular line of which he
speaks, but from what his diagrams symbolize. A further
distinction is that all hypotheses and illegitimate postulates are
either universal or particular, whereas a definition is neither.
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11
So demonstration does not necessarily imply the being of Forms
nor a One beside a Many, but it does necessarily imply the
possibility of truly predicating one of many; since without this
possibility we cannot save the universal, and if the universal
goes, the middle term goes witb. it, and so demonstration
becomes impossible. We conclude, then, that there must be a
single identical term unequivocally predicable of a number of
individuals.
The law that it is impossible to affirm and deny simultaneously
the same predicate of the same subject is not expressly posited
by any demonstration except when the conclusion also has to
be expressed in that form; in which case the proof lays down as
its major premiss that the major is truly affirmed of the middle
but falsely denied. It makes no difference, however, if we add to
the middle, or again to the minor term, the corresponding
negative. For grant a minor term of which it is true to predicate
man - even if it be also true to predicate not-man of it - still
grant simply that man is animal and not not-animal, and the
conclusion follows: for it will still be true to say that Callias -
even if it be also true to say that not-Callias - is animal and not
not-animal. The reason is that the major term is predicable not
only of the middle, but of something other than the middle as
well, being of wider application; so that the conclusion is not
affected even if the middle is extended to cover the original
middle term and also what is not the original middle term.
The law that every predicate can be either truly affirmed or
truly denied of every subject is posited by such demonstration
as uses reductio ad impossibile, and then not always
universally, but so far as it is requisite; within the limits, that is,
of the genus - the genus, I mean (as I have already explained), to
which the man of science applies his demonstrations. In virtue
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of the common elements of demonstration - I mean the
common axioms which are used as premisses of
demonstration, not the subjects nor the attributes
demonstrated as belonging to them - all the sciences have
communion with one another, and in communion with them all
is dialectic and any science which might attempt a universal
proof of axioms such as the law of excluded middle, the law
that the subtraction of equals from equals leaves equal
remainders, or other axioms of the same kind. Dialectic has no
definite sphere of this kind, not being confined to a single
genus. Otherwise its method would not be interrogative; for the
interrogative method is barred to the demonstrator, who cannot
use the opposite facts to prove the same nexus. This was shown
in my work on the syllogism.
12
If a syllogistic question is equivalent to a proposition
embodying one of the two sides of a contradiction, and if each
science has its peculiar propositions from which its peculiar
conclusion is developed, then there is such a thing as a
distinctively scientific question, and it is the interrogative form
of the premisses from which the 'appropriate' conclusion of
each science is developed. Hence it is clear that not every
question will be relevant to geometry, nor to medicine, nor to
any other science: only those questions will be geometrical
which form premisses for the proof of the theorems of
geometry or of any other science, such as optics, which uses the
same basic truths as geometry. Of the other sciences the like is
true. Of these questions the geometer is bound to give his
account, using the basic truths of geometry in conjunction with
his previous conclusions; of the basic truths the geometer, as
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such, is not bound to give any account. The like is true of the
other sciences. There is a limit, then, to the questions which we
may put to each man of science; nor is each man of science
bound to answer all inquiries on each several subject, but only
such as fall within the defined field of his own science. If, then,
in controversy with a geometer qua geometer the disputant
confines himself to geometry and proves anything from
geometrical premisses, he is clearly to be applauded; if he goes
outside these he will be at fault, and obviously cannot even
refute the geometer except accidentally. One should therefore
not discuss geometry among those who are not geometers, for
in such a company an unsound argument will pass unnoticed.
This is correspondingly true in the other sciences.
Since there are 'geometrical' questions, does it follow that there
are also distinctively 'ungeometrical' questions? Further, in each
special science - geometry for instance - what kind of error is it
that may vitiate questions, and yet not exclude them from that
science? Again, is the erroneous conclusion one constructed
from premisses opposite to the true premisses, or is it formal
fallacy though drawn from geometrical premisses? Or, perhaps,
the erroneous conclusion is due to the drawing of premisses
from another science; e.g. in a geometrical controversy a
musical question is distinctively ungeometrical, whereas the
notion that parallels meet is in one sense geometrical, being
ungeometrical in a different fashion: the reason being that
'ungeometrical', like 'unrhythmical', is equivocal, meaning in
the one case not geometry at all, in the other bad geometry? It
is this error, i.e. error based on premisses of this kind - 'of the
science but false - that is the contrary of science. In
mathematics the formal fallacy is not so common, because it is
the middle term in which the ambiguity lies, since the major is
predicated of the whole of the middle and the middle of the
whole of the minor (the predicate of course never has the prefix
'all'); and in mathematics one can, so to speak, see these middle
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terms with an intellectual vision, while in dialectic the
ambiguity may escape detection. E.g. 'Is every circle a figure?' A
diagram shows that this is so, but the minor premiss 'Are epics
circles?' is shown by the diagram to be false.
If a proof has an inductive minor premiss, one should not bring
an 'objection' against it. For since every premiss must be
applicable to a number of cases (otherwise it will not be true in
every instance, which, since the syllogism proceeds from
universals, it must be), then assuredly the same is true of an
'objection'; since premisses and 'objections' are so far the same
that anything which can be validly advanced as an 'objection'
must be such that it could take the form of a premiss, either
demonstrative or dialectical. On the other hand, arguments
formally illogical do sometimes occur through taking as
middles mere attributes of the major and minor terms. An
instance of this is Caeneus' proof that fire increases in
geometrical proportion: 'Fire', he argues, 'increases rapidly, and
so does geometrical proportion'. There is no syllogism so, but
there is a syllogism if the most rapidly increasing proportion is
geometrical and the most rapidly increasing proportion is
attributable to fire in its motion. Sometimes, no doubt, it is
impossible to reason from premisses predicating mere
attributes: but sometimes it is possible, though the possibility is
overlooked. If false premisses could never give true conclusions
'resolution' would be easy, for premisses and conclusion would
in that case inevitably reciprocate. I might then argue thus: let A
be an existing fact; let the existence of A imply such and such
facts actually known to me to exist, which we may call B. I can
now, since they reciprocate, infer A from B.
Reciprocation of premisses and conclusion is more frequent in
mathematics, because mathematics takes definitions, but never
an accident, for its premisses - a second characteristic
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distinguishing mathematical reasoning from dialectical
disputations.
A science expands not by the interposition of fresh middle
terms, but by the apposition of fresh extreme terms. E.g. A is
predicated of B, B of C, C of D, and so indefinitely. Or the
expansion may be lateral: e.g. one major A, may be proved of
two minors, C and E. Thus let A represent number - a number or
number taken indeterminately; B determinate odd number; C
any particular odd number. We can then predicate A of C. Next
let D represent determinate even number, and E even number.
Then A is predicable of E.
13
Knowledge of the fact differs from knowledge of the reasoned
fact. To begin with, they differ within the same science and in
two ways: (1) when the premisses of the syllogism are not
immediate (for then the proximate cause is not contained in
them - a necessary condition of knowledge of the reasoned
fact): (2) when the premisses are immediate, but instead of the
cause the better known of the two reciprocals is taken as the
middle; for of two reciprocally predicable terms the one which
is not the cause may quite easily be the better known and so
become the middle term of the demonstration. Thus (2) (a) you
might prove as follows that the planets are near because they
do not twinkle: let C be the planets, B not twinkling, A
proximity. Then B is predicable of C; for the planets do not
twinkle. But A is also predicable of B, since that which does not
twinkle is near - we must take this truth as having been
reached by induction or sense-perception. Therefore A is a
necessary predicate of C; so that we have demonstrated that the
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planets are near. This syllogism, then, proves not the reasoned
fact but only the fact; since they are not near because they do
not twinkle, but, because they are near, do not twinkle. The
major and middle of the proof, however, may be reversed, and
then the demonstration will be of the reasoned fact. Thus: let C
be the planets, B proximity, A not twinkling. Then B is an
attribute of C, and A - not twinkling - of B. Consequently A is
predicable of C, and the syllogism proves the reasoned fact,
since its middle term is the proximate cause. Another example
is the inference that the moon is spherical from its manner of
waxing. Thus: since that which so waxes is spherical, and since
the moon so waxes, clearly the moon is spherical. Put in this
form, the syllogism turns out to be proof of the fact, but if the
middle and major be reversed it is proof of the reasoned fact;
since the moon is not spherical because it waxes in a certain
manner, but waxes in such a manner because it is spherical.
(Let C be the moon, B spherical, and A waxing.) Again (b), in
cases where the cause and the effect are not reciprocal and the
effect is the better known, the fact is demonstrated but not the
reasoned fact. This also occurs (1) when the middle falls outside
the major and minor, for here too the strict cause is not given,
and so the demonstration is of the fact, not of the reasoned fact.
For example, the question 'Why does not a wall breathe?' might
be answered, 'Because it is not an animal'; but that answer
would not give the strict cause, because if not being an animal
causes the absence of respiration, then being an animal should
be the cause of respiration, according to the rule that if the
negation of causes the non-inherence of y, the affirmation of x
causes the inherence of y; e.g. if the disproportion of the hot
and cold elements is the cause of ill health, their proportion is
the cause of health; and conversely, if the assertion of x causes
the inherence of y, the negation of x must cause y's non-
inherence. But in the case given this consequence does not
result; for not every animal breathes. A syllogism with this kind
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of cause takes place in the second figure. Thus: let A be animal,
B respiration, C wall. Then A is predicable of all B (for all that
breathes is animal), but of no C; and consequently B is
predicable of no C; that is, the wall does not breathe. Such
causes are like far-fetched explanations, which precisely consist
in making the cause too remote, as in Anacharsis' account of
why the Scythians have no flute-players; namely because they
have no vines.
Thus, then, do the syllogism of the fact and the syllogism of the
reasoned fact differ within one science and according to the
position of the middle terms. But there is another way too in
which the fact and the reasoned fact differ, and that is when
they are investigated respectively by different sciences. This
occurs in the case of problems related to one another as
subordinate and superior, as when optical problems are
subordinated to geometry, mechanical problems to stereometry,
harmonic problems to arithmetic, the data of observation to
astronomy. (Some of these sciences bear almost the same
name; e.g. mathematical and nautical astronomy, mathematical
and acoustical harmonics.) Here it is the business of the
empirical observers to know the fact, of the mathematicians to
know the reasoned fact; for the latter are in possession of the
demonstrations giving the causes, and are often ignorant of the
fact: just as we have often a clear insight into a universal, but
through lack of observation are ignorant of some of its
particular instances. These connexions have a perceptible
existence though they are manifestations of forms. For the
mathematical sciences concern forms: they do not demonstrate
properties of a substratum, since, even though the geometrical
subjects are predicable as properties of a perceptible
substratum, it is not as thus predicable that the mathematician
demonstrates properties of them. As optics is related to
geometry, so another science is related to optics, namely the
theory of the rainbow. Here knowledge of the fact is within the
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province of the natural philosopher, knowledge of the reasoned
fact within that of the optician, either qua optician or qua
mathematical optician. Many sciences not standing in this
mutual relation enter into it at points; e.g. medicine and
geometry: it is the physician's business to know that circular
wounds heal more slowly, the geometer's to know the reason
why.
14
Of all the figures the most scientific is the first. Thus, it is the
vehicle of the demonstrations of all the mathematical sciences,
such as arithmetic, geometry, and optics, and practically all of
all sciences that investigate causes: for the syllogism of the
reasoned fact is either exclusively or generally speaking and in
most cases in this figure - a second proof that this figure is the
most scientific; for grasp of a reasoned conclusion is the
primary condition of knowledge. Thirdly, the first is the only
figure which enables us to pursue knowledge of the essence of a
thing. In the second figure no affirmative conclusion is possible,
and knowledge of a thing's essence must be affirmative; while
in the third figure the conclusion can be affirmative, but cannot
be universal, and essence must have a universal character: e.g.
man is not two-footed animal in any qualified sense, but
universally. Finally, the first figure has no need of the others,
while it is by means of the first that the other two figures are
developed, and have their intervals closepacked until
immediate premisses are reached.
Clearly, therefore, the first figure is the primary condition of
knowledge.
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15
Just as an attribute A may (as we saw) be atomically connected
with a subject B, so its disconnexion may be atomic. I call
'atomic' connexions or disconnexions which involve no
intermediate term; since in that case the connexion or
disconnexion will not be mediated by something other than the
terms themselves. It follows that if either A or B, or both A and
B, have a genus, their disconnexion cannot be primary. Thus: let
C be the genus of A. Then, if C is not the genus of B - for A may
well have a genus which is not the genus of B - there will be a
syllogism proving As disconnexion from B thus:
all A is C,
no B is C,
therefore no B is A.
Or if it is B which has a genus D, we have
all B is D,
no D is A,
therefore no B is A, by syllogism;
and the proof will be similar if both A and B have a genus. That
the genus of A need not be the genus of B and vice versa, is
shown by the existence of mutually exclusive coordinate series
of predication. If no term in the series ACD... is predicable of any
term in the series BEE.., and if G - a term in the former series -
is the genus of A, clearly G will not be the genus of B; since, if it
were, the series would not be mutually exclusive. So also if B
has a genus, it will not be the genus of A. If, on the other hand,
neither A nor B has a genus and A does not inhere in B, this
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disconnexion must be atomic. If there be a middle term, one or
other of them is bound to have a genus, for the syllogism will be
either in the first or the second figure. If it is in the first, B will
have a genus - for the premiss containing it must be
affirmative: if in the second, either A or B indifferently, since
syllogism is possible if either is contained in a negative premiss,
but not if both premisses are negative.
Hence it is clear that one thing may be atomically disconnected
from another, and we have stated when and how this is
possible.
16
Ignorance - defined not as the negation of knowledge but as a
positive state of mind - is error produced by inference.
(1) Let us first consider propositions asserting a predicate's
immediate connexion with or disconnexion from a subject.
Here, it is true, positive error may befall one in alternative ways;
for it may arise where one directly believes a connexion or
disconnexion as well as where one's belief is acquired by
inference. The error, however, that consists in a direct belief is
without complication; but the error resulting from inference -
which here concerns us - takes many forms. Thus, let A be
atomically disconnected from all B: then the conclusion inferred
through a middle term C, that all B is A, will be a case of error
produced by syllogism. Now, two cases are possible. Either (a)
both premisses, or (b) one premiss only, may be false, (a) If
neither A is an attribute of any C nor C of any B, whereas the
contrary was posited in both cases, both premisses will be false.
(C may quite well be so related to A and B that C is neither
subordinate to A nor a universal attribute of B: for B, since A was
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said to be primarily disconnected from B, cannot have a genus,
and A need not necessarily be a universal attribute of all things.
Consequently both premisses may be false.) On the other hand,
(b) one of the premisses may be true, though not either
indifferently but only the major A-C since, B having no genus,
the premiss C-B will always be false, while A-C may be true. This
is the case if, for example, A is related atomically to both C and
B; because when the same term is related atomically to more
terms than one, neither of those terms will belong to the other.
It is, of course, equally the case if A-C is not atomic.
Error of attribution, then, occurs through these causes and in
this form only - for we found that no syllogism of universal
attribution was possible in any figure but the first. On the other
hand, an error of non-attribution may occur either in the first or
in the second figure. Let us therefore first explain the various
forms it takes in the first figure and the character of the
premisses in each case.
(c) It may occur when both premisses are false; e.g. supposing A
atomically connected with both C and B, if it be then assumed
that no C is and all B is C, both premisses are false.
(d) It is also possible when one is false. This may be either
premiss indifferently. A-C may be true, C-B false - A-C true
because A is not an attribute of all things, C-B false because C,
which never has the attribute A, cannot be an attribute of B; for
if C-B were true, the premiss A-C would no longer be true, and
besides if both premisses were true, the conclusion would be
true. Or again, C-B may be true and A-C false; e.g. if both C and
A contain B as genera, one of them must be subordinate to the
other, so that if the premiss takes the form No C is A, it will be
false. This makes it clear that whether either or both premisses
are false, the conclusion will equally be false.
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In the second figure the premisses cannot both be wholly false;
for if all B is A, no middle term can be with truth universally
affirmed of one extreme and universally denied of the other:
but premisses in which the middle is affirmed of one extreme
and denied of the other are the necessary condition if one is to
get a valid inference at all. Therefore if, taken in this way, they
are wholly false, their contraries conversely should be wholly
true. But this is impossible. On the other hand, there is nothing
to prevent both premisses being partially false; e.g. if actually
some A is C and some B is C, then if it is premised that all A is C
and no B is C, both premisses are false, yet partially, not wholly,
false. The same is true if the major is made negative instead of
the minor. Or one premiss may be wholly false, and it may be
either of them. Thus, supposing that actually an attribute of all
A must also be an attribute of all B, then if C is yet taken to be a
universal attribute of all but universally non-attributable to B, C-
A will be true but C-B false. Again, actually that which is an
attribute of no B will not be an attribute of all A either; for if it
be an attribute of all A, it will also be an attribute of all B, which
is contrary to supposition; but if C be nevertheless assumed to
be a universal attribute of A, but an attribute of no B, then the
premiss C-B is true but the major is false. The case is similar if
the major is made the negative premiss. For in fact what is an
attribute of no A will not be an attribute of any B either; and if it
be yet assumed that C is universally non-attributable to A, but a
universal attribute of B, the premiss C-A is true but the minor
wholly false. Again, in fact it is false to assume that that which
is an attribute of all B is an attribute of no A, for if it be an
attribute of all B, it must be an attribute of some A. If then C is
nevertheless assumed to be an attribute of all B but of no A, G-B
will be true but C-A false.
It is thus clear that in the case of atomic propositions erroneous
inference will be possible not only when both premisses are
false but also when only one is false.
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17
In the case of attributes not atomically connected with or
disconnected from their subjects, (a) (i) as long as the false
conclusion is inferred through the 'appropriate' middle, only the
major and not both premisses can be false. By 'appropriate
middle' I mean the middle term through which the
contradictory - i.e. the true-conclusion is inferrible. Thus, let A
be attributable to B through a middle term C: then, since to
produce a conclusion the premiss C-B must be taken
affirmatively, it is clear that this premiss must always be true,
for its quality is not changed. But the major A-C is false, for it is
by a change in the quality of A-C that the conclusion becomes
its contradictory - i.e. true. Similarly (ii) if the middle is taken
from another series of predication; e.g. suppose D to be not only
contained within A as a part within its whole but also
predicable of all B. Then the premiss D-B must remain
unchanged, but the quality of A-D must be changed; so that D-B
is always true, A-D always false. Such error is practically
identical with that which is inferred through the 'appropriate'
middle. On the other hand, (b) if the conclusion is not inferred
through the 'appropriate' middle - (i) when the middle is
subordinate to A but is predicable of no B, both premisses must
be false, because if there is to be a conclusion both must be
posited as asserting the contrary of what is actually the fact,
and so posited both become false: e.g. suppose that actually all
D is A but no B is D; then if these premisses are changed in
quality, a conclusion will follow and both of the new premisses
will be false. When, however, (ii) the middle D is not subordinate
to A, A-D will be true, D-B false - A-D true because A was not
subordinate to D, D-B false because if it had been true, the
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conclusion too would have been true; but it is ex hypothesi
false.
When the erroneous inference is in the second figure, both
premisses cannot be entirely false; since if B is subordinate to A,
there can be no middle predicable of all of one extreme and of
none of the other, as was stated before. One premiss, however,
may be false, and it may be either of them. Thus, if C is actually
an attribute of both A and B, but is assumed to be an attribute of
A only and not of B, C-A will be true, C-B false: or again if C be
assumed to be attributable to B but to no A, C-B will be true, C-A
false.
We have stated when and through what kinds of premisses
error will result in cases where the erroneous conclusion is
negative. If the conclusion is affirmative, (a) (i) it may be
inferred through the 'appropriate' middle term. In this case both
premisses cannot be false since, as we said before, C-B must
remain unchanged if there is to be a conclusion, and
consequently A-C, the quality of which is changed, will always
be false. This is equally true if (ii) the middle is taken from
another series of predication, as was stated to be the case also
with regard to negative error; for D-B must remain unchanged,
while the quality of A-D must be converted, and the type of
error is the same as before.
(b) The middle may be inappropriate. Then (i) if D is subordinate
to A, A-D will be true, but D-B false; since A may quite well be
predicable of several terms no one of which can be
subordinated to another. If, however, (ii) D is not subordinate to
A, obviously A-D, since it is affirmed, will always be false, while
D-B may be either true or false; for A may very well be an
attribute of no D, whereas all B is D, e.g. no science is animal, all
music is science. Equally well A may be an attribute of no D, and
D of no B. It emerges, then, that if the middle term is not
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subordinate to the major, not only both premisses but either
singly may be false.
Thus we have made it clear how many varieties of erroneous
inference are liable to happen and through what kinds of
premisses they occur, in the case both of immediate and of
demonstrable truths.
18
It is also clear that the loss of any one of the senses entails the
loss of a corresponding portion of knowledge, and that, since we
learn either by induction or by demonstration, this knowledge
cannot be acquired. Thus demonstration develops from
universals, induction from particulars; but since it is possible to
familiarize the pupil with even the so-called mathematical
abstractions only through induction - i.e. only because each
subject genus possesses, in virtue of a determinate
mathematical character, certain properties which can be treated
as separate even though they do not exist in isolation - it is
consequently impossible to come to grasp universals except
through induction. But induction is impossible for those who
have not sense-perception. For it is sense-perception alone
which is adequate for grasping the particulars: they cannot be
objects of scientific knowledge, because neither can universals
give us knowledge of them without induction, nor can we get it
through induction without sense-perception.
258
19
Every syllogism is effected by means of three terms. One kind of
syllogism serves to prove that A inheres in C by showing that A
inheres in B and B in C; the other is negative and one of its
premisses asserts one term of another, while the other denies
one term of another. It is clear, then, that these are the
fundamentals and so-called hypotheses of syllogism. Assume
them as they have been stated, and proof is bound to follow -
proof that A inheres in C through B, and again that A inheres in
B through some other middle term, and similarly that B inheres
in C. If our reasoning aims at gaining credence and so is merely
dialectical, it is obvious that we have only to see that our
inference is based on premisses as credible as possible: so that
if a middle term between A and B is credible though not real,
one can reason through it and complete a dialectical syllogism.
If, however, one is aiming at truth, one must be guided by the
real connexions of subjects and attributes. Thus: since there are
attributes which are predicated of a subject essentially or
naturally and not coincidentally - not, that is, in the sense in
which we say 'That white (thing) is a man', which is not the
same mode of predication as when we say 'The man is white':
the man is white not because he is something else but because
he is man, but the white is man because 'being white' coincides
with 'humanity' within one substratum - therefore there are
terms such as are naturally subjects of predicates. Suppose,
then, C such a term not itself attributable to anything else as to
a subject, but the proximate subject of the attribute B - i.e. so
that B-C is immediate; suppose further E related immediately to
F, and F to B. The first question is, must this series terminate, or
can it proceed to infinity? The second question is as follows:
Suppose nothing is essentially predicated of A, but A is
predicated primarily of H and of no intermediate prior term, and
suppose H similarly related to G and G to B; then must this
series also terminate, or can it too proceed to infinity? There is
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this much difference between the questions: the first is, is it
possible to start from that which is not itself attributable to
anything else but is the subject of attributes, and ascend to
infinity? The second is the problem whether one can start from
that which is a predicate but not itself a subject of predicates,
and descend to infinity? A third question is, if the extreme
terms are fixed, can there be an infinity of middles? I mean this:
suppose for example that A inheres in C and B is intermediate
between them, but between B and A there are other middles,
and between these again fresh middles; can these proceed to
infinity or can they not? This is the equivalent of inquiring, do
demonstrations proceed to infinity, i.e. is everything
demonstrable? Or do ultimate subject and primary attribute
limit one another?
I hold that the same questions arise with regard to negative
conclusions and premisses: viz. if A is attributable to no B, then
either this predication will be primary, or there will be an
intermediate term prior to B to which a is not attributable - G,
let us say, which is attributable to all B - and there may still be
another term H prior to G, which is attributable to all G. The
same questions arise, I say, because in these cases too either the
series of prior terms to which a is not attributable is infinite or it
terminates.
One cannot ask the same questions in the case of reciprocating
terms, since when subject and predicate are convertible there is
neither primary nor ultimate subject, seeing that all the
reciprocals qua subjects stand in the same relation to one
another, whether we say that the subject has an infinity of
attributes or that both subjects and attributes - and we raised
the question in both cases - are infinite in number. These
questions then cannot be asked - unless, indeed, the terms can
reciprocate by two different modes, by accidental predication in
one relation and natural predication in the other.
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20
Now, it is clear that if the predications terminate in both the
upward and the downward direction (by 'upward' I mean the
ascent to the more universal, by 'downward' the descent to the
more particular), the middle terms cannot be infinite in number.
For suppose that A is predicated of F, and that the intermediates
- call them B B' B"... - are infinite, then clearly you might
descend from and find one term predicated of another ad
infinitum, since you have an infinity of terms between you and
F; and equally, if you ascend from F, there are infinite terms
between you and A. It follows that if these processes are
impossible there cannot be an infinity of intermediates between
A and F. Nor is it of any effect to urge that some terms of the
series AB...F are contiguous so as to exclude intermediates,
while others cannot be taken into the argument at all:
whichever terms of the series B...I take, the number of
intermediates in the direction either of A or of F must be finite
or infinite: where the infinite series starts, whether from the
first term or from a later one, is of no moment, for the
succeeding terms in any case are infinite in number.
21
Further, if in affirmative demonstration the series terminates in
both directions, clearly it will terminate too in negative
demonstration. Let us assume that we cannot proceed to
infinity either by ascending from the ultimate term (by 'ultimate
term' I mean a term such as was, not itself attributable to a
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subject but itself the subject of attributes), or by descending
towards an ultimate from the primary term (by 'primary term' I
mean a term predicable of a subject but not itself a subject). If
this assumption is justified, the series will also terminate in the
case of negation. For a negative conclusion can be proved in all
three figures. In the first figure it is proved thus: no B is A, all C
is B. In packing the interval B-C we must reach immediate
propositions - as is always the case with the minor premiss -
since B-C is affirmative. As regards the other premiss it is plain
that if the major term is denied of a term D prior to B, D will
have to be predicable of all B, and if the major is denied of yet
another term prior to D, this term must be predicable of all D.
Consequently, since the ascending series is finite, the descent
will also terminate and there will be a subject of which A is
primarily non-predicable. In the second figure the syllogism is,
all A is B, no C is B,..no C is A. If proof of this is required, plainly
it may be shown either in the first figure as above, in the second
as here, or in the third. The first figure has been discussed, and
we will proceed to display the second, proof by which will be as
follows: all B is D, no C is D..., since it is required that B should
be a subject of which a predicate is affirmed. Next, since D is to
be proved not to belong to C, then D has a further predicate
which is denied of C. Therefore, since the succession of
predicates affirmed of an ever higher universal terminates, the
succession of predicates denied terminates too.
The third figure shows it as follows: all B is A, some B is not C.
Therefore some A is not C. This premiss, i.e. C-B, will be proved
either in the same figure or in one of the two figures discussed
above. In the first and second figures the series terminates. If
we use the third figure, we shall take as premisses, all E is B,
some E is not C, and this premiss again will be proved by a
similar prosyllogism. But since it is assumed that the series of
descending subjects also terminates, plainly the series of more
universal non-predicables will terminate also. Even supposing
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that the proof is not confined to one method, but employs them
all and is now in the first figure, now in the second or third -
even so the regress will terminate, for the methods are finite in
number, and if finite things are combined in a finite number of
ways, the result must be finite.
Thus it is plain that the regress of middles terminates in the
case of negative demonstration, if it does so also in the case of
affirmative demonstration. That in fact the regress terminates
in both these cases may be made clear by the following
dialectical considerations.
22
In the case of predicates constituting the essential nature of a
thing, it clearly terminates, seeing that if definition is possible,
or in other words, if essential form is knowable, and an infinite
series cannot be traversed, predicates constituting a thing's
essential nature must be finite in number. But as regards
predicates generally we have the following prefatory remarks to
make. (1) We can affirm without falsehood 'the white (thing) is
walking', and that big (thing) is a log'; or again, 'the log is big',
and 'the man walks'. But the affirmation differs in the two
cases. When I affirm 'the white is a log', I mean that something
which happens to be white is a log - not that white is the
substratum in which log inheres, for it was not qua white or qua
a species of white that the white (thing) came to be a log, and
the white (thing) is consequently not a log except incidentally.
On the other hand, when I affirm 'the log is white', I do not
mean that something else, which happens also to be a log, is
white (as I should if I said 'the musician is white,' which would
mean 'the man who happens also to be a musician is white'); on
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the contrary, log is here the substratum - the substratum which
actually came to be white, and did so qua wood or qua a species
of wood and qua nothing else.
If we must lay down a rule, let us entitle the latter kind of
statement predication, and the former not predication at all, or
not strict but accidental predication. 'White' and 'log' will thus
serve as types respectively of predicate and subject.
We shall assume, then, that the predicate is invariably
predicated strictly and not accidentally of the subject, for on
such predication demonstrations depend for their force. It
follows from this that when a single attribute is predicated of a
single subject, the predicate must affirm of the subject either
some element constituting its essential nature, or that it is in
some way qualified, quantified, essentially related, active,
passive, placed, or dated.
(2) Predicates which signify substance signify that the subject is
identical with the predicate or with a species of the predicate.
Predicates not signifying substance which are predicated of a
subject not identical with themselves or with a species of
themselves are accidental or coincidental; e.g. white is a
coincident of man, seeing that man is not identical with white
or a species of white, but rather with animal, since man is
identical with a species of animal. These predicates which do
not signify substance must be predicates of some other subject,
and nothing can be white which is not also other than white.
The Forms we can dispense with, for they are mere sound
without sense; and even if there are such things, they are not
relevant to our discussion, since demonstrations are concerned
with predicates such as we have defined.
(3) If A is a quality of B, B cannot be a quality of A - a quality of a
quality. Therefore A and B cannot be predicated reciprocally of
one another in strict predication: they can be affirmed without
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falsehood of one another, but not genuinely predicated of each
other. For one alternative is that they should be substantially
predicated of one another, i.e. B would become the genus or
differentia of A - the predicate now become subject. But it has
been shown that in these substantial predications neither the
ascending predicates nor the descending subjects form an
infinite series; e.g. neither the series, man is biped, biped is
animal, &c, nor the series predicating animal of man, man of
Callias, Callias of a further, subject as an element of its essential
nature, is infinite. For all such substance is definable, and an
infinite series cannot be traversed in thought: consequently
neither the ascent nor the descent is infinite, since a substance
whose predicates were infinite would not be definable. Hence
they will not be predicated each as the genus of the other; for
this would equate a genus with one of its own species. Nor (the
other alternative) can a quale be reciprocally predicated of a
quale, nor any term belonging to an adjectival category of
another such term, except by accidental predication; for all such
predicates are coincidents and are predicated of substances. On
the other hand - in proof of the impossibility of an infinite
ascending series - every predication displays the subject as
somehow qualified or quantified or as characterized under one
of the other adjectival categories, or else is an element in its
substantial nature: these latter are limited in number, and the
number of the widest kinds under which predications fall is
also limited, for every predication must exhibit its subject as
somehow qualified, quantified, essentially related, acting or
suffering, or in some place or at some time.
I assume first that predication implies a single subject and a
single attribute, and secondly that predicates which are not
substantial are not predicated of one another. We assume this
because such predicates are all coincidents, and though some
are essential coincidents, others of a different type, yet we
maintain that all of them alike are predicated of some
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substratum and that a coincident is never a substratum - since
we do not class as a coincident anything which does not owe its
designation to its being something other than itself, but always
hold that any coincident is predicated of some substratum
other than itself, and that another group of coincidents may
have a different substratum. Subject to these assumptions then,
neither the ascending nor the descending series of predication
in which a single attribute is predicated of a single subject is
infinite. For the subjects of which coincidents are predicated are
as many as the constitutive elements of each individual
substance, and these we have seen are not infinite in number,
while in the ascending series are contained those constitutive
elements with their coincidents - both of which are finite. We
conclude that there is a given subject (D) of which some
attribute (C) is primarily predicable; that there must be an
attribute (B) primarily predicable of the first attribute, and that
the series must end with a term (A) not predicable of any term
prior to the last subject of which it was predicated (B), and of
which no term prior to it is predicable.
The argument we have given is one of the so-called proofs; an
alternative proof follows. Predicates so related to their subjects
that there are other predicates prior to them predicable of those
subjects are demonstrable; but of demonstrable propositions
one cannot have something better than knowledge, nor can one
know them without demonstration. Secondly, if a consequent is
only known through an antecedent (viz. premisses prior to it)
and we neither know this antecedent nor have something
better than knowledge of it, then we shall not have scientific
knowledge of the consequent. Therefore, if it is possible through
demonstration to know anything without qualification and not
merely as dependent on the acceptance of certain premisses -
i.e. hypothetically - the series of intermediate predications must
terminate. If it does not terminate, and beyond any predicate
taken as higher than another there remains another still higher,
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then every predicate is demonstrable. Consequently, since these
demonstrable predicates are infinite in number and therefore
cannot be traversed, we shall not know them by demonstration.
If, therefore, we have not something better than knowledge of
them, we cannot through demonstration have unqualified but
only hypothetical science of anything.
As dialectical proofs of our contention these may carry
conviction, but an analytic process will show more briefly that
neither the ascent nor the descent of predication can be infinite
in the demonstrative sciences which are the object of our
investigation. Demonstration proves the inherence of essential
attributes in things. Now attributes may be essential for two
reasons: either because they are elements in the essential
nature of their subjects, or because their subjects are elements
in their essential nature. An example of the latter is odd as an
attribute of number - though it is number's attribute, yet
number itself is an element in the definition of odd; of the
former, multiplicity or the indivisible, which are elements in the
definition of number. In neither kind of attribution can the
terms be infinite. They are not infinite where each is related to
the term below it as odd is to number, for this would mean the
inherence in odd of another attribute of odd in whose nature
odd was an essential element: but then number will be an
ultimate subject of the whole infinite chain of attributes, and be
an element in the definition of each of them. Hence, since an
infinity of attributes such as contain their subject in their
definition cannot inhere in a single thing, the ascending series
is equally finite. Note, moreover, that all such attributes must so
inhere in the ultimate subject - e.g. its attributes in number and
number in them - as to be commensurate with the subject and
not of wider extent. Attributes which are essential elements in
the nature of their subjects are equally finite: otherwise
definition would be impossible. Hence, if all the attributes
predicated are essential and these cannot be infinite, the
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ascending series will terminate, and consequently the
descending series too.
If this is so, it follows that the intermediates between any two
terms are also always limited in number. An immediately
obvious consequence of this is that demonstrations necessarily
involve basic truths, and that the contention of some - referred
to at the outset - that all truths are demonstrable is mistaken.
For if there are basic truths, (a) not all truths are demonstrable,
and (b) an infinite regress is impossible; since if either (a) or (b)
were not a fact, it would mean that no interval was immediate
and indivisible, but that all intervals were divisible. This is true
because a conclusion is demonstrated by the interposition, not
the apposition, of a fresh term. If such interposition could
continue to infinity there might be an infinite number of terms
between any two terms; but this is impossible if both the
ascending and descending series of predication terminate; and
of this fact, which before was shown dialectically, analytic proof
has now been given.
23
It is an evident corollary of these conclusions that if the same
attribute A inheres in two terms C and D predicable either not at
all, or not of all instances, of one another, it does not always
belong to them in virtue of a common middle term. Isosceles
and scalene possess the attribute of having their angles equal to
two right angles in virtue of a common middle; for they possess
it in so far as they are both a certain kind of figure, and not in so
far as they differ from one another. But this is not always the
case: for, were it so, if we take B as the common middle in virtue
of which A inheres in C and D, clearly B would inhere in C and D
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through a second common middle, and this in turn would
inhere in C and D through a third, so that between two terms an
infinity of intermediates would fall - an impossibility. Thus it
need not always be in virtue of a common middle term that a
single attribute inheres in several subjects, since there must be
immediate intervals. Yet if the attribute to be proved common to
two subjects is to be one of their essential attributes, the middle
terms involved must be within one subject genus and be
derived from the same group of immediate premisses; for we
have seen that processes of proof cannot pass from one genus
to another.
It is also clear that when A inheres in B, this can be
demonstrated if there is a middle term. Further, the 'elements'
of such a conclusion are the premisses containing the middle in
question, and they are identical in number with the middle
terms, seeing that the immediate propositions - or at least such
immediate propositions as are universal - are the 'elements'. If,
on the other hand, there is no middle term, demonstration
ceases to be possible: we are on the way to the basic truths.
Similarly if A does not inhere in B, this can be demonstrated if
there is a middle term or a term prior to B in which A does not
inhere: otherwise there is no demonstration and a basic truth is
reached. There are, moreover, as many 'elements' of the
demonstrated conclusion as there are middle terms, since it is
propositions containing these middle terms that are the basic
premisses on which the demonstration rests; and as there are
some indemonstrable basic truths asserting that 'this is that' or
that 'this inheres in that', so there are others denying that 'this
is that' or that 'this inheres in that' - in fact some basic truths
will affirm and some will deny being.
When we are to prove a conclusion, we must take a primary
essential predicate - suppose it C - of the subject B, and then
suppose A similarly predicable of C. If we proceed in this
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manner, no proposition or attribute which falls beyond A is
admitted in the proof: the interval is constantly condensed until
subject and predicate become indivisible, i.e. one. We have our
unit when the premiss becomes immediate, since the
immediate premiss alone is a single premiss in the unqualified
sense of 'single'. And as in other spheres the basic element is
simple but not identical in all - in a system of weight it is the
mina, in music the quarter-tone, and so on - so in syllogism the
unit is an immediate premiss, and in the knowledge that
demonstration gives it is an intuition. In syllogisms, then, which
prove the inherence of an attribute, nothing falls outside the
major term. In the case of negative syllogisms on the other
hand, (1) in the first figure nothing falls outside the major term
whose inherence is in question; e.g. to prove through a middle C
that A does not inhere in B the premisses required are, all B is C,
no C is A. Then if it has to be proved that no C is A, a middle
must be found between and C; and this procedure will never
vary.
(2) If we have to show that E is not D by means of the premisses,
all D is C; no E, or not all E, is C; then the middle will never fall
beyond E, and E is the subject of which D is to be denied in the
conclusion.
(3) In the third figure the middle will never fall beyond the
limits of the subject and the attribute denied of it.
24
Since demonstrations may be either commensurately universal
or particular, and either affirmative or negative; the question
arises, which form is the better? And the same question may be
put in regard to so-called 'direct' demonstration and reductio ad
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impossibile. Let us first examine the commensurately universal
and the particular forms, and when we have cleared up this
problem proceed to discuss 'direct' demonstration and reductio
ad impossibile.
The following considerations might lead some minds to prefer
particular demonstration.
(1) The superior demonstration is the demonstration which
gives us greater knowledge (for this is the ideal of
demonstration), and we have greater knowledge of a particular
individual when we know it in itself than when we know it
through something else; e.g. we know Coriscus the musician
better when we know that Coriscus is musical than when we
know only that man is musical, and a like argument holds in all
other cases. But commensurately universal demonstration,
instead of proving that the subject itself actually is x, proves
only that something else is x - e.g. in attempting to prove that
isosceles is x, it proves not that isosceles but only that triangle
is x - whereas particular demonstration proves that the subject
itself is x. The demonstration, then, that a subject, as such,
possesses an attribute is superior. If this is so, and if the
particular rather than the commensurately universal forms
demonstrates, particular demonstration is superior.
(2) The universal has not a separate being over against groups of
singulars. Demonstration nevertheless creates the opinion that
its function is conditioned by something like this - some
separate entity belonging to the real world; that, for instance, of
triangle or of figure or number, over against particular triangles,
figures, and numbers. But demonstration which touches the
real and will not mislead is superior to that which moves
among unrealities and is delusory. Now commensurately
universal demonstration is of the latter kind: if we engage in it
we find ourselves reasoning after a fashion well illustrated by
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the argument that the proportionate is what answers to the
definition of some entity which is neither line, number, solid,
nor plane, but a proportionate apart from all these. Since, then,
such a proof is characteristically commensurate and universal,
and less touches reality than does particular demonstration,
and creates a false opinion, it will follow that commensurate
and universal is inferior to particular demonstration.
We may retort thus. (1) The first argument applies no more to
commensurate and universal than to particular demonstration.
If equality to two right angles is attributable to its subject not
qua isosceles but qua triangle, he who knows that isosceles
possesses that attribute knows the subject as qua itself
possessing the attribute, to a less degree than he who knows
that triangle has that attribute. To sum up the whole matter: if a
subject is proved to possess qua triangle an attribute which it
does not in fact possess qua triangle, that is not demonstration:
but if it does possess it qua triangle the rule applies that the
greater knowledge is his who knows the subject as possessing
its attribute qua that in virtue of which it actually does possess
it. Since, then, triangle is the wider term, and there is one
identical definition of triangle - i.e. the term is not equivocal -
and since equality to two right angles belongs to all triangles, it
is isosceles qua triangle and not triangle qua isosceles which
has its angles so related. It follows that he who knows a
connexion universally has greater knowledge of it as it in fact is
than he who knows the particular; and the inference is that
commensurate and universal is superior to particular
demonstration.
(2) If there is a single identical definition i.e. if the
commensurate universal is unequivocal - then the universal
will possess being not less but more than some of the
particulars, inasmuch as it is universals which comprise the
imperishable, particulars that tend to perish.
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(3) Because the universal has a single meaning, we are not
therefore compelled to suppose that in these examples it has
being as a substance apart from its particulars - any more than
we need make a similar supposition in the other cases of
unequivocal universal predication, viz. where the predicate
signifies not substance but quality, essential relatedness, or
action. If such a supposition is entertained, the blame rests not
with the demonstration but with the hearer.
(4) Demonstration is syllogism that proves the cause, i.e. the
reasoned fact, and it is rather the commensurate universal than
the particular which is causative (as may be shown thus: that
which possesses an attribute through its own essential nature is
itself the cause of the inherence, and the commensurate
universal is primary; hence the commensurate universal is the
cause). Consequently commensurately universal demonstration
is superior as more especially proving the cause, that is the
reasoned fact.
(5) Our search for the reason ceases, and we think that we know,
when the coming to be or existence of the fact before us is not
due to the coming to be or existence of some other fact, for the
last step of a search thus conducted is eo ipso the end and limit
of the problem. Thus: 'Why did he come?' 'To get the money -
wherewith to pay a debt - that he might thereby do what was
right.' When in this regress we can no longer find an efficient or
final cause, we regard the last step of it as the end of the coming
- or being or coming to be - and we regard ourselves as then
only having full knowledge of the reason why he came.
If, then, all causes and reasons are alike in this respect, and if
this is the means to full knowledge in the case of final causes
such as we have exemplified, it follows that in the case of the
other causes also full knowledge is attained when an attribute
no longer inheres because of something else. Thus, when we
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learn that exterior angles are equal to four right angles because
they are the exterior angles of an isosceles, there still remains
the question 'Why has isosceles this attribute?' and its answer
'Because it is a triangle, and a triangle has it because a triangle
is a rectilinear figure.' If rectilinear figure possesses the property
for no further reason, at this point we have full knowledge - but
at this point our knowledge has become commensurately
universal, and so we conclude that commensurately universal
demonstration is superior.
(6) The more demonstration becomes particular the more it
sinks into an indeterminate manifold, while universal
demonstration tends to the simple and determinate. But objects
so far as they are an indeterminate manifold are unintelligible,
so far as they are determinate, intelligible: they are therefore
intelligible rather in so far as they are universal than in so far as
they are particular. From this it follows that universals are more
demonstrable: but since relative and correlative increase
concomitantly, of the more demonstrable there will be fuller
demonstration. Hence the commensurate and universal form,
being more truly demonstration, is the superior.
(7) Demonstration which teaches two things is preferable to
demonstration which teaches only one. He who possesses
commensurately universal demonstration knows the particular
as well, but he who possesses particular demonstration does
not know the universal. So that this is an additional reason for
preferring commensurately universal demonstration. And there
is yet this further argument:
(8) Proof becomes more and more proof of the commensurate
universal as its middle term approaches nearer to the basic
truth, and nothing is so near as the immediate premiss which is
itself the basic truth. If, then, proof from the basic truth is more
accurate than proof not so derived, demonstration which
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depends more closely on it is more accurate than
demonstration which is less closely dependent. But
commensurately universal demonstration is characterized by
this closer dependence, and is therefore superior. Thus, if A had
to be proved to inhere in D, and the middles were B and C, B
being the higher term would render the demonstration which it
mediated the more universal.
Some of these arguments, however, are dialectical. The clearest
indication of the precedence of commensurately universal
demonstration is as follows: if of two propositions, a prior and a
posterior, we have a grasp of the prior, we have a kind of
knowledge - a potential grasp - of the posterior as well. For
example, if one knows that the angles of all triangles are equal
to two right angles, one knows in a sense - potentially - that the
isosceles' angles also are equal to two right angles, even if one
does not know that the isosceles is a triangle; but to grasp this
posterior proposition is by no means to know the
commensurate universal either potentially or actually.
Moreover, commensurately universal demonstration is through
and through intelligible; particular demonstration issues in
sense-perception.
25
The preceding arguments constitute our defence of the
superiority of commensurately universal to particular
demonstration. That affirmative demonstration excels negative
may be shown as follows.
(1) We may assume the superiority ceteris paribus of the
demonstration which derives from fewer postulates or
hypotheses - in short from fewer premisses; for, given that all
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these are equally well known, where they are fewer knowledge
will be more speedily acquired, and that is a desideratum. The
argument implied in our contention that demonstration from
fewer assumptions is superior may be set out in universal form
as follows. Assuming that in both cases alike the middle terms
are known, and that middles which are prior are better known
than such as are posterior, we may suppose two demonstrations
of the inherence of A in E, the one proving it through the
middles B, C and D, the other through F and G. Then A-D is
known to the same degree as A-E (in the second proof), but A-D
is better known than and prior to A-E (in the first proof); since
A-E is proved through A-D, and the ground is more certain than
the conclusion.
Hence demonstration by fewer premisses is ceteris paribus
superior. Now both affirmative and negative demonstration
operate through three terms and two premisses, but whereas
the former assumes only that something is, the latter assumes
both that something is and that something else is not, and thus
operating through more kinds of premiss is inferior.
(2) It has been proved that no conclusion follows if both
premisses are negative, but that one must be negative, the other
affirmative. So we are compelled to lay down the following
additional rule: as the demonstration expands, the affirmative
premisses must increase in number, but there cannot be more
than one negative premiss in each complete proof. Thus,
suppose no B is A, and all C is B. Then if both the premisses are
to be again expanded, a middle must be interposed. Let us
interpose D between A and B, and E between B and C. Then
clearly E is affirmatively related to B and C, while D is
affirmatively related to B but negatively to A; for all B is D, but
there must be no D which is A. Thus there proves to be a single
negative premiss, A-D. In the further prosyllogisms too it is the
same, because in the terms of an affirmative syllogism the
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middle is always related affirmatively to both extremes; in a
negative syllogism it must be negatively related only to one of
them, and so this negation comes to be a single negative
premiss, the other premisses being affirmative. If, then, that
through which a truth is proved is a better known and more
certain truth, and if the negative proposition is proved through
the affirmative and not vice versa, affirmative demonstration,
being prior and better known and more certain, will be superior.
(3) The basic truth of demonstrative syllogism is the universal
immediate premiss, and the universal premiss asserts in
affirmative demonstration and in negative denies: and the
affirmative proposition is prior to and better known than the
negative (since affirmation explains denial and is prior to
denial, just as being is prior to not-being). It follows that the
basic premiss of affirmative demonstration is superior to that of
negative demonstration, and the demonstration which uses
superior basic premisses is superior.
(4) Affirmative demonstration is more of the nature of a basic
form of proof, because it is a sine qua non of negative
demonstration.
26
Since affirmative demonstration is superior to negative, it is
clearly superior also to reductio ad impossibile. We must first
make certain what is the difference between negative
demonstration and reductio ad impossibile. Let us suppose that
no B is A, and that all C is B: the conclusion necessarily follows
that no C is A. If these premisses are assumed, therefore, the
negative demonstration that no C is A is direct. Reductio ad
impossibile, on the other hand, proceeds as follows. Supposing
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we are to prove that does not inhere in B, we have to assume
that it does inhere, and further that B inheres in C, with the
resulting inference that A inheres in C. This we have to suppose
a known and admitted impossibility; and we then infer that A
cannot inhere in B. Thus if the inherence of B in C is not
questioned, As inherence in B is impossible.
The order of the terms is the same in both proofs: they differ
according to which of the negative propositions is the better
known, the one denying A of B or the one denying A of C. When
the falsity of the conclusion is the better known, we use
reductio ad impossible; when the major premiss of the
syllogism is the more obvious, we use direct demonstration. All
the same the proposition denying A of B is, in the order of being,
prior to that denying A of C; for premisses are prior to the
conclusion which follows from them, and 'no C is A is the
conclusion, 'no B is A one of its premisses. For the destructive
result of reductio ad impossibile is not a proper conclusion, nor
are its antecedents proper premisses. On the contrary: the
constituents of syllogism are premisses related to one another
as whole to part or part to whole, whereas the premisses A-C
and A-B are not thus related to one another. Now the superior
demonstration is that which proceeds from better known and
prior premisses, and while both these forms depend for
credence on the not-being of something, yet the source of the
one is prior to that of the other. Therefore negative
demonstration will have an unqualified superiority to reductio
ad impossibile, and affirmative demonstration, being superior to
negative, will consequently be superior also to reductio ad
impossibile.
278
27
The science which is knowledge at once of the fact and of the
reasoned fact, not of the fact by itself without the reasoned fact,
is the more exact and the prior science.
A science such as arithmetic, which is not a science of
properties qua inhering in a substratum, is more exact than and
prior to a science like harmonics, which is a science of
properties inhering in a substratum; and similarly a science like
arithmetic, which is constituted of fewer basic elements, is
more exact than and prior to geometry, which requires
additional elements. What I mean by 'additional elements' is
this: a unit is substance without position, while a point is
substance with position; the latter contains an additional
element.
28
A single science is one whose domain is a single genus, viz. all
the subjects constituted out of the primary entities of the genus
- i.e. the parts of this total subject - and their essential
properties.
One science differs from another when their basic truths have
neither a common source nor are derived those of the one
science from those the other. This is verified when we reach the
indemonstrable premisses of a science, for they must be within
one genus with its conclusions: and this again is verified if the
conclusions proved by means of them fall within one genus -
i.e. are homogeneous.
279
29
One can have several demonstrations of the same connexion
not only by taking from the same series of predication middles
which are other than the immediately cohering term e.g. by
taking C, D, and F severally to prove A-B - but also by taking a
middle from another series. Thus let A be change, D alteration
of a property, B feeling pleasure, and G relaxation. We can then
without falsehood predicate D of B and A of D, for he who is
pleased suffers alteration of a property, and that which alters a
property changes. Again, we can predicate A of G without
falsehood, and G of B; for to feel pleasure is to relax, and to relax
is to change. So the conclusion can be drawn through middles
which are different, i.e. not in the same series - yet not so that
neither of these middles is predicable of the other, for they must
both be attributable to some one subject.
A further point worth investigating is how many ways of
proving the same conclusion can be obtained by varying the
figure.
30
There is no knowledge by demonstration of chance
conjunctions; for chance conjunctions exist neither by necessity
nor as general connexions but comprise what comes to be as
something distinct from these. Now demonstration is
concerned only with one or other of these two; for all reasoning
proceeds from necessary or general premisses, the conclusion
being necessary if the premisses are necessary and general if
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the premisses are general. Consequently, if chance conjunctions
are neither general nor necessary, they are not demonstrable.
31
Scientific knowledge is not possible through the act of
perception. Even if perception as a faculty is of 'the such' and
not merely of a 'this somewhat', yet one must at any rate
actually perceive a 'this somewhat', and at a definite present
place and time: but that which is commensurately universal
and true in all cases one cannot perceive, since it is not 'this'
and it is not 'now'; if it were, it would not be commensurately
universal - the term we apply to what is always and
everywhere. Seeing, therefore, that demonstrations are
commensurately universal and universals imperceptible, we
clearly cannot obtain scientific knowledge by the act of
perception: nay, it is obvious that even if it were possible to
perceive that a triangle has its angles equal to two right angles,
we should still be looking for a demonstration - we should not
(as some say) possess knowledge of it; for perception must be of
a particular, whereas scientific knowledge involves the
recognition of the commensurate universal. So if we were on
the moon, and saw the earth shutting out the sun's light, we
should not know the cause of the eclipse: we should perceive
the present fact of the eclipse, but not the reasoned fact at all,
since the act of perception is not of the commensurate
universal. I do not, of course, deny that by watching the
frequent recurrence of this event we might, after tracking the
commensurate universal, possess a demonstration, for the
commensurate universal is elicited from the several groups of
singulars.
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The commensurate universal is precious because it makes clear
the cause; so that in the case of facts like these which have a
cause other than themselves universal knowledge is more
precious than sense-perceptions and than intuition. (As regards
primary truths there is of course a different account to be
given.) Hence it is clear that knowledge of things demonstrable
cannot be acquired by perception, unless the term perception is
applied to the possession of scientific knowledge through
demonstration. Nevertheless certain points do arise with regard
to connexions to be proved which are referred for their
explanation to a failure in sense-perception: there are cases
when an act of vision would terminate our inquiry, not because
in seeing we should be knowing, but because we should have
elicited the universal from seeing; if, for example, we saw the
pores in the glass and the light passing through, the reason of
the kindling would be clear to us because we should at the
same time see it in each instance and intuit that it must be so
in all instances.
32
All syllogisms cannot have the same basic truths. This may be
shown first of all by the following dialectical considerations. (1)
Some syllogisms are true and some false: for though a true
inference is possible from false premisses, yet this occurs once
only - I mean if A for instance, is truly predicable of C, but B, the
middle, is false, both A-B and B-C being false; nevertheless, if
middles are taken to prove these premisses, they will be false
because every conclusion which is a falsehood has false
premisses, while true conclusions have true premisses, and
false and true differ in kind. Then again, (2) falsehoods are not
all derived from a single identical set of principles: there are
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falsehoods which are the contraries of one another and cannot
coexist, e.g. 'justice is injustice', and 'justice is cowardice'; 'man
is horse', and 'man is ox'; 'the equal is greater', and 'the equal is
less.' From established principles we may argue the case as
follows, confining ourselves therefore to true conclusions. Not
even all these are inferred from the same basic truths; many of
them in fact have basic truths which differ generically and are
not transferable; units, for instance, which are without position,
cannot take the place of points, which have position. The
transferred terms could only fit in as middle terms or as major
or minor terms, or else have some of the other terms between
them, others outside them.
Nor can any of the common axioms - such, I mean, as the law
of excluded middle - serve as premisses for the proof of all
conclusions. For the kinds of being are different, and some
attributes attach to quanta and some to qualia only; and proof
is achieved by means of the common axioms taken in
conjunction with these several kinds and their attributes.
Again, it is not true that the basic truths are much fewer than
the conclusions, for the basic truths are the premisses, and the
premisses are formed by the apposition of a fresh extreme term
or the interposition of a fresh middle. Moreover, the number of
conclusions is indefinite, though the number of middle terms is
finite; and lastly some of the basic truths are necessary, others
variable.
Looking at it in this way we see that, since the number of
conclusions is indefinite, the basic truths cannot be identical or
limited in number. If, on the other hand, identity is used in
another sense, and it is said, e.g. 'these and no other are the
fundamental truths of geometry, these the fundamentals of
calculation, these again of medicine'; would the statement
mean anything except that the sciences have basic truths? To
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call them identical because they are self-identical is absurd,
since everything can be identified with everything in that sense
of identity. Nor again can the contention that all conclusions
have the same basic truths mean that from the mass of all
possible premisses any conclusion may be drawn. That would
be exceedingly naive, for it is not the case in the clearly evident
mathematical sciences, nor is it possible in analysis, since it is
the immediate premisses which are the basic truths, and a
fresh conclusion is only formed by the addition of a new
immediate premiss: but if it be admitted that it is these primary
immediate premisses which are basic truths, each subject-
genus will provide one basic truth. If, however, it is not argued
that from the mass of all possible premisses any conclusion
may be proved, nor yet admitted that basic truths differ so as to
be generically different for each science, it remains to consider
the possibility that, while the basic truths of all knowledge are
within one genus, special premisses are required to prove
special conclusions. But that this cannot be the case has been
shown by our proof that the basic truths of things generically
different themselves differ generically. For fundamental truths
are of two kinds, those which are premisses of demonstration
and the subject-genus; and though the former are common, the
latter - number, for instance, and magnitude - are peculiar.
33
Scientific knowledge and its object differ from opinion and the
object of opinion in that scientific knowledge is
commensurately universal and proceeds by necessary
connexions, and that which is necessary cannot be otherwise.
So though there are things which are true and real and yet can
be otherwise, scientific knowledge clearly does not concern
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them: if it did, things which can be otherwise would be
incapable of being otherwise. Nor are they any concern of
rational intuition - by rational intuition I mean an originative
source of scientific knowledge - nor of indemonstrable
knowledge, which is the grasping of the immediate premiss.
Since then rational intuition, science, and opinion, and what is
revealed by these terms, are the only things that can be 'true', it
follows that it is opinion that is concerned with that which may
be true or false, and can be otherwise: opinion in fact is the
grasp of a premiss which is immediate but not necessary. This
view also fits the observed facts, for opinion is unstable, and so
is the kind of being we have described as its object. Besides,
when a man thinks a truth incapable of being otherwise he
always thinks that he knows it, never that he opines it. He
thinks that he opines when he thinks that a connexion, though
actually so, may quite easily be otherwise; for he believes that
such is the proper object of opinion, while the necessary is the
object of knowledge.
In what sense, then, can the same thing be the object of both
opinion and knowledge? And if any one chooses to maintain
that all that he knows he can also opine, why should not
opinion be knowledge? For he that knows and he that opines
will follow the same train of thought through the same middle
terms until the immediate premisses are reached; because it is
possible to opine not only the fact but also the reasoned fact,
and the reason is the middle term; so that, since the former
knows, he that opines also has knowledge.
The truth perhaps is that if a man grasp truths that cannot be
other than they are, in the way in which he grasps the
definitions through which demonstrations take place, he will
have not opinion but knowledge: if on the other hand he
apprehends these attributes as inhering in their subjects, but
not in virtue of the subjects' substance and essential nature
285
possesses opinion and not genuine knowledge; and his opinion,
if obtained through immediate premisses, will be both of the
fact and of the reasoned fact; if not so obtained, of the fact
alone. The object of opinion and knowledge is not quite
identical; it is only in a sense identical, just as the object of true
and false opinion is in a sense identical. The sense in which
some maintain that true and false opinion can have the same
object leads them to embrace many strange doctrines,
particularly the doctrine that what a man opines falsely he does
not opine at all. There are really many senses of 'identical', and
in one sense the object of true and false opinion can be the
same, in another it cannot. Thus, to have a true opinion that the
diagonal is commensurate with the side would be absurd: but
because the diagonal with which they are both concerned is the
same, the two opinions have objects so far the same: on the
other hand, as regards their essential definable nature these
objects differ. The identity of the objects of knowledge and
opinion is similar. Knowledge is the apprehension of, e.g. the
attribute 'animal' as incapable of being otherwise, opinion the
apprehension of 'animal' as capable of being otherwise - e.g. the
apprehension that animal is an element in the essential nature
of man is knowledge; the apprehension of animal as predicable
of man but not as an element in man's essential nature is
opinion: man is the subject in both judgements, but the mode
of inherence differs.
This also shows that one cannot opine and know the same
thing simultaneously; for then one would apprehend the same
thing as both capable and incapable of being otherwise - an
impossibility. Knowledge and opinion of the same thing can co-
exist in two different people in the sense we have explained,
but not simultaneously in the same person. That would involve
a man's simultaneously apprehending, e.g. (1) that man is
essentially animal - i.e. cannot be other than animal - and (2)
286
that man is not essentially animal, that is, we may assume, may
be other than animal.
Further consideration of modes of thinking and their
distribution under the heads of discursive thought, intuition,
science, art, practical wisdom, and metaphysical thinking,
belongs rather partly to natural science, partly to moral
philosophy.
34
Quick wit is a faculty of hitting upon the middle term
instantaneously. It would be exemplified by a man who saw
that the moon has her bright side always turned towards the
sun, and quickly grasped the cause of this, namely that she
borrows her light from him; or observed somebody in
conversation with a man of wealth and divined that he was
borrowing money, or that the friendship of these people sprang
from a common enmity. In all these instances he has seen the
major and minor terms and then grasped the causes, the
middle terms.
Let A represent 'bright side turned sunward', B 'lighted from the
sun', C the moon. Then B, 'lighted from the sun' is predicable of
C, the moon, and A, 'having her bright side towards the source
of her light', is predicable of B. So A is predicable of C through B.
287
Book II
The kinds of question we ask are as many as the kinds of things
which we know. They are in fact four: - (1) whether the
connexion of an attribute with a thing is a fact, (2) what is the
reason of the connexion, (3) whether a thing exists, (4) What is
the nature of the thing. Thus, when our question concerns a
complex of thing and attribute and we ask whether the thing is
thus or otherwise qualified - whether, e.g. the sun suffers
eclipse or not - then we are asking as to the fact of a connexion.
That our inquiry ceases with the discovery that the sun does
suffer eclipse is an indication of this; and if we know from the
start that the sun suffers eclipse, we do not inquire whether it
does so or not. On the other hand, when we know the fact we
ask the reason; as, for example, when we know that the sun is
being eclipsed and that an earthquake is in progress, it is the
reason of eclipse or earthquake into which we inquire.
Where a complex is concerned, then, those are the two
questions we ask; but for some objects of inquiry we have a
different kind of question to ask, such as whether there is or is
not a centaur or a God. (By 'is or is not' I mean 'is or is not,
without further qualification'; as opposed to 'is or is not [e.g.]
white'.) On the other hand, when we have ascertained the
thing's existence, we inquire as to its nature, asking, for
instance, 'what, then, is God?' or 'what is man?'.
288
These, then, are the four kinds of question we ask, and it is in
the answers to these questions that our knowledge consists.
Now when we ask whether a connexion is a fact, or whether a
thing without qualification is, we are really asking whether the
connexion or the thing has a 'middle'; and when we have
ascertained either that the connexion is a fact or that the thing
is - i.e. ascertained either the partial or the unqualified being of
the thing-and are proceeding to ask the reason of the connexion
or the nature of the thing, then we are asking what the 'middle'
is.
(By distinguishing the fact of the connexion and the existence
of the thing as respectively the partial and the unqualified being
of the thing, I mean that if we ask 'does the moon suffer
eclipse?', or 'does the moon wax?', the question concerns a part
of the thing's being; for what we are asking in such questions is
whether a thing is this or that, i.e. has or has not this or that
attribute: whereas, if we ask whether the moon or night exists,
the question concerns the unqualified being of a thing.)
We conclude that in all our inquiries we are asking either
whether there is a 'middle' or what the 'middle' is: for the
'middle' here is precisely the cause, and it is the cause that we
seek in all our inquiries. Thus, 'Does the moon suffer eclipse?'
means 'Is there or is there not a cause producing eclipse of the
moon?', and when we have learnt that there is, our next
question is, 'What, then, is this cause? for the cause through
which a thing is - not is this or that, i.e. has this or that
attribute, but without qualification is - and the cause through
which it is - not is without qualification, but is this or that as
having some essential attribute or some accident - are both
alike the middle'. By that which is without qualification I mean
the subject, e.g. moon or earth or sun or triangle; by that which
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a subject is (in the partial sense) I mean a property, e.g. eclipse,
equality or inequality, interposition or non-interposition. For in
all these examples it is clear that the nature of the thing and
the reason of the fact are identical: the question 'What is
eclipse?' and its answer 'The privation of the moon's light by the
interposition of the earth' are identical with the question 'What
is the reason of eclipse?' or 'Why does the moon suffer eclipse?'
and the reply 'Because of the failure of light through the earth's
shutting it out'. Again, for 'What is a concord? A commensurate
numerical ratio of a high and a low note', we may substitute
'What ratio makes a high and a low note concordant? Their
relation according to a commensurate numerical ratio.' 'Are the
high and the low note concordant?' is equivalent to 'Is their
ratio commensurate?'; and when we find that it is
commensurate, we ask 'What, then, is their ratio?'.
Cases in which the 'middle' is sensible show that the object of
our inquiry is always the 'middle': we inquire, because we have
not perceived it, whether there is or is not a 'middle' causing,
e.g. an eclipse. On the other hand, if we were on the moon we
should not be inquiring either as to the fact or the reason, but
both fact and reason would be obvious simultaneously. For the
act of perception would have enabled us to know the universal
too; since, the present fact of an eclipse being evident,
perception would then at the same time give us the present fact
of the earth's screening the sun's light, and from this would
arise the universal.
Thus, as we maintain, to know a thing's nature is to know the
reason why it is; and this is equally true of things in so far as
they are said without qualification to he as opposed to being
possessed of some attribute, and in so far as they are said to be
possessed of some attribute such as equal to right angles, or
greater or less.
290
It is clear, then, that all questions are a search for a 'middle'. Let
us now state how essential nature is revealed and in what way
it can be reduced to demonstration; what definition is, and
what things are definable. And let us first discuss certain
difficulties which these questions raise, beginning what we
have to say with a point most intimately connected with our
immediately preceding remarks, namely the doubt that might
be felt as to whether or not it is possible to know the same thing
in the same relation, both by definition and by demonstration. It
might, I mean, be urged that definition is held to concern
essential nature and is in every case universal and affirmative;
whereas, on the other hand, some conclusions are negative and
some are not universal; e.g. all in the second figure are negative,
none in the third are universal. And again, not even all
affirmative conclusions in the first figure are definable, e.g.
'every triangle has its angles equal to two right angles'. An
argument proving this difference between demonstration and
definition is that to have scientific knowledge of the
demonstrable is identical with possessing a demonstration of it:
hence if demonstration of such conclusions as these is possible,
there clearly cannot also be definition of them. If there could,
one might know such a conclusion also in virtue of its
definition without possessing the demonstration of it; for there
is nothing to stop our having the one without the other.
Induction too will sufficiently convince us of this difference; for
never yet by defining anything - essential attribute or accident -
did we get knowledge of it. Again, if to define is to acquire
knowledge of a substance, at any rate such attributes are not
substances.
291
It is evident, then, that not everything demonstrable can be
defined. What then? Can everything definable be demonstrated,
or not? There is one of our previous arguments which covers
this too. Of a single thing qua single there is a single scientific
knowledge. Hence, since to know the demonstrable
scientifically is to possess the demonstration of it, an
impossible consequence will follow: - possession of its
definition without its demonstration will give knowledge of the
demonstrable.
Moreover, the basic premisses of demonstrations are
definitions, and it has already been shown that these will be
found indemonstrable; either the basic premisses will be
demonstrable and will depend on prior premisses, and the
regress will be endless; or the primary truths will be
indemonstrable definitions.
But if the definable and the demonstrable are not wholly the
same, may they yet be partially the same? Or is that impossible,
because there can be no demonstration of the definable? There
can be none, because definition is of the essential nature or
being of something, and all demonstrations evidently posit and
assume the essential nature - mathematical demonstrations,
for example, the nature of unity and the odd, and all the other
sciences likewise. Moreover, every demonstration proves a
predicate of a subject as attaching or as not attaching to it, but
in definition one thing is not predicated of another; we do not,
e.g. predicate animal of biped nor biped of animal, nor yet figure
of plane - plane not being figure nor figure plane. Again, to
prove essential nature is not the same as to prove the fact of a
connexion. Now definition reveals essential nature,
demonstration reveals that a given attribute attaches or does
not attach to a given subject; but different things require
different demonstrations - unless the one demonstration is
related to the other as part to whole. I add this because if all
292
triangles have been proved to possess angles equal to two right
angles, then this attribute has been proved to attach to
isosceles; for isosceles is a part of which all triangles constitute
the whole. But in the case before us the fact and the essential
nature are not so related to one another, since the one is not a
part of the other.
So it emerges that not all the definable is demonstrable nor all
the demonstrable definable; and we may draw the general
conclusion that there is no identical object of which it is
possible to possess both a definition and a demonstration. It
follows obviously that definition and demonstration are neither
identical nor contained either within the other: if they were,
their objects would be related either as identical or as whole
and part.
So much, then, for the first stage of our problem. The next step
is to raise the question whether syllogism - i.e. demonstration -
of the definable nature is possible or, as our recent argument
assumed, impossible.
We might argue it impossible on the following grounds: - (a)
syllogism proves an attribute of a subject through the middle
term; on the other hand (b) its definable nature is both 'peculiar'
to a subject and predicated of it as belonging to its essence. But
in that case (1) the subject, its definition, and the middle term
connecting them must be reciprocally predicable of one
another; for if A is to C, obviously A is 'peculiar' to B and B to C -
in fact all three terms are 'peculiar' to one another: and further
(2) if A inheres in the essence of all B and B is predicated
293
universally of all C as belonging to C's essence, A also must be
predicated of C as belonging to its essence.
If one does not take this relation as thus duplicated - if, that is,
A is predicated as being of the essence of B, but B is not of the
essence of the subjects of which it is predicated - A will not
necessarily be predicated of C as belonging to its essence. So
both premisses will predicate essence, and consequently B also
will be predicated of C as its essence. Since, therefore, both
premisses do predicate essence - i.e. definable form - C's
definable form will appear in the middle term before the
conclusion is drawn.
We may generalize by supposing that it is possible to prove the
essential nature of man. Let C be man, A man's essential nature
- two-footed animal, or aught else it may be. Then, if we are to
syllogize, A must be predicated of all B. But this premiss will be
mediated by a fresh definition, which consequently will also be
the essential nature of man. Therefore the argument assumes
what it has to prove, since B too is the essential nature of man.
It is, however, the case in which there are only the two
premisses - i.e. in which the premisses are primary and
immediate - which we ought to investigate, because it best
illustrates the point under discussion.
Thus they who prove the essential nature of soul or man or
anything else through reciprocating terms beg the question. It
would be begging the question, for example, to contend that the
soul is that which causes its own life, and that what causes its
own life is a self-moving number; for one would have to
postulate that the soul is a self-moving number in the sense of
being identical with it. For if A is predicable as a mere
consequent of B and B of C, A will not on that account be the
definable form of C: A will merely be what it was true to say of
C. Even if A is predicated of all B inasmuch as B is identical with
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a species of A, still it will not follow: being an animal is
predicated of being a man - since it is true that in all instances
to be human is to be animal, just as it is also true that every
man is an animal - but not as identical with being man.
We conclude, then, that unless one takes both the premisses as
predicating essence, one cannot infer that A is the definable
form and essence of C: but if one does so take them, in
assuming B one will have assumed, before drawing the
conclusion, what the definable form of C is; so that there has
been no inference, for one has begged the question.
Nor, as was said in my formal logic, is the method of division a
process of inference at all, since at no point does the
characterization of the subject follow necessarily from the
premising of certain other facts: division demonstrates as little
as does induction. For in a genuine demonstration the
conclusion must not be put as a question nor depend on a
concession, but must follow necessarily from its premisses,
even if the respondent deny it. The definer asks 'Is man animal
or inanimate?' and then assumes - he has not inferred - that
man is animal. Next, when presented with an exhaustive
division of animal into terrestrial and aquatic, he assumes that
man is terrestrial. Moreover, that man is the complete formula,
terrestrial-animal, does not follow necessarily from the
premisses: this too is an assumption, and equally an
assumption whether the division comprises many differentiae
or few. (Indeed as this method of division is used by those who
proceed by it, even truths that can be inferred actually fail to
appear as such.) For why should not the whole of this formula
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be true of man, and yet not exhibit his essential nature or
definable form? Again, what guarantee is there against an
unessential addition, or against the omission of the final or of
an intermediate determinant of the substantial being?
The champion of division might here urge that though these
lapses do occur, yet we can solve that difficulty if all the
attributes we assume are constituents of the definable form,
and if, postulating the genus, we produce by division the
requisite uninterrupted sequence of terms, and omit nothing;
and that indeed we cannot fail to fulfil these conditions if what
is to be divided falls whole into the division at each stage, and
none of it is omitted; and that this - the dividendum - must
without further question be (ultimately) incapable of fresh
specific division. Nevertheless, we reply, division does not
involve inference; if it gives knowledge, it gives it in another
way. Nor is there any absurdity in this: induction, perhaps, is
not demonstration any more than is division, et it does make
evident some truth. Yet to state a definition reached by division
is not to state a conclusion: as, when conclusions are drawn
without their appropriate middles, the alleged necessity by
which the inference follows from the premisses is open to a
question as to the reason for it, so definitions reached by
division invite the same question.
Thus to the question 'What is the essential nature of man?' the
divider replies 'Animal, mortal, footed, biped, wingless'; and
when at each step he is asked 'Why?', he will say, and, as he
thinks, proves by division, that all animal is mortal or immortal:
but such a formula taken in its entirety is not definition; so that
even if division does demonstrate its formula, definition at any
rate does not turn out to be a conclusion of inference.
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Can we nevertheless actually demonstrate what a thing
essentially and substantially is, but hypothetically, i.e. by
premising (1) that its definable form is constituted by the
'peculiar' attributes of its essential nature; (2) that such and
such are the only attributes of its essential nature, and that the
complete synthesis of them is peculiar to the thing; and thus -
since in this synthesis consists the being of the thing -
obtaining our conclusion? Or is the truth that, since proof must
be through the middle term, the definable form is once more
assumed in this minor premiss too?
Further, just as in syllogizing we do not premise what syllogistic
inference is (since the premisses from which we conclude must
be related as whole and part), so the definable form must not
fall within the syllogism but remain outside the premisses
posited. It is only against a doubt as to its having been a
syllogistic inference at all that we have to defend our argument
as conforming to the definition of syllogism. It is only when
some one doubts whether the conclusion proved is the
definable form that we have to defend it as conforming to the
definition of definable form which we assumed. Hence
syllogistic inference must be possible even without the express
statement of what syllogism is or what definable form is.
The following type of hypothetical proof also begs the question.
If evil is definable as the divisible, and the definition of a thing's
contrary - if it has one the contrary of the thing's definition;
then, if good is the contrary of evil and the indivisible of the
divisible, we conclude that to be good is essentially to be
indivisible. The question is begged because definable form is
assumed as a premiss, and as a premiss which is to prove
definable form. 'But not the same definable form', you may
object. That I admit, for in demonstrations also we premise that
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'this' is predicable of 'that'; but in this premiss the term we
assert of the minor is neither the major itself nor a term
identical in definition, or convertible, with the major.
Again, both proof by division and the syllogism just described
are open to the question why man should be animal-biped-
terrestrial and not merely animal and terrestrial, since what
they premise does not ensure that the predicates shall
constitute a genuine unity and not merely belong to a single
subject as do musical and grammatical when predicated of the
same man.
How then by definition shall we prove substance or essential
nature? We cannot show it as a fresh fact necessarily following
from the assumption of premisses admitted to be facts - the
method of demonstration: we may not proceed as by induction
to establish a universal on the evidence of groups of particulars
which offer no exception, because induction proves not what
the essential nature of a thing is but that it has or has not some
attribute. Therefore, since presumably one cannot prove
essential nature by an appeal to sense perception or by pointing
with the finger, what other method remains?
To put it another way: how shall we by definition prove
essential nature? He who knows what human - or any other -
nature is, must know also that man exists; for no one knows the
nature of what does not exist - one can know the meaning of
the phrase or name 'goat-stag' but not what the essential
nature of a goat-stag is. But further, if definition can prove what
is the essential nature of a thing, can it also prove that it exists?
And how will it prove them both by the same process, since
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definition exhibits one single thing and demonstration another
single thing, and what human nature is and the fact that man
exists are not the same thing? Then too we hold that it is by
demonstration that the being of everything must be proved -
unless indeed to be were its essence; and, since being is not a
genus, it is not the essence of anything. Hence the being of
anything as fact is matter for demonstration; and this is the
actual procedure of the sciences, for the geometer assumes the
meaning of the word triangle, but that it is possessed of some
attribute he proves. What is it, then, that we shall prove in
defining essential nature? Triangle? In that case a man will
know by definition what a thing's nature is without knowing
whether it exists. But that is impossible.
Moreover it is clear, if we consider the methods of defining
actually in use, that definition does not prove that the thing
defined exists: since even if there does actually exist something
which is equidistant from a centre, yet why should the thing
named in the definition exist? Why, in other words, should this
be the formula defining circle? One might equally well call it the
definition of mountain copper. For definitions do not carry a
further guarantee that the thing defined can exist or that it is
what they claim to define: one can always ask why.
Since, therefore, to define is to prove either a thing's essential
nature or the meaning of its name, we may conclude that
definition, if it in no sense proves essential nature, is a set of
words signifying precisely what a name signifies. But that were
a strange consequence; for (1) both what is not substance and
what does not exist at all would be definable, since even non-
existents can be signified by a name: (2) all sets of words or
sentences would be definitions, since any kind of sentence
could be given a name; so that we should all be talking in
definitions, and even the Iliad would be a definition: (3) no
demonstration can prove that any particular name means any
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particular thing: neither, therefore, do definitions, in addition to
revealing the meaning of a name, also reveal that the name has
this meaning. It appears then from these considerations that
neither definition and syllogism nor their objects are identical,
and further that definition neither demonstrates nor proves
anything, and that knowledge of essential nature is not to be
obtained either by definition or by demonstration.
8
We must now start afresh and consider which of these
conclusions are sound and which are not, and what is the
nature of definition, and whether essential nature is in any
sense demonstrable and definable or in none.
Now to know its essential nature is, as we said, the same as to
know the cause of a thing's existence, and the proof of this
depends on the fact that a thing must have a cause. Moreover,
this cause is either identical with the essential nature of the
thing or distinct from it; and if its cause is distinct from it, the
essential nature of the thing is either demonstrable or
indemonstrable. Consequently, if the cause is distinct from the
thing's essential nature and demonstration is possible, the
cause must be the middle term, and, the conclusion proved
being universal and affirmative, the proof is in the first figure.
So the method just examined of proving it through another
essential nature would be one way of proving essential nature,
because a conclusion containing essential nature must be
inferred through a middle which is an essential nature just as a
'peculiar' property must be inferred through a middle which is a
'peculiar' property; so that of the two definable natures of a
single thing this method will prove one and not the other.
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Now it was said before that this method could not amount to
demonstration of essential nature - it is actually a dialectical
proof of it - so let us begin again and explain by what method it
can be demonstrated. When we are aware of a fact we seek its
reason, and though sometimes the fact and the reason dawn on
us simultaneously, yet we cannot apprehend the reason a
moment sooner than the fact; and clearly in just the same way
we cannot apprehend a thing's definable form without
apprehending that it exists, since while we are ignorant
whether it exists we cannot know its essential nature. Moreover
we are aware whether a thing exists or not sometimes through
apprehending an element in its character, and sometimes
accidentally, as, for example, when we are aware of thunder as a
noise in the clouds, of eclipse as a privation of light, or of man
as some species of animal, or of the soul as a self-moving thing.
As often as we have accidental knowledge that the thing exists,
we must be in a wholly negative state as regards awareness of
its essential nature; for we have not got genuine knowledge
even of its existence, and to search for a thing's essential nature
when we are unaware that it exists is to search for nothing. On
the other hand, whenever we apprehend an element in the
thing's character there is less difficulty. Thus it follows that the
degree of our knowledge of a thing's essential nature is
determined by the sense in which we are aware that it exists.
Let us then take the following as our first instance of being
aware of an element in the essential nature. Let A be eclipse, C
the moon, B the earth's acting as a screen. Now to ask whether
the moon is eclipsed or not is to ask whether or not B has
occurred. But that is precisely the same as asking whether A has
a defining condition; and if this condition actually exists, we
assert that A also actually exists. Or again we may ask which
side of a contradiction the defining condition necessitates: does
it make the angles of a triangle equal or not equal to two right
angles? When we have found the answer, if the premisses are
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immediate, we know fact and reason together; if they are not
immediate, we know the fact without the reason, as in the
following example: let C be the moon, A eclipse, B the fact that
the moon fails to produce shadows though she is full and
though no visible body intervenes between us and her. Then if
B, failure to produce shadows in spite of the absence of an
intervening body, is attributable A to C, and eclipse, is
attributable to B, it is clear that the moon is eclipsed, but the
reason why is not yet clear, and we know that eclipse exists, but
we do not know what its essential nature is. But when it is clear
that A is attributable to C and we proceed to ask the reason of
this fact, we are inquiring what is the nature of B: is it the
earth's acting as a screen, or the moon's rotation or her
extinction? But B is the definition of the other term, viz. in these
examples, of the major term A; for eclipse is constituted by the
earth acting as a screen. Thus, (1) 'What is thunder?' 'The
quenching of fire in cloud', and (2) 'Why does it thunder?'
'Because fire is quenched in the cloud', are equivalent. Let C be
cloud, A thunder, B the quenching of fire. Then B is attributable
to C, cloud, since fire is quenched in it; and A, noise, is
attributable to B; and B is assuredly the definition of the major
term A. If there be a further mediating cause of B, it will be one
of the remaining partial definitions of A.
We have stated then how essential nature is discovered and
becomes known, and we see that, while there is no syllogism -
i.e. no demonstrative syllogism - of essential nature, yet it is
through syllogism, viz. demonstrative syllogism, that essential
nature is exhibited. So we conclude that neither can the
essential nature of anything which has a cause distinct from
itself be known without demonstration, nor can it be
demonstrated; and this is what we contended in our
preliminary discussions.
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Now while some things have a cause distinct from themselves,
others have not. Hence it is evident that there are essential
natures which are immediate, that is are basic premisses; and
of these not only that they are but also what they are must be
assumed or revealed in some other way. This too is the actual
procedure of the arithmetician, who assumes both the nature
and the existence of unit. On the other hand, it is possible (in
the manner explained) to exhibit through demonstration the
essential nature of things which have a 'middle', i.e. a cause of
their substantial being other than that being itself; but we do
not thereby demonstrate it.
10
Since definition is said to be the statement of a thing's nature,
obviously one kind of definition will be a statement of the
meaning of the name, or of an equivalent nominal formula. A
definition in this sense tells you, e.g. the meaning of the phrase
'triangular character'. When we are aware that triangle exists,
we inquire the reason why it exists. But it is difficult thus to
learn the definition of things the existence of which we do not
genuinely know - the cause of this difficulty being, as we said
before, that we only know accidentally whether or not the thing
exists. Moreover, a statement may be a unity in either of two
ways, by conjunction, like the Iliad, or because it exhibits a
single predicate as inhering not accidentally in a single subject.
That then is one way of defining definition. Another kind of
definition is a formula exhibiting the cause of a thing's
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existence. Thus the former signifies without proving, but the
latter will clearly be a quasi-demonstration of essential nature,
differing from demonstration in the arrangement of its terms.
For there is a difference between stating why it thunders, and
stating what is the essential nature of thunder; since the first
statement will be 'Because fire is quenched in the clouds', while
the statement of what the nature of thunder is will be 'The
noise of fire being quenched in the clouds'. Thus the same
statement takes a different form: in one form it is continuous
demonstration, in the other definition. Again, thunder can be
defined as noise in the clouds, which is the conclusion of the
demonstration embodying essential nature. On the other hand
the definition of immediates is an indemonstrable positing of
essential nature.
We conclude then that definition is (a) an indemonstrable
statement of essential nature, or (b) a syllogism of essential
nature differing from demonstration in grammatical form, or (c)
the conclusion of a demonstration giving essential nature.
Our discussion has therefore made plain (1) in what sense and
of what things the essential nature is demonstrable, and in
what sense and of what things it is not; (2) what are the various
meanings of the term definition, and in what sense and of what
things it proves the essential nature, and in what sense and of
what things it does not; (3) what is the relation of definition to
demonstration, and how far the same thing is both definable
and demonstrable and how far it is not.
11
We think we have scientific knowledge when we know the
cause, and there are four causes: (1) the definable form, (2) an
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antecedent which necessitates a consequent, (3) the efficient
cause, (4) the final cause. Hence each of these can be the middle
term of a proof, for (a) though the inference from antecedent to
necessary consequent does not hold if only one premiss is
assumed - two is the minimum - still when there are two it
holds on condition that they have a single common middle
term. So it is from the assumption of this single middle term
that the conclusion follows necessarily. The following example
will also show this. Why is the angle in a semicircle a right
angle? - or from what assumption does it follow that it is a right
angle? Thus, let A be right angle, B the half of two right angles, C
the angle in a semicircle. Then B is the cause in virtue of which
A, right angle, is attributable to C, the angle in a semicircle,
since B=A and the other, viz. C,=B, for C is half of two right
angles. Therefore it is the assumption of B, the half of two right
angles, from which it follows that A is attributable to C, i.e. that
the angle in a semicircle is a right angle. Moreover, B is identical
with (b) the defining form of A, since it is what As definition
signifies. Moreover, the formal cause has already been shown to
be the middle, (c) 'Why did the Athenians become involved in
the Persian war?' means 'What cause originated the waging of
war against the Athenians?' and the answer is, 'Because they
raided Sardis with the Eretrians', since this originated the war.
Let A be war, B unprovoked raiding, C the Athenians. Then B,
unprovoked raiding, is true of C, the Athenians, and A is true of
B, since men make war on the unjust aggressor. So A, having
war waged upon them, is true of B, the initial aggressors, and B
is true of C, the Athenians, who were the aggressors. Hence here
too the cause - in this case the efficient cause - is the middle
term, (d) This is no less true where the cause is the final cause.
E.g. why does one take a walk after supper? For the sake of one's
health. Why does a house exist? For the preservation of one's
goods. The end in view is in the one case health, in the other
preservation. To ask the reason why one must walk after supper
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is precisely to ask to what end one must do it. Let C be walking
after supper, B the non-regurgitation of food, A health. Then let
walking after supper possess the property of preventing food
from rising to the orifice of the stomach, and let this condition
be healthy; since it seems that B, the non-regurgitation of food,
is attributable to C, taking a walk, and that A, health, is
attributable to B. What, then, is the cause through which A, the
final cause, inheres in C? It is B, the non-regurgitation of food;
but B is a kind of definition of A, for A will be explained by it.
Why is B the cause of A's belonging to C? Because to be in a
condition such as B is to be in health. The definitions must be
transposed, and then the detail will become clearer.
Incidentally, here the order of coming to be is the reverse of
what it is in proof through the efficient cause: in the efficient
order the middle term must come to be first, whereas in the
teleological order the minor, C, must first take place, and the
end in view comes last in time.
The same thing may exist for an end and be necessitated as
well. For example, light shines through a lantern (1) because
that which consists of relatively small particles necessarily
passes through pores larger than those particles - assuming
that light does issue by penetration - and (2) for an end, namely
to save us from stumbling. If then, a thing can exist through two
causes, can it come to be through two causes - as for instance if
thunder be a hiss and a roar necessarily produced by the
quenching of fire, and also designed, as the Pythagoreans say,
for a threat to terrify those that lie in Tartarus? Indeed, there are
very many such cases, mostly among the processes and
products of the natural world; for nature, in different senses of
the term 'nature', produces now for an end, now by necessity.
Necessity too is of two kinds. It may work in accordance with a
thing's natural tendency, or by constraint and in opposition to it;
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as, for instance, by necessity a stone is borne both upwards and
downwards, but not by the same necessity.
Of the products of man's intelligence some are never due to
chance or necessity but always to an end, as for example a
house or a statue; others, such as health or safety, may result
from chance as well.
It is mostly in cases where the issue is indeterminate (though
only where the production does not originate in chance, and the
end is consequently good), that a result is due to an end, and
this is true alike in nature or in art. By chance, on the other
hand, nothing comes to be for an end.
12
The effect may be still coming to be, or its occurrence may be
past or future, yet the cause will be the same as when it is
actually existent - for it is the middle which is the cause -
except that if the effect actually exists the cause is actually
existent, if it is coming to be so is the cause, if its occurrence is
past the cause is past, if future the cause is future. For example,
the moon was eclipsed because the earth intervened, is
becoming eclipsed because the earth is in process of
intervening, will be eclipsed because the earth will intervene, is
eclipsed because the earth intervenes.
To take a second example: assuming that the definition of ice is
solidified water, let C be water, A solidified, B the middle, which
is the cause, namely total failure of heat. Then B is attributed to
C, and A, solidification, to B: ice when B is occurring, has formed
when B has occurred, and will form when B shall occur.
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This sort of cause, then, and its effect come to be
simultaneously when they are in process of becoming, and exist
simultaneously when they actually exist; and the same holds
good when they are past and when they are future. But what of
cases where they are not simultaneous? Can causes and effects
different from one another form, as they seem to us to form, a
continuous succession, a past effect resulting from a past cause
different from itself, a future effect from a future cause different
from it, and an effect which is coming-to-be from a cause
different from and prior to it? Now on this theory it is from the
posterior event that we reason (and this though these later
events actually have their source of origin in previous events - a
fact which shows that also when the effect is coming-to-be we
still reason from the posterior event), and from the event we
cannot reason (we cannot argue that because an event A has
occurred, therefore an event B has occurred subsequently to A
but still in the past - and the same holds good if the occurrence
is future) - cannot reason because, be the time interval definite
or indefinite, it will never be possible to infer that because it is
true to say that A occurred, therefore it is true to say that B, the
subsequent event, occurred; for in the interval between the
events, though A has already occurred, the latter statement will
be false. And the same argument applies also to future events;
i.e. one cannot infer from an event which occurred in the past
that a future event will occur. The reason of this is that the
middle must be homogeneous, past when the extremes are
past, future when they are future, coming to be when they are
coming-to-be, actually existent when they are actually existent;
and there cannot be a middle term homogeneous with
extremes respectively past and future. And it is a further
difficulty in this theory that the time interval can be neither
indefinite nor definite, since during it the inference will be false.
We have also to inquire what it is that holds events together so
that the coming-to-be now occurring in actual things follows
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upon a past event. It is evident, we may suggest, that a past
event and a present process cannot be 'contiguous', for not even
two past events can be 'contiguous'. For past events are limits
and atomic; so just as points are not 'contiguous' neither are
past events, since both are indivisible. For the same reason a
past event and a present process cannot be 'contiguous', for the
process is divisible, the event indivisible. Thus the relation of
present process to past event is analogous to that of line to
point, since a process contains an infinity of past events. These
questions, however, must receive a more explicit treatment in
our general theory of change.
The following must suffice as an account of the manner in
which the middle would be identical with the cause on the
supposition that coming-to-be is a series of consecutive events:
for in the terms of such a series too the middle and major terms
must form an immediate premiss; e.g. we argue that, since C
has occurred, therefore A occurred: and C's occurrence was
posterior, A's prior; but C is the source of the inference because
it is nearer to the present moment, and the starting-point of
time is the present. We next argue that, since D has occurred,
therefore C occurred. Then we conclude that, since D has
occurred, therefore A must have occurred; and the cause is C,
for since D has occurred C must have occurred, and since C has
occurred A must previously have occurred.
If we get our middle term in this way, will the series terminate
in an immediate premiss, or since, as we said, no two events are
'contiguous', will a fresh middle term always intervene because
there is an infinity of middles? No: though no two events are
'contiguous', yet we must start from a premiss consisting of a
middle and the present event as major. The like is true of future
events too, since if it is true to say that D will exist, it must be a
prior truth to say that A will exist, and the cause of this
conclusion is C; for if D will exist, C will exist prior to D, and if C
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will exist, A will exist prior to it. And here too the same infinite
divisibility might be urged, since future events are not
'contiguous'. But here too an immediate basic premiss must be
assumed. And in the world of fact this is so: if a house has been
built, then blocks must have been quarried and shaped. The
reason is that a house having been built necessitates a
foundation having been laid, and if a foundation has been laid
blocks must have been shaped beforehand. Again, if a house
will be built, blocks will similarly be shaped beforehand; and
proof is through the middle in the same way, for the foundation
will exist before the house.
Now we observe in Nature a certain kind of circular process of
coming-to-be; and this is possible only if the middle and
extreme terms are reciprocal, since conversion is conditioned by
reciprocity in the terms of the proof. This - the convertibility of
conclusions and premisses - has been proved in our early
chapters, and the circular process is an instance of this. In
actual fact it is exemplified thus: when the earth had been
moistened an exhalation was bound to rise, and when an
exhalation had risen cloud was bound to form, and from the
formation of cloud rain necessarily resulted and by the fall of
rain the earth was necessarily moistened: but this was the
starting-point, so that a circle is completed; for posit any one of
the terms and another follows from it, and from that another,
and from that again the first.
Some occurrences are universal (for they are, or come-to-be
what they are, always and in ever case); others again are not
always what they are but only as a general rule: for instance,
not every man can grow a beard, but it is the general rule. In the
case of such connexions the middle term too must be a general
rule. For if A is predicated universally of B and B of C, A too must
be predicated always and in every instance of C, since to hold in
every instance and always is of the nature of the universal. But
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we have assumed a connexion which is a general rule;
consequently the middle term B must also be a general rule. So
connexions which embody a general rule - i.e. which exist or
come to be as a general rule - will also derive from immediate
basic premisses.
13
We have already explained how essential nature is set out in
the terms of a demonstration, and the sense in which it is or is
not demonstrable or definable; so let us now discuss the
method to be adopted in tracing the elements predicated as
constituting the definable form.
Now of the attributes which inhere always in each several thing
there are some which are wider in extent than it but not wider
than its genus (by attributes of wider extent mean all such as
are universal attributes of each several subject, but in their
application are not confined to that subject), while an attribute
may inhere in every triad, yet also in a subject not a triad - as
being inheres in triad but also in subjects not numbers at all -
odd on the other hand is an attribute inhering in every triad and
of wider application (inhering as it does also in pentad), but
which does not extend beyond the genus of triad; for pentad is a
number, but nothing outside number is odd. It is such attributes
which we have to select, up to the exact point at which they are
severally of wider extent than the subject but collectively
coextensive with it; for this synthesis must be the substance of
the thing. For example every triad possesses the attributes
number, odd, and prime in both senses, i.e. not only as
possessing no divisors, but also as not being a sum of numbers.
This, then, is precisely what triad is, viz. a number, odd, and
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prime in the former and also the latter sense of the term: for
these attributes taken severally apply, the first two to all odd
numbers, the last to the dyad also as well as to the triad, but,
taken collectively, to no other subject. Now since we have
shown above' that attributes predicated as belonging to the
essential nature are necessary and that universals are
necessary, and since the attributes which we select as inhering
in triad, or in any other subject whose attributes we select in
this way, are predicated as belonging to its essential nature,
triad will thus possess these attributes necessarily. Further, that
the synthesis of them constitutes the substance of triad is
shown by the following argument. If it is not identical with the
being of triad, it must be related to triad as a genus named or
nameless. It will then be of wider extent than triad - assuming
that wider potential extent is the character of a genus. If on the
other hand this synthesis is applicable to no subject other than
the individual triads, it will be identical with the being of triad,
because we make the further assumption that the substance of
each subject is the predication of elements in its essential
nature down to the last differentia characterizing the
individuals. It follows that any other synthesis thus exhibited
will likewise be identical with the being of the subject.
The author of a hand-book on a subject that is a generic whole
should divide the genus into its first infimae species - number
e.g. into triad and dyad - and then endeavour to seize their
definitions by the method we have described - the definition,
for example, of straight line or circle or right angle. After that,
having established what the category is to which the subaltern
genus belongs - quantity or quality, for instance - he should
examine the properties 'peculiar' to the species, working
through the proximate common differentiae. He should proceed
thus because the attributes of the genera compounded of the
infimae species will be clearly given by the definitions of the
species; since the basic element of them all is the definition, i.e.
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the simple infirma species, and the attributes inhere essentially
in the simple infimae species, in the genera only in virtue of
these.
Divisions according to differentiae are a useful accessory to this
method. What force they have as proofs we did, indeed, explain
above, but that merely towards collecting the essential nature
they may be of use we will proceed to show. They might, indeed,
seem to be of no use at all, but rather to assume everything at
the start and to be no better than an initial assumption made
without division. But, in fact, the order in which the attributes
are predicated does make a difference - it matters whether we
say animal-tame-biped, or biped-animal-tame. For if every
definable thing consists of two elements and 'animal-tame'
forms a unity, and again out of this and the further differentia
man (or whatever else is the unity under construction) is
constituted, then the elements we assume have necessarily
been reached by division. Again, division is the only possible
method of avoiding the omission of any element of the
essential nature. Thus, if the primary genus is assumed and we
then take one of the lower divisions, the dividendum will not
fall whole into this division: e.g. it is not all animal which is
either whole-winged or split-winged but all winged animal, for
it is winged animal to which this differentiation belongs. The
primary differentiation of animal is that within which all
animal falls. The like is true of every other genus, whether
outside animal or a subaltern genus of animal; e.g. the primary
differentiation of bird is that within which falls every bird, of
fish that within which falls every fish. So, if we proceed in this
way, we can be sure that nothing has been omitted: by any
other method one is bound to omit something without knowing
it.
To define and divide one need not know the whole of existence.
Yet some hold it impossible to know the differentiae
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distinguishing each thing from every single other thing without
knowing every single other thing; and one cannot, they say,
know each thing without knowing its differentiae, since
everything is identical with that from which it does not differ,
and other than that from which it differs. Now first of all this is
a fallacy: not every differentia precludes identity, since many
differentiae inhere in things specifically identical, though not in
the substance of these nor essentially Secondly, when one has
taken one's differing pair of opposites and assumed that the
two sides exhaust the genus, and that the subject one seeks to
define is present in one or other of them, and one has further
verified its presence in one of them; then it does not matter
whether or not one knows all the other subjects of which the
differentiae are also predicated. For it is obvious that when by
this process one reaches subjects incapable of further
differentiation one will possess the formula defining the
substance. Moreover, to postulate that the division exhausts the
genus is not illegitimate if the opposites exclude a middle; since
if it is the differentia of that genus, anything contained in the
genus must lie on one of the two sides.
In establishing a definition by division one should keep three
objects in view: (1) the admission only of elements in the
definable form, (2) the arrangement of these in the right order,
(3) the omission of no such elements. The first is feasible
because one can establish genus and differentia through the
topic of the genus, just as one can conclude the inherence of an
accident through the topic of the accident. The right order will
be achieved if the right term is assumed as primary, and this
will be ensured if the term selected is predicable of all the
others but not all they of it; since there must be one such term.
Having assumed this we at once proceed in the same way with
the lower terms; for our second term will be the first of the
remainder, our third the first of those which follow the second
in a 'contiguous' series, since when the higher term is excluded,
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that term of the remainder which is 'contiguous' to it will be
primary, and so on. Our procedure makes it clear that no
elements in the definable form have been omitted: we have
taken the differentia that comes first in the order of division,
pointing out that animal, e.g. is divisible exhaustively into A and
B, and that the subject accepts one of the two as its predicate.
Next we have taken the differentia of the whole thus reached,
and shown that the whole we finally reach is not further
divisible - i.e. that as soon as we have taken the last differentia
to form the concrete totality, this totality admits of no division
into species. For it is clear that there is no superfluous addition,
since all these terms we have selected are elements in the
definable form; and nothing lacking, since any omission would
have to be a genus or a differentia. Now the primary term is a
genus, and this term taken in conjunction with its differentiae
is a genus: moreover the differentiae are all included, because
there is now no further differentia; if there were, the final
concrete would admit of division into species, which, we said, is
not the case.
To resume our account of the right method of investigation: We
must start by observing a set of similar - i.e. specifically
identical - individuals, and consider what element they have in
common. We must then apply the same process to another set
of individuals which belong to one species and are generically
but not specifically identical with the former set. When we have
established what the common element is in all members of this
second species, and likewise in members of further species, we
should again consider whether the results established possess
any identity, and persevere until we reach a single formula,
since this will be the definition of the thing. But if we reach not
one formula but two or more, evidently the definiendum cannot
be one thing but must be more than one. I may illustrate my
meaning as follows. If we were inquiring what the essential
nature of pride is, we should examine instances of proud men
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we know of to see what, as such, they have in common; e.g. if
Alcibiades was proud, or Achilles and Ajax were proud, we
should find on inquiring what they all had in common, that it
was intolerance of insult; it was this which drove Alcibiades to
war, Achilles wrath, and Ajax to suicide. We should next
examine other cases, Lysander, for example, or Socrates, and
then if these have in common indifference alike to good and ill
fortune, I take these two results and inquire what common
element have equanimity amid the vicissitudes of life and
impatience of dishonour. If they have none, there will be two
genera of pride. Besides, every definition is always universal and
commensurate: the physician does not prescribe what is
healthy for a single eye, but for all eyes or for a determinate
species of eye. It is also easier by this method to define the
single species than the universal, and that is why our procedure
should be from the several species to the universal genera - this
for the further reason too that equivocation is less readily
detected in genera than in infimae species. Indeed, perspicuity
is essential in definitions, just as inferential movement is the
minimum required in demonstrations; and we shall attain
perspicuity if we can collect separately the definition of each
species through the group of singulars which we have
established e.g. the definition of similarity not unqualified but
restricted to colours and to figures; the definition of acuteness,
but only of sound - and so proceed to the common universal
with a careful avoidance of equivocation. We may add that if
dialectical disputation must not employ metaphors, clearly
metaphors and metaphorical expressions are precluded in
definition: otherwise dialectic would involve metaphors.
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14
In order to formulate the connexions we wish to prove we have
to select our analyses and divisions. The method of selection
consists in laying down the common genus of all our subjects of
investigation - if e.g. they are animals, we lay down what the
properties are which inhere in every animal. These established,
we next lay down the properties essentially connected with the
first of the remaining classes - e.g. if this first subgenus is bird,
the essential properties of every bird - and so on, always
characterizing the proximate subgenus. This will clearly at once
enable us to say in virtue of what character the subgenera -
man, e.g. or horse - possess their properties. Let A be animal, B
the properties of every animal, C D E various species of animal.
Then it is clear in virtue of what character B inheres in D -
namely A - and that it inheres in C and E for the same reason:
and throughout the remaining subgenera always the same rule
applies.
We are now taking our examples from the traditional class-
names, but we must not confine ourselves to considering these.
We must collect any other common character which we
observe, and then consider with what species it is connected
and what.properties belong to it. For example, as the common
properties of horned animals we collect the possession of a
third stomach and only one row of teeth. Then since it is clear
in virtue of what character they possess these attributes -
namely their horned character - the next question is, to what
species does the possession of horns attach?
Yet a further method of selection is by analogy: for we cannot
find a single identical name to give to a squid's pounce, a fish's
spine, and an animal's bone, although these too possess
common properties as if there were a single osseous nature.
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15
Some connexions that require proof are identical in that they
possess an identical 'middle' e.g. a whole group might be proved
through 'reciprocal replacement' - and of these one class are
identical in genus, namely all those whose difference consists
in their concerning different subjects or in their mode of
manifestation. This latter class may be exemplified by the
questions as to the causes respectively of echo, of reflection,
and of the rainbow: the connexions to be proved which these
questions embody are identical generically, because all three are
forms of repercussion; but specifically they are different.
Other connexions that require proof only differ in that the
'middle' of the one is subordinate to the 'middle' of the other.
For example: Why does the Nile rise towards the end of the
month? Because towards its close the month is more stormy.
Why is the month more stormy towards its close? Because the
moon is waning. Here the one cause is subordinate to the other.
16
The question might be raised with regard to cause and effect
whether when the effect is present the cause also is present;
whether, for instance, if a plant sheds its leaves or the moon is
eclipsed, there is present also the cause of the eclipse or of the
fall of the leaves - the possession of broad leaves, let us say, in
the latter case, in the former the earth's interposition. For, one
might argue, if this cause is not present, these phenomena will
have some other cause: if it is present, its effect will be at once
implied by it - the eclipse by the earth's interposition, the fall of
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the leaves by the possession of broad leaves; but if so, they will
be logically coincident and each capable of proof through the
other. Let me illustrate: Let A be deciduous character, B the
possession of broad leaves, C vine. Now if A inheres in B (for
every broad-leaved plant is deciduous), and B in C (every vine
possessing broad leaves); then A inheres in C (every vine is
deciduous), and the middle term B is the cause. But we can also
demonstrate that the vine has broad leaves because it is
deciduous. Thus, let D be broad-leaved, E deciduous, F vine.
Then E inheres in F (since every vine is deciduous), and D in E
(for every deciduous plant has broad leaves): therefore every
vine has broad leaves, and the cause is its deciduous character.
If, however, they cannot each be the cause of the other (for
cause is prior to effect, and the earth's interposition is the cause
of the moon's eclipse and not the eclipse of the interposition) -
if, then, demonstration through the cause is of the reasoned
fact and demonstration not through the cause is of the bare
fact, one who knows it through the eclipse knows the fact of the
earth's interposition but not the reasoned fact. Moreover, that
the eclipse is not the cause of the interposition, but the
interposition of the eclipse, is obvious because the interposition
is an element in the definition of eclipse, which shows that the
eclipse is known through the interposition and not vice versa.
On the other hand, can a single effect have more than one
cause? One might argue as follows: if the same attribute is
predicable of more than one thing as its primary subject, let B
be a primary subject in which A inheres, and C another primary
subject of A, and D and E primary subjects of B and C
respectively. A will then inhere in D and E, and B will be the
cause of As inherence in D, C of As inherence in E.The presence
of the cause thus necessitates that of the effect, but the
presence of the effect necessitates the presence not of all that
may cause it but only of a cause which yet need not be the
whole cause. We may, however, suggest that if the connexion to
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be proved is always universal and commensurate, not only will
the cause be a whole but also the effect will be universal and
commensurate. For instance, deciduous character will belong
exclusively to a subject which is a whole, and, if this whole has
species, universally and commensurately to those species - i.e.
either to all species of plant or to a single species. So in these
universal and commensurate connexions the 'middle' and its
effect must reciprocate, i.e. be convertible. Supposing, for
example, that the reason why trees are deciduous is the
coagulation of sap, then if a tree is deciduous, coagulation must
be present, and if coagulation is present - not in any subject but
in a tree - then that tree must be deciduous.
17
Can the cause of an identical effect be not identical in every
instance of the effect but different? Or is that impossible?
Perhaps it is impossible if the effect is demonstrated as
essential and not as inhering in virtue of a symptom or an
accident - because the middle is then the definition of the
major term - though possible if the demonstration is not
essential. Now it is possible to consider the effect and its subject
as an accidental conjunction, though such conjunctions would
not be regarded as connexions demanding scientific proof. But
if they are accepted as such, the middle will correspond to the
extremes, and be equivocal if they are equivocal, generically one
if they are generically one. Take the question why proportionals
alternate. The cause when they are lines, and when they are
numbers, is both different and identical; different in so far as
lines are lines and not numbers, identical as involving a given
determinate increment. In all proportionals this is so. Again, the
cause of likeness between colour and colour is other than that
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between figure and figure; for likeness here is equivocal,
meaning perhaps in the latter case equality of the ratios of the
sides and equality of the angles, in the case of colours identity
of the act of perceiving them, or something else of the sort.
Again, connexions requiring proof which are identical by
analogy middles also analogous.
The truth is that cause, effect, and subject are reciprocally
predicable in the following way. If the species are taken
severally, the effect is wider than the subject (e.g. the possession
of external angles equal to four right angles is an attribute
wider than triangle or are), but it is coextensive with the species
taken collectively (in this instance with all figures whose
external angles are equal to four right angles). And the middle
likewise reciprocates, for the middle is a definition of the major;
which is incidentally the reason why all the sciences are built
up through definition.
We may illustrate as follows. Deciduous is a universal attribute
of vine, and is at the same time of wider extent than vine; and
of fig, and is of wider extent than fig: but it is not wider than but
coextensive with the totality of the species. Then if you take the
middle which is proximate, it is a definition of deciduous. I say
that, because you will first reach a middle next the subject, and
a premiss asserting it of the whole subject, and after that a
middle - the coagulation of sap or something of the sort -
proving the connexion of the first middle with the major: but it
is the coagulation of sap at the junction of leaf-stalk and stem
which defines deciduous.
If an explanation in formal terms of the inter-relation of cause
and effect is demanded, we shall offer the following. Let A be an
attribute of all B, and B of every species of D, but so that both A
and B are wider than their respective subjects. Then B will be a
universal attribute of each species of D (since I call such an
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attribute universal even if it is not commensurate, and I call an
attribute primary universal if it is commensurate, not with each
species severally but with their totality), and it extends beyond
each of them taken separately.
Thus, B is the cause of A's inherence in the species of D:
consequently A must be of wider extent than B; otherwise why
should B be the cause of A's inherence in D any more than A the
cause of B's inherence in D? Now if A is an attribute of all the
species of E, all the species of E will be united by possessing
some common cause other than B: otherwise how shall we be
able to say that A is predicable of all of which E is predicable,
while E is not predicable of all of which A can be predicated? I
mean how can there fail to be some special cause of A's
inherence in E, as there was of A's inherence in all the species of
D? Then are the species of E, too, united by possessing some
common cause? This cause we must look for. Let us call it C.
We conclude, then, that the same effect may have more than
one cause, but not in subjects specifically identical. For
instance, the cause of longevity in quadrupeds is lack of bile, in
birds a dry constitution - or certainly something different.
18
If immediate premisses are not reached at once, and there is
not merely one middle but several middles, i.e. several causes; is
the cause of the property's inherence in the several species the
middle which is proximate to the primary universal, or the
middle which is proximate to the species? Clearly the cause is
that nearest to each species severally in which it is manifested,
for that is the cause of the subject's falling under the universal.
To illustrate formally: C is the cause of B's inherence in D; hence
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C is the cause of A's inherence in D, B of A's inherence in C,
while the cause of A's inherence in B is B itself.
19
As regards syllogism and demonstration, the definition of, and
the conditions required to produce each of them, are now clear,
and with that also the definition of, and the conditions required
to produce, demonstrative knowledge, since it is the same as
demonstration. As to the basic premisses, how they become
known and what is the developed state of knowledge of them is
made clear by raising some preliminary problems.
We have already said that scientific knowledge through
demonstration is impossible unless a man knows the primary
immediate premisses. But there are questions which might be
raised in respect of the apprehension of these immediate
premisses: one might not only ask whether it is of the same
kind as the apprehension of the conclusions, but also whether
there is or is not scientific knowledge of both; or scientific
knowledge of the latter, and of the former a different kind of
knowledge; and, further, whether the developed states of
knowledge are not innate but come to be in us, or are innate but
at first unnoticed. Now it is strange if we possess them from
birth; for it means that we possess apprehensions more
accurate than demonstration and fail to notice them. If on the
other hand we acquire them and do not previously possess
them, how could we apprehend and learn without a basis of
pre-existent knowledge? For that is impossible, as we used to
find in the case of demonstration. So it emerges that neither
can we possess them from birth, nor can they come to be in us
if we are without knowledge of them to the extent of having no
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such developed state at all. Therefore we must possess a
capacity of some sort, but not such as to rank higher in accuracy
than these developed states. And this at least is an obvious
characteristic of all animals, for they possess a congenital
discriminative capacity which is called sense-perception. But
though sense-perception is innate in all animals, in some the
sense-impression comes to persist, in others it does not. So
animals in which this persistence does not come to be have
either no knowledge at all outside the act of perceiving, or no
knowledge of objects of which no impression persists; animals
in which it does come into being have perception and can
continue to retain the sense-impression in the soul: and when
such persistence is frequently repeated a further distinction at
once arises between those which out of the persistence of such
sense-impressions develop a power of systematizing them and
those which do not. So out of sense-perception comes to be
what we call memory, and out of frequently repeated memories
of the same thing develops experience; for a number of
memories constitute a single experience. From experience again
- i.e. from the universal now stabilized in its entirety within the
soul, the one beside the many which is a single identity within
them all - originate the skill of the craftsman and the
knowledge of the man of science, skill in the sphere of coming
to be and science in the sphere of being.
We conclude that these states of knowledge are neither innate
in a determinate form, nor developed from other higher states
of knowledge, but from sense-perception. It is like a rout in
battle stopped by first one man making a stand and then
another, until the original formation has been restored. The soul
is so constituted as to be capable of this process.
Let us now restate the account given already, though with
insufficient clearness. When one of a number of logically
indiscriminable particulars has made a stand, the earliest
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universal is present in the soul: for though the act of sense-
perception is of the particular, its content is universal - is man,
for example, not the man Callias. A fresh stand is made among
these rudimentary universals, and the process does not cease
until the indivisible concepts, the true universals, are
established: e.g. such and such a species of animal is a step
towards the genus animal, which by the same process is a step
towards a further generalization.
Thus it is clear that we must get to know the primary premisses
by induction; for the method by which even sense-perception
implants the universal is inductive. Now of the thinking states
by which we grasp truth, some are unfailingly true, others admit
of error - opinion, for instance, and calculation, whereas
scientific knowing and intuition are always true: further, no
other kind of thought except intuition is more accurate than
scientific knowledge, whereas primary premisses are more
knowable than demonstrations, and all scientific knowledge is
discursive. From these considerations it follows that there will
be no scientific knowledge of the primary premisses, and since
except intuition nothing can be truer than scientific knowledge,
it will be intuition that apprehends the primary premisses - a
result which also follows from the fact that demonstration
cannot be the originative source of demonstration, nor,
consequently, scientific knowledge of scientific knowledge. If,
therefore, it is the only other kind of true thinking except
scientific knowing, intuition will be the originative source of
scientific knowledge. And the originative source of science
grasps the original basic premiss, while science as a whole is
similarly related as originative source to the whole body of fact.
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Aristotle - Topics
[Translated by W. A. Pickard-Cambridge]
Book I
Our treatise proposes to find a line of inquiry whereby we shall
be able to reason from opinions that are generally accepted
about every problem propounded to us, and also shall ourselves,
when standing up to an argument, avoid saying anything that
will obstruct us. First, then, we must say what reasoning is, and
what its varieties are, in order to grasp dialectical reasoning: for
this is the object of our search in the treatise before us.
Now reasoning is an argument in which, certain things being
laid down, something other than these necessarily comes about
through them, (a) It is a 'demonstration', when the premisses
from which the reasoning starts are true and primary, or are
such that our knowledge of them has originally come through
premisses which are primary and true: (b) reasoning, on the
other hand, is 'dialectical', if it reasons from opinions that are
generally accepted. Things are 'true' and 'primary' which are
believed on the strength not of anything else but of themselves:
for in regard to the first principles of science it is improper to
ask any further for the why and wherefore of them; each of the
first principles should command belief in and by itself. On the
other hand, those opinions are 'generally accepted' which are
accepted by every one or by the majority or by the philosophers
- i.e. by all, or by the majority, or by the most notable and
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illustrious of them. Again (c), reasoning is 'contentious' if it
starts from opinions that seem to be generally accepted, but are
not really such, or again if it merely seems to reason from
opinions that are or seem to be generally accepted. For not
every opinion that seems to be generally accepted actually is
generally accepted. For in none of the opinions which we call
generally accepted is the illusion entirely on the surface, as
happens in the case of the principles of contentious arguments;
for the nature of the fallacy in these is obvious immediately,
and as a rule even to persons with little power of
comprehension. So then, of the contentious reasonings
mentioned, the former really deserves to be called 'reasoning'
as well, but the other should be called 'contentious reasoning',
but not 'reasoning', since it appears to reason, but does not
really do so. Further (d), besides all the reasonings we have
mentioned there are the mis-reasonings that start from the
premisses peculiar to the special sciences, as happens (for
example) in the case of geometry and her sister sciences. For
this form of reasoning appears to differ from the reasonings
mentioned above; the man who draws a false figure reasons
from things that are neither true and primary, nor yet generally
accepted. For he does not fall within the definition; he does not
assume opinions that are received either by every one or by the
majority or by philosophers - that is to say, by all, or by most, or
by the most illustrious of them - but he conducts his reasoning
upon assumptions which, though appropriate to the science in
question, are not true; for he effects his mis-reasoning either by
describing the semicircles wrongly or by drawing certain lines in
a way in which they could not be drawn.
The foregoing must stand for an outline survey of the species of
reasoning. In general, in regard both to all that we have already
discussed and to those which we shall discuss later, we may
remark that that amount of distinction between them may
serve, because it is not our purpose to give the exact definition
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of any of them; we merely want to describe them in outline; we
consider it quite enough from the point of view of the line of
inquiry before us to be able to recognize each of them in some
sort of way.
Next in order after the foregoing, we must say for how many
and for what purposes the treatise is useful. They are three -
intellectual training, casual encounters, and the philosophical
sciences. That it is useful as a training is obvious on the face of
it. The possession of a plan of inquiry will enable us more easily
to argue about the subject proposed. For purposes of casual
encounters, it is useful because when we have counted up the
opinions held by most people, we shall meet them on the
ground not of other people's convictions but of their own, while
we shift the ground of any argument that they appear to us to
state unsoundly. For the study of the philosophical sciences it is
useful, because the ability to raise searching difficulties on both
sides of a subject will make us detect more easily the truth and
error about the several points that arise. It has a further use in
relation to the ultimate bases of the principles used in the
several sciences. For it is impossible to discuss them at all from
the principles proper to the particular science in hand, seeing
that the principles are the prius of everything else: it is through
the opinions generally held on the particular points that these
have to be discussed, and this task belongs properly, or most
appropriately, to dialectic: for dialectic is a process of criticism
wherein lies the path to the principles of all inquiries.
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We shall be in perfect possession of the way to proceed when
we are in a position like that which we occupy in regard to
rhetoric and medicine and faculties of that kind: this means the
doing of that which we choose with the materials that are
available. For it is not every method that the rhetorician will
employ to persuade, or the doctor to heal; still, if he omits none
of the available means, we shall say that his grasp of the science
is adequate.
First, then, we must see of what parts our inquiry consists. Now
if we were to grasp (a) with reference to how many, and what
kind of, things arguments take place, and with what materials
they start, and (b) how we are to become well supplied with
these, we should have sufficiently won our goal. Now the
materials with which arguments start are equal in number, and
are identical, with the subjects on which reasonings take place.
For arguments start with 'propositions', while the subjects on
which reasonings take place are 'problems'. Now every
proposition and every problem indicates either a genus or a
peculiarity or an accident - for the differentia too, applying as it
does to a class (or genus), should be ranked together with the
genus. Since, however, of what is peculiar to anything part
signifies its essence, while part does not, let us divide the
'peculiar' into both the aforesaid parts, and call that part which
indicates the essence a 'definition', while of the remainder let
us adopt the terminology which is generally current about these
things, and speak of it as a 'property'. What we have said, then,
makes it clear that according to our present division, the
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elements turn out to be four, all told, namely either property or
definition or genus or accident. Do not let any one suppose us
to mean that each of these enunciated by itself constitutes a
proposition or problem, but only that it is from these that both
problems and propositions are formed. The difference between
a problem and a proposition is a difference in the turn of the
phrase. For if it be put in this way, «'An animal that walks on
two feet» is the definition of man, is it not?' or '«Animal» is the
genus of man, is it not?' the result is a proposition: but if thus,
'Is «an animal that walks on two feet» a definition of man or
no?' [or 'Is «animal» his genus or no?'] the result is a problem.
Similarly too in other cases. Naturally, then, problems and
propositions are equal in number: for out of every proposition
you will make a problem if you change the turn of the phrase.
We must now say what are 'definition', 'property', 'genus', and
'accident'. A 'definition' is a phrase signifying a thing's essence.
It is rendered in the form either of a phrase in lieu of a term, or
of a phrase in lieu of another phrase; for it is sometimes
possible to define the meaning of a phrase as well. People
whose rendering consists of a term only, try it as they may,
clearly do not render the definition of the thing in question,
because a definition is always a phrase of a certain kind. One
may, however, use the word 'definitory' also of such a remark as
'The «becoming» is «beautiful»', and likewise also of the
question, 'Are sensation and knowledge the same or different?',
for argument about definitions is mostly concerned with
questions of sameness and difference. In a word we may call
'definitory' everything that falls under the same branch of
inquiry as definitions; and that all the above-mentioned
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examples are of this character is clear on the face of them. For if
we are able to argue that two things are the same or are
different, we shall be well supplied by the same turn of
argument with lines of attack upon their definitions as well: for
when we have shown that they are not the same we shall have
demolished the definition. Observe, please, that the converse of
this last statement does not hold: for to show that they are the
same is not enough to establish a definition. To show, however,
that they are not the same is enough of itself to overthrow it.
A 'property' is a predicate which does not indicate the essence
of a thing, but yet belongs to that thing alone, and is predicated
convertibly of it. Thus it is a property of man to-be-capable of
learning grammar: for if A be a man, then he is capable of
learning grammar, and if he be capable of learning grammar, he
is a man. For no one calls anything a 'property' which may
possibly belong to something else, e.g. 'sleep' in the case of
man, even though at a certain time it may happen to belong to
him alone. That is to say, if any such thing were actually to be
called a property, it will be called not a 'property' absolutely, but
a 'temporary' or a 'relative' property: for 'being on the right
hand side' is a temporary property, while 'two-footed' is in point
of fact ascribed as a property in certain relations; e.g. it is a
property of man relatively to a horse and a dog. That nothing
which may belong to anything else than A is a convertible
predicate of A is clear: for it does not necessarily follow that if
something is asleep it is a man.
A 'genus' is what is predicated in the category of essence of a
number of things exhibiting differences in kind. We should treat
as predicates in the category of essence all such things as it
would be appropriate to mention in reply to the question, 'What
is the object before you?'; as, for example, in the case of man, if
asked that question, it is appropriate to say 'He is an animal'.
The question, 'Is one thing in the same genus as another or in a
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different one?' is also a 'generic' question; for a question of that
kind as well falls under the same branch of inquiry as the
genus: for having argued that 'animal' is the genus of man, and
likewise also of ox, we shall have argued that they are in the
same genus; whereas if we show that it is the genus of the one
but not of the other, we shall have argued that these things are
not in the same genus.
An 'accident' is (i) something which, though it is none of the
foregoing - i.e. neither a definition nor a property nor a genus
yet belongs to the thing: (something which may possibly either
belong or not belong to any one and the self-same thing, as
(e.g.) the 'sitting posture' may belong or not belong to some self-
same thing. Likewise also 'whiteness', for there is nothing to
prevent the same thing being at one time white, and at another
not white. Of the definitions of accident the second is the
better: for if he adopts the first, any one is bound, if he is to
understand it, to know already what 'definition' and 'genus' and
'property' are, whereas the second is sufficient of itself to tell us
the essential meaning of the term in question. To Accident are
to be attached also all comparisons of things together, when
expressed in language that is drawn in any kind of way from
what happens (accidit) to be true of them; such as, for example,
the question, 'Is the honourable or the expedient preferable?'
and 'Is the life of virtue or the life of self-indulgence the
pleasanter?', and any other problem which may happen to be
phrased in terms like these. For in all such cases the question is
'to which of the two does the predicate in question happen
(accidit) to belong more closely?' It is clear on the face of it that
there is nothing to prevent an accident from becoming a
temporary or relative property. Thus the sitting posture is an
accident, but will be a temporary property, whenever a man is
the only person sitting, while if he be not the only one sitting, it
is still a property relatively to those who are not sitting. So then,
there is nothing to prevent an accident from becoming both a
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relative and a temporary property; but a property absolutely it
will never be.
We must not fail to observe that all remarks made in criticism
of a 'property' and 'genus' and 'accident' will be applicable to
'definitions' as well. For when we have shown that the attribute
in question fails to belong only to the term defined, as we do
also in the case of a property, or that the genus rendered in the
definition is not the true genus, or that any of the things
mentioned in the phrase used does not belong, as would be
remarked also in the case of an accident, we shall have
demolished the definition; so that, to use the phrase previously
employed,' all the points we have enumerated might in a
certain sense be called 'definitory'. But we must not on this
account expect to find a single line of inquiry which will apply
universally to them all: for this is not an easy thing to find, and,
even were one found, it would be very obscure indeed, and of
little service for the treatise before us. Rather, a special plan of
inquiry must be laid down for each of the classes we have
distinguished, and then, starting from the rules that are
appropriate in each case, it will probably be easier to make our
way right through the task before us. So then, as was said
before,' we must outline a division of our subject, and other
questions we must relegate each to the particular branch to
which it most naturally belongs, speaking of them as 'definitory'
and 'generic' questions. The questions I mean have practically
been already assigned to their several branches.
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First of all we must define the number of senses borne by the
term 'Sameness'. Sameness would be generally regarded as
falling, roughly speaking, into three divisions. We generally
apply the term numerically or specifically or generically -
numerically in cases where there is more than one name but
only one thing, e.g. 'doublet' and 'cloak'; specifically, where
there is more than one thing, but they present no differences in
respect of their species, as one man and another, or one horse
and another: for things like this that fall under the same species
are said to be 'specifically the same'. Similarly, too, those things
are called generically the same which fall under the same
genus, such as a horse and a man. It might appear that the
sense in which water from the same spring is called 'the same
water' is somehow different and unlike the senses mentioned
above: but really such a case as this ought to be ranked in the
same class with the things that in one way or another are called
'the same' in view of unity of species. For all such things seem
to be of one family and to resemble one another. For the reaon
why all water is said to be specifically the same as all other
water is because of a certain likeness it bears to it, and the only
difference in the case of water drawn from the same spring is
this, that the likeness is more emphatic: that is why we do not
distinguish it from the things that in one way or another are
called 'the same' in view of unity of species. It is generally
supposed that the term 'the same' is most used in a sense
agreed on by every one when applied to what is numerically
one. But even so, it is apt to be rendered in more than one
sense; its most literal and primary use is found whenever the
sameness is rendered in reference to an alternative name or
definition, as when a cloak is said to be the same as a doublet,
or an animal that walks on two feet is said to be the same as a
man: a second sense is when it is rendered in reference to a
property, as when what can acquire knowledge is called the
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same as a man, and what naturally travels upward the same as
fire: while a third use is found when it is rendered in reference
to some term drawn from Accident, as when the creature who is
sitting, or who is musical, is called the same as Socrates. For all
these uses mean to signify numerical unity. That what I have
just said is true may be best seen where one form of appellation
is substituted for another. For often when we give the order to
call one of the people who are sitting down, indicating him by
name, we change our description, whenever the person to
whom we give the order happens not to understand us; he will,
we think, understand better from some accidental feature; so
we bid him call to us 'the man who is sitting' or 'who is
conversing over there' - clearly supposing ourselves to be
indicating the same object by its name and by its accident.
8
Of 'sameness' then, as has been said,' three senses are to be
distinguished. Now one way to confirm that the elements
mentioned above are those out of which and through which and
to which arguments proceed, is by induction: for if any one were
to survey propositions and problems one by one, it would be
seen that each was formed either from the definition of
something or from its property or from its genus or from its
accident. Another way to confirm it is through reasoning. For
every predicate of a subject must of necessity be either
convertible with its subject or not: and if it is convertible, it
would be its definition or property, for if it signifies the essence,
it is the definition; if not, it is a property: for this was what a
property is, viz. what is predicated convertibly, but does not
signify the essence. If, on the other hand, it is not predicated
convertibly of the thing, it either is or is not one of the terms
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contained in the definition of the subject: and if it be one of
those terms, then it will be the genus or the differentia,
inasmuch as the definition consists of genus and differentiae;
whereas, if it be not one of those terms, clearly it would be an
accident, for accident was said' to be what belongs as an
attribute to a subject without being either its definition or its
genus or a property.
Next, then, we must distinguish between the classes of
predicates in which the four orders in question are found. These
are ten in number: Essence, Quantity, Quality, Relation, Place,
Time, Position, State, Activity, Passivity. For the accident and
genus and property and definition of anything will always be in
one of these categories: for all the propositions found through
these signify either something's essence or its quality or
quantity or some one of the other types of predicate. It is clear,
too, on the face of it that the man who signifies something's
essence signifies sometimes a substance, sometimes a quality,
sometimes some one of the other types of predicate. For when
man is set before him and he says that what is set there is 'a
man' or 'an animal', he states its essence and signifies a
substance; but when a white colour is set before him and he
says that what is set there is 'white' or is 'a colour', he states its
essence and signifies a quality. Likewise, also, if a magnitude of
a cubit be set before him and he says that what is set there is a
magnitude of a cubit, he will be describing its essence and
signifying a quantity. Likewise, also, in the other cases: for each
of these kinds of predicate, if either it be asserted of itself, or its
genus be asserted of it, signifies an essence: if, on the other
hand, one kind of predicate is asserted of another kind, it does
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not signify an essence, but a quantity or a quality or one of the
other kinds of predicate. Such, then, and so many, are the
subjects on which arguments take place, and the materials with
which they start. How we are to acquire them, and by what
means we are to become well supplied with them, falls next to
be told.
10
First, then, a definition must be given of a 'dialectical
proposition' and a 'dialectical problem'. For it is not every
proposition nor yet every problem that is to be set down as
dialectical: for no one in his senses would make a proposition of
what no one holds, nor yet make a problem of what is obvious
to everybody or to most people: for the latter admits of no
doubt, while to the former no one would assent. Now a
dialectical proposition consists in asking something that is held
by all men or by most men or by the philosophers, i.e. either by
all, or by most, or by the most notable of these, provided it be
not contrary to the general opinion; for a man would probably
assent to the view of the philosophers, if it be not contrary to
the opinions of most men. Dialectical propositions also include
views which are like those generally accepted; also propositions
which contradict the contraries of opinions that are taken to be
generally accepted, and also all opinions that are in accordance
with the recognized arts. Thus, supposing it to be a general
opinion that the knowledge of contraries is the same, it might
probably pass for a general opinion also that the perception of
contraries is the same: also, supposing it to be a general opinion
that there is but one single science of grammar, it might pass
for a general opinion that there is but one science of flute-
playing as well, whereas, if it be a general opinion that there is
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more than one science of grammar, it might pass for a general
opinion that there is more than one science of flute-playing as
well: for all these seem to be alike and akin. Likewise, also,
propositions contradicting the contraries of general opinions
will pass as general opinions: for if it be a general opinion that
one ought to do good to one's friends, it will also be a general
opinion that one ought not to do them harm. Here, that one
ought to do harm to one's friends is contrary to the general
view, and that one ought not to do them harm is the
contradictory of that contrary. Likewise also, if one ought to do
good to one's friends, one ought not to do good to one's
enemies: this too is the contradictory of the view contrary to the
general view; the contrary being that one ought to do good to
one's enemies. Likewise, also, in other cases. Also, on
comparison, it will look like a general opinion that the contrary
predicate belongs to the contrary subject: e.g. if one ought to do
good to one's friends, one ought also to do evil to one's enemies,
it might appear also as if doing good to one's friends were a
contrary to doing evil to one's enemies: but whether this is or is
not so in reality as well will be stated in the course of the
discussion upon contraries. Clearly also, all opinions that are in
accordance with the arts are dialectical propositions; for people
are likely to assent to the views held by those who have made a
study of these things, e.g. on a question of medicine they will
agree with the doctor, and on a question of geometry with the
geometrician; and likewise also in other cases.
11
A dialectical problem is a subject of inquiry that contributes
either to choice and avoidance, or to truth and knowledge, and
that either by itself, or as a help to the solution of some other
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such problem. It must, moreover, be something on which either
people hold no opinion either way, or the masses hold a
contrary opinion to the philosophers, or the philosophers to the
masses, or each of them among themselves. For some problems
it is useful to know with a view to choice or avoidance, e.g.
whether pleasure is to be chosen or not, while some it is useful
to know merely with a view to knowledge, e.g. whether the
universe is eternal or not: others, again, are not useful in and by
themselves for either of these purposes, but yet help us in
regard to some such problems; for there are many things which
we do not wish to know in and by themselves, but for the sake
of other things, in order that through them we may come to
know something else. Problems also include questions in regard
to which reasonings conflict (the difficulty then being whether
so - and so is so or not, there being convincing arguments for
both views); others also in regard to which we have no
argument because they are so vast, and we find it difficult to
give our reasons, e.g. the question whether the universe is
eternal or no: for into questions of that kind too it is possible to
inquire.
Problems, then, and propositions are to be defined as aforesaid.
A 'thesis' is a supposition of some eminent philosopher that
conflicts with the general opinion; e.g. the view that
contradiction is impossible, as Antisthenes said; or the view of
Heraclitus that all things are in motion; or that Being is one, as
Melissus says: for to take notice when any ordinary person
expresses views contrary to men's usual opinions would be silly.
Or it may be a view about which we have a reasoned theory
contrary to men's usual opinions, e.g. the view maintained by
the sophists that what is need not in every case either have
come to be or be eternal: for a musician who is a grammarian
'is' so without ever having 'come to be' so, or being so eternally.
For even if a man does not accept this view, he might do so on
the ground that it is reasonable.
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Now a 'thesis' also is a problem, though a problem is not always
a thesis, inasmuch as some problems are such that we have no
opinion about them either way. That a thesis, however, also
forms a problem, is clear: for it follows of necessity from what
has been said that either the mass of men disagree with the
philosophers about the thesis, or that the one or the other class
disagree among themselves, seeing that the thesis is a
supposition in conflict with general opinion. Practically all
dialectical problems indeed are now called 'theses'. But it
should make no difference whichever description is used; for
our object in thus distinguishing them has not been to create a
terminology, but to recognize what differences happen to be
found between them.
Not every problem, nor every thesis, should be examined, but
only one which might puzzle one of those who need argument,
not punishment or perception. For people who are puzzled to
know whether one ought to honour the gods and love one's
parents or not need punishment, while those who are puzzled
to know whether snow is white or not need perception. The
subjects should not border too closely upon the sphere of
demonstration, nor yet be too far removed from it: for the
former cases admit of no doubt, while the latter involve
difficulties too great for the art of the trainer.
12
Having drawn these definitions, we must distinguish how many
species there are of dialectical arguments. There is on the one
hand Induction, on the other Reasoning. Now what reasoning is
has been said before: induction is a passage from individuals to
universals, e.g. the argument that supposing the skilled pilot is
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the most effective, and likewise the skilled charioteer, then in
general the skilled man is the best at his particular task.
Induction is the more convincing and clear: it is more readily
learnt by the use of the senses, and is applicable generally to
the mass of men, though reasoning is more forcible and
effective against contradictious people.
13
The classes, then, of things about which, and of things out of
which, arguments are constructed, are to be distinguished in
the way we have said before. The means whereby we are to
become well supplied with reasonings are four: (1) the securing
of propositions; (2) the power to distinguish in how many
senses particular expression is used; (3) the discovery of the
differences of things; (4) the investigation of likeness. The last
three, as well, are in a certain sense propositions: for it is
possible to make a proposition corresponding to each of them,
e.g. (1) 'The desirable may mean either the honourable or the
pleasant or the expedient'; and (2) Sensation differs from
knowledge in that the latter may be recovered again after it has
been lost, while the former cannot'; and (3) The relation of the
healthy to health is like that of the vigorous to vigour'. The first
proposition depends upon the use of one term in several senses,
the second upon the differences of things, the third upon their
likenesses.
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14
Propositions should be selected in a number of ways
corresponding to the number of distinctions drawn in regard to
the proposition: thus one may first take in hand the opinions
held by all or by most men or by the philosophers, i.e. by all, or
most, or the most notable of them; or opinions contrary to those
that seem to be generally held; and, again, all opinions that are
in accordance with the arts. We must make propositions also of
the contradictories of opinions contrary to those that seem to
be generally held, as was laid down before. It is useful also to
make them by selecting not only those opinions that actually
are accepted, but also those that are like these, e.g. 'The
perception of contraries is the same' - the knowledge of them
being so - and 'we see by admission of something into
ourselves, not by an emission'; for so it is, too, in the case of the
other senses; for in hearing we admit something into ourselves;
we do not emit; and we taste in the same way. Likewise also in
the other cases. Moreover, all statements that seem to be true in
all or in most cases, should be taken as a principle or accepted
position; for they are posited by those who do not also see what
exception there may be. We should select also from the written
handbooks of argument, and should draw up sketch-lists of
them upon each several kind of subject, putting them down
under separate headings, e.g. 'On Good', or 'On Life' - and that
'On Good' should deal with every form of good, beginning with
the category of essence. In the margin, too, one should indicate
also the opinions of individual thinkers, e.g. 'Empedocles said
that the elements of bodies were four': for any one might assent
to the saying of some generally accepted authority.
Of propositions and problems there are - to comprehend the
matter in outline - three divisions: for some are ethical
propositions, some are on natural philosophy, while some are
logical. Propositions such as the following are ethical, e.g.
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'Ought one rather to obey one's parents or the laws, if they
disagree?'; such as this are logical, e.g. 'Is the knowledge of
opposites the same or not?'; while such as this are on natural
philosophy, e.g. 'Is the universe eternal or not?' Likewise also
with problems. The nature of each of the aforesaid kinds of
proposition is not easily rendered in a definition, but we have to
try to recognize each of them by means of the familiarity
attained through induction, examining them in the light of the
illustrations given above.
For purposes of philosophy we must treat of these things
according to their truth, but for dialectic only with an eye to
general opinion. All propositions should be taken in their most
universal form; then, the one should be made into many. E.g.
'The knowledge of opposites is the same'; next, 'The knowledge
of contraries is the same', and that 'of relative terms'. In the
same way these two should again be divided, as long as division
is possible, e.g. the knowledge of 'good and evil', of 'white and
black', or 'cold and hot'. Likewise also in other cases.
15
On the formation, then, of propositions, the above remarks are
enough. As regards the number of senses a term bears, we must
not only treat of those terms which bear different senses, but
we must also try to render their definitions; e.g. we must not
merely say that justice and courage are called 'good' in one
sense, and that what conduces to vigour and what conduces to
health are called so in another, but also that the former are so
called because of a certain intrinsic quality they themselves
have, the latter because they are productive of a certain result
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and not because of any intrinsic quality in themselves. Similarly
also in other cases.
Whether a term bears a number of specific meanings or one
only, may be considered by the following means. First, look and
see if its contrary bears a number of meanings, whether the
discrepancy between them be one of kind or one of names. For
in some cases a difference is at once displayed even in the
names; e.g. the contrary of 'sharp' in the case of a note is 'flat',
while in the case of a solid edge it is 'dull'. Clearly, then, the
contrary of 'sharp' bears several meanings, and if so, also does
'sharp'; for corresponding to each of the former terms the
meaning of its contrary will be different. For 'sharp' will not be
the same when contrary to 'dull' and to 'flat', though 'sharp' is
the contrary of each. Again Barhu ('flat', 'heavy') in the case of a
note has 'sharp' as its contrary, but in the case of a solid mass
'light', so that Barhu is used with a number of meanings,
inasmuch as its contrary also is so used. Likewise, also, 'fine' as
applied to a picture has 'ugly' as its contrary, but, as applied to a
house, 'ramshackle'; so that 'fine' is an ambiguous term.
In some cases there is no discrepancy of any sort in the names
used, but a difference of kind between the meanings is at once
obvious: e.g. in the case of 'clear' and 'obscure': for sound is
called 'clear' and 'obscure', just as 'colour' is too. As regards the
names, then, there is no discrepancy, but the difference in kind
between the meanings is at once obvious: for colour is not
called 'clear' in a like sense to sound. This is plain also through
sensation: for of things that are the same in kind we have the
same sensation, whereas we do not judge clearness by the same
sensation in the case of sound and of colour, but in the latter
case we judge by sight, in the former by hearing. Likewise also
with 'sharp' and 'dull' in regard to flavours and solid edges: here
in the latter case we judge by touch, but in the former by taste.
For here again there is no discrepancy in the names used, in the
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case either of the original terms or of their contraries: for the
contrary also of sharp in either sense is 'dull'.
Moreover, see if one sense of a term has a contrary, while
another has absolutely none; e.g. the pleasure of drinking has a
contrary in the pain of thirst, whereas the pleasure of seeing
that the diagonal is incommensurate with the side has none, so
that 'pleasure' is used in more than one sense. To 'love' also,
used of the frame of mind, has to 'hate' as its contrary, while as
used of the physical activity (kissing) it has none: clearly,
therefore, to 'love' is an ambiguous term. Further, see in regard
to their intermediates, if some meanings and their contraries
have an intermediate, others have none, or if both have one but
not the same one, e.g. 'clear' and 'obscure' in the case of colours
have 'grey' as an intermediate, whereas in the case of sound
they have none, or, if they have, it is 'harsh', as some people say
that a harsh sound is intermediate. 'Clear', then, is an
ambiguous term, and likewise also 'obscure'. See, moreover, if
some of them have more than one intermediate, while others
have but one, as is the case with 'clear' and 'obscure', for in the
case of colours there are numbers of intermediates, whereas in
regard to sound there is but one, viz. 'harsh'.
Again, in the case of the contradictory opposite, look and see if
it bears more than one meaning. For if this bears more than one
meaning, then the opposite of it also will be used in more than
one meaning; e.g. 'to fail to see' a phrase with more than one
meaning, viz. (1) to fail to possess the power of sight, (2) to fail
to put that power to active use. But if this has more than one
meaning, it follows necessarily that 'to see' also has more than
one meaning: for there will be an opposite to each sense of 'to
fail to see'; e.g. the opposite of 'not to possess the power of
sight' is to possess it, while of 'not to put the power of sight to
active use', the opposite is to put it to active use.
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Moreover, examine the case of terms that denote the privation
or presence of a certain state: for if the one term bears more
than one meaning, then so will the remaining term: e.g. if 'to
have sense' be used with more than one meaning, as applied to
the soul and to the body, then 'to be wanting in sense' too will
be used with more than one meaning, as applied to the soul and
to the body. That the opposition between the terms now in
question depends upon the privation or presence of a certain
state is clear, since animals naturally possess each kind of
'sense', both as applied to the soul and as applied to the body.
Moreover, examine the inflected forms. For if 'justly' has more
than one meaning, then 'just', also, will be used with more than
one meaning; for there will be a meaning of 'just' to each of the
meanings of 'justly'; e.g. if the word 'justly' be used of judging
according to one's own opinion, and also of judging as one
ought, then 'just' also will be used in like manner. In the same
way also, if 'healthy' has more than one meaning, then
'healthily' also will be used with more than one meaning: e.g. if
'healthy' describes both what produces health and what
preserves health and what betokens health, then 'healthily' also
will be used to mean 'in such a way as to produce' or 'preserve'
or 'betoken' health. Likewise also in other cases, whenever the
original term bears more than one meaning, the inflexion also
that is formed from it will be used with more than one
meaning, and vice versa.
Look also at the classes of the predicates signified by the term,
and see if they are the same in all cases. For if they are not the
same, then clearly the term is ambiguous: e.g. 'good' in the case
of food means 'productive of pleasure', and in the case of
medicine 'productive of health', whereas as applied to the soul
it means to be of a certain quality, e.g. temperate or courageous
or just: and likewise also, as applied to 'man'. Sometimes it
signifies what happens at a certain time, as (e.g.) the good that
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happens at the right time: for what happens at the right time is
called good. Often it signifies what is of certain quantity, e.g. as
applied to the proper amount: for the proper amount too is
called good. So then the term 'good' is ambiguous. In the same
way also 'clear', as applied to a body, signifies a colour, but in
regard to a note it denotes what is 'easy to hear'. 'Sharp', too, is
in a closely similar case: for the same term does not bear the
same meaning in all its applications: for a sharp note is a swift
note, as the mathematical theorists of harmony tell us, whereas
a sharp (acute) angle is one that is less than a right angle, while
a sharp dagger is one containing a sharp angle (point).
Look also at the genera of the objects denoted by the same
term, and see if they are different without being subaltern, as
(e.g.) 'donkey', which denotes both the animal and the engine.
For the definition of them that corresponds to the name is
different: for the one will be declared to be an animal of a
certain kind, and the other to be an engine of a certain kind. If,
however, the genera be subaltern, there is no necessity for the
definitions to be different. Thus (e.g.) 'animal' is the genus of
'raven', and so is 'bird'. Whenever therefore we say that the
raven is a bird, we also say that it is a certain kind of animal, so
that both the genera are predicated of it. Likewise also
whenever we call the raven a 'flying biped animal', we declare it
to be a bird: in this way, then, as well, both the genera are
predicated of raven, and also their definition. But in the case of
genera that are not subaltern this does not happen, for
whenever we call a thing an 'engine', we do not call it an
animal, nor vice versa.
Look also and see not only if the genera of the term before you
are different without being subaltern, but also in the case of its
contrary: for if its contrary bears several senses, clearly the term
before you does so as well.
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It is useful also to look at the definition that arises from the use
of the term in combination, e.g. of a 'clear (lit. white) body' of a
'clear note'. For then if what is peculiar in each case be
abstracted, the same expression ought to remain over. This does
not happen in the case of ambiguous terms, e.g. in the cases
just mentioned. For the former will be body possessing such
and such a colour', while the latter will be 'a note easy to hear'.
Abstract, then, 'a body 'and' a note', and the remainder in each
case is not the same. It should, however, have been had the
meaning of 'clear' in each case been synonymous.
Often in the actual definitions as well ambiguity creeps in
unawares, and for this reason the definitions also should be
examined. If (e.g.) any one describes what betokens and what
produces health as 'related commensurably to health', we must
not desist but go on to examine in what sense he has used the
term 'commensurably' in each case, e.g. if in the latter case it
means that 'it is of the right amount to produce health',
whereas in the for it means that 'it is such as to betoken what
kind of state prevails'.
Moreover, see if the terms cannot be compared as 'more or less'
or as 'in like manner', as is the case (e.g.) with a 'clear' (lit.
white) sound and a 'clear' garment, and a 'sharp' flavour and a
'sharp' note. For neither are these things said to be clear or
sharp 'in a like degree', nor yet is the one said to be clearer or
sharper than the other. 'Clear', then, and 'sharp' are ambiguous.
For synonyms are always comparable; for they will always be
used either in like manner, or else in a greater degree in one
case.
Now since of genera that are different without being subaltern
the differentiae also are different in kind, e.g. those of 'animal'
and 'knowledge' (for the differentiae of these are different), look
and see if the meanings comprised under the same term are
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differentiae of genera that are different without being subaltern,
as e.g. 'sharp' is of a 'note' and a 'solid'. For being 'sharp'
differentiates note from note, and likewise also one solid from
another. 'Sharp', then, is an ambiguous term: for it forms
differentiae of genera that are different without being subaltern.
Again, see if the actual meanings included under the same term
themselves have different differentiae, e.g. 'colour' in bodies
and 'colour' in tunes: for the differentiae of 'colour' in bodies are
'sight-piercing' and 'sight compressing', whereas 'colour' in
melodies has not the same differentiae. Colour, then, is an
ambiguous term; for things that are the same have the same
differentiae.
Moreover, since the species is never the differentia of anything,
look and see if one of the meanings included under the same
term be a species and another a differentia, as (e.g.) clear' (lit.
white) as applied to a body is a species of colour, whereas in the
case of a note it is a differentia; for one note is differentiated
from another by being 'clear'.
16
The presence, then, of a number of meanings in a term may be
investigated by these and like means. The differences which
things present to each other should be examined within the
same genera, e.g. 'Wherein does justice differ from courage, and
wisdom from temperance?' - for all these belong to the same
genus; and also from one genus to another, provided they be not
very much too far apart, e.g. 'Wherein does sensation differ
from knowledge?: for in the case of genera that are very far
apart, the differences are entirely obvious.
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17
Likeness should be studied, first, in the case of things belonging
to different genera, the formulae being 'A:B = C:D' (e.g. as
knowledge stands to the object of knowledge, so is sensation
related to the object of sensation), and 'As A is in B, so is C in D'
(e.g. as sight is in the eye, so is reason in the soul, and as is a
calm in the sea, so is windlessness in the air). Practice is more
especially needed in regard to terms that are far apart; for in the
case of the rest, we shall be more easily able to see in one
glance the points of likeness. We should also look at things
which belong to the same genus, to see if any identical attribute
belongs to them all, e.g. to a man and a horse and a dog; for in
so far as they have any identical attribute, in so far they are
alike.
18
It is useful to have examined the number of meanings of a term
both for clearness' sake (for a man is more likely to know what
it is he asserts, if it bas been made clear to him how many
meanings it may have), and also with a view to ensuring that
our reasonings shall be in accordance with the actual facts and
not addressed merely to the term used. For as long as it is not
clear in how many senses a term is used, it is possible that the
answerer and the questioner are not directing their minds upon
the same thing: whereas when once it has been made clear how
many meanings there are, and also upon which of them the
former directs his mind when he makes his assertion, the
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questioner would then look ridiculous if he failed to address his
argument to this. It helps us also both to avoid being misled and
to mislead by false reasoning: for if we know the number of
meanings of a term, we shall certainly never be misled by false
reasoning, but shall know if the questioner fails to address his
argument to the same point; and when we ourselves put the
questions we shall be able to mislead him, if our answerer
happens not to know the number of meanings of our terms.
This, however, is not possible in all cases, but only when of the
many senses some are true and others are false. This manner of
argument, however, does not belong properly to dialectic;
dialecticians should therefore by all means beware of this kind
of verbal discussion, unless any one is absolutely unable to
discuss the subject before him in any other way.
The discovery of the differences of things helps us both in
reasonings about sameness and difference, and also in
recognizing what any particular thing is. That it helps us in
reasoning about sameness and difference is clear: for when we
have discovered a difference of any kind whatever between the
objects before us, we shall already have shown that they are not
the same: while it helps us in recognizing what a thing is,
because we usually distinguish the expression that is proper to
the essence of each particular thing by means of the
differentiae that are proper to it.
The examination of likeness is useful with a view both to
inductive arguments and to hypothetical reasonings, and also
with a view to the rendering of definitions. It is useful for
inductive arguments, because it is by means of an induction of
individuals in cases that are alike that we claim to bring the
universal in evidence: for it is not easy to do this if we do not
know the points of likeness. It is useful for hypothetical
reasonings because it is a general opinion that among similars
what is true of one is true also of the rest. If, then, with regard
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to any of them we are well supplied with matter for a
discussion, we shall secure a preliminary admission that
however it is in these cases, so it is also in the case before us:
then when we have shown the former we shall have shown, on
the strength of the hypothesis, the matter before us as well: for
we have first made the hypothesis that however it is in these
cases, so it is also in the case before us, and have then proved
the point as regards these cases. It is useful for the rendering of
definitions because, if we are able to see in one glance what is
the same in each individual case of it, we shall be at no loss into
what genus we ought to put the object before us when we
define it: for of the common predicates that which is most
definitely in the category of essence is likely to be the genus.
Likewise, also, in the case of objects widely divergent, the
examination of likeness is useful for purposes of definition, e.g.
the sameness of a calm at sea, and windlessness in the air (each
being a form of rest), and of a point on a line and the unit in
number - each being a starting point. If, then, we render as the
genus what is common to all the cases, we shall get the credit
of defining not inappropriately. Definition-mongers too nearly
always render them in this way: they declare the unit to be the
startingpoint of number, and the point the startingpoint of a
line. It is clear, then, that they place them in that which is
common to both as their genus.
The means, then, whereby reasonings are effected, are these:
the commonplace rules, for the observance of which the
aforesaid means are useful, are as follows.
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Book II
Of problems some are universal, others particular. Universal
problems are such as 'Every pleasure is good' and 'No pleasure
is good'; particular problems are such as 'Some pleasure is good'
and 'Some pleasure is not good'. The methods of establishing
and overthrowing a view universally are common to both kinds
of problems; for when we have shown that a predicate belongs
in every case, we shall also have shown that it belongs in some
cases. Likewise, also, if we show that it does not belong in any
case, we shall also have shown that it does not belong in every
case. First, then, we must speak of the methods of overthrowing
a view universally, because such are common to both universal
and particular problems, and because people more usually
introduce theses asserting a predicate than denying it, while
those who argue with them overthrow it. The conversion of an
appropriate name which is drawn from the element 'accident' is
an extremely precarious thing; for in the case of accidents and
in no other it is possible for something to be true conditionally
and not universally. Names drawn from the elements
'definition' and 'property' and 'genus' are bound to be
convertible; e.g. if 'to be an animal that walks on two feet is an
attribute of S', then it will be true by conversion to say that 'S is
an animal that walks on two feet'. Likewise, also, if drawn from
the genus; for if 'to be an animal is an attribute of S', then 'S is
an animal'. The same is true also in the case of a property; for if
'to be capable of learning grammar is an attribute of S', then 'S
will be capable of learning grammar'. For none of these
attributes can possibly belong or not belong in part; they must
either belong or not belong absolutely. In the case of accidents,
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on the other hand, there is nothing to prevent an attribute (e.g.
whiteness or justice) belonging in part, so that it is not enough
to show that whiteness or justice is an attribute of a man in
order to show that he is white or just; for it is open to dispute it
and say that he is white or just in part only. Conversion, then, is
not a necessary process in the case of accidents.
We must also define the errors that occur in problems. They are
of two kinds, caused either by false statement or by
transgression of the established diction. For those who make
false statements, and say that an attribute belongs to thing
which does not belong to it, commit error; and those who call
objects by the names of other objects (e.g. calling a planetree a
'man') transgress the established terminology.
Now one commonplace rule is to look and see if a man has
ascribed as an accident what belongs in some other way. This
mistake is most commonly made in regard to the genera of
things, e.g. if one were to say that white happens (accidit) to be
a colour - for being a colour does not happen by accident to
white, but colour is its genus. The assertor may of course define
it so in so many words, saying (e.g.) that 'Justice happens
(accidit) to be a virtue'; but often even without such definition it
is obvious that he has rendered the genus as an accident; e.g.
suppose that one were to say that whiteness is coloured or that
walking is in motion. For a predicate drawn from the genus is
never ascribed to the species in an inflected form, but always
the genera are predicated of their species literally; for the
species take on both the name and the definition of their
genera. A man therefore who says that white is 'coloured' has
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not rendered 'coloured' as its genus, seeing that he has used an
inflected form, nor yet as its property or as its definition: for the
definition and property of a thing belong to it and to nothing
else, whereas many things besides white are coloured, e.g. a log,
a stone, a man, and a horse. Clearly then he renders it as an
accident.
Another rule is to examine all cases where a predicate has been
either asserted or denied universally to belong to something.
Look at them species by species, and not in their infinite
multitude: for then the inquiry will proceed more directly and
in fewer steps. You should look and begin with the most
primary groups, and then proceed in order down to those that
are not further divisible: e.g. if a man has said that the
knowledge of opposites is the same, you should look and see
whether it be so of relative opposites and of contraries and of
terms signifying the privation or presence of certain states, and
of contradictory terms. Then, if no clear result be reached so far
in these cases, you should again divide these until you come to
those that are not further divisible, and see (e.g.) whether it be
so of just deeds and unjust, or of the double and the half, or of
blindness and sight, or of being and not-being: for if in any case
it be shown that the knowledge of them is not the same we
shall have demolished the problem. Likewise, also, if the
predicate belongs in no case. This rule is convertible for both
destructive and constructive purposes: for if, when we have
suggested a division, the predicate appears to hold in all or in a
large number of cases, we may then claim that the other should
actually assert it universally, or else bring a negative instance to
show in what case it is not so: for if he does neither of these
things, a refusal to assert it will make him look absurd.
Another rule is to make definitions both of an accident and of
its subject, either of both separately or else of one of them, and
then look and see if anything untrue has been assumed as true
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in the definitions. Thus (e.g.) to see if it is possible to wrong a
god, ask what is 'to wrong? For if it be 'to injure deliberately',
clearly it is not possible for a god to be wronged: for it is
impossible that God should be injured. Again, to see if the good
man is jealous, ask who is the 'jealous' man and what is
'jealousy'. For if 'jealousy' is pain at the apparent success of
some well-behaved person, clearly the good man is not jealous:
for then he would be bad. Again, to see if the indignant man is
jealous, ask who each of them is: for then it will be obvious
whether the statement is true or false; e.g. if he is 'jealous' who
grieves at the successes of the good, and he is 'indignant' who
grieves at the successes of the evil, then clearly the indignant
man would not be jealous. A man should substitute definitions
also for the terms contained in his definitions, and not stop
until he comes to a familiar term: for often if the definition be
rendered whole, the point at issue is not cleared up, whereas if
for one of the terms used in the definition a definition be stated,
it becomes obvious.
Moreover, a man should make the problem into a proposition
for himself, and then bring a negative instance against it: for the
negative instance will be a ground of attack upon the assertion.
This rule is very nearly the same as the rule to look into cases
where a predicate has been attributed or denied universally: but
it differs in the turn of the argument.
Moreover, you should define what kind of things should be
called as most men call them, and what should not. For this is
useful both for establishing and for overthrowing a view: e.g.
you should say that we ought to use our terms to mean the
same things as most people mean by them, but when we ask
what kind of things are or are not of such and such a kind, we
should not here go with the multitude: e.g. it is right to call
'healthy' whatever tends to produce health, as do most men:
but in saying whether the object before us tends to produce
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health or not, we should adopt the language no longer of the
multitude but of the doctor.
Moreover, if a term be used in several senses, and it has been
laid down that it is or that it is not an attribute of S, you should
show your case of one of its several senses, if you cannot show
it of both. This rule is to be observed in cases where the
difference of meaning is undetected; for supposing this to be
obvious, then the other man will object that the point which he
himself questioned has not been discussed, but only the other
point. This commonplace rule is convertible for purposes both
of establishing and of overthrowing a view. For if we want to
establish a statement, we shall show that in one sense the
attribute belongs, if we cannot show it of both senses: whereas
if we are overthrowing a statement, we shall show that in one
sense the attribute does not belong, if we cannot show it of both
senses. Of course, in overthrowing a statement there is no need
to start the discussion by securing any admission, either when
the statement asserts or when it denies the attribute
universally: for if we show that in any case whatever the
attribute does not belong, we shall have demolished the
universal assertion of it, and likewise also if we show that it
belongs in a single case, we shall demolish the universal denial
of it. Whereas in establishing a statement we ought to secure a
preliminary admission that if it belongs in any case whatever, it
belongs universally, supposing this claim to be a plausible one.
For it is not enough to discuss a single instance in order to show
that an attribute belongs universally; e.g. to argue that if the
soul of man be immortal, then every soul is immortal, so that a
previous admission must be secured that if any soul whatever
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be immortal, then every soul is immortal. This is not to be done
in every case, but only whenever we are not easily able to quote
any single argument applying to all cases in common, as (e.g.)
the geometrician can argue that the triangle has its angles
equal to two right angles.
If, again, the variety of meanings of a term be obvious,
distinguish how many meanings it has before proceeding either
to demolish or to establish it: e.g. supposing 'the right' to mean
'the expedient' or 'the honourable', you should try either to
establish or to demolish both descriptions of the subject in
question; e.g. by showing that it is honourable and expedient, or
that it is neither honourable nor expedient. Supposing, however,
that it is impossible to show both, you should show the one,
adding an indication that it is true in the one sense and not in
the other. The same rule applies also when the number of
senses into which it is divided is more than two.
Again, consider those expressions whose meanings are many,
but differ not by way of ambiguity of a term, but in some other
way: e.g. 'The science of many things is one': here 'many things'
may mean the end and the means to that end, as (e.g.) medicine
is the science both of producing health and of dieting; or they
may be both of them ends, as the science of contraries is said to
be the same (for of contraries the one is no more an end than
the other); or again they may be an essential and an accidental
attribute, as (e.g.) the essential fact that the triangle has its
angles equal to two right angles, and the accidental fact that the
equilateral figure has them so: for it is because of the accident
of the equilateral triangle happening to be a triangle that we
know that it has its angles equal to two right angles. If, then, it
is not possible in any sense of the term that the science of
many things should be the same, it clearly is altogether
impossible that it should be so; or, if it is possible in some sense,
then clearly it is possible. Distinguish as many meanings as are
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required: e.g. if we want to establish a view, we should bring
forward all such meanings as admit that view and should divide
them only into those meanings which also are required for the
establishment of our case: whereas if we want to overthrow a
view, we should bring forward all that do not admit that view,
and leave the rest aside. We must deal also in these cases as
well with any uncertainty about the number of meanings
involved. Further, that one thing is, or is not, 'of another should
be established by means of the same commonplace rules; e.g.
that a particular science is of a particular thing, treated either
as an end or as a means to its end, or as accidentally connected
with it; or again that it is not 'of it in any of the aforesaid ways.
The same rule holds true also of desire and all other terms that
have more than one object. For the 'desire of X' may mean the
desire of it as an end (e.g. the desire of health) or as a means to
an end (e.g. the desire of being doctored), or as a thing desired
accidentally, as, in the case of wine, the sweet-toothed person
desires it not because it is wine but because it is sweet. For
essentially he desires the sweet, and only accidentally the wine:
for if it be dry, he no longer desires it. His desire for it is
therefore accidental. This rule is useful in dealing with relative
terms: for cases of this kind are generally cases of relative
terms.
Moreover, it is well to alter a term into one more familiar, e.g. to
substitute 'clear' for 'exact' in describing a conception, and
'being fussy' for 'being busy': for when the expression is made
more familiar, the thesis becomes easier to attack. This
commonplace rule also is available for both purposes alike, both
for establishing and for overthrowing a view.
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In order to show that contrary attributes belong to the same
thing, look at its genus; e.g. if we want to show that Tightness
and wrongness are possible in regard to perception, and to
perceive is to judge, while it is possible to judge rightly or
wrongly, then in regard to perception as well Tightness and
wrongness must be possible. In the present instance the proof
proceeds from the genus and relates to the species: for 'to
judge' is the genus of 'to perceive'; for the man who perceives
judges in a certain way. But per contra it may proceed from the
species to the genus: for all the attributes that belong to the
species belong to the genus as well; e.g. if there is a bad and a
good knowledge there is also a bad and a good disposition: for
'disposition' is the genus of knowledge. Now the former
commonplace argument is fallacious for purposes of
establishing a view, while the second is true. For there is no
necessity that all the attributes that belong to the genus should
belong also to the species; for 'animal' is flying and quadruped,
but not so 'man'. All the attributes, on the other hand, that
belong to the species must of necessity belong also to the
genus; for if 'man' is good, then animal also is good. On the
other hand, for purposes of overthrowing a view, the former
argument is true while the latter is fallacious; for all the
attributes which do not belong to the genus do not belong to the
species either; whereas all those that are wanting to the species
are not of necessity wanting to the genus.
Since those things of which the genus is predicated must also of
necessity have one of its species predicated of them, and since
those things that are possessed of the genus in question, or are
described by terms derived from that genus, must also of
necessity be possessed of one of its species or be described by
terms derived from one of its species (e.g. if to anything the
term 'scientific knowledge' be applied, then also there will be
applied to it the term 'grammatical' or 'musical' knowledge, or
knowledge of one of the other sciences; and if any one
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possesses scientific knowledge or is described by a term derived
from 'science', then he will also possess grammatical or musical
knowledge or knowledge of one of the other sciences, or will be
described by a term derived from one of them, e.g. as a
'grammarian' or a 'musician') - therefore if any expression be
asserted that is in any way derived from the genus (e.g. that the
soul is in motion), look and see whether it be possible for the
soul to be moved with any of the species of motion; whether
(e.g.) it can grow or be destroyed or come to be, and so forth
with all the other species of motion. For if it be not moved in
any of these ways, clearly it does not move at all. This
commonplace rule is common for both purposes, both for
overthrowing and for establishing a view: for if the soul moves
with one of the species of motion, clearly it does move; while if
it does not move with any of the species of motion, clearly it
does not move.
If you are not well equipped with an argument against the
assertion, look among the definitions, real or apparent, of the
thing before you, and if one is not enough, draw upon several.
For it will be easier to attack people when committed to a
definition: for an attack is always more easily made on
definitions.
Moreover, look and see in regard to the thing in question, what
it is whose reality conditions the reality of the thing in question,
or what it is whose reality necessarily follows if the thing in
question be real: if you wish to establish a view inquire what
there is on whose reality the reality of the thing in question will
follow (for if the former be shown to be real, then the thing in
question will also have been shown to be real); while if you
want to overthrow a view, ask what it is that is real if the thing
in question be real, for if we show that what follows from the
thing in question is unreal, we shall have demolished the thing
in question.
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Moreover, look at the time involved, to see if there be any
discrepancy anywhere: e.g. suppose a man to have stated that
what is being nourished of necessity grows: for animals are
always of necessity being nourished, but they do not always
grow. Likewise, also, if he has said that knowing is
remembering: for the one is concerned with past time, whereas
the other has to do also with the present and the future. For we
are said to know things present and future (e.g. that there will
be an eclipse), whereas it is impossible to remember anything
save what is in the past.
Moreover, there is the sophistic turn of argument, whereby we
draw our opponent into the kind of statement against which we
shall be well supplied with lines of argument. This process is
sometimes a real necessity, sometimes an apparent necessity,
sometimes neither an apparent nor a real necessity. It is really
necessary whenever the answerer has denied any view that
would be useful in attacking the thesis, and the questioner
thereupon addresses his arguments to the support of this view,
and when moreover the view in question happens to be one of a
kind on which he has a good stock of lines of argument.
Likewise, also, it is really necessary whenever he (the
questioner) first, by an induction made by means of the view
laid down, arrives at a certain statement and then tries to
demolish that statement: for when once this has been
demolished, the view originally laid down is demolished as well.
It is an apparent necessity, when the point to which the
discussion comes to be directed appears to be useful, and
relevant to the thesis, without being really so; whether it be that
the man who is standing up to the argument has refused to
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concede something, or whether he (the questioner) has first
reached it by a plausible induction based upon the thesis and
then tries to demolish it. The remaining case is when the point
to which the discussion comes to be directed is neither really
nor apparently necessary, and it is the answerer's luck to be
confuted on a mere side issue You should beware of the last of
the aforesaid methods; for it appears to be wholly disconnected
from, and foreign to, the art of dialectic. For this reason,
moreover, the answerer should not lose his temper, but assent
to those statements that are of no use in attacking the thesis,
adding an indication whenever he assents although he does not
agree with the view. For, as a rule, it increases the confusion of
questioners if, after all propositions of this kind have been
granted them, they can then draw no conclusion.
Moreover, any one who has made any statement whatever has
in a certain sense made several statements, inasmuch as each
statement has a number of necessary consequences: e.g. the
man who said 'X is a man' has also said that it is an animal and
that it is animate and a biped and capable of acquiring reason
and knowledge, so that by the demolition of any single one of
these consequences, of whatever kind, the original statement is
demolished as well. But you should beware here too of making a
change to a more difficult subject: for sometimes the
consequence, and sometimes the original thesis, is the easier to
demolish.
In regard to subjects which must have one and one only of two
predicates, as (e.g.) a man must have either a disease or health,
supposing we are well supplied as regards the one for arguing
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its presence or absence, we shall be well equipped as regards
the remaining one as well. This rule is convertible for both
purposes: for when we have shown that the one attribute
belongs, we shall have shown that the remaining one does not
belong; while if we show that the one does not belong, we shall
have shown that the remaining one does belong. Clearly then
the rule is useful for both purposes.
Moreover, you may devise a line of attack by reinterpreting a
term in its literal meaning, with the implication that it is most
fitting so to take it rather than in its established meaning: e.g.
the expression 'strong at heart' will suggest not the courageous
man, according to the use now established, but the man the
state of whose heart is strong; just as also the expression 'of a
good hope' may be taken to mean the man who hopes for good
things. Likewise also 'well-starred' may be taken to mean the
man whose star is good, as Xenocrates says 'well-starred is he
who has a noble soul'.' For a man's star is his soul.
Some things occur of necessity, others usually, others however it
may chance; if therefore a necessary event has been asserted to
occur usually, or if a usual event (or, failing such an event itself,
its contrary) has been stated to occur of necessity, it always
gives an opportunity for attack. For if a necessary event has
been asserted to occur usually, clearly the speaker has denied
an attribute to be universal which is universal, and so has made
a mistake: and so he has if he has declared the usual attribute
to be necessary: for then he declares it to belong universally
when it does not so belong. Likewise also if he has declared the
contrary of what is usual to be necessary. For the contrary of a
usual attribute is always a comparatively rare attribute: e.g. if
men are usually bad, they are comparatively seldom good, so
that his mistake is even worse if he has declared them to be
good of necessity. The same is true also if he has declared a
mere matter of chance to happen of necessity or usually; for a
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chance event happens neither of necessity nor usually. If the
thing happens usually, then even supposing his statement does
not distinguish whether he meant that it happens usually or
that it happens necessarily, it is open to you to discuss it on the
assumption that he meant that it happens necessarily: e.g. if he
has stated without any distinction that disinherited persons are
bad, you may assume in discussing it that he means that they
are so necessarily.
Moreover, look and see also if he has stated a thing to be an
accident of itself, taking it to be a different thing because it has
a different name, as Prodicus used to divide pleasures into joy
and delight and good cheer: for all these are names of the same
thing, to wit, Pleasure. If then any one says that joyfulness is an
accidental attribute of cheerfulness, he would be declaring it to
be an accidental attribute of itself.
Inasmuch as contraries can be conjoined with each other in six
ways, and four of these conjunctions constitute a contrariety,
we must grasp the subject of contraries, in order that it may
help us both in demolishing and in establishing a view. Well
then, that the modes of conjunction are six is clear: for either (1)
each of the contrary verbs will be conjoined to each of the
contrary objects; and this gives two modes: e.g. to do good to
friends and to do evil to enemies, or per contra to do evil to
friends and to do good to enemies. Or else (2) both verbs may be
attached to one object; and this too gives two modes, e.g. to do
good to friends and to do evil to friends, or to do good to
enemies and to do evil to enemies. Or (3) a single verb may be
attached to both objects: and this also gives two modes; e.g. to
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do good to friends and to do good to enemies, or to do evil to
friends and evil to enemies.
The first two then of the aforesaid conjunctions do not
constitute any contrariety; for the doing of good to friends is not
contrary to the doing of evil to enemies: for both courses are
desirable and belong to the same disposition. Nor is the doing of
evil to friends contrary to the doing of good to enemies: for both
of these are objectionable and belong to the same disposition:
and one objectionable thing is not generally thought to be the
contrary of another, unless the one be an expression denoting
an excess, and the other an expression denoting a defect: for an
excess is generally thought to belong to the class of
objectionable things, and likewise also a defect. But the other
four all constitute a contrariety. For to do good to friends is
contrary to the doing of evil to friends: for it proceeds from the
contrary disposition, and the one is desirable, and the other
objectionable. The case is the same also in regard to the other
conjunctions: for in each combination the one course is
desirable, and the other objectionable, and the one belongs to a
reasonable disposition and the other to a bad. Clearly, then,
from what has been said, the same course has more than one
contrary. For the doing of good to friends has as its contrary
both the doing of good to enemies and the doing of evil to
friends. Likewise, if we examine them in the same way, we shall
find that the contraries of each of the others also are two in
number. Select therefore whichever of the two contraries is
useful in attacking the thesis.
Moreover, if the accident of a thing have a contrary, see whether
it belongs to the subject to which the accident in question has
been declared to belong: for if the latter belongs the former
could not belong; for it is impossible that contrary predicates
should belong at the same time to the same thing.
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Or again, look and see if anything has been said about
something, of such a kind that if it be true, contrary predicates
must necessarily belong to the thing: e.g. if he has said that the
'Ideas' exist in us. For then the result will be that they are both
in motion and at rest, and moreover that they are objects both
of sensation and of thought. For according to the views of those
who posit the existence of Ideas, those Ideas are at rest and are
objects of thought; while if they exist in us, it is impossible that
they should be unmoved: for when we move, it follows
necessarily that all that is in us moves with us as well. Clearly
also they are objects of sensation, if they exist in us: for it is
through the sensation of sight that we recognize the Form
present in each individual.
Again, if there be posited an accident which has a contrary, look
and see if that which admits of the accident will admit of its
contrary as well: for the same thing admits of contraries. Thus
(e.g.) if he has asserted that hatred follows anger, hatred would
in that case be in the 'spirited faculty': for that is where anger is.
You should therefore look and see if its contrary, to wit,
friendship, be also in the 'spirited faculty': for if not - if
friendship is in the faculty of desire - then hatred could not
follow anger. Likewise also if he has asserted that the faculty of
desire is ignorant. For if it were capable of ignorance, it would be
capable of knowledge as well: and this is not generally held - I
mean that the faculty of desire is capable of knowledge. For
purposes, then, of overthrowing a view, as has been said, this
rule should be observed: but for purposes of establishing one,
though the rule will not help you to assert that the accident
actually belongs, it will help you to assert that it may possibly
belong. For having shown that the thing in question will not
admit of the contrary of the accident asserted, we shall have
shown that the accident neither belongs nor can possibly
belong; while on the other hand, if we show that the contrary
belongs, or that the thing is capable of the contrary, we shall not
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indeed as yet have shown that the accident asserted does
belong as well; our proof will merely have gone to this point,
that it is possible for it to belong.
8
Seeing that the modes of opposition are four in number, you
should look for arguments among the contradictories of your
terms, converting the order of their sequence, both when
demolishing and when establishing a view, and you should
secure them by means of induction - such arguments (e.g.) as
that man be an animal, what is not an animal is not a man':
and likewise also in other instances of contradictories. For in
those cases the sequence is converse: for 'animal' follows upon
'man but 'not-animal' does not follow upon 'not-man', but
conversely 'not-man' upon 'not-animal'. In all cases, therefore, a
postulate of this sort should be made, (e.g.) that 'If the
honourable is pleasant, what is not pleasant is not honourable,
while if the latter be untrue, so is the former'. Likewise, also, 'If
what is not pleasant be not honourable, then what is
honourable is pleasant'. Clearly, then, the conversion of the
sequence formed by contradiction of the terms of the thesis is a
method convertible for both purposes.
Then look also at the case of the contraries of S and P in the
thesis, and see if the contrary of the one follows upon the
contrary of the other, either directly or conversely, both when
you are demolishing and when you are establishing a view:
secure arguments of this kind as well by means of induction, so
far as may be required. Now the sequence is direct in a case
such as that of courage and cowardice: for upon the one of
them virtue follows, and vice upon the other; and upon the one
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it follows that it is desirable, while upon the other it follows that
it is objectionable. The sequence, therefore, in the latter case
also is direct; for the desirable is the contrary of the
objectionable. Likewise also in other cases. The sequence is, on
the other hand, converse in such a case as this: Health follows
upon vigour, but disease does not follow upon debility; rather
debility follows upon disease. In this case, then, clearly the
sequence is converse. Converse sequence is, however, rare in
the case of contraries; usually the sequence is direct. If,
therefore, the contrary of the one term does not follow upon the
contrary of the other either directly or conversely, clearly
neither does the one term follow upon the other in the
statement made: whereas if the one followed the other in the
case of the contraries, it must of necessity do so as well in the
original statement.
You should look also into cases of the privation or presence of a
state in like manner to the case of contraries. Only, in the case
of such privations the converse sequence does not occur: the
sequence is always bound to be direct: e.g. as sensation follows
sight, while absence of sensation follows blindness. For the
opposition of sensation to absence of sensation is an opposition
of the presence to the privation of a state: for the one of them is
a state, and the other the privation of it.
The case of relative terms should also be studied in like manner
to that of a state and its privation: for the sequence of these as
well is direct; e.g. if 3/1 is a multiple, then 1/3 is a fraction: for
3/1 is relative to 1/3, and so is a multiple to a fraction. Again, if
knowledge be a conceiving, then also the object of knowledge is
an object of conception; and if sight be a sensation, then also
the object of sight is an object of sensation. An objection may be
made that there is no necessity for the sequence to take place,
in the case of relative terms, in the way described: for the object
of sensation is an object of knowledge, whereas sensation is not
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knowledge. The objection is, however, not generally received as
really true; for many people deny that there is knowledge of
objects of sensation. Moreover, the principle stated is just as
useful for the contrary purpose, e.g. to show that the object of
sensation is not an object of knowledge, on the ground that
neither is sensation knowledge.
Again look at the case of the co-ordinates and inflected forms of
the terms in the thesis, both in demolishing and in establishing
it. By co-ordinates' are meant terms such as the following: 'Just
deeds' and the 'just man' are coordinates of 'justice', and
'courageous deeds' and the 'courageous man' are co-ordinates
of courage. Likewise also things that tend to produce and to
preserve anything are called co-ordinates of that which they
tend to produce and to preserve, as e.g. 'healthy habits' are co-
ordinates of 'health' and a 'vigorous constitutional' of a
'vigorous constitution' and so forth also in other cases. 'Co-
ordinate', then, usually describes cases such as these, whereas
'inflected forms' are such as the following: 'justly',
'courageously', 'healthily', and such as are formed in this way. It
is usually held that words when used in their inflected forms as
well are co-ordinates, as (e.g.) 'justly' in relation to justice, and
'courageously' to courage; and then 'co-ordinate' describes all
the members of the same kindred series, e.g. 'justice', 'just', of a
man or an act, 'justly'. Clearly, then, when any one member,
whatever its kind, of the same kindred series is shown to be
good or praiseworthy, then all the rest as well come to be shown
to be so: e.g. if 'justice' be something praiseworthy, then so will
'just', of a man or thing, and 'justly' connote something
praiseworthy. Then 'justly' will be rendered also 'praiseworthily',
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derived will by the same inflexion from 'the praiseworthy'
whereby 'justly' is derived from 'justice'.
Look not only in the case of the subject mentioned, but also in
the case of its contrary, for the contrary predicate: e.g. argue
that good is not necessarily pleasant; for neither is evil painful:
or that, if the latter be the case, so is the former. Also, if justice
be knowledge, then injustice is ignorance: and if 'justly' means
'knowingly' and 'skilfully', then 'unjustly' means 'ignorantly'
and 'unskilfully': whereas if the latter be not true, neither is the
former, as in the instance given just now: for 'unjustly' is more
likely to seem equivalent to 'skilfully' than to 'unskilfully'. This
commonplace rule has been stated before in dealing with the
sequence of contraries; for all we are claiming now is that the
contrary of P shall follow the contrary of S.
Moreover, look at the modes of generation and destruction of a
thing, and at the things which tend to produce or to destroy it,
both in demolishing and in establishing a view. For those things
whose modes of generation rank among good things, are
themselves also good; and if they themselves be good, so also
are their modes of generation. If, on the other hand, their
modes of generation be evil, then they themselves also are evil.
In regard to modes of destruction the converse is true: for if the
modes of destruction rank as good things, then they themselves
rank as evil things; whereas if the modes of destruction count
as evil, they themselves count as good. The same argument
applies also to things tending to produce and destroy: for things
whose productive causes are good, themselves also rank as
good; whereas if causes destructive of them are good, they
themselves rank as evil.
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10
Again, look at things which are like the subject in question, and
see if they are in like case; e.g. if one branch of knowledge has
more than one object, so also will one opinion; and if to possess
sight be to see, then also to possess hearing will be to hear.
Likewise also in the case of other things, both those which are
and those which are generally held to be like. The rule in
question is useful for both purposes; for if it be as stated in the
case of some one like thing, it is so with the other like things as
well, whereas if it be not so in the case of some one of them,
neither is it so in the case of the others. Look and see also
whether the cases are alike as regards a single thing and a
number of things: for sometimes there is a discrepancy. Thus, if
to 'know' a thing be to 'think of it, then also to 'know many
things' is to 'be thinking of many things'; whereas this is not
true; for it is possible to know many things but not to be
thinking of them. If, then, the latter proposition be not true,
neither was the former that dealt with a single thing, viz. that to
'know' a thing is to 'think of it.
Moreover, argue from greater and less degrees. In regard to
greater degrees there are four commonplace rules. One is: See
whether a greater degree of the predicate follows a greater
degree of the subject: e.g. if pleasure be good, see whether also a
greater pleasure be a greater good: and if to do a wrong be evil,
see whether also to do a greater wrong is a greater evil. Now
this rule is of use for both purposes: for if an increase of the
accident follows an increase of the subject, as we have said,
clearly the accident belongs; while if it does not follow, the
accident does not belong. You should establish this by
induction. Another rule is: If one predicate be attributed to two
subjects; then supposing it does not belong to the subject to
which it is the more likely to belong, neither does it belong
where it is less likely to belong; while if it does belong where it
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is less likely to belong, then it belongs as well where it is more
likely. Again: If two predicates be attributed to one subject, then
if the one which is more generally thought to belong does not
belong, neither does the one that is less generally thought to
belong; or, if the one that is less generally thought to belong
does belong, so also does the other. Moreover: If two predicates
be attributed to two subjects, then if the one which is more
usually thought to belong to the one subject does not belong,
neither does the remaining predicate belong to the remaining
subject; or, if the one which is less usually thought to belong to
the one subject does belong, so too does the remaining
predicate to the remaining subject.
Moreover, you can argue from the fact that an attribute belongs,
or is generally supposed to belong, in a like degree, in three
ways, viz. those described in the last three rules given in regard
to a greater degree.' For supposing that one predicate belongs, or
is supposed to belong, to two subjects in a like degree, then if it
does not belong to the one, neither does it belong to the other;
while if it belongs to the one, it belongs to the remaining one as
well. Or, supposing two predicates to belong in a like degree to
the same subject, then, if the one does not belong, neither does
the remaining one; while if the one does belong, the remaining
one belongs as well. The case is the same also if two predicates
belong in a like degree to two subjects; for if the one predicate
does not belong to the one subject, neither does the remaining
predicate belong to the remaining subject, while if the one
predicate does belong to the one subject, the remaining
predicate belongs to the remaining subject as well.
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11
You can argue, then, from greater or less or like degrees of truth
in the aforesaid number of ways. Moreover, you should argue
from the addition of one thing to another. If the addition of one
thing to another makes that other good or white, whereas
formerly it was not white or good, then the thing added will be
white or good - it will possess the character it imparts to the
whole as well. Moreover, if an addition of something to a given
object intensifies the character which it had as given, then the
thing added will itself as well be of that character. Likewise,
also, in the case of other attributes. The rule is not applicable in
all cases, but only in those in which the excess described as an
'increased intensity' is found to take place. The above rule is,
however, not convertible for overthrowing a view. For if the
thing added does not make the other good, it is not thereby
made clear whether in itself it may not be good: for the addition
of good to evil does not necessarily make the whole good, any
more than the addition of white to black makes the whole
white.
Again, any predicate of which we can speak of greater or less
degrees belongs also absolutely: for greater or less degrees of
good or of white will not be attributed to what is not good or
white: for a bad thing will never be said to have a greater or less
degree of goodness than another, but always of badness. This
rule is not convertible, either, for the purpose of overthrowing a
predication: for several predicates of which we cannot speak of
a greater degree belong absolutely: for the term 'man' is not
attributed in greater and less degrees, but a man is a man for all
that.
You should examine in the same way predicates attributed in a
given respect, and at a given time and place: for if the predicate
be possible in some respect, it is possible also absolutely.
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Likewise, also, is what is predicated at a given time or place: for
what is absolutely impossible is not possible either in any
respect or at any place or time. An objection may be raised that
in a given respect people may be good by nature, e.g. they may
be generous or temperately inclined, while absolutely they are
not good by nature, because no one is prudent by nature.
Likewise, also, it is possible for a destructible thing to escape
destruction at a given time, whereas it is not possible for it to
escape absolutely. In the same way also it is a good thing at
certain places to follow see and such a diet, e.g. in infected
areas, though it is not a good thing absolutely. Moreover, in
certain places it is possible to live singly and alone, but
absolutely it is not possible to exist singly and alone. In the
same way also it is in certain places honourable to sacrifice
one's father, e.g. among the Triballi, whereas, absolutely, it is not
honourable. Or possibly this may indicate a relativity not to
places but to persons: for it is all the same wherever they may
be: for everywhere it will be held honourable among the Triballi
themselves, just because they are Triballi. Again, at certain
times it is a good thing to take medicines, e.g. when one is ill,
but it is not so absolutely. Or possibly this again may indicate a
relativity not to a certain time, but to a certain state of health:
for it is all the same whenever it occurs, if only one be in that
state. A thing is 'absolutely' so which without any addition you
are prepared to say is honourable or the contrary. Thus (e.g.) you
will deny that to sacrifice one's father is honourable: it is
honourable only to certain persons: it is not therefore
honourable absolutely. On the other hand, to honour the gods
you will declare to be honourable without adding anything,
because that is honourable absolutely. So that whatever without
any addition is generally accounted to be honourable or
dishonourable or anything else of that kind, will be said to be so
'absolutely'.
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Book III
The question which is the more desirable, or the better, of two
or more things, should be examined upon the following lines:
only first of all it must be clearly laid down that the inquiry we
are making concerns not things that are widely divergent and
that exhibit great differences from one another (for nobody
raises any doubt whether happiness or wealth is more
desirable), but things that are nearly related and about which
we commonly discuss for which of the two we ought rather to
vote, because we do not see any advantage on either side as
compared with the other. Clearly, in such cases if we can show a
single advantage, or more than one, our judgement will record
our assent that whichever side happens to have the advantage
is the more desirable.
First, then, that which is more lasting or secure is more
desirable than that which is less so: and so is that which is
more likely to be chosen by the prudent or by the good man or
by the right law, or by men who are good in any particular line,
when they make their choice as such, or by the experts in
regard to any particular class of things; i.e. either whatever most
of them or what all of them would choose; e.g. in medicine or in
carpentry those things are more desirable which most, or all,
doctors would choose; or, in general, whatever most men or all
men or all things would choose, e.g. the good: for everything
aims at the good. You should direct the argument you intend to
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employ to whatever purpose you require. Of what is 'better' or
'more desirable' the absolute standard is the verdict of the
better science, though relatively to a given individual the
standard may be his own particular science.
In the second place, that which is known as 'an x' is more
desirable than that which does not come within the genus 'x' -
e.g. justice than a just man; for the former falls within the
genus 'good', whereas the other does not, and the former is
called 'a good', whereas the latter is not: for nothing which does
not happen to belong to the genus in question is called by the
generic name; e.g. a 'white man' is not 'a colour'. Likewise also
in other cases.
Also, that which is desired for itself is more desirable than that
which is desired for something else; e.g. health is more
desirable than gymnastics: for the former is desired for itself,
the latter for something else. Also, that which is desirable in
itself is more desirable than what is desirable per accidens; e.g.
justice in our friends than justice in our enemies: for the former
is desirable in itself, the latter per accidens: for we desire that
our enemies should be just per accidens, in order that they may
do us no harm. This last principle is the same as the one that
precedes it, with, however, a different turn of expression. For we
desire justice in our friends for itself, even though it will make
no difference to us, and even though they be in India; whereas
in our enemies we desire it for something else, in order that
they may do us no harm.
Also, that which is in itself the cause of good is more desirable
than what is so per accidens, e.g. virtue than luck (for the
former in itself, and the latter per accidens, the cause of good
things), and so in other cases of the same kind. Likewise also in
the case of the contrary; for what is in itself the cause of evil is
more objectionable than what is so per accidens, e.g. vice and
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chance: for the one is bad in itself, whereas chance is so per
accidens.
Also, what is good absolutely is more desirable than what is
good for a particular person, e.g. recovery of health than a
surgical operation; for the former is good absolutely, the latter
only for a particular person, viz. the man who needs an
operation. So too what is good by nature is more desirable than
the good that is not so by nature, e.g. justice than the just man;
for the one is good by nature, whereas in the other case the
goodness is acquired. Also the attribute is more desirable which
belongs to the better and more honourable subject, e.g. to a god
rather than to a man, and to the soul rather than to the body. So
too the property of the better thing is better than the property
of the worse; e.g. the property of God than the property of man:
for whereas in respect of what is common in both of them they
do not differ at all from each other, in respect of their properties
the one surpasses the other. Also that is better which is
inherent in things better or prior or more honourable: thus (e.g.)
health is better than strength and beauty: for the former is
inherent in the moist and the dry, and the hot and the cold, in
fact in all the primary constituents of an animal, whereas the
others are inherent in what is secondary, strength being a
feature of the sinews and bones, while beauty is generally
supposed to consist in a certain symmetry of the limbs. Also the
end is generally supposed to be more desirable than the means,
and of two means, that which lies nearer the end. In general,
too, a means directed towards the end of life is more desirable
than a means to anything else, e.g. that which contributes to
happiness than that which contributes to prudence. Also the
competent is more desirable than the incompetent. Moreover, of
two productive agents that one is more desirable whose end is
better; while between a productive agent and an end we can
decide by a proportional sum whenever the excess of the one
end over the other is greater than that of the latter over its own
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productive means: e.g. supposing the excess of happiness over
health to be greater than that of health over what produces
health, then what produces happiness is better than health. For
what produces happiness exceeds what produces health just as
much as happiness exceeds health. But health exceeds what
produces health by a smaller amount; ergo, the excess of what
produces happiness over what produces health is greater than
that of health over what produces health. Clearly, therefore,
what produces happiness is more desirable than health: for it
exceeds the same standard by a greater amount. Moreover,
what is in itself nobler and more precious and praiseworthy is
more desirable than what is less so, e.g. friendship than wealth,
and justice than strength. For the former belong in themselves
to the class of things precious and praiseworthy, while the latter
do so not in themselves but for something else: for no one
prizes wealth for itself but always for something else, whereas
we prize friendship for itself, even though nothing else is likely
to come to us from it.
Moreover, whenever two things are very much like one another,
and we cannot see any superiority in the one over the other of
them, we should look at them from the standpoint of their
consequences. For the one which is followed by the greater good
is the more desirable: or, if the consequences be evil, that is
more desirable which is followed by the less evil. For though
both may be desirable, yet there may possibly be some
unpleasant consequence involved to turn the scale. Our survey
from the point of view of consequences lies in two directions,
for there are prior consequences and later consequences: e.g. if
a man learns, it follows that he was ignorant before and knows
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afterwards. As a rule, the later consequence is the better to
consider. You should take, therefore, whichever of the
consequences suits your purpose.
Moreover, a greater number of good things is more desirable
than a smaller, either absolutely or when the one is included in
the other, viz. the smaller number in the greater. An objection
may be raised suppose in some particular case the one is valued
for the sake of the other; for then the two together are not more
desirable than the one; e.g. recovery of health and health, than
health alone, inasmuch as we desire recovery of health for the
sake of health. Also it is quite possible for what is not good,
together with what is, to be more desirable than a greater
number of good things, e.g. the combination of happiness and
something else which is not good may be more desirable than
the combination of justice and courage. Also, the same things
are more valuable if accompanied than if unaccompanied by
pleasure, and likewise when free from pain than when attended
with pain.
Also, everything is more desirable at the season when it is of
greater consequence; e.g. freedom from pain in old age more
than in youth: for it is of greater consequence in old age. On the
same principle also, prudence is more desirable in old age; for
no man chooses the young to guide him, because he does not
expect them to be prudent. With courage, the converse is the
case, for it is in youth that the active exercise of courage is more
imperatively required. Likewise also with temperance; for the
young are more troubled by their passions than are their elders.
Also, that is more desirable which is more useful at every
season or at most seasons, e.g. justice and temperance rather
than courage: for they are always useful, while courage is only
useful at times. Also, that one of two things which if all possess,
we do not need the other thing, is more desirable than that
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which all may possess and still we want the other one as well.
Take the case of justice and courage; if everybody were just,
there would be no use for courage, whereas all might be
courageous, and still justice would be of use.
Moreover, judge by the destructions and losses and generations
and acquisitions and contraries of things: for things whose
destruction is more objectionable are themselves more
desirable. Likewise also with the losses and contraries of things;
for a thing whose loss or whose contrary is more objectionable
is itself more desirable. With the generations or acquisitions of
things the opposite is the case: for things whose acquisition or
generation is more desirable are themselves also desirable.
Another commonplace rule is that what is nearer to the good is
better and more desirable, i.e. what more nearly resembles the
good: thus justice is better than a just man. Also, that which is
more like than another thing to something better than itself, as
e.g. some say that Ajax was a better man than Odysseus
because he was more like Achilles. An objection may be raised
to this that it is not true: for it is quite possible that Ajax did not
resemble Achilles more nearly than Odysseus in the points
which made Achilles the best of them, and that Odysseus was a
good man, though unlike Achilles. Look also to see whether the
resemblance be that of a caricature, like the resemblance of a
monkey to a man, whereas a horse bears none: for the monkey
is not the more handsome creature, despite its nearer
resemblance to a man. Again, in the case of two things, if one is
more like the better thing while another is more like the worse,
then that is likely to be better which is more like the better. This
too, however, admits of an objection: for quite possibly the one
only slightly resembles the better, while the other strongly
resembles the worse, e.g. supposing the resemblance of Ajax to
Achilles to be slight, while that of Odysseus to Nestor is strong.
Also it may be that the one which is like the better type shows a
degrading likeness, whereas the one which is like the worse
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type improves upon it: witness the likeness of a horse to a
donkey, and that of a monkey to a man.
Another rule is that the more conspicuous good is more
desirable than the less conspicuous, and the more difficult than
the easier: for we appreciate better the possession of things that
cannot be easily acquired. Also the more personal possession is
more desirable than the more widely shared. Also, that which is
more free from connexion with evil: for what is not attended by
any unpleasantness is more desirable than what is so attended.
Moreover, if A be without qualification better than B, then also
the best of the members of A is better than the best of the
members of B; e.g. if Man be better than Horse, then also the
best man is better than the best horse. Also, if the best in A be
better than the best in B, then also A is better than B without
qualification; e.g. if the best man be better than the best horse,
then also Man is better than Horse without qualification.
Moreover, things which our friends can share are more desirable
than those they cannot. Also, things which we like rather to do
to our friend are more desirable than those we like to do to the
man in the street, e.g. just dealing and the doing of good rather
than the semblance of them: for we would rather really do good
to our friends than seem to do so, whereas towards the man in
the street the converse is the case.
Also, superfluities are better than necessities, and are
sometimes more desirable as well: for the good life is better
than mere life, and good life is a superfluity, whereas mere life
itself is a necessity. Sometimes, though, what is better is not
also more desirable: for there is no necessity that because it is
better it should also be more desirable: at least to be a
philosopher is better than to make money, but it is not more
desirable for a man who lacks the necessities of life. The
expression 'superfluity' applies whenever a man possesses the
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necessities of life and sets to work to secure as well other noble
acquisitions. Roughly speaking, perhaps, necessities are more
desirable, while superfluities are better.
Also, what cannot be got from another is more desirable than
what can be got from another as well, as (e.g.) is the case of
justice compared with courage. Also, A is more desirable if A is
desirable without B, but not B without A: power (e.g.) is not
desirable without prudence, but prudence is desirable without
power. Also, if of two things we repudiate the one in order to be
thought to possess the other, then that one is more desirable
which we wish to be thought to possess; thus (e.g.) we repudiate
the love of hard work in order that people may think us
geniuses.
Moreover, that is more desirable in whose absence it is less
blameworthy for people to be vexed; and that is more desirable
in whose absence it is more blameworthy for a man not to be
vexed.
Moreover, of things that belong to the same species one which
possesses the peculiar virtue of the species is more desirable
than one which does not. If both possess it, then the one which
possesses it in a greater degree is more desirable.
Moreover, if one thing makes good whatever it touches, while
another does not, the former is more desirable, just as also what
makes things warm is warmer than what does not. If both do
so, then that one is more desirable which does so in a greater
degree, or if it render good the better and more important object
- if (e.g.), the one makes good the soul, and the other the body.
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Moreover, judge things by their inflexions and uses and actions
and works, and judge these by them: for they go with each
other: e.g. if 'justly' means something more desirable than
'courageously', then also justice means something more
desirable than courage; and if justice be more desirable than
courage, then also 'justly' means something more desirable
than 'courageously'. Similarly also in the other cases.
Moreover, if one thing exceeds while the other falls short of the
same standard of good, the one which exceeds is the more
desirable; or if the one exceeds an even higher standard. Nay
more, if there be two things both preferable to something, the
one which is more highly preferable to it is more desirable than
the less highly preferable. Moreover, when the excess of a thing
is more desirable than the excess of something else, that thing
is itself also more desirable than the other, as (e.g.) friendship
than money: for an excess of friendship is more desirable than
an excess of money. So also that of which a man would rather
that it were his by his own doing is more desirable than what he
would rather get by another's doing, e.g. friends than money.
Moreover, judge by means of an addition, and see if the addition
of A to the same thing as B makes the whole more desirable
than does the addition of B. You must, however, beware of
adducing a case in which the common term uses, or in some
other way helps the case of, one of the things added to it, but
not the other, as (e.g.) if you took a saw and a sickle in
combination with the art of carpentry: for in the combination
the saw is a more desirable thing, but it is not a more desirable
thing without qualification. Again, a thing is more desirable if,
when added to a lesser good, it makes the whole greater good.
Likewise, also, you should judge by means of subtraction: for
the thing upon whose subtraction the remainder is a lesser
good may be taken to be a greater good, whichever it be whose
subtraction makes the remainder a lesser good.
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Also, if one thing be desirable for itself, and the other for the
look of it, the former is more desirable, as (e.g.) health than
beauty. A thing is defined as being desired for the look of it if,
supposing no one knew of it, you would not care to have it. Also,
it is more desirable both for itself and for the look of it, while
the other thing is desirable on the one ground alone. Also,
whichever is the more precious for itself, is also better and more
desirable. A thing may be taken to be more precious in itself
which we choose rather for itself, without anything else being
likely to come of it.
Moreover, you should distinguish in how many senses
'desirable' is used, and with a view to what ends, e.g.
expediency or honour or pleasure. For what is useful for all or
most of them may be taken to be more desirable than what is
not useful in like manner. If the same characters belong to both
things you should look and see which possesses them more
markedly, i.e. which of the two is the more pleasant or more
honourable or more expedient. Again, that is more desirable
which serves the better purpose, e.g. that which serves to
promote virtue more than that which serves to promote
pleasure. Likewise also in the case of objectionable things; for
that is more objectionable which stands more in the way of
what is desirable, e.g. disease more than ugliness: for disease is
a greater hindrance both to pleasure and to being good.
Moreover, argue by showing that the thing in question is in like
measure objectionable and desirable: for a thing of such a
character that a man might well desire and object to it alike is
less desirable than the other which is desirable only.
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Comparisons of things together should therefore be conducted
in the manner prescribed. The same commonplace rules are
useful also for showing that anything is simply desirable or
objectionable: for we have only to subtract the excess of one
thing over another. For if what is more precious be more
desirable, then also what is precious is desirable; and if what is
more useful be more desirable, then also what is useful is
desirable. Likewise, also, in the case of other things which admit
of comparisons of that kind. For in some cases in the very
course of comparing the things together we at once assert also
that each of them, or the one of them, is desirable, e.g.
whenever we call the one good 'by nature' and the other 'not by
nature': for dearly what is good by nature is desirable.
The commonplace rules relating to comparative degrees and
amounts ought to be taken in the most general possible form:
for when so taken they are likely to be useful in a larger number
of instances. It is possible to render some of the actual rules
given above more universal by a slight alteration of the
expression, e.g. that what by nature exhibits such and such a
quality exhibits that quality in a greater degree than what
exhibits it not by nature. Also, if one thing does, and another
does not, impart such and such a quality to that which
possesses it, or to which it belongs, then whichever does impart
it is of that quality in greater degree than the one which does
not impart it; and if both impart it, then that one exhibits it in a
greater degree which imparts it in a greater degree.
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Moreover, if in any character one thing exceeds and another
falls short of the same standard; also, if the one exceeds
something which exceeds a given standard, while the other
does not reach that standard, then clearly the first-named thing
exhibits that character in a greater degree. Moreover, you should
judge by means of addition, and see if A when added to the
same thing as B imparts to the whole such and such a character
in a more marked degree than B, or if, when added to a thing
which exhibits that character in a less degree, it imparts that
character to the whole in a greater degree. Likewise, also, you
may judge by means of subtraction: for a thing upon whose
subtraction the remainder exhibits such and such a character in
a less degree, itself exhibits that character in a greater degree.
Also, things exhibit such and such a character in a greater
degree if more free from admixture with their contraries; e.g.
that is whiter which is more free from admixture with black.
Moreover, apart from the rules given above, that has such and
such a character in greater degree which admits in a greater
degree of the definition proper to the given character; e.g. if the
definition of 'white' be 'a colour which pierces the vision', then
that is whiter which is in a greater degree a colour that pierces
the vision.
If the question be put in a particular and not in a universal
form, in the first place the universal constructive or destructive
commonplace rules that have been given may all be brought
into use. For in demolishing or establishing a thing universally
we also show it in particular: for if it be true of all, it is true also
of some, and if untrue of all, it is untrue of some. Especially
handy and of general application are the commonplace rules
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that are drawn from the opposites and co-ordinates and
inflexions of a thing: for public opinion grants alike the claim
that if all pleasure be good, then also all pain is evil, and the
claim that if some pleasure be good, then also some pain is evil.
Moreover, if some form of sensation be not a capacity, then also
some form of failure of sensation is not a failure of capacity.
Also, if the object of conception is in some cases an object of
knowledge, then also some form of conceiving is knowledge.
Again, if what is unjust be in some cases good, then also what is
just is in some cases evil; and if what happens justly is in some
cases evil, then also what happens unjustly is in some cases
good. Also, if what is pleasant is in some cases objectionable,
then pleasure is in some cases an objectionable thing. On the
same principle, also, if what is pleasant is in some cases
beneficial, then pleasure is in some cases a beneficial thing. The
case is the same also as regards the things that destroy, and the
processes of generation and destruction. For if anything that
destroys pleasure or knowledge be in some cases good, then we
may take it that pleasure or knowledge is in some cases an evil
thing. Likewise, also, if the destruction of knowledge be in some
cases a good thing or its production an evil thing, then
knowledge will be in some cases an evil thing; e.g. if for a man
to forget his disgraceful conduct be a good thing, and to
remember it be an evil thing, then the knowledge of his
disgraceful conduct may be taken to be an evil thing. The same
holds also in other cases: in all such cases the premiss and the
conclusion are equally likely to be accepted.
Moreover you should judge by means of greater or smaller or
like degrees: for if some member of another genus exhibit such
and such a character in a more marked degree than your object,
while no member of that genus exhibits that character at all,
then you may take it that neither does the object in question
exhibit it; e.g. if some form of knowledge be good in a greater
degree than pleasure, while no form of knowledge is good, then
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you may take it that pleasure is not good either. Also, you
should judge by a smaller or like degree in the same way: for so
you will find it possible both to demolish and to establish a
view, except that whereas both are possible by means of like
degrees, by means of a smaller degree it is possible only to
establish, not to overthrow. For if a certain form of capacity be
good in a like degree to knowledge, and a certain form of
capacity be good, then so also is knowledge; while if no form of
capacity be good, then neither is knowledge. If, too, a certain
form of capacity be good in a less degree than knowledge, and a
certain form of capacity be good, then so also is knowledge; but
if no form of capacity be good, there is no necessity that no
form of knowledge either should be good. Clearly, then, it is only
possible to establish a view by means of a less degree.
Not only by means of another genus can you overthrow a view,
but also by means of the same, if you take the most marked
instance of the character in question; e.g. if it be maintained
that some form of knowledge is good, then, suppose it to be
shown that prudence is not good, neither will any other kind be
good, seeing that not even the kind upon which there is most
general agreement is so. Moreover, you should go to work by
means of an hypothesis; you should claim that the attribute, if it
belongs or does not belong in one case, does so in a like degree
in all, e.g. that if the soul of man be immortal, so are other souls
as well, while if this one be not so, neither are the others. If,
then, it be maintained that in some instance the attribute
belongs, you must show that in some instance it does not
belong: for then it will follow, by reason of the hypothesis, that
it does not belong to any instance at all. If, on the other hand, it
be maintained that it does not belong in some instance, you
must show that it does belong in some instance, for in this way
it will follow that it belongs to all instances. It is clear that the
maker of the hypothesis universalizes the question, whereas it
was stated in a particular form: for he claims that the maker of
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a particular admission should make a universal admission,
inasmuch as he claims that if the attribute belongs in one
instance, it belongs also in all instances alike.
If the problem be indefinite, it is possible to overthrow a
statement in only one way; e.g. if a man has asserted that
pleasure is good or is not good, without any further definition.
For if he meant that a particular pleasure is good, you must
show universally that no pleasure is good, if the proposition in
question is to be demolished. And likewise, also, if he meant
that some particular pleasure is not good you must show
universally that all pleasure is good: it is impossible to demolish
it in any other way. For if we show that some particular pleasure
is not good or is good, the proposition in question is not yet
demolished. It is clear, then, that it is possible to demolish an
indefinite statement in one way only, whereas it can be
established in two ways: for whether we show universally that
all pleasure is good, or whether we show that a particular
pleasure is good, the proposition in question will have been
proved. Likewise, also, supposing we are required to argue that
some particular pleasure is not good, if we show that no
pleasure is good or that a particular pleasure is not good, we
shall have produced an argument in both ways, both universally
and in particular, to show that some particular pleasure is not
good. If, on the other hand, the statement made be definite, it
will be possible to demolish it in two ways; e.g. if it be
maintained that it is an attribute of some particular pleasure to
be good, while of some it is not: for whether it be shown that all
pleasure, or that no pleasure, is good, the proposition in
question will have been demolished. If, however, he has stated
that only one single pleasure is good, it is possible to demolish
it in three ways: for by showing that all pleasure, or that no
pleasure, or that more than one pleasure, is good, we shall have
demolished the statement in question. If the statement be
made still more definite, e.g. that prudence alone of the virtues
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is knowledge, there are four ways of demolishing it: for if it be
shown that all virtue is knowledge, or that no virtue is so, or
that some other virtue (e.g. justice) is so, or that prudence itself
is not knowledge, the proposition in question will have been
demolished.
It is useful also to take a look at individual instances, in cases
where some attribute has been said to belong or not to belong,
as in the case of universal questions. Moreover, you should take
a glance among genera, dividing them by their species until you
come to those that are not further divisible, as has been said
before:' for whether the attribute is found to belong in all cases
or in none, you should, after adducing several instances, claim
that he should either admit your point universally, or else bring
an objection showing in what case it does not hold. Moreover, in
cases where it is possible to make the accident definite either
specifically or numerically, you should look and see whether
perhaps none of them belongs, showing e.g. that time is not
moved, nor yet a movement, by enumerating how many species
there are of movement: for if none of these belong to time,
clearly it does not move, nor yet is a movement. Likewise, also,
you can show that the soul is not a number, by dividing all
numbers into either odd or even: for then, if the soul be neither
odd nor even, clearly it is not a number.
In regard then to Accident, you should set to work by means like
these, and in this manner.
Book IV
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Next we must go on to examine questions relating to Genus and
Property. These are elements in the questions that relate to
definitions, but dialecticians seldom address their inquiries to
these by themselves. If, then, a genus be suggested for
something that is, first take a look at all objects which belong to
the same genus as the thing mentioned, and see whether the
genus suggested is not predicated of one of them, as happens in
the case of an accident: e.g. if 'good' be laid down to be the
genus of 'pleasure', see whether some particular pleasure be not
good: for, if so, clearly good' is not the genus of pleasure: for the
genus is predicated of all the members of the same species.
Secondly, see whether it be predicated not in the category of
essence, but as an accident, as 'white' is predicated of 'snow', or
'self-moved' of the soul. For 'snow' is not a kind of 'white', and
therefore 'white' is not the genus of snow, nor is the soul a kind
of 'moving object': its motion is an accident of it, as it often is of
an animal to walk or to be walking. Moreover, 'moving' does not
seem to indicate the essence, but rather a state of doing or of
having something done to it. Likewise, also, 'white': for it
indicates not the essence of snow, but a certain quality of it. So
that neither of them is predicated in the category of 'essence'.
Especially you should take a look at the definition of Accident,
and see whether it fits the genus mentioned, as (e.g.) is also the
case in the instances just given. For it is possible for a thing to
be and not to be self-moved, and likewise, also, for it to be and
not to be white. So that neither of these attributes is the genus
but an accident, since we were saying that an accident is an
attribute which can belong to a thing and also not belong.
Moreover, see whether the genus and the species be not found
in the same division, but the one be a substance while the other
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is a quality, or the one be a relative while the other is a quality,
as (e.g.) 'slow' and 'swan' are each a substance, while 'white' is
not a substance but a quality, so that 'white' is not the genus
either of 'snow' or of 'swan'. Again, knowledge' is a relative,
while 'good' and 'noble' are each a quality, so that good, or
noble, is not the genus of knowledge. For the genera of relatives
ought themselves also to be relatives, as is the case with
'double': for multiple', which is the genus of 'double', is itself
also a relative. To speak generally, the genus ought to fall under
the same division as the species: for if the species be a
substance, so too should be the genus, and if the species be a
quality, so too the genus should be a quality; e.g. if white be a
quality, so too should colour be. Likewise, also, in other cases.
Again, see whether it be necessary or possible for the genus to
partake of the object which has been placed in the genus. 'To
partake' is defined as 'to admit the definition of that which is
partaken. Clearly, therefore, the species partake of the genera,
but not the genera of the species: for the species admits the
definition of the genus, whereas the genus does not admit that
of the species. You must look, therefore, and see whether the
genus rendered partakes or can possibly partake of the species,
e.g. if any one were to render anything as genus of 'being' or of
'unity': for then the result will be that the genus partakes of the
species: for of everything that is, 'being' and 'unity' are
predicated, and therefore their definition as well.
Moreover, see if there be anything of which the species rendered
is true, while the genus is not so, e.g. supposing 'being' or 'object
of knowledge' were stated to be the genus of 'object of opinion'.
For 'object of opinion' will be a predicate of what does not exist;
for many things which do not exist are objects of opinion;
whereas that 'being' or 'object of knowledge' is not predicated
of what does not exist is clear. So that neither 'being' nor 'object
of knowledge' is the genus of 'object of opinion': for of the
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objects of which the species is predicated, the genus ought to be
predicated as well.
Again, see whether the object placed in the genus be quite
unable to partake of any of its species: for it is impossible that it
should partake of the genus if it do not partake of any of its
species, except it be one of the species reached by the first
division: these do partake of the genus alone. If, therefore,
'Motion' be stated as the genus of pleasure, you should look and
see if pleasure be neither locomotion nor alteration, nor any of
the rest of the given modes of motion: for clearly you may then
take it that it does not partake of any of the species, and
therefore not of the genus either, since what partakes of the
genus must necessarily partake of one of the species as well: so
that pleasure could not be a species of Motion, nor yet be one of
the individual phenomena comprised under the term 'motion'.
For individuals as well partake in the genus and the species, as
(e.g.) an individual man partakes of both 'man' and 'animal'.
Moreover, see if the term placed in the genus has a wider
denotation than the genus, as (e.g.) 'object of opinion' has, as
compared with 'being': for both what is and what is not are
objects of opinion, so that 'object of opinion' could not be a
species of being: for the genus is always of wider denotation
than the species. Again, see if the species and its genus have an
equal denotation; suppose, for instance, that of the attributes
which go with everything, one were to be stated as a species
and the other as its genus, as for example Being and Unity: for
everything has being and unity, so that neither is the genus of
the other, since their denotation is equal. Likewise, also, if the
'first' of a series and the 'beginning' were to be placed one
under the other: for the beginning is first and the first is the
beginning, so that either both expressions are identical or at
any rate neither is the genus of the other. The elementary
principle in regard to all such cases is that the genus has a
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wider denotation than the species and its differentia: for the
differentia as well has a narrower denotation than the genus.
See also whether the genus mentioned fails, or might be
generally thought to fail, to apply to some object which is not
specifically different from the thing in question; or, if your
argument be constructive, whether it does so apply. For all
things that are not specifically different have the same genus. If,
therefore, it be shown to apply to one, then clearly it applies to
all, and if it fails to apply to one, clearly it fails to apply to any;
e.g. if any one who assumes 'indivisible lines' were to say that
the 'indivisible' is their genus. For the aforesaid term is not the
genus of divisible lines, and these do not differ as regards their
species from indivisible: for straight lines are never different
from each other as regards their species.
Look and see, also, if there be any other genus of the given
species which neither embraces the genus rendered nor yet
falls under it, e.g. suppose any one were to lay down that
'knowledge' is the genus of justice. For virtue is its genus as
well, and neither of these genera embraces the remaining one,
so that knowledge could not be the genus of justice: for it is
generally accepted that whenever one species falls under two
genera, the one is embraced by the other. Yet a principle of this
kind gives rise to a difficulty in some cases. For some people
hold that prudence is both virtue and knowledge, and that
neither of its genera is embraced by the other: although
certainly not everybody admits that prudence is knowledge. If,
however, any one were to admit the truth of this assertion, yet it
would still be generally agreed to be necessary that the genera
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of the same object must at any rate be subordinate either the
one to the other or both to the same, as actually is the case with
virtue and knowledge. For both fall under the same genus; for
each of them is a state and a disposition. You should look,
therefore, and see whether neither of these things is true of the
genus rendered; for if the genera be subordinate neither the one
to the other nor both to the same, then what is rendered could
not be the true genus.
Look, also, at the genus of the genus rendered, and so
continually at the next higher genus, and see whether all are
predicated of the species, and predicated in the category of
essence: for all the higher genera should be predicated of the
species in the category of essence. If, then, there be anywhere a
discrepancy, clearly what is rendered is not the true genus.
[Again, see whether either the genus itself, or one of its higher
genera, partakes of the species: for the higher genus does not
partake of any of the lower.] If, then, you are overthrowing a
view, follow the rule as given: if establishing one, then - suppose
that what has been named as genus be admitted to belong to
the species, only it be disputed whether it belongs as genus - it
is enough to show that one of its higher genera is predicated of
the species in the category of essence. For if one of them be
predicated in the category of essence, all of them, both higher
and lower than this one, if predicated at all of the species, will
be predicated of it in the category of essence: so that what has
been rendered as genus is also predicated in the category of
essence. The premiss that when one genus is predicated in the
category of essence, all the rest, if predicated at all, will be
predicated in the category of essence, should be secured by
induction. Supposing, however, that it be disputed whether
what has been rendered as genus belongs at all, it is not enough
to show that one of the higher genera is predicated of the
species in the category of essence: e.g. if any one has rendered
'locomotion' as the genus of walking, it is not enough to show
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that walking is 'motion' in order to show that it is 'locomotion',
seeing that there are other forms of motion as well; but one
must show in addition that walking does not partake of any of
the species of motion produced by the same division except
locomotion. For of necessity what partakes of the genus
partakes also of one of the species produced by the first division
of the genus. If, therefore, walking does not partake either of
increase or decrease or of the other kinds of motion, clearly it
would partake of locomotion, so that locomotion would be the
genus of walking.
Again, look among the things of which the given species is
predicated as genus, and see if what is rendered as its genus be
also predicated in the category of essence of the very things of
which the species is so predicated, and likewise if all the genera
higher than this genus are so predicated as well. For if there be
anywhere a discrepancy, clearly what has been rendered is not
the true genus: for had it been the genus, then both the genera
higher than it, and it itself, would all have been predicated in
the category of essence of those objects of which the species too
is predicated in the category of essence. If, then, you are
overthrowing a view, it is useful to see whether the genus fails
to be predicated in the category of essence of those things of
which the species too is predicated. If establishing a view, it is
useful to see whether it is predicated in the category of essence:
for if so, the result will be that the genus and the species will be
predicated of the same object in the category of essence, so that
the same object falls under two genera: the genera must
therefore of necessity be subordinate one to the other, and
therefore if it be shown that the one we wish to establish as
genus is not subordinate to the species, clearly the species
would be subordinate to it, so that you may take it as shown
that it is the genus.
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Look, also, at the definitions of the genera, and see whether
they apply both to the given species and to the objects which
partake of the species. For of necessity the definitions of its
genera must be predicated of the species and of the objects
which partake of the species: if, then, there be anywhere a
discrepancy, clearly what has been rendered is not the genus.
Again, see if he has rendered the differentia as the genus, e.g.
'immortal' as the genus of 'God'. For 'immortal' is a differentia
of 'living being', seeing that of living beings some are mortal
and others immortal. Clearly, then, a bad mistake has been
made; for the differentia of a thing is never its genus. And that
this is true is clear: for a thing's differentia never signifies its
essence, but rather some quality, as do 'walking' and 'biped'.
Also, see whether he has placed the differentia inside the
genus, e.g. by taking 'odd' as a number'. For 'odd' is a differentia
of number, not a species. Nor is the differentia generally
thought to partake of the genus: for what partakes of the genus
is always either a species or an individual, whereas the
differentia is neither a species nor an individual. Clearly,
therefore, the differentia does not partake of the genus, so that
'odd' too is no species but a differentia, seeing that it does not
partake of the genus.
Moreover, see whether he has placed the genus inside the
species, e.g. by taking 'contact' to be a 'juncture', or 'mixture' a
'fusion', or, as in Plato's definition,' 'locomotion' to be the same
as 'carriage'. For there is no necessity that contact should be
juncture: rather, conversely, juncture must be contact: for what
is in contact is not always joined, though what is joined is
always in contact. Likewise, also, in the remaining instances: for
mixture is not always a 'fusion' (for to mix dry things does not
fuse them), nor is locomotion always 'carriage'. For walking is
not generally thought to be carriage: for 'carriage' is mostly used
398
of things that change one place for another involuntarily, as
happens in the case of inanimate things. Clearly, also, the
species, in the instances given, has a wider denotation than the
genus, whereas it ought to be vice versa. Again, see whether he
has placed the differentia inside the species, by taking (e.g.)
'immortal' to be 'a god'. For the result will be that the species
has an equal or wider denotation: and this cannot be, for always
the differentia has an equal or a wider denotation than the
species. Moreover, see whether he has placed the genus inside
the differentia, by making 'colour' (e.g.) to be a thing that
'pierces', or 'number' a thing that is 'odd'. Also, see if he has
mentioned the genus as differentia: for it is possible for a man
to bring forward a statement of this kind as well, e.g. that
'mixture' is the differentia of 'fusion', or that change of place' is
the differentia of 'carriage'. All such cases should be examined
by means of the same principles: for they depend upon
common rules: for the genus should have a wider denotation
that its differentia, and also should not partake of its
differentia; whereas, if it be rendered in this manner, neither of
the aforesaid requirements can be satisfied: for the genus will
both have a narrower denotation than its differentia, and will
partake of it.
Again, if no differentia belonging to the genus be predicated of
the given species, neither will the genus be predicated of it; e.g.
of 'soul' neither 'odd' nor 'even' is predicated: neither therefore
is 'number'. Moreover, see whether the species is naturally prior
and abolishes the genus along with itself: for the contrary is the
general view. Moreover, if it be possible for the genus stated, or
for its differentia, to be absent from the alleged species, e.g. for
'movement' to be absent from the 'soul', or 'truth and falsehood'
from 'opinion', then neither of the terms stated could be its
genus or its differentia: for the general view is that the genus
and the differentia accompany the species, as long as it exists.
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Look and see, also, if what is placed in the genus partakes or
could possibly partake of any contrary of the genus: for in that
case the same thing will at the same time partake of contrary
things, seeing that the genus is never absent from it, while it
partakes, or can possibly partake, of the contrary genus as well.
Moreover, see whether the species shares in any character
which it is utterly impossible for any member of the genus to
have. Thus (e.g.) if the soul has a share in life, while it is
impossible for any number to live, then the soul could not be a
species of number.
You should look and see, also, if the species be a homonym of
the genus, and employ as your elementary principles those
already stated for dealing with homonymity: for the genus and
the species are synonymous.
Seeing that of every genus there is more than one species, look
and see if it be impossible that there should be another species
than the given one belonging to the genus stated: for if there
should be none, then clearly what has been stated could not be
a genus at all.
Look and see, also, if he has rendered as genus a metaphorical
expression, describing (e.g. 'temperance' as a 'harmony': a
'harmony': for a genus is always predicated of its species in its
literal sense, whereas 'harmony' is predicated of temperance
not in a literal sense but metaphorically: for a harmony always
consists in notes.
Moreover, if there be any contrary of the species, examine it.
The examination may take different forms; first of all see if the
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contrary as well be found in the same genus as the species,
supposing the genus to have no contrary; for contraries ought to
be found in the same genus, if there be no contrary to the
genus. Supposing, on the other hand, that there is a contrary to
the genus, see if the contrary of the species be found in the
contrary genus: for of necessity the contrary species must be in
the contrary genus, if there be any contrary to the genus. Each
of these points is made plain by means of induction. Again, see
whether the contrary of the species be not found in any genus
at all, but be itself a genus, e.g. 'good': for if this be not found in
any genus, neither will its contrary be found in any genus, but
will itself be a genus, as happens in the case of 'good' and 'evil':
for neither of these is found in a genus, but each of them is a
genus. Moreover, see if both genus and species be contrary to
something, and one pair of contraries have an intermediary, but
not the other. For if the genera have an intermediary, so should
their species as well, and if the species have, so should their
genera as well, as is the case with (1) virtue and vice and (2)
justice and injustice: for each pair has an intermediary. An
objection to this is that there is no intermediary between health
and disease, although there is one between evil and good. Or
see whether, though there be indeed an intermediary between
both pairs, i.e. both between the species and between the
genera, yet it be not similarly related, but in one case be a mere
negation of the extremes, whereas in the other case it is a
subject. For the general view is that the relation should be
similar in both cases, as it is in the cases of virtue and vice and
of justice and injustice: for the intermediaries between both are
mere negations. Moreover, whenever the genus has no contrary,
look and see not merely whether the contrary of the species be
found in the same genus, but the intermediate as well: for the
genus containing the extremes contains the intermediates as
well, as (e.g.) in the case of white and black: for 'colour' is the
genus both of these and of all the intermediate colours as well.
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An objection may be raised that 'defect' and 'excess' are found
in the same genus (for both are in the genus 'evil'), whereas
moderate amount', the intermediate between them, is found
not in 'evil' but in 'good'. Look and see also whether, while the
genus has a contrary, the species has none; for if the genus be
contrary to anything, so too is the species, as virtue to vice and
justice to injustice.
Likewise, also, if one were to look at other instances, one would
come to see clearly a fact like this. An objection may be raised
in the case of health and disease: for health in general is the
contrary of disease, whereas a particular disease, being a
species of disease, e.g. fever and ophthalmia and any other
particular disease, has no contrary.
If, therefore, you are demolishing a view, there are all these
ways in which you should make your examination: for if the
aforesaid characters do not belong to it, clearly what has been
rendered is not the genus. If, on the other hand, you are
establishing a view, there are three ways: in the first place, see
whether the contrary of the species be found in the genus
stated, suppose the genus have no contrary: for if the contrary
be found in it, clearly the species in question is found in it as
well. Moreover, see if the intermediate species is found in the
genus stated: for whatever genus contains the intermediate
contains the extremes as well. Again, if the genus have a
contrary, look and see whether also the contrary species is
found in the contrary genus: for if so, clearly also the species in
question is found in the genus in question.
Again, consider in the case of the inflexions and the co-
ordinates of species and genus, and see whether they follow
likewise, both in demolishing and in establishing a view. For
whatever attribute belongs or does not belong to one belongs or
does not belong at the same time to all; e.g. if justice be a
402
particular form of knowledge, then also 'justly' is 'knowingly'
and the just man is a man of knowledge: whereas if any of
these things be not so, then neither is any of the rest of them.
Again, consider the case of things that bear a like relation to
one another. Thus (e.g.) the relation of the pleasant to pleasure
is like that of the useful to the good: for in each case the one
produces the other. If therefore pleasure be a kind of 'good',
then also the pleasant will be a kind of 'useful': for clearly it
may be taken to be productive of good, seeing that pleasure is
good. In the same way also consider the case of processes of
generation and destruction; if (e.g.) to build be to be active, then
to have built is to have been active, and if to learn be to
recollect, then also to have learnt is to have recollected, and if to
be decomposed be to be destroyed, then to have been
decomposed is to have been destroyed, and decomposition is a
kind of destruction. Consider also in the same way the case of
things that generate or destroy, and of the capacities and uses
of things; and in general, both in demolishing and in
establishing an argument, you should examine things in the
light of any resemblance of whatever description, as we were
saying in the case of generation and destruction. For if what
tends to destroy tends to decompose, then also to be destroyed
is to be decomposed: and if what tends to generate tends to
produce, then to be generated is to be produced, and generation
is production. Likewise, also, in the case of the capacities and
uses of things: for if a capacity be a disposition, then also to be
capable of something is to be disposed to it, and if the use of
anything be an activity, then to use it is to be active, and to have
used it is to have been active.
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If the opposite of the species be a privation, there are two ways
of demolishing an argument, first of all by looking to see if the
opposite be found in the genus rendered: for either the
privation is to be found absolutely nowhere in the same genus,
or at least not in the same ultimate genus: e.g. if the ultimate
genus containing sight be sensation, then blindness will not be
a sensation. Secondly, if there be a sensation. Secondly, if there
be a privation opposed to both genus and species, but the
opposite of the species be not found in the opposite of the
genus, then neither could the species rendered be in the genus
rendered. If, then, you are demolishing a view, you should follow
the rule as stated; but if establishing one there is but one way:
for if the opposite species be found in the opposite genus, then
also the species in question would be found in the genus in
question: e.g. if 'blindness' be a form of 'insensibility', then
'sight' is a form of 'sensation'.
Again, look at the negations of the genus and species and
convert the order of terms, according to the method described
in the case of Accident: e.g. if the pleasant be a kind of good,
what is not good is not pleasant. For were this no something not
good as well would then be pleasant. That, however, cannot be,
for it is impossible, if 'good' be the genus of pleasant, that
anything not good should be pleasant: for of things of which the
genus is not predicated, none of the species is predicated either.
Also, in establishing a view, you should adopt the same method
of examination: for if what is not good be not pleasant, then
what is pleasant is good, so that 'good' is the genus of
'pleasant'.
If the species be a relative term, see whether the genus be a
relative term as well: for if the species be a relative term, so too
is the genus, as is the case with 'double' and 'multiple': for each
is a relative term. If, on the other hand, the genus be a relative
term, there is no necessity that the species should be so as well:
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for 'knowledge 'is a relative term, but not so 'grammar'. Or
possibly not even the first statement would be generally
considered true: for virtue is a kind of 'noble' and a kind of
'good' thing, and yet, while 'virtue' is a relative term, 'good' and
'noble' are not relatives but qualities. Again, see whether the
species fails to be used in the same relation when called by its
own name, and when called by the name of its genus: e.g. if the
term 'double' be used to mean the double of a 'half, then also
the term 'multiple' ought to be used to mean multiple of a 'half.
Otherwise 'multiple' could not be the genus of 'double'.
Moreover, see whether the term fail to be used in the same
relation both when called by the name of its genus, and also
when called by those of all the genera of its genus. For if the
double be a multiple of a half, then 'in excess of 'will also be
used in relation to a 'half: and, in general, the double will be
called by the names of all the higher genera in relation to a
'half. An objection may be raised that there is no necessity for a
term to be used in the same relation when called by its own
name and when called by that of its genus: for 'knowledge' is
called knowledge 'of an object', whereas it is called a 'state' and
'disposition' not of an 'object' but of the 'soul'.
Again, see whether the genus and the species be used in the
same way in respect of the inflexions they take, e.g. datives and
genitives and all the rest. For as the species is used, so should
the genus be as well, as in the case of 'double' and its higher
genera: for we say both 'double of and 'multiple of a thing.
Likewise, also, in the case of 'knowledge': for both knowledge'
itself and its genera, e.g. 'disposition' and 'state', are said to be
'of something. An objection may be raised that in some cases it
is not so: for we say 'superior to' and 'contrary to' so and so,
whereas 'other', which is the genus of these terms, demands
not 'to' but 'than': for the expression is 'other than' so and so.
405
Again, see whether terms used in like case relationships fail to
yield a like construction when converted, as do 'double' and
'multiple'. For each of these terms takes a genitive both in itself
and in its converted form: for we say both a half of and 'a
fraction of something. The case is the same also as regards
both 'knowledge' and 'conception': for these take a genitive, and
by conversion an 'object of knowledge' and an 'object of
conception' are both alike used with a dative. If, then, in any
cases the constructions after conversion be not alike, clearly the
one term is not the genus of the other.
Again, see whether the species and the genus fail to be used in
relation to an equal number of things: for the general view is
that the uses of both are alike and equal in number, as is the
case with 'present' and 'grant'. For a present' is of something or
to some one, and also a 'grant' is of something and to some one:
and 'grant' is the genus of 'present', for a 'present' is a 'grant
that need not be returned'. In some cases, however, the number
of relations in which the terms are used happens not to be
equal, for while 'double' is double of something, we speak of 'in
excess' or 'greater' in something, as well as of or than
something: for what is in excess or greater is always in excess
in something, as well as in excess of something. Hence the
terms in question are not the genera of 'double', inasmuch as
they are not used in relation to an equal number of things with
the species. Or possibly it is not universally true that species
and genus are used in relation to an equal number of things.
See, also, if the opposite of the species have the opposite of the
genus as its genus, e.g. whether, if 'multiple' be the genus of
'double', 'fraction' be also the genus of 'half. For the opposite of
the genus should always be the genus of the opposite species. If,
then, any one were to assert that knowledge is a kind of
sensation, then also the object of knowledge will have to be a
kind of object of sensation, whereas it is not: for an object of
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knowledge is not always an object of sensation: for objects of
knowledge include some of the objects of intuition as well.
Hence 'object of sensation' is not the genus of 'object of
knowledge': and if this be so, neither is 'sensation' the genus of
'knowledge'.
Seeing that of relative terms some are of necessity found in, or
used of, the things in relation to which they happen at any time
to be used (e.g. 'disposition' and 'state' and 'balance'; for in
nothing else can the aforesaid terms possibly be found except
in the things in relation to which they are used), while others
need not be found in the things in relation to which they are
used at any time, though they still may be (e.g. if the term
'object of knowledge' be applied to the soul: for it is quite
possible that the knowledge of itself should be possessed by the
soul itself, but it is not necessary, for it is possible for this same
knowledge to be found in some one else), while for others,
again, it is absolutely impossible that they should be found in
the things in relation to which they happen at any time to be
used (as e.g. that the contrary should be found in the contrary
or knowledge in the object of knowledge, unless the object of
knowledge happen to be a soul or a man) - you should look,
therefore, and see whether he places a term of one kind inside a
genus that is not of that kind, e.g. suppose he has said that
'memory' is the 'abiding of knowledge'. For 'abiding' is always
found in that which abides, and is used of that, so that the
abiding of knowledge also will be found in knowledge. Memory,
then, is found in knowledge, seeing that it is the abiding of
knowledge. But this is impossible, for memory is always found
in the soul. The aforesaid commonplace rule is common to the
subject of Accident as well: for it is all the same to say that
'abiding' is the genus of memory, or to allege that it is an
accident of it. For if in any way whatever memory be the abiding
of knowledge, the same argument in regard to it will apply.
407
Again, see if he has placed what is a 'state' inside the genus
'activity', or an activity inside the genus 'state', e.g. by defining
'sensation' as 'movement communicated through the body': for
sensation is a 'state', whereas movement is an 'activity'.
Likewise, also, if he has said that memory is a 'state that is
retentive of a conception', for memory is never a state, but
rather an activity.
They also make a bad mistake who rank a 'state' within the
'capacity' that attends it, e.g. by defining 'good temper' as the
'control of anger', and 'courage' and 'justice' as 'control of fears'
and of 'gains': for the terms 'courageous' and 'good-tempered'
are applied to a man who is immune from passion, whereas
'self-controlled' describes the man who is exposed to passion
and not led by it. Quite possibly, indeed, each of the former is
attended by a capacity such that, if he were exposed to passion,
he would control it and not be led by it: but, for all that, this is
not what is meant by being 'courageous' in the one case, and
'good tempered' in the other; what is meant is an absolute
immunity from any passions of that kind at all.
Sometimes, also, people state any kind of attendant feature as
the genus, e.g. 'pain' as the genus of 'anger' and 'conception' as
that of conviction'. For both of the things in question follow in a
certain sense upon the given species, but neither of them is
genus to it. For when the angry man feels pain, the pain bas
appeared in him earlier than the anger: for his anger is not the
cause of his pain, but his pain of his anger, so that anger
emphatically is not pain. By the same reasoning, neither is
conviction conception: for it is possible to have the same
408
conception even without being convinced of it, whereas this is
impossible if conviction be a species of conception: for it is
impossible for a thing still to remain the same if it be entirely
transferred out of its species, just as neither could the same
animal at one time be, and at another not be, a man. If, on the
other hand, any one says that a man who has a conception
must of necessity be also convinced of it, then 'conception' and
'conviction' will be used with an equal denotation, so that not
even so could the former be the genus of the latter: for the
denotation of the genus should be wider.
See, also, whether both naturally come to be anywhere in the
same thing: for what contains the species contains the genus as
well: e.g. what contains 'white' contains 'colour' as well, and
what contains 'knowledge of grammar' contains 'knowledge' as
well. If, therefore, any one says that 'shame' is 'fear', or that
'anger' is 'pain', the result will be that genus and species are not
found in the same thing: for shame is found in the 'reasoning'
faculty, whereas fear is in the 'spirited' faculty, and 'pain' is
found in the faculty of 'desires', (for in this pleasure also is
found), whereas 'anger' is found in the 'spirited' faculty. Hence
the terms rendered are not the genera, seeing that they do not
naturally come to be in the same faculty as the species.
Likewise, also, if 'friendship' be found in the faculty of desires,
you may take it that it is not a form of 'wishing': for wishing is
always found in the 'reasoning' faculty. This commonplace rule
is useful also in dealing with Accident: for the accident and that
of which it is an accident are both found in the same thing, so
that if they do not appear in the same thing, clearly it is not an
accident.
Again, see if the species partakes of the genus attributed only in
some particular respect: for it is the general view that the genus
is not thus imparted only in some particular respect: for a man
is not an animal in a particular respect, nor is grammar
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knowledge in a particular respect only. Likewise also in other
instances. Look, therefore, and see if in the case of any of its
species the genus be imparted only in a certain respect; e.g. if
'animal' has been described as an 'object of perception' or of
'sight'. For an animal is an object of perception or of sight in a
particular respect only; for it is in respect of its body that it is
perceived and seen, not in respect of its soul, so that - 'object of
sight' and 'object of perception' could not be the genus of
'animal'.
Sometimes also people place the whole inside the part without
detection, defining (e.g.) 'animal' as an 'animate body'; whereas
the part is not predicated in any sense of the whole, so that
'body' could not be the genus of animal, seeing that it is a part.
See also if he has put anything that is blameworthy or
objectionable into the class 'capacity' or 'capable', e.g. by
defining a 'sophist' or a 'slanderer', or a 'thief as 'one who is
capable of secretly thieving other people's property'. For none of
the aforesaid characters is so called because he is 'capable' in
one of these respects: for even God and the good man are
capable of doing bad things, but that is not their character: for it
is always in respect of their choice that bad men are so called.
Moreover, a capacity is always a desirable thing: for even the
capacities for doing bad things are desirable, and therefore it is
we say that even God and the good man possess them; for they
are capable (we say) of doing evil. So then 'capacity' can never
be the genus of anything blameworthy. Else, the result will be
that what is blameworthy is sometimes desirable: for there will
be a certain form of capacity that is blameworthy.
Also, see if he has put anything that is precious or desirable for
its own sake into the class 'capacity' or 'capable' or 'productive'
of anything. For capacity, and what is capable or productive of
anything, is always desirable for the sake of something else.
410
Or see if he has put anything that exists in two genera or more
into one of them only. For some things it is impossible to place
in a single genus, e.g. the 'cheat' and the 'slanderer': for neither
he who has the will without the capacity, nor he who has the
capacity without the will, is a slanderer or cheat, but he who
has both of them. Hence he must be put not into one genus, but
into both the aforesaid genera.
Moreover, people sometimes in converse order render genus as
differentia, and differentia as genus, defining (e.g.)
astonishment as 'excess of wonderment' and conviction as
'vehemence of conception'. For neither 'excess' nor 'vehemence'
is the genus, but the differentia: for astonishment is usually
taken to be an 'excessive wonderment', and conviction to be a
'vehement conception', so that 'wonderment' and 'conception'
are the genus, while 'excess' and 'vehemence' are the
differentia. Moreover, if any one renders 'excess' and
'vehemence' as genera, then inanimate things will be convinced
and astonished. For 'vehemence' and 'excess' of a thing are
found in a thing which is thus vehement and in excess. If,
therefore, astonishment be excess of wonderment the
astonishment will be found in the wonderment, so that
'wonderment' will be astonished! Likewise, also, conviction will
be found in the conception, if it be 'vehemence of conception',
so that the conception will be convinced. Moreover, a man who
renders an answer in this style will in consequence find himself
calling vehemence vehement and excess excessive: for there is
such a thing as a vehement conviction: if then conviction be
'vehemence', there would be a 'vehement vehemence'. Likewise,
also, there is such a thing as excessive astonishment: if then
astonishment be an excess, there would be an 'excessive
excess'. Whereas neither of these things is generally believed,
any more than that knowledge is a knower or motion a moving
thing.
411
Sometimes, too, people make the bad mistake of putting an
affection into that which is affected, as its genus, e.g. those who
say that immortality is everlasting life: for immortality seems to
be a certain affection or accidental feature of life. That this
saying is true would appear clear if any one were to admit that a
man can pass from being mortal and become immortal: for no
one will assert that he takes another life, but that a certain
accidental feature or affection enters into this one as it is. So
then 'life' is not the genus of immortality.
Again, see if to an affection he has ascribed as genus the object
of which it is an affection, by defining (e.g.) wind as 'air in
motion'. Rather, wind is 'a movement of air': for the same air
persists both when it is in motion and when it is still. Hence
wind is not 'air' at all: for then there would also have been wind
when the air was not in motion, seeing that the same air which
formed the wind persists. Likewise, also, in other cases of the
kind. Even, then, if we ought in this instance to admit the point
that wind is 'air in motion', yet we should accept a definition of
the kind, not about all those things of which the genus is not
true, but only in cases where the genus rendered is a true
predicate. For in some cases, e.g. 'mud' or 'snow', it is not
generally held to be true. For people tell you that snow is 'frozen
water' and mud is earth mixed with moisture', whereas snow is
not water, nor mud earth, so that neither of the terms rendered
could be the genus: for the genus should be true of all its
species. Likewise neither is wine 'fermented water', as
Empedocles speaks of 'water fermented in wood';' for it simply
is not water at all.
412
Moreover, see whether the term rendered fail to be the genus of
anything at all; for then clearly it also fails to be the genus of
the species mentioned. Examine the point by seeing whether
the objects that partake of the genus fail to be specifically
different from one another, e.g. white objects: for these do not
differ specifically from one another, whereas of a genus the
species are always different, so that 'white' could not be the
genus of anything.
Again, see whether he has named as genus or differentia some
feature that goes with everything: for the number of attributes
that follow everything is comparatively large: thus (e.g.) 'Being'
and 'Unity' are among the number of attributes that follow
everything. If, therefore, he has rendered 'Being' as a genus,
clearly it would be the genus of everything, seeing that it is
predicated of everything; for the genus is never predicated of
anything except of its species. Hence Unity, inter alia, will be a
species of Being. The result, therefore, is that of all things of
which the genus is predicated, the species is predicated as well,
seeing that Being and Unity are predicates of absolutely
everything, whereas the predication of the species ought to be
of narrower range. If, on the other hand, he has named as
differentia some attribute that follows everything, clearly the
denotation of the differentia will be equal to, or wider than, that
of the genus. For if the genus, too, be some attribute that follows
everything, the denotation of the differentia will be equal to its
denotation, while if the genus do not follow everything, it will
be still wider.
Moreover, see if the description 'inherent in S' be used of the
genus rendered in relation to its species, as it is used of 'white'
in the case of snow, thus showing clearly that it could not be the
genus: for 'true of S' is the only description used of the genus in
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relation to its species. Look and see also if the genus fails to be
synonymous with its species. For the genus is always predicated
of its species synonymously.
Moreover, beware, whenever both species and genus have a
contrary, and he places the better of the contraries inside the
worse genus: for the result will be that the remaining species
will be found in the remaining genus, seeing that contraries are
found in contrary genera, so that the better species will be
found in the worse genus and the worse in the better: whereas
the usual view is that of the better species the genus too is
better. Also see if he has placed the species inside the worse
and not inside the better genus, when it is at the same time
related in like manner to both, as (e.g.) if he has defined the
'soul' as a 'form of motion' or 'a form of moving thing'. For the
same soul is usually thought to be a principle alike of rest and
of motion, so that, if rest is the better of the two, this is the
genus into which the soul should have been put.
Moreover, judge by means of greater and less degrees: if
overthrowing a view, see whether the genus admits of a greater
degree, whereas neither the species itself does so, nor any term
that is called after it: e.g. if virtue admits of a greater degree, so
too does justice and the just man: for one man is called 'more
just than another'. If, therefore, the genus rendered admits of a
greater degree, whereas neither the species does so itself nor
yet any term called after it, then what has been rendered could
not be the genus.
Again, if what is more generally, or as generally, thought to be
the genus be not so, clearly neither is the genus rendered. The
commonplace rule in question is useful especially in cases
where the species appears to have several predicates in the
category of essence, and where no distinction has been drawn
between them, and we cannot say which of them is genus; e.g.
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both 'pain' and the 'conception of a slight' are usually thought
to be predicates of 'anger in the category of essence: for the
angry man is both in pain and also conceives that he is slighted.
The same mode of inquiry may be applied also to the case of
the species, by comparing it with some other species: for if the
one which is more generally, or as generally, thought to be
found in the genus rendered be not found therein, then clearly
neither could the species rendered be found therein.
In demolishing a view, therefore, you should follow the rule as
stated. In establishing one, on the other hand, the
commonplace rule that you should see if both the genus
rendered and the species admit of a greater degree will not
serve: for even though both admit it, it is still possible for one
not to be the genus of the other. For both 'beautiful' and 'white'
admit of a greater degree, and neither is the genus of the other.
On the other hand, the comparison of the genera and of the
species one with another is of use: e.g. supposing A and B to
have a like claim to be genus, then if one be a genus, so also is
the other. Likewise, also, if what has less claim be a genus, so
also is what has more claim: e.g. if 'capacity' have more claim
than 'virtue' to be the genus of self-control, and virtue be the
genus, so also is capacity. The same observations will apply also
in the case of the species. For instance, supposing A and B to
have a like claim to be a species of the genus in question, then if
the one be a species, so also is the other: and if that which is
less generally thought to be so be a species, so also is that
which is more generally thought to be so.
Moreover, to establish a view, you should look and see if the
genus is predicated in the category of essence of those things of
which it has been rendered as the genus, supposing the species
rendered to be not one single species but several different ones:
for then clearly it will be the genus. If, on the other, the species
rendered be single, look and see whether the genus be
415
predicated in the category of essence of other species as well:
for then, again, the result will be that it is predicated of several
different species.
Since some people think that the differentia, too, is a predicate
of the various species in the category of essence, you should
distinguish the genus from the differentia by employing the
aforesaid elementary principles - (a) that the genus has a wider
denotation than the differentia; (b) that in rendering the
essence of a thing it is more fitting to state the genus than the
differentia: for any one who says that 'man' is an 'animal'
shows what man is better than he who describes him as
'walking'; also (c) that the differentia always signifies a quality
of the genus, whereas the genus does not do this of the
differentia: for he who says 'walking' describes an animal of a
certain quality, whereas he who says 'animal' describes an
animal of a certain quality, whereas he who says 'animal' does
not describe a walking thing of a certain quality
The differentia, then, should be distinguished from the genus in
this manner. Now seeing it is generally held that if what is
musical, in being musical, possesses knowledge in some
respect, then also 'music' is a particular kind of 'knowledge';
and also that if what walks is moved in walking, then 'walking'
is a particular kind of 'movement'; you should therefore
examine in the aforesaid manner any genus in which you want
to establish the existence of something; e.g. if you wish to prove
that 'knowledge' is a form of 'conviction', see whether the
knower in knowing is convinced: for then clearly knowledge
would be a particular kind of conviction. You should proceed in
the same way also in regard to the other cases of this kind.
Moreover, seeing that it is difficult to distinguish whatever
always follows along with a thing, and is not convertible with it,
from its genus, if A follows B universally, whereas B does not
416
follow A universally - as e.g. 'rest' always follows a 'calm' and
'divisibility' follows 'number', but not conversely (for the
divisible is not always a number, nor rest a calm) - you may
yourself assume in your treatment of them that the one which
always follows is the genus, whenever the other is not
convertible with it: if, on the other hand, some one else puts
forward the proposition, do not accept it universally. An
objection to it is that 'not-being' always follows what is 'coming
to be' (for what is coming to be is not) and is not convertible
with it (for what is not is not always coming to be), and that still
'not-being' is not the genus of 'coming to be': for 'not-being' has
not any species at all. Questions, then, in regard to Genus
should be investigated in the ways described.
BookV
The question whether the attribute stated is or is not a property,
should be examined by the following methods:
Any 'property' rendered is always either essential and
permanent or relative and temporary: e.g. it is an 'essential
property' of man to be 'by nature a civilized animal': a 'relative
property' is one like that of the soul in relation to the body, viz.
that the one is fitted to command, and the other to obey: a
'permanent property' is one like the property which belongs to
God, of being an 'immortal living being': a 'temporary property'
417
is one like the property which belongs to any particular man of
walking in the gymnasium.
[The rendering of a property 'relatively' gives rise either to two
problems or to four. For if he at the same time render this
property of one thing and deny it of another, only two problems
arise, as in the case of a statement that it is a property of a man,
in relation to a horse, to be a biped. For one might try both to
show that a man is not a biped, and also that a horse is a biped:
in both ways the property would be upset. If on the other hand
he render one apiece of two attributes to each of two things,
and deny it in each case of the other, there will then be four
problems; as in the case of a statement that it is a property of a
man in relation to a horse for the former to be a biped and the
latter a quadruped. For then it is possible to try to show both
that a man is not naturally a biped, and that he is a quadruped,
and also that the horse both is a biped, and is not a quadruped.
If you show any of these at all, the intended attribute is
demolished.]
An 'essential' property is one which is rendered of a thing in
comparison with everything else and distinguishes the said
thing from everything else, as does 'a mortal living being
capable of receiving knowledge' in the case of man. A 'relative'
property is one which separates its subject off not from
everything else but only from a particular definite thing, as does
the property which virtue possesses, in comparison with
knowledge, viz. that the former is naturally produced in more
than one faculty, whereas the latter is produced in that of
reason alone, and in those who have a reasoning faculty. A
'permanent' property is one which is true at every time, and
never fails, like being' compounded of soul and body', in the
case of a living creature. A 'temporary' property is one which is
true at some particular time, and does not of necessity always
418
follow; as, of some particular man, that he walks in the market-
place.
To render a property 'relatively' to something else means to
state the difference between them as it is found either
universally and always, or generally and in most cases: thus a
difference that is found universally and always, is one such as
man possesses in comparison with a horse, viz. being a biped:
for a man is always and in every case a biped, whereas a horse
is never a biped at any time. On the other hand, a difference
that is found generally and in most cases, is one such as the
faculty of reason possesses in comparison with that of desire
and spirit, in that the former commands, while the latter obeys:
for the reasoning faculty does not always command, but
sometimes also is under command, nor is that of desire and
spirit always under command, but also on occasion assumes
the command, whenever the soul of a man is vicious.
Of 'properties' the most 'arguable' are the essential and
permanent and the relative. For a relative property gives rise, as
we said before, to several questions: for of necessity the
questions arising are either two or four, or that arguments in
regard to these are several. An essential and a permanent
property you can discuss in relation to many things, or can
observe in relation to many periods of time: if essential', discuss
it in comparison with many things: for the property ought to
belong to its subject in comparison with every single thing that
is, so that if the subject be not distinguished by it in comparison
with everything else, the property could not have been rendered
correctly. So a permanent property you should observe in
relation to many periods of time; for if it does not or did not, or
is not going to, belong, it will not be a property. On the other
hand, about a temporary property we do not inquire further
than in regard to the time called 'the present'; and so
arguments in regard to it are not many; whereas an arguable'
419
question is one in regard to which it is possible for arguments
both numerous and good to arise.
The so-called 'relative' property, then, should be examined by
means of the commonplace arguments relating to Accident, to
see whether it belongs to the one thing and not to the other: on
the other hand, permanent and essential properties should be
considered by the following methods.
First, see whether the property has or has not been rendered
correctly. Of a rendering being incorrect or correct, one test is to
see whether the terms in which the property is stated are not or
are more intelligible - for destructive purposes, whether they
are not so, and for constructive purposes, whether they are so.
Of the terms not being more intelligible, one test is to see
whether the property which he renders is altogether more
unintelligible than the subject whose property he has stated:
for, if so, the property will not have been stated correctly. For the
object of getting a property constituted is to be intelligible: the
terms therefore in which it is rendered should be more
intelligible: for in that case it will be possible to conceive it more
adequately, e.g. any one who has stated that it is a property of
'fire' to 'bear a very close resemblance to the soul', uses the
term 'soul', which is less intelligible than 'fire' - for we know
better what fire is than what soul is -, and therefore a 'very
close resemblance to the soul' could not be correctly stated to
be a property of fire. Another test is to see whether the
attribution of A (property) to B (subject) fails to be more
intelligible. For not only should the property be more intelligible
than its subject, but also it should be something whose
420
attribution to the particular subject is a more intelligible
attribution. For he who does not know whether it is an attribute
of the particular subject at all, will not know either whether it
belongs to it alone, so that whichever of these results happens,
its character as a property becomes obscure. Thus (e.g.) a man
who has stated that it is a property of fire to be 'the primary
element wherein the soul is naturally found', has introduced a
subject which is less intelligible than 'fire', viz. whether the soul
is found in it, and whether it is found there primarily; and
therefore to be 'the primary element in which the soul is
naturally found' could not be correctly stated to be a property of
'fire'. On the other hand, for constructive purposes, see whether
the terms in which the property is stated are more intelligible,
and if they are more intelligible in each of the aforesaid ways.
For then the property will have been correctly stated in this
respect: for of constructive arguments, showing the correctness
of a rendering, some will show the correctness merely in this
respect, while others will show it without qualification. Thus
(e.g.) a man who has said that the 'possession of sensation' is a
property of 'animal' has both used more intelligible terms and
has rendered the property more intelligible in each of the
aforesaid senses; so that to 'possess sensation' would in this
respect have been correctly rendered as a property of 'animal'.
Next, for destructive purposes, see whether any of the terms
rendered in the property is used in more than one sense, or
whether the whole expression too signifies more than one
thing. For then the property will not have been correctly stated.
Thus (e.g.) seeing that to 'being natural sentient' signifies more
than one thing, viz. (1) to possess sensation, (2) to use one's
sensation, being naturally sentient' could not be a correct
statement of a property of 'animal'. The reason why the term
you use, or the whole expression signifying the property, should
not bear more than one meaning is this, that an expression
bearing more than one meaning makes the object described
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obscure, because the man who is about to attempt an argument
is in doubt which of the various senses the expression bears:
and this will not do, for the object of rendering the property is
that he may understand. Moreover, in addition to this, it is
inevitable that those who render a property after this fashion
should be somehow refuted whenever any one addresses his
syllogism to that one of the term's several meanings which does
not agree. For constructive purposes, on the other hand, see
whether both all the terms and also the expression as a whole
avoid bearing more than one sense: for then the property will
have been correctly stated in this respect. Thus (e.g.) seeing that
'body' does not bear several meanings, nor quickest to move
upwards in space', nor yet the whole expression made by
putting them together, it would be correct in this respect to say
that it is a property of fire to be the 'body quickest to move
upwards in space'.
Next, for destructive purposes, see if the term of which he
renders the property is used in more than one sense, and no
distinction has been drawn as to which of them it is whose
property he is stating: for then the property will not have been
correctly rendered. The reasons why this is so are quite clear
from what has been said above: for the same results are bound
to follow. Thus (e.g.) seeing that 'the knowledge of this' signifies
many things for it means (1) the possession of knowledge by it,
(2) the use of its knowledge by it, (3) the existence of knowledge
about it, (4) the use of knowledge about it - no property of the
'knowledge of this' could be rendered correctly unless he draw a
distinction as to which of these it is whose property he is
rendering. For constructive purposes, a man should see if the
term of which he is rendering the property avoids bearing many
senses and is one and simple: for then the property will have
been correctly stated in this respect. Thus (e.g.) seeing that
'man' is used in a single sense, 'naturally civilized animal'
would be correctly stated as a property of man.
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Next, for destructive purposes, see whether the same term has
been repeated in the property. For people often do this
undetected in rendering 'properties' also, just as they do in their
'definitions' as well: but a property to which this has happened
will not have been correctly stated: for the repetition of it
confuses the hearer; thus inevitably the meaning becomes
obscure, and further, such people are thought to babble.
Repetition of the same term is likely to happen in two ways; one
is, when a man repeatedly uses the same word, as would
happen if any one were to render, as a property of fire, 'the body
which is the most rarefied of bodies' (for he has repeated the
word 'body'); the second is, if a man replaces words by their
definitions, as would happen if any one were to render, as a
property of earth, 'the substance which is by its nature most
easily of all bodies borne downwards in space', and were then to
substitute 'substances of such and such a kind' for the word
'bodies': for 'body' and 'a substance of such and such a kind'
mean one and the same thing. For he will have repeated the
word 'substance', and accordingly neither of the properties
would be correctly stated. For constructive purposes, on the
other hand, see whether he avoids ever repeating the same
term; for then the property will in this respect have been
correctly rendered. Thus (e.g.) seeing that he who has stated
'animal capable of acquiring knowledge' as a property of man
has avoided repeating the same term several times, the
property would in this respect have been correctly rendered of
man.
Next, for destructive purposes, see whether he has rendered in
the property any such term as is a universal attribute. For one
which does not distinguish its subject from other things is
useless, and it is the business of the language Of 'properties', as
also of the language of definitions, to distinguish. In the case
contemplated, therefore, the property will not have been
correctly rendered. Thus (e.g.) a man who has stated that it is a
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property of knowledge to be a 'conception incontrovertible by
argument, because of its unity', has used in the property a term
of that kind, viz. 'unity', which is a universal attribute; and
therefore the property of knowledge could not have been
correctly stated. For constructive purposes, on the other hand,
see whether he has avoided all terms that are common to
everything and used a term that distinguishes the subject from
something: for then the property will in this respect have been
correctly stated. Thus (e.g.) inasmuch as he who has said that it
is a property of a 'living creature' to 'have a soul' has used no
term that is common to everything, it would in this respect
have been correctly stated to be a property of a 'living creature'
to 'have a soul'.
Next, for destructive purposes see whether he renders more
than one property of the same thing, without a definite proviso
that he is stating more than one: for then the property will not
have been correctly stated. For just as in the case of definitions
too there should be no further addition beside the expression
which shows the essence, so too in the case of properties
nothing further should be rendered beside the expression that
constitutes the property mentioned: for such an addition is
made to no purpose. Thus (e.g.) a man who has said that it is a
property of fire to be 'the most rarefied and lightest body' has
rendered more than one property (for each term is a true
predicate of fire alone); and so it could not be a correctly stated
property of fire to be 'the most rarefied and lightest body'. On
the other hand, for constructive purposes, see whether he has
avoided rendering more than one property of the same thing,
and has rendered one only: for then the property will in this
respect have been correctly stated. Thus (e.g.) a man who has
said that it is a property of a liquid to be a 'body adaptable to
every shape' has rendered as its property a single character and
not several, and so the property of 'liquid' would in this respect
have been correctly stated.
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Next, for destructive purposes, see whether he has employed
either the actual subject whose property he is rendering, or any
of its species: for then the property will not have been correctly
stated. For the object of rendering the property is that people
may understand: now the subject itself is just as unintelligible
as it was to start with, while any one of its species is posterior
to it, and so is no more intelligible. Accordingly it is impossible
to understand anything further by the use of these terms. Thus
(e.g.) any one who has said that it is property of 'animal' to be
'the substance to which «man» belongs as a species' has
employed one of its species, and therefore the property could
not have been correctly stated. For constructive purposes, on
the other hand, see whether he avoids introducing either the
subject itself or any of its species: for then the property will in
this respect have been correctly stated. Thus (e.g.) a man who
has stated that it is a property of a living creature to be
'compounded of soul and body' has avoided introducing among
the rest either the subject itself or any of its species, and
therefore in this respect the property of a 'living creature' would
have been correctly rendered.
You should inquire in the same way also in the case of other
terms that do or do not make the subject more intelligible: thus,
for destructive purposes, see whether he has employed
anything either opposite to the subject or, in general, anything
simultaneous by nature with it or posterior to it: for then the
property will not have been correctly stated. For an opposite is
simultaneous by nature with its opposite, and what is
simultaneous by nature or is posterior to it does not make its
subject more intelligible. Thus (e.g.) any one who has said that it
425
is a property of good to be 'the most direct opposite of evil', has
employed the opposite of good, and so the property of good
could not have been correctly rendered. For constructive
purposes, on the other hand, see whether he has avoided
employing anything either opposite to, or, in general,
simultaneous by nature with the subject, or posterior to it: for
then the property will in this respect have been correctly
rendered. Thus (e.g.) a man who has stated that it is a property
of knowledge to be 'the most convincing conception' has
avoided employing anything either opposite to, or simultaneous
by nature with, or posterior to, the subject; and so the property
of knowledge would in this respect have been correctly stated.
Next, for destructive purposes, see whether he has rendered as
property something that does not always follow the subject but
sometimes ceases to be its property: for then the property will
not have been correctly described. For there is no necessity
either that the name of the subject must also be true of
anything to which we find such an attribute belonging; nor yet
that the name of the subject will be untrue of anything to which
such an attribute is found not to belong. Moreover, in addition
to this, even after he has rendered the property it will not be
clear whether it belongs, seeing that it is the kind of attribute
that may fall: and so the property will not be clear. Thus (e.g.) a
man who has stated that it is a property of animal 'sometimes
to move and sometimes to stand still' rendered the kind of
property which sometimes is not a property, and so the
property could not have been correctly stated. For constructive
purposes, on the other hand, see whether he has rendered
something that of necessity must always be a property: for then
the property will have been in this respect correctly stated. Thus
(e.g.) a man who has stated that it is a property of virtue to be
'what makes its possessor good' has rendered as property
something that always follows, and so the property of virtue
would in this respect have been correctly rendered.
426
Next, for destructive purposes, see whether in rendering the
property of the present time he has omitted to make a definite
proviso that it is the property of the present time which he is
rendering: for else the property will not have been correctly
stated. For in the first place, any unusual procedure always
needs a definite proviso: and it is the usual procedure for
everybody to render as property some attribute that always
follows. In the second place, a man who omits to provide
definitely whether it was the property of the present time
which he intended to state, is obscure: and one should not give
any occasion for adverse criticism. Thus (e.g.) a man who has
stated it as the property of a particular man 'to be sitting with a
particular man', states the property of the present time, and so
he cannot have rendered the property correctly, seeing that he
has described it without any definite proviso. For constructive
purposes, on the other hand, see whether, in rendering the
property of the present time, he has, in stating it, made a
definite proviso that it is the property of the present time that
he is stating: for then the property will in this respect have been
correctly stated. Thus (e.g.) a man who has said that it is the
property of a particular man 'to be walking now', has made this
distinction in his statement, and so the property would have
been correctly stated.
Next, for destructive purposes, see whether he has rendered a
property of the kind whose appropriateness is not obvious
except by sensation: for then the property will not have been
correctly stated. For every sensible attribute, once it is taken
beyond the sphere of sensation, becomes uncertain. For it is not
clear whether it still belongs, because it is evidenced only by
sensation. This principle will be true in the case of any
attributes that do not always and necessarily follow. Thus (e.g.)
any one who has stated that it is a property of the sun to be 'the
brightest star that moves over the earth', has used in describing
the property an expression of that kind, viz. 'to move over the
427
earth', which is evidenced by sensation; and so the sun's
property could not have been correctly rendered: for it will be
uncertain, whenever the sun sets, whether it continues to move
over the earth, because sensation then fails us. For constructive
purposes, on the other hand, see whether he has rendered the
property of a kind that is not obvious to sensation, or, if it be
sensible, must clearly belong of necessity: for then the property
will in this respect have been correctly stated. Thus (e.g.) a man
who has stated that it is a property of a surface to be 'the
primary thing that is coloured', has introduced amongst the rest
a sensible quality, 'to be coloured', but still a quality such as
manifestly always belongs, and so the property of 'surface'
would in this respect have been correctly rendered.
Next, for destructive purposes, see whether he has rendered the
definition as a property: for then the property will not have
been correctly stated: for the property of a thing ought not to
show its essence. Thus (e.g.) a man who has said that it is the
property of man to be 'a walking, biped animal' has rendered a
property of man so as to signify his essence, and so the property
of man could not have been correctly rendered. For constructive
purposes, on the other hand, see whether the property which
he has rendered forms a predicate convertible with its subject,
without, however, signifying its essence: for then the property
will in this respect have been correctly rendered. Thus (e.g.) he
who has stated that it is a property of man to be a 'naturally
civilized animal' has rendered the property so as to be
convertible with its subject, without, however, showing its
essence, and so the property of man' would in this respect have
been correctly rendered.
Next, for destructive purposes, see whether he has rendered the
property without having placed the subject within its essence.
For of properties, as also of definitions, the first term to be
rendered should be the genus, and then the rest of it should be
428
appended immediately afterwards, and should distinguish its
subject from other things. Hence a property which is not stated
in this way could not have been correctly rendered. Thus (e.g.) a
man who has said that it is a property of a living creature to
'have a soul' has not placed 'living creature' within its essence,
and so the property of a living creature could not have been
correctly stated. For constructive purposes, on the other hand,
see whether a man first places within its essence the subject
whose property he is rendering, and then appends the rest: for
then the property will in this respect have been correctly
rendered. Thus (e.g.) he who has stated that is a property of
man to be an 'animal capable of receiving knowledge', has
rendered the property after placing the subject within its
essence, and so the property of 'man' would in this respect have
been correctly rendered.
The inquiry, then, whether the property has been correctly
rendered or no, should be made by these means. The question,
on the other hand, whether what is stated is or is not a property
at all, you should examine from the following points of view. For
the commonplace arguments which establish absolutely that
the property is accurately stated will be the same as those that
constitute it a property at all: accordingly they will be described
in the course of them.
Firstly, then, for destructive purposes, take a look at each
subject of which he has rendered the property, and see (e.g.) if it
fails to belong to any of them at all, or to be true of them in that
particular respect, or to be a property of each of them in respect
of that character of which he has rendered the property: for
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then what is stated to be a property will not be a property. Thus,
for example, inasmuch as it is not true of the geometrician that
he 'cannot be deceived by an argument' (for a geometrician is
deceived when his figure is misdrawn), it could not be a
property of the man of science that he is not deceived by an
argument. For constructive purposes, on the other hand, see
whether the property rendered be true of every instance, and
true in that particular respect: for then what is stated not to be
a property will be a property. Thus, for example, in as much as
the description 'an animal capable of receiving knowledge' is
true of every man, and true of him qua man, it would be a
property of man to be 'an animal capable of receiving
knowledge', commonplace rule means - for destructive
purposes, see if the description fails to be true of that of which
the name is true; and if the name fails to be true of that of
which the description is true: for constructive purposes, on the
other hand, see if the description too is predicated of that of
which the name is predicated, and if the name too is predicated
of that of which the description is predicated.]
Next, for destructive purposes, see if the description fails to
apply to that to which the name applies, and if the name fails to
apply to that to which the description applies: for then what is
stated to be a property will not be a property. Thus (e.g.)
inasmuch as the description 'a living being that partakes of
knowledge' is true of God, while 'man' is not predicated of God,
to be a living being that partakes of knowledge' could not be a
property of man. For constructive purposes, on the other hand,
see if the name as well be predicated of that of which the
description is predicated, and if the description as well be
predicated of that of which the name is predicated. For then
what is stated not to be a property will be a property. Thus (e.g.)
the predicate 'living creature' is true of that of which 'having a
soul' is true, and 'having a soul' is true of that of which the
430
predicate 'living creature' is true; and so 'having a soul would be
a property of 'living creature'.
Next, for destructive purposes, see if he has rendered a subject
as a property of that which is described as 'in the subject': for
then what has been stated to be a property will not be a
property. Thus (e.g.) inasmuch as he who has rendered 'fire' as
the property of 'the body with the most rarefied particles', has
rendered the subject as the property of its predicate, 'fire' could
not be a property of 'the body with the most rarefied particles'.
The reason why the subject will not be a property of that which
is found in the subject is this, that then the same thing will be
the property of a number of things that are specifically
different. For the same thing has quite a number of specifically
different predicates that belong to it alone, and the subject will
be a property of all of these, if any one states the property in
this way. For constructive purposes, on the other hand, see if he
has rendered what is found in the subject as a property of the
subject: for then what has been stated not to be a property will
be a property, if it be predicated only of the things of which it
has been stated to be the property. Thus (e.g.) he who has said
that it is a property of 'earth' to be 'specifically the heaviest
body' has rendered of the subject as its property something that
is said of the thing in question alone, and is said of it in the
manner in which a property is predicated, and so the property
of earth would have been rightly stated.
Next, for destructive purposes, see if he has rendered the
property as partaken of: for then what is stated to be a property
will not be a property. For an attribute of which the subject
partakes is a constituent part of its essence: and an attribute of
that kind would be a differentia applying to some one species.
E.g. inasmuch as he who has said that 'walking on two feet' is
property of man has rendered the property as partaken of,
'walking on two feet' could not be a property of 'man'. For
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constructive purposes, on the other hand, see if he has avoided
rendering the property as partaken of, or as showing the
essence, though the subject is predicated convertibly with it: for
then what is stated not to be a property will be a property. Thus
(e.g.) he who has stated that to be 'naturally sentient' is a
property of 'animal' has rendered the property neither as
partaken of nor as showing the essence, though the subject is
predicated convertibly with it; and so to be 'naturally sentient'
would be a property of 'animal'.
Next, for destructive purposes, see if the property cannot
possibly belong simultaneously, but must belong either as
posterior or as prior to the attribute described in the name: for
then what is stated to be a property will not be a property either
never, or not always. Thus (e.g.) inasmuch as it is possible for
the attribute 'walking through the market-place' to belong to an
object as prior and as posterior to the attribute 'man', 'walking
through the market-place' could not be a property of 'man'
either never, or not always. For constructive purposes, on the
other hand, see if it always and of necessity belongs
simultaneously, without being either a definition or a
differentia: for then what is stated not to be a property will be a
property. Thus (e.g.) the attribute 'an animal capable of receiving
knowledge' always and of necessity belongs simultaneously
with the attribute 'man', and is neither differentia nor definition
of its subject, and so 'an animal capable of receiving knowledge'
would be a property of 'man'.
Next, for destructive purposes, see if the same thing fails to be a
property of things that are the same as the subject, so far as
they are the same: for then what is stated to be a property will
not be a property. Thus, for example, inasmuch as it is no
property of a 'proper object of pursuit' to 'appear good to certain
persons', it could not be a property of the 'desirable' either to
'appear good to certain persons': for 'proper object of pursuit'
432
and 'desirable' mean the same. For constructive purposes, on
the other hand, see if the same thing be a property of
something that is the same as the subject, in so far as it is the
same. For then is stated not to be a property will be a property.
Thus (e.g.) inasmuch as it is called a property of a man, in so far
as he is a man, 'to have a tripartite soul', it would also be a
property of a mortal, in so far as he is a mortal, to have a
tripartite soul. This commonplace rule is useful also in dealing
with Accident: for the same attributes ought either to belong or
not belong to the same things, in so far as they are the same.
Next, for destructive purposes, see if the property of things that
are the same in kind as the subject fails to be always the same
in kind as the alleged property: for then neither will what is
stated to be the property of the subject in question. Thus (e.g.)
inasmuch as a man and a horse are the same in kind, and it is
not always a property of a horse to stand by its own initiative, it
could not be a property of a man to move by his own initiative;
for to stand and to move by his own initiative are the same in
kind, because they belong to each of them in so far as each is an
'animal'. For constructive purposes, on the other hand, see if of
things that are the same in kind as the subject the property that
is the same as the alleged property is always true: for then what
is stated not to be a property will be a property. Thus (e.g.) since
it is a property of man to be a 'walking biped,' it would also be a
property of a bird to be a 'flying biped': for each of these is the
same in kind, in so far as the one pair have the sameness of
species that fall under the same genus, being under the genus
'animal', while the other pair have that of differentiae of the
genus, viz. of 'animal'. This commonplace rule is deceptive
whenever one of the properties mentioned belongs to some one
species only while the other belongs to many, as does 'walking
quadruped'.
433
Inasmuch as 'same' and 'different' are terms used in several
senses, it is a job to render to a sophistical questioner a
property that belongs to one thing and that only. For an
attribute that belongs to something qualified by an accident will
also belong to the accident taken along with the subject which
it qualifies; e.g. an attribute that belongs to 'man' will belong
also to 'white man', if there be a white man, and one that
belongs to 'white man' will belong also to 'man'. One might,
then, bring captious criticism against the majority of properties,
by representing the subject as being one thing in itself, and
another thing when combined with its accident, saying, for
example, that 'man' is one thing, and white man' another, and
moreover by representing as different a certain state and what
is called after that state. For an attribute that belongs to the
state will belong also to what is called after that state, and one
that belongs to what is called after a state will belong also to
the state: e.g. inasmuch as the condition of the scientist is
called after his science, it could not be a property of 'science'
that it is 'incontrovertible by argument'; for then the scientist
also will be incontrovertible by argument. For constructive
purposes, however, you should say that the subject of an
accident is not absolutely different from the accident taken
along with its subject; though it is called 'another' thing
because the mode of being of the two is different: for it is not
the same thing for a man to be a man and for a white man to be
a white man. Moreover, you should take a look along at the
inflections, and say that the description of the man of science is
wrong: one should say not 'it' but 'he is incontrovertible by
argument'; while the description of Science is wrong too: one
should say not 'it' but 'she is incontrovertible by argument'. For
against an objector who sticks at nothing the defence should
stick at nothing.
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Next, for destructive purposes, see if, while intending to render
an attribute that naturally belongs, he states it in his language
in such a way as to indicate one that invariably belongs: for
then it would be generally agreed that what has been stated to
be a property is upset. Thus (e.g.) the man who has said that
'biped' is a property of man intends to render the attribute that
naturally belongs, but his expression actually indicates one that
invariably belongs: accordingly, 'biped' could not be a property
of man: for not every man is possessed of two feet. For
constructive purposes, on the other hand, see if he intends to
render the property that naturally belongs, and indicates it in
that way in his language: for then the property will not be upset
in this respect. Thus (e.g.) he who renders as a property of 'man'
the phrase 'an animal capable of receiving knowledge' both
intends, and by his language indicates, the property that
belongs by nature, and so 'an animal capable of receiving
knowledge' would not be upset or shown in that respect not to
be a property of man.
Moreover, as regards all the things that are called as they are
primarily after something else, or primarily in themselves, it is a
job to render the property of such things. For if you render a
property as belonging to the subject that is so called after
something else, then it will be true of its primary subject as
well; whereas if you state it of its primary subject, then it will be
predicated also of the thing that is so called after this other.
Thus (e.g.) if any one renders , coloured' as the property of
'surface', 'coloured' will be true of body as well; whereas if he
render it of 'body', it will be predicated also of 'surface'. Hence
the name as well will not be true of that of which the
description is true.
435
In the case of some properties it mostly happens that some
error is incurred because of a failure to define how as well as to
what things the property is stated to belong. For every one tries
to render as the property of a thing something that belongs to it
either naturally, as 'biped' belongs to 'man', or actually, as
'having four fingers' belongs to a particular man, or specifically,
as 'consisting of most rarefied particles' belongs to 'fire', or
absolutely, as 'life' to 'living being', or one that belongs to a
thing only as called after something else, as 'wisdom' to the
'soul', or on the other hand primarily, as 'wisdom' to the
'rational faculty', or because the thing is in a certain state, as
'incontrovertible by argument' belongs to a 'scientist' (for simply
and solely by reason of his being in a certain state will he be
'incontrovertible by argument'), or because it is the state
possessed by something, as 'incontrovertible by argument'
belongs to 'science', or because it is partaken of, as 'sensation'
belongs to 'animal' (for other things as well have sensation, e.g.
man, but they have it because they already partake of 'animal'),
or because it partakes of something else, as 'life' belongs to a
particular kind of 'living being'. Accordingly he makes a mistake
if he has failed to add the word 'naturally', because what
belongs naturally may fail to belong to the thing to which it
naturally belongs, as (e.g.) it belongs to a man to have two feet:
so too he errs if he does not make a definite proviso that he is
rendering what actually belongs, because one day that attribute
will not be what it now is, e.g. the man's possession of four
fingers. So he errs if he has not shown that he states a thing to
be such and such primarily, or that he calls it so after something
else, because then its name too will not be true of that of which
the description is true, as is the case with 'coloured', whether
rendered as a property of 'surface' or of 'body'. So he errs if he
has not said beforehand that he has rendered a property to a
thing either because that thing possesses a state, or because it
is a state possessed by something; because then it will not be a
436
property. For, supposing he renders the property to something
as being a state possessed, it will belong to what possesses that
state; while supposing he renders it to what possesses the state,
it will belong to the state possessed, as did 'incontrovertible by
argument' when stated as a property of 'science' or of the
'scientist'. So he errs if he has not indicated beforehand that the
property belongs because the thing partakes of, or is partaken
of by, something; because then the property will belong to
certain other things as well. For if he renders it because its
subject is partaken of, it will belong to the things which partake
of it; whereas if he renders it because its subject partakes of
something else, it will belong to the things partaken of, as (e.g.)
if he were to state 'life' to be a property of a 'particular kind of
living being', or just of 'living being. So he errs if he has not
expressly distinguished the property that belongs specifically,
because then it will belong only to one of the things that fall
under the term of which he states the property: for the
superlative belongs only to one of them, e.g. 'lightest' as applied
to 'fire'. Sometimes, too, a man may even add the word
'specifically', and still make a mistake. For the things in
question should all be of one species, whenever the word
'specifically' is added: and in some cases this does not occur, as
it does not, in fact, in the case of fire. For fire is not all of one
species; for live coals and flame and light are each of them 'fire',
but are of different species. The reason why, whenever
'specifically' is added, there should not be any species other
than the one mentioned, is this, that if there be, then the
property in question will belong to some of them in a greater
and to others in a less degree, as happens with 'consisting of
most rarefied particles' in the case of fire: for 'light' consists of
more rarefied particles than live coals and flame. And this
should not happen unless the name too be predicated in a
greater degree of that of which the description is truer;
otherwise the rule that where the description is truer the name
437
too should be truer is not fulfilled. Moreover, in addition to this,
the same attribute will be the property both of the term which
has it absolutely and of that element therein which has it in the
highest degree, as is the condition of the property 'consisting of
most rarefied particles' in the case of 'fire': for this same
attribute will be the property of 'light' as well: for it is 'light' that
'consists of the most rarefied particles'. If, then, any one else
renders a property in this way one should attack it; for oneself,
one should not give occasion for this objection, but should
define in what manner one states the property at the actual
time of making the statement.
Next, for destructive purposes, see if he has stated a thing as a
property of itself: for then what has been stated to be a property
will not be a property. For a thing itself always shows its own
essence, and what shows the essence is not a property but a
definition. Thus (e.g.) he who has said that 'becoming' is a
property of 'beautiful' has rendered the term as a property of
itself (for 'beautiful' and 'becoming' are the same); and so
'becoming' could not be a property of 'beautiful'. For
constructive purposes, on the other hand, see if he has avoided
rendering a thing as a property of itself, but has yet stated a
convertible predicate: for then what is stated not to be a
property will be a property. Thus he who has stated 'animate
substance' as a property of 'living-creature' has not stated
'living-creature' as a property of itself, but has rendered a
convertible predicate, so that 'animate substance' would be a
property of 'living-creature'.
Next, in the case of things consisting of like parts, you should
look and see, for destructive purposes, if the property of the
whole be not true of the part, or if that of the part be not
predicated of the whole: for then what has been stated to be the
property will not be a property. In some cases it happens that
this is so: for sometimes in rendering a property in the case of
438
things that consist of like parts a man may have his eye on the
whole, while sometimes he may address himself to what is
predicated of the part: and then in neither case will it have been
rightly rendered. Take an instance referring to the whole: the
man who has said that it is a property of the 'sea' to be 'the
largest volume of salt water', has stated the property of
something that consists of like parts, but has rendered an
attribute of such a kind as is not true of the part (for a particular
sea is not 'the largest volume of salt water'); and so the largest
volume of salt water' could not be a property of the 'sea'. Now
take one referring to the part: the man who has stated that it is
a property of 'air' to be 'breathable' has stated the property of
something that consists of like parts, but he has stated an
attribute such as, though true of some air, is still not predicable
of the whole (for the whole of the air is not breathable); and so
'breathable' could not be a property of 'air'. For constructive
purposes, on the other hand, see whether, while it is true of
each of the things with similar parts, it is on the other hand a
property of them taken as a collective whole: for then what has
been stated not to be a property will be a property. Thus (e.g.)
while it is true of earth everywhere that it naturally falls
downwards, it is a property of the various particular pieces of
earth taken as 'the Earth', so that it would be a property of
'earth' 'naturally to fall downwards'.
Next, look from the point of view of the respective opposites,
and first (a) from that of the contraries, and see, for destructive
purposes, if the contrary of the term rendered fails to be a
property of the contrary subject. For then neither will the
contrary of the first be a property of the contrary of the second.
439
Thus (e.g.) inasmuch as injustice is contrary to justice, and the
lowest evil to the highest good, but 'to be the highest good' is
not a property of 'justice', therefore 'to be the lowest evil' could
not be a property of 'injustice'. For constructive purposes, on the
other hand, see if the contrary is the property of the contrary:
for then also the contrary of the first will be the property of the
contrary of the second. Thus (e.g.) inasmuch as evil is contrary
to good, and objectionable to desirable, and 'desirable' is a
property of 'good', 'objectionable' would be a property of 'evil'.
Secondly (h) look from the point of view of relative opposites
and see, for destructive purposes, if the correlative of the term
rendered fails to be a property of the correlative of the subject:
for then neither will the correlative of the first be a property of
the correlative of the second. Thus (e.g.) inasmuch as 'double' is
relative to 'half, and 'in excess' to 'exceeded', while 'in excess'
is not a property of 'double', exceeded' could not be a property
of 'half. For constructive purposes, on the other hand, see if the
correlative of the alleged property is a property of the subject's
correlative: for then also the correlative of the first will be a
property of the correlative of the second: e.g. inasmuch as
'double' is relative to 'half, and the proportion 1:2 is relative to
the proportion 2:1, while it is a property of 'double' to be 'in the
proportion of 2 to 1', it would be a property of 'half to be 'in the
proportion of 1 to 2'.
Thirdly (c) for destructive purposes, see if an attribute described
in terms of a state (X) fails to be a property of the given state (Y):
for then neither will the attribute described in terms of the
privation (of X) be a property of the privation (of Y). Also if, on
the other hand, an attribute described in terms of the privation
(of X) be not a property of the given privation (of Y), neither will
the attribute described in terms of the state (X) be a property of
the state (Y).Thus, for example, inasmuch as it is not predicated
as a property of 'deafness' to be a 'lack of sensation', neither
440
could it be a property of 'hearing' to be a 'sensation'. For
constructive purposes, on the other hand, see if an attribute
described in terms of a state (X) is a property of the given state
(Y): for then also the attribute that is described in terms of the
privation (of X) will be a property of the privation (of Y). Also, if
an attribute described in terms of a privation (of X) be a
property of the privation (of Y), then also the attribute that is
described in terms of the state (X) will be a property of the state
(Y). Thus (e.g.) inasmuch as 'to see' is a property of 'sight',
inasmuch as we have sight, 'failure to see' would be a property
of 'blindness', inasmuch as we have not got the sight we should
naturally have.
Next, look from the point of view of positive and negative terms;
and first (a) from the point of view of the predicates taken by
themselves. This common-place rule is useful only for a
destructive purpose. Thus (e.g.) see if the positive term or the
attribute described in terms of it is a property of the subject: for
then the negative term or the attribute described in terms of it
will not be a property of the subject. Also if, on the other hand,
the negative term or the attribute described in terms of it is a
property of the subject, then the positive term or the attribute
described in terms of it will not be a property of the subject: e.g.
inasmuch as 'animate' is a property of 'living creature',
'inanimate' could not be a property of 'living creature'.
Secondly (b) look from the point of view of the predicates,
positive or negative, and their respective subjects; and see, for
destructive purposes, if the positive term falls to be a property
of the positive subject: for then neither will the negative term
be a property of the negative subject. Also, if the negative term
fails to be a property of the negative subject, neither will the
positive term be a property of the positive subject. Thus (e.g.)
inasmuch as 'animal' is not a property of 'man', neither could
'not-animal' be a property of 'not-man'. Also if 'not-animal'
441
seems not to be a property of 'not-man', neither will 'animal' be
a property of 'man'. For constructive purposes, on the other
hand, see if the positive term is a property of the positive
subject: for then the negative term will be a property of the
negative subject as well. Also if the negative term be a property
of the negative subject, the positive will be a property of the
positive as well. Thus (e.g.) inasmuch as it is a property of 'not-
living being' 'not to live', it would be a property of 'living being'
'to live': also if it seems to be a property of 'living being' 'to live',
it will also seem to be a property of 'not-living being' 'not to
live'.
Thirdly (c) look from the point of view of the subjects taken by
themselves, and see, for destructive purposes, if the property
rendered is a property of the positive subject: for then the same
term will not be a property of the negative subject as well. Also,
if the term rendered be a property of the negative subject, it will
not be a property of the positive. Thus (e.g.) inasmuch as
'animate' is a property of 'living creature', 'animate' could not
be a property of 'not-living creature'. For constructive purposes,
on the other hand, if the term rendered fails to be a property of
the affirmative subject it would be a property of the negative.
This commonplace rule is, however, deceptive: for a positive
term is not a property of a negative, or a negative of a positive.
For a positive term does not belong at all to a negative, while a
negative term, though it belongs to a positive, does not belong
as a property.
Next, look from the point of view of the coordinate members of
a division, and see, for destructive purposes, if none of the co-
ordinate members (parallel with the property rendered) be a
property of any of the remaining set of co-ordinate members
(parallel with the subject): for then neither will the term stated
be a property of that of which it is stated to be a property. Thus
(e.g.) inasmuch as 'sensible living being' is not a property of any
442
of the other living beings, 'intelligible living being' could not be
a property of God. For constructive purposes, on the other hand,
see if some one or other of the remaining co-ordinate members
(parallel with the property rendered) be a property of each of
these co-ordinate members (parallel with the subject): for then
the remaining one too will be a property of that of which it has
been stated not to be a property. Thus (e.g.) inasmuch as it is a
property of 'wisdom' to be essentially 'the natural virtue of the
rational faculty', then, taking each of the other virtues as well in
this way, it would be a property of 'temperance' to be essentially
'the natural virtue of the faculty of desire'.
Next, look from the point of view of the inflexions, and see, for
destructive purposes, if the inflexion of the property rendered
fails to be a property of the inflexion of the subject: for then
neither will the other inflexion be a property of the other
inflexion. Thus (e.g.) inasmuch as 'beautifully' is not a property
of 'justly', neither could 'beautiful' be a property of 'just'. For
constructive purposes, on the other hand, see if the inflexion of
the property rendered is a property of the inflexion of the
subject: for then also the other inflexion will be a property of
the other inflexion. Thus (e.g.) inasmuch as 'walking biped' is a
property of man, it would also be any one's property 'as a man'
to be described 'as a walking biped'. Not only in the case of the
actual term mentioned should one look at the inflexions, but
also in the case of its opposites, just as has been laid down in
the case of the former commonplace rules as well.' Thus, for
destructive purposes, see if the inflexion of the opposite of the
property rendered fails to be the property of the inflexion of the
opposite of the subject: for then neither will the inflexion of the
other opposite be a property of the inflexion of the other
opposite. Thus (e.g.) inasmuch as 'well' is not a property of
'justly', neither could 'badly' be a property of 'unjustly'. For
constructive purposes, on the other hand, see if the inflexion of
the opposite of the property originally suggested is a property of
443
the inflexion of the opposite of the original subject: for then
also the inflexion of the other opposite will be a property of the
inflexion of the other opposite. Thus (e.g.) inasmuch as 'best' is
a property of 'the good', 'worst' also will be a property of 'the
evil'.
Next, look from the point of view of things that are in a like
relation, and see, for destructive purposes, if what is in a
relation like that of the property rendered fails to be a property
of what is in a relation like that of the subject: for then neither
will what is in a relation like that of the first be a property of
what is in a relation like that of the second. Thus (e.g.)
inasmuch as the relation of the builder towards the production
of a house is like that of the doctor towards the production of
health, and it is not a property of a doctor to produce health, it
could not be a property of a builder to produce a house. For
constructive purposes, on the other hand, see if what is in a
relation like that of the property rendered is a property of what
is in a relation like that of the subject: for then also what is in a
relation like that of the first will be a property of what is in a
relation like that of the second. Thus (e.g.) inasmuch as the
relation of a doctor towards the possession of ability to produce
health is like that of a trainer towards the possession of ability
to produce vigour, and it is a property of a trainer to possess the
ability to produce vigour, it would be a property of a doctor to
possess the ability to produce health.
Next look from the point of view of things that are identically
related, and see, for destructive purposes, if the predicate that is
identically related towards two subjects fails to be a property of
444
the subject which is identically related to it as the subject in
question; for then neither will the predicate that is identically
related to both subjects be a property of the subject which is
identically related to it as the first. If, on the other hand, the
predicate which is identically related to two subjects is the
property of the subject which is identically related to it as the
subject in question, then it will not be a property of that of
which it has been stated to be a property, (e.g.) inasmuch as
prudence is identically related to both the noble and the base,
since it is knowledge of each of them, and it is not a property of
prudence to be knowledge of the noble, it could not be a
property of prudence to be knowledge of the base. If, on the
other hand, it is a property of prudence to be the knowledge of
the noble, it could not be a property of it to be the knowledge of
the base.] For it is impossible for the same thing to be a property
of more than one subject. For constructive purposes, on the
other hand, this commonplace rule is of no use: for what is
'identically related' is a single predicate in process of
comparison with more than one subject.
Next, for destructive purposes, see if the predicate qualified by
the verb 'to be' fails to be a property of the subject qualified by
the verb 'to be': for then neither will the destruction of the one
be a property of the other qualified by the verb 'to be destroyed',
nor will the 'becoming'the one be a property of the other
qualified by the verb 'to become'. Thus (e.g.) inasmuch as it is
not a property of 'man' to be an animal, neither could it be a
property of becoming a man to become an animal; nor could
the destruction of an animal be a property of the destruction of
a man. In the same way one should derive arguments also from
'becoming' to 'being' and 'being destroyed', and from 'being
destroyed' to 'being' and to 'becoming' exactly as they have just
been given from 'being' to 'becoming' and 'being destroyed'. For
constructive purposes, on the other hand, see if the subject set
down as qualified by the verb 'to be' has the predicate set down
445
as so qualified, as its property: for then also the subject
qualified by the very 'to become' will have the predicate
qualified by 'to become' as its property, and the subject
qualified by the verb to be destroyed' will have as its property
the predicate rendered with this qualification. Thus, for
example, inasmuch as it is a property of man to be a mortal, it
would be a property of becoming a man to become a mortal,
and the destruction of a mortal would be a property of the
destruction of a man. In the same way one should derive
arguments also from 'becoming' and 'being destroyed' both to
'being' and to the conclusions that follow from them, exactly as
was directed also for the purpose of destruction.
Next take a look at the 'idea' of the subject stated, and see, for
destructive purposes, if the suggested property fails to belong to
the 'idea' in question, or fails to belong to it in virtue of that
character which causes it to bear the description of which the
property was rendered: for then what has been stated to be a
property will not be a property. Thus (e.g.) inasmuch as 'being
motionless' does not belong to 'man-himself qua 'man', but
qua 'idea', it could not be a property of 'man' to be motionless.
For constructive purposes, on the other hand, see if the property
in question belongs to the idea, and belongs to it in that respect
in virtue of which there is predicated of it that character of
which the predicate in question has been stated not to be a
property: for then what has been stated not to be a property will
be a property. Thus (e.g.) inasmuch as it belongs to 'living-
creature-itself to be compounded of soul and body, and further
this belongs to it qua 'living-creature', it would be a property of
'living-creature' to be compounded of soul and body.
446
8
Next look from the point of view of greater and less degrees,
and first (a) for destructive purposes, see if what is more-P fails
to be a property of what is more-S: for then neither will what is
less-P be a property of what is less-S, nor least-P of least-S, nor
most-P of most-S, nor P simply of S simply. Thus (e.g.) inasmuch
as being more highly coloured is not a property of what is more
a body, neither could being less highly coloured be a property of
what is less a body, nor being coloured be a property of body at
all. For constructive purposes, on the other hand, see if what is
more-P is a property of what is more-S: for then also what is
less-P will be a property of what is less S, and least-P of least-S,
and most-P of most-S, and P simply of S simply. Thus (e.g.)
inasmuch as a higher degree of sensation is a property of a
higher degree of life, a lower degree of sensation also would be a
property of a lower degree of life, and the highest of the highest
and the lowest of the lowest degree, and sensation simply of life
simply.
Also you should look at the argument from a simple predication
to the same qualified types of predication, and see, for
destructive purposes, if P simply fails to be a property of S
simply; for then neither will more-P be a property of more-S,
nor less-P of less-S, nor most-P of most-S, nor least-P of least-S.
Thus (e.g.) inasmuch as 'virtuous' is not a property of 'man',
neither could 'more virtuous' be a property of what is 'more
human'. For constructive purposes, on the other hand, see if P
simply is a property of S simply: for then more P also will be a
property of more-S, and less-P of less-S, and least-P of least-S,
and most-P of most-S. Thus (e.g.) a tendency to move upwards
by nature is a property of fire, and so also a greater tendency to
move upwards by nature would be a property of what is more
fiery. In the same way too one should look at all these matters
from the point of view of the others as well.
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Secondly (b) for destructive purposes, see if the more likely
property fails to be a property of the more likely subject: for
then neither will the less likely property be a property of the
less likely subject. Thus (e.g.) inasmuch as 'perceiving' is more
likely to be a property of 'animal' than 'knowing' of 'man', and
'perceiving' is not a property of 'animal', 'knowing' could not be
a property of 'man'. For constructive purposes, on the other
hand, see if the less likely property is a property of the less
likely subject; for then too the more likely property will be a
property of the more likely subject. Thus (e.g.) inasmuch as 'to
be naturally civilized' is less likely to be a property of man than
'to live' of an animal, and it is a property of man to be naturally
civilized, it would be a property of animal to live.
Thirdly (c) for destructive purposes, see if the predicate fails to
be a property of that of which it is more likely to be a property:
for then neither will it be a property of that of which it is less
likely to be a property: while if it is a property of the former, it
will not be a property of the latter. Thus (e.g.) inasmuch as 'to be
coloured' is more likely to be a property of a 'surface' than of a
'body', and it is not a property of a surface, 'to be coloured'
could not be a property of 'body'; while if it is a property of a
'surface', it could not be a property of a 'body'. For constructive
purposes, on the other hand, this commonplace rule is not of
any use: for it is impossible for the same thing to be a property
of more than one thing.
Fourthly (d) for destructive purposes, see if what is more likely
to be a property of a given subject fails to be its property: for
then neither will what is less likely to be a property of it be its
property. Thus (e.g.) inasmuch as 'sensible' is more likely than
'divisible' to be a property of 'animal', and 'sensible' is not a
property of animal, 'divisible' could not be a property of animal.
For constructive purposes, on the other hand, see if what is less
likely to be a property of it is a property; for then what is more
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likely to be a property of it will be a property as well. Thus, for
example, inasmuch as 'sensation' is less likely to be a property
of 'animal' than life', and 'sensation' is a property of animal,
'life' would be a property of animal.
Next, look from the point of view of the attributes that belong in
a like manner, and first (a) for destructive purposes, see if what
is as much a property fails to be a property of that of which it is
as much a property: for then neither will that which is as much
a property as it be a property of that of which it is as much a
property. Thus (e.g.) inasmuch as 'desiring' is as much a
property of the faculty of desire as reasoning' is a property of
the faculty of reason, and desiring is not a property of the
faculty of desire, reasoning could not be a property of the
faculty of reason. For constructive purposes, on the other hand,
see if what is as much a property is a property of that of which
it is as much a property: for then also what is as much a
property as it will be a property of that of which it is as much a
property. Thus (e.g.) inasmuch as it is as much a property of 'the
faculty of reason' to be 'the primary seat of wisdom' as it is of
'the faculty of desire' to be 'the primary seat of temperance',
and it is a property of the faculty of reason to be the primary
seat of wisdom, it would be a property of the faculty of desire to
be the primary seat of temperance.
Secondly (b) for destructive purposes, see if what is as much a
property of anything fails to be a property of it: for then neither
will what is as much a property be a property of it. Thus (e.g.)
inasmuch as 'seeing' is as much a property of man as 'hearing',
and 'seeing' is not a property of man, 'hearing' could not be a
property of man. For constructive purposes, on the other hand,
see if what is as much a property of it is its property: for then
what is as much a property of it as the former will be its
property as well. Thus (e.g.) it is as much a property of the soul
to be the primary possessor of a part that desires as of a part
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that reasons, and it is a property of the soul to be the primary-
possessor of a part that desires, and so it be a property of the
soul to be the primary possessor of a part that reasons.
Thirdly (c) for destructive purposes, see if it fails to be a
property of that of which it is as much a property: for then
neither will it be a property of that of which it is as much a
property as of the former, while if it be a property of the former,
it will not be a property of the other. Thus (e.g.) inasmuch as 'to
burn' is as much a property of 'flame' as of 'live coals', and 'to
burn' is not a property of flame, 'to burn' could not be a
property of live coals: while if it is a property of flame, it could
not be a property of live coals. For constructive purposes, on the
other hand, this commonplace rule is of no use.
The rule based on things that are in a like relation' differs from
the rule based on attributes that belong in a like manner,'
because the former point is secured by analogy, not from
reflection on the belonging of any attribute, while the latter is
judged by a comparison based on the fact that an attribute
belongs.
Next, for destructive purposes, see if in rendering the property
potentially, he has also through that potentiality rendered the
property relatively to something that does not exist, when the
potentiality in question cannot belong to what does not exist:
for then what is stated to be a property will not be a property.
Thus (e.g.) he who has said that 'breathable' is a property of 'air'
has, on the one hand, rendered the property potentially (for that
is 'breathable' which is such as can be breathed), and on the
other hand has also rendered the property relatively to what
does not exist: - for while air may exist, even though there exist
no animal so constituted as to breathe the air, it is not possible
to breathe it if no animal exist: so that it will not, either, be a
property of air to be such as can be breathed at a time when
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there exists no animal such as to breathe it and so it follows
that 'breathable' could not be a property of air.
For constructive purposes, see if in rendering the property
potentially he renders the property either relatively to
something that exists, or to something that does not exist,
when the potentiality in question can belong to what does not
exist: for then what has been stated not to be a property will be
a property. Thus e.g.) he who renders it as a property of 'being'
to be 'capable of being acted upon or of acting', in rendering the
property potentially, has rendered the property relatively to
something that exists: for when 'being' exists, it will also be
capable of being acted upon or of acting in a certain way: so
that to be 'capable of being acted upon or of acting' would be a
property of 'being'.
Next, for destructive purposes, see if he has stated the property
in the superlative: for then what has been stated to be a
property will not be a property. For people who render the
property in that way find that of the object of which the
description is true, the name is not true as well: for though the
object perish the description will continue in being none the
less; for it belongs most nearly to something that is in being. An
example would be supposing any one were to render 'the
lightest body' as a property of 'fire': for, though fire perish, there
eh re will still be some form of body that is the lightest, so that
'the lightest body' could not be a property of fire. For
constructive purposes, on the other hand, see if he has avoided
rendering the property in the superlative: for then the property
will in this respect have been property of man has not rendered
the property correctly stated. Thus (e.g.) inasmuch as he in the
superlative, the property would in who states 'a naturally
civilized animal' as a this respect have been correctly stated.
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Book VI
The discussion of Definitions falls into five parts. For you have
to show either (1) that it is not true at all to apply the expression
as well to that to which the term is applied (for the definition of
Man ought to be true of every man); or (2) that though the object
has a genus, he has failed to put the object defined into the
genus, or to put it into the appropriate genus (for the framer of a
definition should first place the object in its genus, and then
append its differences: for of all the elements of the definition
the genus is usually supposed to be the principal mark of the
essence of what is defined): or (3) that the expression is not
peculiar to the object (for, as we said above as well, a definition
ought to be peculiar): or else (4) see if, though he has observed
all the aforesaid cautions, he has yet failed to define the object,
that is, to express its essence. (5) It remains, apart from the
foregoing, to see if he has defined it, but defined it incorrectly.
Whether, then, the expression be not also true of that of which
the term is true you should proceed to examine according to the
commonplace rules that relate to Accident. For there too the
question is always 'Is so and so true or untrue?': for whenever
we argue that an accident belongs, we declare it to be true,
while whenever we argue that it does not belong, we declare it
to be untrue. If, again, he has failed to place the object in the
appropriate genus, or if the expression be not peculiar to the
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object, we must go on to examine the case according to the
commonplace rules that relate to genus and property.
It remains, then, to prescribe how to investigate whether the
object has been either not defined at all, or else defined
incorrectly. First, then, we must proceed to examine if it has
been defined incorrectly: for with anything it is easier to do it
than to do it correctly. Clearly, then, more mistakes are made in
the latter task on account of its greater difficulty. Accordingly
the attack becomes easier in the latter case than in the former.
Incorrectness falls into two branches: (1) first, the use of obscure
language (for the language of a definition ought to be the very
clearest possible, seeing that the whole purpose of rendering it
is to make something known); (secondly, if the expression used
be longer than is necessary: for all additional matter in a
definition is superfluous. Again, each of the aforesaid branches
is divided into a number of others.
One commonplace rule, then, in regard to obscurity is, See if the
meaning intended by the definition involves an ambiguity with
any other, e.g. 'Becoming is a passage into being', or 'Health is
the balance of hot and cold elements'. Here 'passage' and
'balance' are ambiguous terms: it is accordingly not clear which
of the several possible senses of the term he intends to convey.
Likewise also, if the term defined be used in different senses
and he has spoken without distinguishing between them: for
then it is not clear to which of them the definition rendered
applies, and one can then bring a captious objection on the
ground that the definition does not apply to all the things
whose definition he has rendered: and this kind of thing is
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particularly easy in the case where the definer does not see the
ambiguity of his terms. Or, again, the questioner may himself
distinguish the various senses of the term rendered in the
definition, and then institute his argument against each: for if
the expression used be not adequate to the subject in any of its
senses, it is clear that he cannot have defined it in any sense
aright.
Another rule is, See if he has used a metaphorical expression,
as, for instance, if he has defined knowledge as
'unsupplantable', or the earth as a 'nurse', or temperance as a
'harmony'. For a metaphorical expression is always obscure. It is
possible, also, to argue sophistically against the user of a
metaphorical expression as though he had used it in its literal
sense: for the definition stated will not apply to the term
defined, e.g. in the case of temperance: for harmony is always
found between notes. Moreover, if harmony be the genus of
temperance, then the same object will occur in two genera of
which neither contains the other: for harmony does not contain
virtue, nor virtue harmony. Again, see if he uses terms that are
unfamiliar, as when Plato describes the eye as 'brow-shaded', or
a certain spider as poison-fanged', or the marrow as
'boneformed'. For an unusual phrase is always obscure.
Sometimes a phrase is used neither ambiguously, nor yet
metaphorically, nor yet literally, as when the law is said to be
the 'measure' or 'image' of the things that are by nature just.
Such phrases are worse than metaphor; for the latter does make
its meaning to some extent clear because of the likeness
involved; for those who use metaphors do so always in view of
some likeness: whereas this kind of phrase makes nothing
clear; for there is no likeness to justify the description 'measure'
or 'image', as applied to the law, nor is the law ordinarily so
called in a literal sense. So then, if a man says that the law is
literally a 'measure' or an 'image', he speaks falsely: for an
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image is something produced by imitation, and this is not found
in the case of the law. If, on the other hand, he does not mean
the term literally, it is clear that he has used an unclear
expression, and one that is worse than any sort of metaphorical
expression.
Moreover, see if from the expression used the definition of the
contrary be not clear; for definitions that have been correctly
rendered also indicate their contraries as well. Or, again, see if,
when it is merely stated by itself, it is not evident what it
defines: just as in the works of the old painters, unless there
were an inscription, the figures used to be unrecognizable.
If, then, the definition be not clear, you should proceed to
examine on lines such as these. If, on the other hand, he has
phrased the definition redundantly, first of all look and see
whether he has used any attribute that belongs universally,
either to real objects in general, or to all that fall under the
same genus as the object defined: for the mention of this is sure
to be redundant. For the genus ought to divide the object from
things in general, and the differentia from any of the things
contained in the same genus. Now any term that belongs to
everything separates off the given object from absolutely
nothing, while any that belongs to all the things that fall under
the same genus does not separate it off from the things
contained in the same genus. Any addition, then, of that kind
will be pointless.
Or see if, though the additional matter may be peculiar to the
given term, yet even when it is struck out the rest of the
expression too is peculiar and makes clear the essence of the
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term. Thus, in the definition of man, the addition 'capable of
receiving knowledge' is superfluous; for strike it out, and still
the expression is peculiar and makes clear his essence.
Speaking generally, everything is superfluous upon whose
removal the remainder still makes the term that is being
defined clear. Such, for instance, would also be the definition of
the soul, assuming it to be stated as a 'self-moving number'; for
the soul is just 'the self-moving', as Plato defined it. Or perhaps
the expression used, though appropriate, yet does not declare
the essence, if the word 'number' be eliminated. Which of the
two is the real state of the case it is difficult to determine
clearly: the right way to treat the matter in all cases is to be
guided by convenience. Thus (e.g.) it is said that the definition of
phlegm is the 'undigested moisture that comes first off food'.
Here the addition of the word 'undigested' is superfluous,
seeing that 'the first' is one and not many, so that even when
undigested' is left out the definition will still be peculiar to the
subject: for it is impossible that both phlegm and also
something else should both be the first to arise from the food.
Or perhaps the phlegm is not absolutely the first thing to come
off the food, but only the first of the undigested matters, so that
the addition 'undigested' is required; for stated the other way
the definition would not be true unless the phlegm comes first
of all.
Moreover, see if anything contained in the definition fails to
apply to everything that falls under the same species: for this
sort of definition is worse than those which include an attribute
belonging to all things universally. For in that case, if the
remainder of the expression be peculiar, the whole too will be
peculiar: for absolutely always, if to something peculiar
anything whatever that is true be added, the whole too becomes
peculiar. Whereas if any part of the expression do not apply to
everything that falls under the same species, it is impossible
that the expression as a whole should be peculiar: for it will not
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be predicated convertibly with the object; e.g. 'a walking biped
animal six feet high': for an expression of that kind is not
predicated convertibly with the term, because the attribute 'six
feet high' does not belong to everything that falls under the
same species.
Again, see if he has said the same thing more than once, saying
(e.g.) 'desire' is a 'conation for the pleasant'. For 'desire' is
always 'for the pleasant', so that what is the same as desire will
also be 'for the pleasant'. Accordingly our definition of desire
becomes 'conation-for-the-pleasant': for the word 'desire' is the
exact equivalent of the words 'conation-for-the-pleasant', so
that both alike will be 'for the pleasant'. Or perhaps there is no
absurdity in this; for consider this instance: 'Man is a biped':
therefore, what is the same as man is a biped: but 'a walking
biped animal' is the same as man, and therefore walking biped
animal is a biped'. But this involves no real absurdity. For 'biped'
is not a predicate of 'walking animal': if it were, then we should
certainly have 'biped' predicated twice of the same thing; but as
a matter of fact the subject said to be a biped is'a walking biped
animal', so that the word 'biped' is only used as a predicate
once. Likewise also in the case of 'desire' as well: for it is not
'conation' that is said to be 'for the pleasant', but rather the
whole idea, so that there too the predication is only made once.
Absurdity results, not when the same word is uttered twice, but
when the same thing is more than once predicated of a subject;
e.g. if he says, like Xenocrates, that wisdom defines and
contemplates reality:' for definition is a certain type of
contemplation, so that by adding the words 'and contemplates'
over again he says the same thing twice over. Likewise, too,
those fail who say that 'cooling' is 'the privation of natural heat'.
For all privation is a privation of some natural attribute, so that
the addition of the word 'natural' is superfluous: it would have
been enough to say 'privation of heat', for the word 'privation'
shows of itself that the heat meant is natural heat.
457
Again, see if a universal have been mentioned and then a
particular case of it be added as well, e.g. 'Equity is a remission
of what is expedient and just'; for what is just is a branch of
what is expedient and is therefore included in the latter term:
its mention is therefore redundant, an addition of the particular
after the universal has been already stated. So also, if he defines
'medicine' as 'knowledge of what makes for health in animals
and men', or 'the law' as 'the image of what is by nature noble
and just'; for what is just is a branch of what is noble, so that he
says the same thing more than once.
Whether, then, a man defines a thing correctly or incorrectly
you should proceed to examine on these and similar lines. But
whether he has mentioned and defined its essence or no,
should be examined as follows: First of all, see if he has failed to
make the definition through terms that are prior and more
intelligible. For the reason why the definition is rendered is to
make known the term stated, and we make things known by
taking not any random terms, but such as are prior and more
intelligible, as is done in demonstrations (for so it is with all
teaching and learning); accordingly, it is clear that a man who
does not define through terms of this kind has not defined at
all. Otherwise, there will be more than one definition of the
same thing: for clearly he who defines through terms that are
prior and more intelligible has also framed a definition, and a
better one, so that both would then be definitions of the same
object. This sort of view, however, does not generally find
acceptance: for of each real object the essence is single: if, then,
there are to be a number of definitions of the same thing, the
essence of the object will be the same as it is represented to be
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in each of the definitions, and these representations are not the
same, inasmuch as the definitions are different. Clearly, then,
any one who has not defined a thing through terms that are
prior and more intelligible has not defined it at all.
The statement that a definition has not been made through
more intelligible terms may be understood in two senses, either
supposing that its terms are absolutely less intelligible, or
supposing that they are less intelligible to us: for either sense is
possible. Thus absolutely the prior is more intelligible than the
posterior, a point, for instance, than a line, a line than a plane,
and a plane than a solid; just as also a unit is more intelligible
than a number; for it is the prius and starting-point of all
number. Likewise, also, a letter is more intelligible than a
syllable. Whereas to us it sometimes happens that the converse
is the case: for the solid falls under perception most of all -
more than a plane - and a plane more than a line, and a line
more than a point; for most people learn things like the former
earlier than the latter; for any ordinary intelligence can grasp
them, whereas the others require an exact and exceptional
understanding.
Absolutely, then, it is better to try to make what is posterior
known through what is prior, inasmuch as such a way of
procedure is more scientific. Of course, in dealing with persons
who cannot recognize things through terms of that kind, it may
perhaps be necessary to frame the expression through terms
that are intelligible to them. Among definitions of this kind are
those of a point, a line, and a plane, all of which explain the
prior by the posterior; for they say that a point is the limit of a
line, a line of a plane, a plane of a solid. One must, however, not
fail to observe that those who define in this way cannot show
the essential nature of the term they define, unless it so
happens that the same thing is more intelligible both to us and
also absolutely, since a correct definition must define a thing
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through its genus and its differentiae, and these belong to the
order of things which are absolutely more intelligible than, and
prior to, the species. For annul the genus and differentia, and
the species too is annulled, so that these are prior to the
species. They are also more intelligible; for if the species be
known, the genus and differentia must of necessity be known
as well (for any one who knows what a man is knows also what
'animal' and 'walking' are), whereas if the genus or the
differentia be known it does not follow of necessity that the
species is known as well: thus the species is less intelligible.
Moreover, those who say that such definitions, viz. those which
proceed from what is intelligible to this, that, or the other man,
are really and truly definitions, will have to say that there are
several definitions of one and the same thing. For, as it happens,
different things are more intelligible to different people, not the
same things to all; and so a different definition would have to
be rendered to each several person, if the definition is to be
constructed from what is more intelligible to particular
individuals. Moreover, to the same people different things are
more intelligible at different times; first of all the objects of
sense; then, as they become more sharpwitted, the converse; so
that those who hold that a definition ought to be rendered
through what is more intelligible to particular individuals would
not have to render the same definition at all times even to the
same person. It is clear, then, that the right way to define is not
through terms of that kind, but through what is absolutely more
intelligible: for only in this way could the definition come
always to be one and the same. Perhaps, also, what is absolutely
intelligible is what is intelligible, not to all, but to those who are
in a sound state of understanding, just as what is absolutely
healthy is what is healthy to those in a sound state of body. All
such points as this ought to be made very precise, and made
use of in the course of discussion as occasion requires. The
demolition of a definition will most surely win a general
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approval if the definer happens to have framed his expression
neither from what is absolutely more intelligible nor yet from
what is so to us.
One form, then, of the failure to work through more intelligible
terms is the exhibition of the prior through the posterior, as we
remarked before.' Another form occurs if we find that the
definition has been rendered of what is at rest and definite
through what is indefinite and in motion: for what is still and
definite is prior to what is indefinite and in motion.
Of the failure to use terms that are prior there are three forms:
(1) The first is when an opposite has been defined through its
opposite, e.g.i. good through evil: for opposites are always
simultaneous by nature. Some people think, also, that both are
objects of the same science, so that the one is not even more
intelligible than the other. One must, however, observe that it is
perhaps not possible to define some things in any other way,
e.g. the double without the half, and all the terms that are
essentially relative: for in all such cases the essential being is
the same as a certain relation to something, so that it is
impossible to understand the one term without the other, and
accordingly in the definition of the one the other too must be
embraced. One ought to learn up all such points as these, and
use them as occasion may seem to require.
(2) Another is - if he has used the term defined itself. This
passes unobserved when the actual name of the object is not
used, e.g. supposing any one had defined the sun as a star that
appears by day'. For in bringing in 'day' he brings in the sun. To
detect errors of this sort, exchange the word for its definition,
e.g. the definition of 'day' as the 'passage of the sun over the
earth'. Clearly, whoever has said 'the passage of the sun over
the earth' has said 'the sun', so that in bringing in the 'day' he
has brought in the sun.
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(3) Again, see if he has defined one coordinate member of a
division by another, e.g. 'an odd number' as 'that which is
greater by one than an even number'. For the co-ordinate
members of a division that are derived from the same genus are
simultaneous by nature and 'odd' and 'even' are such terms: for
both are differentiae of number.
Likewise also, see if he has defined a superior through a
subordinate term, e.g. 'An «even number» is «a number divisible
into halves»', or '«the good» is a «state of virtue» '. For 'half is
derived from 'two', and 'two' is an even number: virtue also is a
kind of good, so that the latter terms are subordinate to the
former. Moreover, in using the subordinate term one is bound to
use the other as well: for whoever employs the term 'virtue'
employs the term 'good', seeing that virtue is a certain kind of
good: likewise, also, whoever employs the term 'half employs
the term 'even', for to be 'divided in half means to be divided
into two, and two is even.
Generally speaking, then, one commonplace rule relates to the
failure to frame the expression by means of terms that are prior
and more intelligible: and of this the subdivisions are those
specified above. A second is, see whether, though the object is in
a genus, it has not been placed in a genus. This sort of error is
always found where the essence of the object does not stand
first in the expression, e.g. the definition of 'body' as 'that which
has three dimensions', or the definition of 'man', supposing any
one to give it, as 'that which knows how to count': for it is not
stated what it is that has three dimensions, or what it is that
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knows how to count: whereas the genus is meant to indicate
just this, and is submitted first of the terms in the definition.
Moreover, see if, while the term to be defined is used in relation
to many things, he has failed to render it in relation to all of
them; as (e.g.) if he define 'grammar' as the 'knowledge how to
write from dictation': for he ought also to say that it is a
knowledge how to read as well. For in rendering it as
'knowledge of writing' has no more defined it than by rendering
it as 'knowledge of reading': neither in fact has succeeded, but
only he who mentions both these things, since it is impossible
that there should be more than one definition of the same
thing. It is only, however, in some cases that what has been said
corresponds to the actual state of things: in some it does not,
e.g. all those terms which are not used essentially in relation to
both things: as medicine is said to deal with the production of
disease and health; for it is said essentially to do the latter, but
the former only by accident: for it is absolutely alien to
medicine to produce disease. Here, then, the man who renders
medicine as relative to both of these things has not defined it
any better than he who mentions the one only. In fact he has
done it perhaps worse, for any one else besides the doctor is
capable of producing disease.
Moreover, in a case where the term to be defined is used in
relation to several things, see if he has rendered it as relative to
the worse rather than to the better; for every form of knowledge
and potentiality is generally thought to be relative to the best.
Again, if the thing in question be not placed in its own proper
genus, one must examine it according to the elementary rules
in regard to genera, as has been said before.'
Moreover, see if he uses language which transgresses the genera
of the things he defines, defining, e.g. justice as a 'state that
produces equality' or 'distributes what is equal': for by defining
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it so he passes outside the sphere of virtue, and so by leaving
out the genus of justice he fails to express its essence: for the
essence of a thing must in each case bring in its genus. It is the
same thing if the object be not put into its nearest genus; for
the man who puts it into the nearest one has stated all the
higher genera, seeing that all the higher genera are predicated
of the lower. Either, then, it ought to be put into its nearest
genus, or else to the higher genus all the differentiae ought to
be appended whereby the nearest genus is defined. For then he
would not have left out anything: but would merely have
mentioned the subordinate genus by an expression instead of
by name. On the other hand, he who mentions merely the
higher genus by itself, does not state the subordinate genus as
well: in saying 'plant' a man does not specify 'a tree'.
Again, in regard to the differentiae, we must examine in like
manner whether the differentiae, too, that he has stated be
those of the genus. For if a man has not defined the object by
the differentiae peculiar to it, or has mentioned something such
as is utterly incapable of being a differentia of anything, e.g.
'animal' or 'substance', clearly he has not defined it at all: for
the aforesaid terms do not differentiate anything at all. Further,
we must see whether the differentia stated possesses anything
that is co-ordinate with it in a division; for, if not, clearly the
one stated could not be a differentia of the genus. For a genus is
always divided by differentiae that are co-ordinate members of
a division, as, for instance, by the terms 'walking', 'flying',
'aquatic', and 'biped'. Or see if, though the contrasted differentia
exists, it yet is not true of the genus, for then, clearly, neither of
them could be a differentia of the genus; for differentiae that
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are co-ordinates in a division with the differentia of a thing are
all true of the genus to which the thing belongs. Likewise, also,
see if, though it be true, yet the addition of it to the genus fails
to make a species. For then, clearly, this could not be a specific
differentia of the genus: for a specific differentia, if added to the
genus, always makes a species. If, however, this be no true
differentia, no more is the one adduced, seeing that it is a co-
ordinate member of a division with this.
Moreover, see if he divides the genus by a negation, as those do
who define line as 'length without breadth': for this means
simply that it has not any breadth. The genus will then be found
to partake of its own species: for, since of everything either an
affirmation or its negation is true, length must always either
lack breadth or possess it, so that 'length' as well, i.e. the genus
of 'line', will be either with or without breadth. But 'length
without breadth' is the definition of a species, as also is 'length
with breadth': for 'without breadth' and 'with breadth' are
differentiae, and the genus and differentia constitute the
definition of the species. Hence the genus would admit of the
definition of its species. Likewise, also, it will admit of the
definition of the differentia, seeing that one or the other of the
aforesaid differentiae is of necessity predicated of the genus.
The usefulness of this principle is found in meeting those who
assert the existence of 'Ideas': for if absolute length exist, how
will it be predicable of the genus that it has breadth or that it
lacks it? For one assertion or the other will have to be true of
'length' universally, if it is to be true of the genus at all: and this
is contrary to the fact: for there exist both lengths which have,
and lengths which have not, breadth. Hence the only people
against whom the rule can be employed are those who assert
that a genus is always numerically one; and this is what is done
by those who assert the real existence of the 'Ideas'; for they
allege that absolute length and absolute animal are the genus.
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It may be that in some cases the definer is obliged to employ a
negation as well, e.g. in defining privations. For 'blind' means a
thing which cannot see when its nature is to see. There is no
difference between dividing the genus by a negation, and
dividing it by such an affirmation as is bound to have a negation
as its co-ordinate in a division, e.g. supposing he had defined
something as 'length possessed of breadth'; for co-ordinate in
the division with that which is possessed of breadth is that
which possesses no breadth and that only, so that again the
genus is divided by a negation.
Again, see if he rendered the species as a differentia, as do
those who define 'contumely' as 'insolence accompanied by
jeering'; for jeering is a kind of insolence, i.e. it is a species and
not a differentia.
Moreover, see if he has stated the genus as the differentia, e.g.
'Virtue is a good or noble state: for 'good' is the genus of 'virtue'.
Or possibly 'good' here is not the genus but the differentia, on
the principle that the same thing cannot be in two genera of
which neither contains the other: for 'good' does not include
'state', nor vice versa: for not every state is good nor every good
a 'state'. Both, then, could not be genera, and consequently, if
'state' is the genus of virtue, clearly 'good' cannot be its genus:
it must rather be the differentia'. Moreover, 'a state' indicates
the essence of virtue, whereas 'good' indicates not the essence
but a quality: and to indicate a quality is generally held to be
the function of the differentia. See, further, whether the
differentia rendered indicates an individual rather than a
quality: for the general view is that the differentia always
expresses a quality.
Look and see, further, whether the differentia belongs only by
accident to the object defined. For the differentia is never an
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accidental attribute, any more than the genus is: for the
differentia of a thing cannot both belong and not belong to it.
Moreover, if either the differentia or the species, or any of the
things which are under the species, is predicable of the genus,
then he could not have defined the term. For none of the
aforesaid can possibly be predicated of the genus, seeing that
the genus is the term with the widest range of all. Again, see if
the genus be predicated of the differentia; for the general view
is that the genus is predicated, not of the differentia, but of the
objects of which the differentia is predicated. Animal (e.g.) is
predicated of 'man' or 'ox' or other walking animals, not of the
actual differentia itself which we predicate of the species. For if
'animal' is to be predicated of each of its differentiae, then
'animal' would be predicated of the species several times over;
for the differentiae are predicates of the species. Moreover, the
differentiae will be all either species or individuals, if they are
animals; for every animal is either a species or an individual.
Likewise you must inquire also if the species or any of the
objects that come under it is predicated of the differentia: for
this is impossible, seeing that the differentia is a term with a
wider range than the various species. Moreover, if any of the
species be predicated of it, the result will be that the differentia
is a species: if, for instance, 'man' be predicated, the differentia
is clearly the human race. Again, see if the differentia fails to be
prior to the species: for the differentia ought to be posterior to
the genus, but prior to the species.
Look and see also if the differentia mentioned belongs to a
different genus, neither contained in nor containing the genus
in question. For the general view is that the same differentia
cannot be used of two non-subaltern genera. Else the result will
be that the same species as well will be in two non-subaltern
genera: for each of the differentiae imports its own genus, e.g.
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'walking' and 'biped' import with them the genus 'animal'. If,
then, each of the genera as well is true of that of which the
differentia is true, it clearly follows that the species must be in
two non-subaltern genera. Or perhaps it is not impossible for
the same differentia to be used of two non-subaltern genera,
and we ought to add the words 'except they both be subordinate
members of the same genus'. Thus 'walking animal' and 'flying
animal' are non-subaltern genera, and 'biped' is the differentia
of both. The words 'except they both be subordinate members of
the same genus' ought therefore to be added; for both these are
subordinate to 'animal'. From this possibility, that the same
differentia may be used of two non-subaltern genera, it is clear
also that there is no necessity for the differentia to carry with it
the whole of the genus to which it belongs, but only the one or
the other of its limbs together with the genera that are higher
than this, as 'biped' carries with it either 'flying' or 'walking
animal'.
See, too, if he has rendered 'existence in' something as the
differentia of a thing's essence: for the general view is that
locality cannot differentiate between one essence and another.
Hence, too, people condemn those who divide animals by
means of the terms 'walking' and 'aquatic', on the ground that
'walking' and 'aquatic' indicate mere locality. Or possibly in this
case the censure is undeserved; for 'aquatic' does not mean 'in'
anything; nor does it denote a locality, but a certain quality: for
even if the thing be on the dry land, still it is aquatic: and
likewise a land-animal, even though it be in the water, will still
be a and not an aquatic-animal. But all the same, if ever the
differentia does denote existence in something, clearly he will
have made a bad mistake.
Again, see if he has rendered an affection as the differentia: for
every affection, if intensified, subverts the essence of the thing,
while the differentia is not of that kind: for the differentia is
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generally considered rather to preserve that which it
differentiates; and it is absolutely impossible for a thing to exist
without its own special differentia: for if there be no 'walking',
there will be no 'man'. In fact, we may lay down absolutely that
a thing cannot have as its differentia anything in respect of
which it is subject to alteration: for all things of that kind, if
intensified, destroy its essence. If, then, a man has rendered any
differentia of this kind, he has made a mistake: for we undergo
absolutely no alteration in respect of our differentiae.
Again, see if he has failed to render the differentia of a relative
term relatively to something else; for the differentiae of relative
terms are themselves relative, as in the case also of knowledge.
This is classed as speculative, practical and productive; and
each of these denotes a relation: for it speculates upon
something, and produces something and does something.
Look and see also if the definer renders each relative term
relatively to its natural purpose: for while in some cases the
particular relative term can be used in relation to its natural
purpose only and to nothing else, some can be used in relation
to something else as well. Thus sight can only be used for
seeing, but a strigil can also be used to dip up water. Still, if any
one were to define a strigil as an instrument for dipping water,
he has made a mistake: for that is not its natural function. The
definition of a thing's natural function is 'that for which it
would be used by the prudent man, acting as such, and by the
science that deals specially with that thing'.
Or see if, whenever a term happens to be used in a number of
relations, he has failed to introduce it in its primary relation: e.g.
by defining 'wisdom' as the virtue of 'man' or of the 'soul,'
rather than of the 'reasoning faculty': for 'wisdom' is the virtue
primarily of the reasoning faculty: for it is in virtue of this that
both the man and his soul are said to be wise.
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Moreover, if the thing of which the term defined has been
stated to be an affection or disposition, or whatever it may be,
be unable to admit it, the definer has made a mistake. For every
disposition and every affection is formed naturally in that of
which it is an affection or disposition, as knowledge, too, is
formed in the soul, being a disposition of soul. Sometimes,
however, people make bad mistakes in matters of this sort, e.g.
all those who say that 'sleep' is a 'failure of sensation', or that
'perplexity' is a state of 'equality between contrary reasonings',
or that 'pain' is a 'violent disruption of parts that are naturally
conjoined'. For sleep is not an attribute of sensation, whereas it
ought to be, if it is a failure of sensation. Likewise, perplexity is
not an attribute of opposite reasonings, nor pain of parts
naturally conjoined: for then inanimate things will be in pain,
since pain will be present in them. Similar in character, too, is
the definition of 'health', say, as a 'balance of hot and cold
elements': for then health will be necessarily exhibited by the
hot and cold elements: for balance of anything is an attribute
inherent in those things of which it is the balance, so that
health would be an attribute of them. Moreover, people who
define in this way put effect for cause, or cause for effect. For
the disruption of parts naturally conjoined is not pain, but only
a cause of pain: nor again is a failure of sensation sleep, but the
one is the cause of the other: for either we go to sleep because
sensation fails, or sensation fails because we go to sleep.
Likewise also an equality between contrary reasonings would be
generally considered to be a cause of perplexity: for it is when
we reflect on both sides of a question and find everything alike
to be in keeping with either course that we are perplexed which
of the two we are to do.
Moreover, with regard to all periods of time look and see
whether there be any discrepancy between the differentia and
the thing defined: e.g. supposing the 'immortal' to be defined as
a 'living thing immune at present from destruction'. For a living
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thing that is immune 'at present' from destruction will be
immortal 'at present'. Possibly, indeed, in this case this result
does not follow, owing to the ambiguity of the words 'immune
at present from destruction': for it may mean either that the
thing has not been destroyed at present, or that it cannot be
destroyed at present, or that at present it is such that it never
can be destroyed. Whenever, then, we say that a living thing is
at present immune from destruction, we mean that it is at
present a living thing of such a kind as never to be destroyed:
and this is equivalent to saying that it is immortal, so that it is
not meant that it is immortal only at present. Still, if ever it does
happen that what has been rendered according to the definition
belongs in the present only or past, whereas what is meant by
the word does not so belong, then the two could not be the
same. So, then, this commonplace rule ought to be followed, as
we have said.
You should look and see also whether the term being defined is
applied in consideration of something other than the definition
rendered. Suppose (e.g.) a definition of 'justice' as the 'ability to
distribute what is equal'. This would not be right, for 'just'
describes rather the man who chooses, than the man who is
able to distribute what is equal: so that justice could not be an
ability to distribute what is equal: for then also the most just
man would be the man with the most ability to distribute what
is equal.
Moreover, see if the thing admits of degrees, whereas what is
rendered according to the definition does not, or, vice versa,
what is rendered according to the definition admits of degrees
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while the thing does not. For either both must admit them or
else neither, if indeed what is rendered according to the
definition is the same as the thing. Moreover, see if, while both
of them admit of degrees, they yet do not both become greater
together: e.g. suppose sexual love to be the desire for
intercourse: for he who is more intensely in love has not a more
intense desire for intercourse, so that both do not become
intensified at once: they certainly should, however, had they
been the same thing.
Moreover, suppose two things to be before you, see if the term
to be defined applies more particularly to the one to which the
content of the definition is less applicable. Take, for instance,
the definition of 'fire' as the 'body that consists of the most
rarefied particles'. For 'fire' denotes flame rather than light, but
flame is less the body that consists of the most rarefied
particles than is light: whereas both ought to be more applicable
to the same thing, if they had been the same. Again, see if the
one expression applies alike to both the objects before you,
while the other does not apply to both alike, but more
particularly to one of them.
Moreover, see if he renders the definition relative to two things
taken separately: thus, the beautiful' is 'what is pleasant to the
eyes or to the ears»: or 'the real' is 'what is capable of being
acted upon or of acting'. For then the same thing will be both
beautiful and not beautiful, and likewise will be both real and
not real. For 'pleasant to the ears' will be the same as 'beautiful',
so that 'not pleasant to the ears' will be the same as 'not
beautiful': for of identical things the opposites, too, are
identical, and the opposite of 'beautiful' is 'not beautiful', while
of 'pleasant to the ears' the opposite is not pleasant to the cars':
clearly, then, 'not pleasant to the ears' is the same thing as 'not
beautiful'. If, therefore, something be pleasant to the eyes but
not to the ears, it will be both beautiful and not beautiful. In like
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manner we shall show also that the same thing is both real and
unreal.
Moreover, of both genera and differentiae and all the other
terms rendered in definitions you should frame definitions in
lieu of the terms, and then see if there be any discrepancy
between them.
8
If the term defined be relative, either in itself or in respect of its
genus, see whether the definition fails to mention that to which
the term, either in itself or in respect of its genus, is relative, e.g.
if he has defined 'knowledge' as an 'incontrovertible conception'
or 'wishing' as 'painless conation'. For of everything relative the
essence is relative to something else, seeing that the being of
every relative term is identical with being in a certain relation to
something. He ought, therefore, to have said that knowledge is
'conception of a knowable' and that wishing is 'conation for a
good'. Likewise, also, if he has defined 'grammar' as 'knowledge
of letters': whereas in the definition there ought to be rendered
either the thing to which the term itself is relative, or that,
whatever it is, to which its genus is relative. Or see if a relative
term has been described not in relation to its end, the end in
anything being whatever is best in it or gives its purpose to the
rest. Certainly it is what is best or final that should be stated,
e.g. that desire is not for the pleasant but for pleasure: for this is
our purpose in choosing what is pleasant as well.
Look and see also if that in relation to which he has rendered
the term be a process or an activity: for nothing of that kind is
an end, for the completion of the activity or process is the end
rather than the process or activity itself. Or perhaps this rule is
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not true in all cases, for almost everybody prefers the present
experience of pleasure to its cessation, so that they would count
the activity as the end rather than its completion.
Again see in some cases if he has failed to distinguish the
quantity or quality or place or other differentiae of an object;
e.g. the quality and quantity of the honour the striving for
which makes a man ambitious: for all men strive for honour, so
that it is not enough to define the ambitious man as him who
strives for honour, but the aforesaid differentiae must be added.
Likewise, also, in defining the covetous man the quantity of
money he aims at, or in the case of the incontinent man the
quality of the pleasures, should be stated. For it is not the man
who gives way to any sort of pleasure whatever who is called
incontinent, but only he who gives way to a certain kind of
pleasure. Or again, people sometimes define night as a 'shadow
on the earth', or an earthquake as a movement of the earth', or
a cloud as 'condensation of the air', or a wind as a 'movement of
the air'; whereas they ought to specify as well quantity, quality,
place, and cause. Likewise, also, in other cases of the kind: for by
omitting any differentiae whatever he fails to state the essence
of the term. One should always attack deficiency. For a
movement of the earth does not constitute an earthquake, nor a
movement of the air a wind, irrespective of its manner and the
amount involved.
Moreover, in the case of conations, and in any other cases
where it applies, see if the word 'apparent' is left out, e.g.
'wishing is a conation after the good', or 'desire is a conation
after the pleasant' - instead of saying 'the apparently good', or
'pleasant'. For often those who exhibit the conation do not
perceive what is good or pleasant, so that their aim need not be
really good or pleasant, but only apparently so. They ought,
therefore, to have rendered the definition also accordingly. On
the other hand, any one who maintains the existence of Ideas
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ought to be brought face to face with his Ideas, even though he
does render the word in question: for there can be no Idea of
anything merely apparent: the general view is that an Idea is
always spoken of in relation to an Idea: thus absolute desire is
for the absolutely pleasant, and absolute wishing is for the
absolutely good; they therefore cannot be for an apparent good
or an apparently pleasant: for the existence of an absolutely -
apparently - good or pleasant would be an absurdity.
Moreover, if the definition be of the state of anything, look at
what is in the state, while if it be of what is in the state, look at
the state: and likewise also in other cases of the kind. Thus if
the pleasant be identical with the beneficial, then, too, the man
who is pleased is benefited. Speaking generally, in definitions of
this sort it happens that what the definer defines is in a sense
more than one thing: for in defining knowledge, a man in a
sense defines ignorance as well, and likewise also what has
knowledge and what lacks it, and what it is to know and to be
ignorant. For if the first be made clear, the others become in a
certain sense clear as well. We have, then, to be on our guard in
all such cases against discrepancy, using the elementary
principles drawn from consideration of contraries and of
coordinates.
Moreover, in the case of relative terms, see if the species is
rendered as relative to a species of that to which the genus is
rendered as relative, e.g. supposing belief to be relative to some
object of belief, see whether a particular belief is made relative
to some particular object of belief: and, if a multiple be relative
to a fraction, see whether a particular multiple be made relative
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to a particular fraction. For if it be not so rendered, clearly a
mistake has been made.
See, also, if the opposite of the term has the opposite definition,
whether (e.g.) the definition of 'half is the opposite of that of
'double': for if 'double' is 'that which exceeds another by an
equal amount to that other', 'half is 'that which is exceeded by
an amount equal to itself. In the same way, too, with contraries.
For to the contrary term will apply the definition that is
contrary in some one of the ways in which contraries are
conjoined. Thus (e.g.) if 'useful'='productive of good',
'injurious'=productive of evil' or 'destructive of good', for one or
the other of thee is bound to be contrary to the term originally
used. Suppose, then, neither of these things to be the contrary
of the term originally used, then clearly neither of the
definitions rendered later could be the definition of the contrary
of the term originally defined: and therefore the definition
originally rendered of the original term has not been rightly
rendered either. Seeing, moreover, that of contraries, the one is
sometimes a word forced to denote the privation of the other, as
(e.g.) inequality is generally held to be the privation of equality
(for 'unequal' merely describes things that are not equal'), it is
therefore clear that that contrary whose form denotes the
privation must of necessity be defined through the other;
whereas the other cannot then be defined through the one
whose form denotes the privation; for else we should find that
each is being interpreted by the other. We must in the case of
contrary terms keep an eye on this mistake, e.g. supposing any
one were to define equality as the contrary of inequality: for
then he is defining it through the term which denotes privation
of it. Moreover, a man who so defines is bound to use in his
definition the very term he is defining; and this becomes clear,
if for the word we substitute its definition. For to say 'inequality'
is the same as to say 'privation of equality'. Therefore equality
so defined will be 'the contrary of the privation of equality', so
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that he would have used the very word to be defined. Suppose,
however, that neither of the contraries be so formed as to
denote privation, but yet the definition of it be rendered in a
manner like the above, e.g. suppose 'good' to be defined as 'the
contrary of evil', then, since it is clear that 'evil' too will be 'the
contrary of good' (for the definition of things that are contrary
in this must be rendered in a like manner), the result again is
that he uses the very term being defined: for 'good' is inherent
in the definition of 'evil'. If, then, 'good' be the contrary of evil,
and evil be nothing other than the 'contrary of good', then
'good' will be the 'contrary of the contrary of good'. Clearly,
then, he has used the very word to be defined.
Moreover, see if in rendering a term formed to denote privation,
he has failed to render the term of which it is the privation, e.g.
the state, or contrary, or whatever it may be whose privation it
is: also if he has omitted to add either any term at all in which
the privation is naturally formed, or else that in which it is
naturally formed primarily, e.g. whether in defining 'ignorance'
a privation he has failed to say that it is the privation of
'knowledge'; or has failed to add in what it is naturally formed,
or, though he has added this, has failed to render the thing in
which it is primarily formed, placing it (e.g.) in 'man' or in 'the
soul', and not in the 'reasoning faculty': for if in any of these
respects he fails, he has made a mistake. Likewise, also, if he
has failed to say that 'blindness' is the 'privation of sight in an
eye': for a proper rendering of its essence must state both of
what it is the privation and what it is that is deprived.
Examine further whether he has defined by the expression 'a
privation' a term that is not used to denote a privation: thus a
mistake of this sort also would be generally thought to be
incurred in the case of 'error' by any one who is not using it as a
merely negative term. For what is generally thought to be in
error is not that which has no knowledge, but rather that which
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has been deceived, and for this reason we do not talk of
inanimate things or of children as 'erring'. 'Error', then, is not
used to denote a mere privation of knowledge.
10
Moreover, see whether the like inflexions in the definition apply
to the like inflexions of the term; e.g. if 'beneficial' means
'productive of health', does 'beneficially' mean productively of
health' and a 'benefactor' a 'producer of health?
Look too and see whether the definition given will apply to the
Idea as well. For in some cases it will not do so; e.g. in the
Platonic definition where he adds the word 'mortal' in his
definitions of living creatures: for the Idea (e.g. the absolute
Man) is not mortal, so that the definition will not fit the Idea. So
always wherever the words 'capable of acting on' or 'capable of
being acted upon' are added, the definition and the Idea are
absolutely bound to be discrepant: for those who assert the
existence of Ideas hold that they are incapable of being acted
upon, or of motion. In dealing with these people even
arguments of this kind are useful.
Further, see if he has rendered a single common definition of
terms that are used ambiguously. For terms whose definition
corresponding their common name is one and the same, are
synonymous; if, then, the definition applies in a like manner to
the whole range of the ambiguous term, it is not true of any one
of the objects described by the term. This is, moreover, what
happens to Dionysius' definition of 'life' when stated as 'a
movement of a creature sustained by nutriment, congenitally
present with it': for this is found in plants as much as in
animals, whereas 'life' is generally understood to mean not one
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kind of thing only, but to be one thing in animals and another in
plants. It is possible to hold the view that life is a synonymous
term and is always used to describe one thing only, and
therefore to render the definition in this way on purpose: or it
may quite well happen that a man may see the ambiguous
character of the word, and wish to render the definition of the
one sense only, and yet fail to see that he has rendered a
definition common to both senses instead of one peculiar to the
sense he intends. In either case, whichever course he pursues,
he is equally at fault. Since ambiguous terms sometimes pass
unobserved, it is best in questioning to treat such terms as
though they were synonymous (for the definition of the one
sense will not apply to the other, so that the answerer will be
generally thought not to have defined it correctly, for to a
synonymous term the definition should apply in its full range),
whereas in answering you should yourself distinguish between
the senses. Further, as some answerers call 'ambiguous' what is
really synonymous, whenever the definition rendered fails to
apply universally, and, vice versa, call synonymous what is
really ambiguous supposing their definition applies to both
senses of the term, one should secure a preliminary admission
on such points, or else prove beforehand that so-and-so is
ambiguous or synonymous, as the case may be: for people are
more ready to agree when they do not foresee what the
consequence will be. If, however, no admission has been made,
and the man asserts that what is really synonymous is
ambiguous because the definition he has rendered will not
apply to the second sense as well, see if the definition of this
second meaning applies also to the other meanings: for if so,
this meaning must clearly be synonymous with those others.
Otherwise, there will be more than one definition of those other
meanings, for there are applicable to them two distinct
definitions in explanation of the term, viz. the one previously
rendered and also the later one. Again, if any one were to define
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a term used in several senses, and, finding that his definition
does not apply to them all, were to contend not that the term is
ambiguous, but that even the term does not properly apply to
all those senses, just because his definition will not do so either,
then one may retort to such a man that though in some things
one must not use the language of the people, yet in a question
of terminology one is bound to employ the received and
traditional usage and not to upset matters of that sort.
11
Suppose now that a definition has been rendered of some
complex term, take away the definition of one of the elements
in the complex, and see if also the rest of the definition defines
the rest of it: if not, it is clear that neither does the whole
definition define the whole complex. Suppose, e.g. that some
one has defined a 'finite straight line' as 'the limit of a finite
plane, such that its centre is in a line with its extremes'; if now
the definition of a finite line' be the 'limit of a finite plane', the
rest (viz. 'such that its centre is in a line with its extremes')
ought to be a definition of straight'. But an infinite straight line
has neither centre nor extremes and yet is straight so that this
remainder does not define the remainder of the term.
Moreover, if the term defined be a compound notion, see if the
definition rendered be equimembral with the term defined. A
definition is said to be equimembral with the term defined
when the number of the elements compounded in the latter is
the same as the number of nouns and verbs in the definition.
For the exchange in such cases is bound to be merely one of
term for term, in the case of some if not of all, seeing that there
are no more terms used now than formerly; whereas in a
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definition terms ought to be rendered by phrases, if possible in
every case, or if not, in the majority. For at that rate, simple
objects too could be defined by merely calling them by a
different name, e.g. 'cloak' instead of 'doublet'.
The mistake is even worse, if actually a less well known term be
substituted, e.g. 'pellucid mortal' for 'white man': for it is no
definition, and moreover is less intelligible when put in that
form.
Look and see also whether, in the exchange of words, the sense
fails still to be the same. Take, for instance, the explanation of
'speculative knowledge' as 'speculative conception': for
conception is not the same as knowledge - as it certainly ought
to be if the whole is to be the same too: for though the word
'speculative' is common to both expressions, yet the remainder
is different.
Moreover, see if in replacing one of the terms by something else
he has exchanged the genus and not the differentia, as in the
example just given: for 'speculative' is a less familiar term than
knowledge; for the one is the genus and the other the
differentia, and the genus is always the most familiar term of
all; so that it is not this, but the differentia, that ought to have
been changed, seeing that it is the less familiar. It might be held
that this criticism is ridiculous: because there is no reason why
the most familiar term should not describe the differentia, and
not the genus; in which case, clearly, the term to be altered
would also be that denoting the genus and not the differentia.
If, however, a man is substituting for a term not merely another
term but a phrase, clearly it is of the differentia rather than of
the genus that a definition should be rendered, seeing that the
object of rendering the definition is to make the subject
familiar; for the differentia is less familiar than the genus.
481
If he has rendered the definition of the differentia, see whether
the definition rendered is common to it and something else as
well: e.g. whenever he says that an odd number is a 'number
with a middle', further definition is required of how it has a
middle: for the word 'number' is common to both expressions,
and it is the word 'odd' for which the phrase has been
substituted. Now both a line and a body have a middle, yet they
are not 'odd'; so that this could not be a definition of 'odd'. If, on
the other hand, the phrase 'with a middle' be used in several
senses, the sense here intended requires to be defined. So that
this will either discredit the definition or prove that it is no
definition at all.
12
Again, see if the term of which he renders the definition is a
reality, whereas what is contained in the definition is not, e.g.
Suppose 'white' to be defined as 'colour mingled with fire': for
what is bodiless cannot be mingled with body, so that 'colour'
'mingled with fire' could not exist, whereas 'white' does exist.
Moreover, those who in the case of relative terms do not
distinguish to what the object is related, but have described it
only so as to include it among too large a number of things, are
wrong either wholly or in part; e.g. suppose some one to have
defined 'medicine' as a science of Reality'. For if medicine be
not a science of anything that is real, the definition is clearly
altogether false; while if it be a science of some real thing, but
not of another, it is partly false; for it ought to hold of all reality,
if it is said to be of Reality essentially and not accidentally: as is
the case with other relative terms: for every object of knowledge
is a term relative to knowledge: likewise, also, with other
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relative terms, inasmuch as all such are convertible. Moreover, if
the right way to render account of a thing be to render it as it is
not in itself but accidentally, then each and every relative term
would be used in relation not to one thing but to a number of
things. For there is no reason why the same thing should not be
both real and white and good, so that it would be a correct
rendering to render the object in relation to any one whatsoever
of these, if to render what it is accidentally be a correct way to
render it. It is, moreover, impossible that a definition of this sort
should be peculiar to the term rendered: for not only but the
majority of the other sciences too, have for their object some
real thing, so that each will be a science of reality. Clearly, then,
such a definition does not define any science at all; for a
definition ought to be peculiar to its own term, not general.
Sometimes, again, people define not the thing but only the
thing in a good or perfect condition. Such is the definition of a
rhetorician as 'one who can always see what will persuade in
the given circumstances, and omit nothing'; or of a thief, as 'one
who pilfers in secret': for clearly, if they each do this, then the
one will be a good rhetorician, and the other a good thief:
whereas it is not the actual pilfering in secret, but the wish to
do it, that constitutes the thief.
Again, see if he has rendered what is desirable for its own sake
as desirable for what it produces or does, or as in any way
desirable because of something else, e.g. by saying that justice is
'what preserves the laws' or that wisdom is 'what produces
happiness'; for what produces or preserves something else is
one of the things desirable for something else. It might be said
that it is possible for what is desirable in itself to be desirable
for something else as well: but still to define what is desirable in
itself in such a way is none the less wrong: for the essence
contains par excellence what is best in anything, and it is better
for a thing to be desirable in itself than to be desirable for
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something else, so that this is rather what the definition too
ought to have indicated.
13
See also whether in defining anything a man has defined it as
an 'A and B', or as a 'product of A and B' or as an A+B\ If he
defines it as and B', the definition will be true of both and yet of
neither of them; suppose, e.g. justice to be defined as
'temperance and courage.' For if of two persons each has one of
the two only, both and yet neither will be just: for both together
have justice, and yet each singly fails to have it. Even if the
situation here described does not so far appear very absurd
because of the occurrence of this kind of thing in other cases
also (for it is quite possible for two men to have a mina between
them, though neither of them has it by himself), yet least that
they should have contrary attributes surely seems quite absurd;
and yet this will follow if the one be temperate and yet a
coward, and the other, though brave, be a profligate; for then
both will exhibit both justice and injustice: for if justice be
temperance and bravery, then injustice will be cowardice and
profligacy. In general, too, all the ways of showing that the
whole is not the same as the sum of its parts are useful in
meeting the type just described; for a man who defines in this
way seems to assert that the parts are the same as the whole.
The arguments are particularly appropriate in cases where the
process of putting the parts together is obvious, as in a house
and other things of that sort: for there, clearly, you may have the
parts and yet not have the whole, so that parts and whole
cannot be the same.
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If, however, he has said that the term being defined is not 'A and
B' but the 'product of A and B', look and see in the first place if A
and B cannot in the nature of things have a single product: for
some things are so related to one another that nothing can
come of them, e.g. a line and a number. Moreover, see if the
term that has been defined is in the nature of things found
primarily in some single subject, whereas the things which he
has said produce it are not found primarily in any single subject,
but each in a separate one. If so, clearly that term could not be
the product of these things: for the whole is bound to be in the
same things wherein its parts are, so that the whole will then be
found primarily not in one subject only, but in a number of
them. If, on the other hand, both parts and whole are found
primarily in some single subject, see if that medium is not the
same, but one thing in the case of the whole and another in
that of the parts. Again, see whether the parts perish together
with the whole: for it ought to happen, vice versa, that the
whole perishes when the parts perish; when the whole
perishes, there is no necessity that the parts should perish too.
Or again, see if the whole be good or evil, and the parts neither,
or, vice versa, if the parts be good or evil and the whole neither.
For it is impossible either for a neutral thing to produce
something good or bad, or for things good or bad to produce a
neutral thing. Or again, see if the one thing is more distinctly
good than the other is evil, and yet the product be no more good
than evil, e.g. suppose shamelessness be defined as 'the product
of courage and false opinion': here the goodness of courage
exceeds the evil of false opinion; accordingly the product of
these ought to have corresponded to this excess, and to be
either good without qualification, or at least more good than
evil. Or it may be that this does not necessarily follow, unless
each be in itself good or bad; for many things that are
productive are not good in themselves, but only in combination;
or, per contra, they are good taken singly, and bad or neutral in
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combination. What has just been said is most clearly illustrated
in the case of things that make for health or sickness; for some
drugs are such that each taken alone is good, but if they are
both administered in a mixture, bad.
Again, see whether the whole, as produced from a better and
worse, fails to be worse than the better and better than the
worse element. This again, however, need not necessarily be the
case, unless the elements compounded be in themselves good;
if they are not, the whole may very well not be good, as in the
cases just instanced.
Moreover, see if the whole be synonymous with one of the
elements: for it ought not to be, any more than in the case of
syllables: for the syllable is not synonymous with any of the
letters of which it is made up.
Moreover, see if he has failed to state the manner of their
composition: for the mere mention of its elements is not
enough to make the thing intelligible. For the essence of any
compound thing is not merely that it is a product of so-and-so,
but that it is a product of them compounded in such and such a
way, just as in the case of a house: for here the materials do not
make a house irrespective of the way they are put together.
If a man has defined an object as 'A+B', the first thing to be said
is that A+B' means the same either as A and B', or as the
'product of A and B.' for 'honey+water' means either the honey
and the water, or the 'drink made of honey and water'. If, then,
he admits that A+B' is + B' is the same as either of these two
things, the same criticisms will apply as have already been
given for meeting each of them. Moreover, distinguish between
the different senses in which one thing may be said to be '+'
another, and see if there is none of them in which A could be
said to exist '+ B.' Thus e.g. supposing the expression to mean
that they exist either in some identical thing capable of
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containing them (as e.g. justice and courage are found in the
soul), or else in the same place or in the same time, and if this
be in no way true of the A and B in question, clearly the
definition rendered could not hold of anything, as there is no
possible way in which A can exist B'. If, however, among the
various senses above distinguished, it be true that A and B are
each found in the same time as the other, look and see if
possibly the two are not used in the same relation. Thus e.g.
suppose courage to have been defined as 'daring with right
reasoning': here it is possible that the person exhibits daring in
robbery, and right reasoning in regard to the means of health:
but he may have 'the former quality+the latter' at the same
time, and not as yet be courageous! Moreover, even though both
be used in the same relation as well, e.g. in relation to medical
treatment (for a man may exhibit both daring and right
reasoning in respect of medical treatment), still, none the less,
not even this combination of 'the one+the other 'makes him
'courageous'. For the two must not relate to any casual object
that is the same, any more than each to a different object;
rather, they must relate to the function of courage, e.g. meeting
the perils of war, or whatever is more properly speaking its
function than this.
Some definitions rendered in this form fail to come under the
aforesaid division at all, e.g. a definition of anger as 'pain with a
consciousness of being slighted'. For what this means to say is
that it is because of a consciousness of this sort that the pain
occurs; but to occur 'because of a thing is not the same as to
occur '+ a thing' in any of its aforesaid senses.
487
14
Again, if he have described the whole compounded as the
'composition' of these things (e.g. 'a living creature' as a
'composition of soul and body'), first of all see whether he has
omitted to state the kind of composition, as (e.g.) in a definition
of 'flesh' or 'bone' as the 'composition of fire, earth, and air'. For
it is not enough to say it is a composition, but you should also
go on to define the kind of composition: for these things do not
form flesh irrespective of the manner of their composition, but
when compounded in one way they form flesh, when in
another, bone. It appears, moreover, that neither of the
aforesaid substances is the same as a 'composition' at all: for a
composition always has a decomposition as its contrary,
whereas neither of the aforesaid has any contrary. Moreover, if
it is equally probable that every compound is a composition or
else that none is, and every kind of living creature, though a
compound, is never a composition, then no other compound
could be a composition either.
Again, if in the nature of a thing two contraries are equally
liable to occur, and the thing has been defined through the one,
clearly it has not been defined; else there will be more than one
definition of the same thing; for how is it any more a definition
to define it through this one than through the other, seeing that
both alike are naturally liable to occur in it? Such is the
definition of the soul, if defined as a substance capable of
receiving knowledge: for it has a like capacity for receiving
ignorance.
Also, even when one cannot attack the definition as a whole for
lack of acquaintance with the whole, one should attack some
part of it, if one knows that part and sees it to be incorrectly
rendered: for if the part be demolished, so too is the whole
definition. Where, again, a definition is obscure, one should first
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of all correct and reshape it in order to make some part of it
clear and get a handle for attack, and then proceed to examine
it. For the answerer is bound either to accept the sense as taken
by the questioner, or else himself to explain clearly whatever it
is that his definition means. Moreover, just as in the assemblies
the ordinary practice is to move an emendation of the existing
law and, if the emendation is better, they repeal the existing
law, so one ought to do in the case of definitions as well: one
ought oneself to propose a second definition: for if it is seen to
be better, and more indicative of the object defined, clearly the
definition already laid down will have been demolished, on the
principle that there cannot be more than one definition of the
same thing.
In combating definitions it is always one of the chief
elementary principles to take by oneself a happy shot at a
definition of the object before one, or to adopt some correctly
expressed definition. For one is bound, with the model (as it
were) before one's eyes, to discern both any shortcoming in any
features that the definition ought to have, and also any
superfluous addition, so that one is better supplied with lines of
attack.
As to definitions, then, let so much suffice.
Book VII
489
Whether two things are 'the same' or 'different', in the most
literal of the meanings ascribed to 'sameness' (and we said' that
'the same' applies in the most literal sense to what is
numerically one), may be examined in the light of their
inflexions and coordinates and opposites. For if justice be the
same as courage, then too the just man is the same as the brave
man, and 'justly' is the same as 'bravely'. Likewise, too, in the
case of their opposites: for if two things be the same, their
opposites also will be the same, in any of the recognized forms
of opposition. For it is the same thing to take the opposite of the
one or that of the other, seeing that they are the same. Again it
may be examined in the light of those things which tend to
produce or to destroy the things in question of their formation
and destruction, and in general of any thing that is related in
like manner to each. For where things are absolutely the same,
their formations and destructions also are the same, and so are
the things that tend to produce or to destroy them. Look and
see also, in a case where one of two things is said to be
something or other in a superlative degree, if the other of these
alleged identical things can also be described by a superlative in
the same respect. Thus Xenocrates argues that the happy life
and the good life are the same, seeing that of all forms of life
the good life is the most desirable and so also is the happy life:
for 'the most desirable' and the greatest' apply but to one thing.'
Likewise also in other cases of the kind. Each, however, of the
two things termed 'greatest' or most desirable' must be
numerically one: otherwise no proof will have been given that
they are the same; for it does not follow because
Peloponnesians and Spartans are the bravest of the Greeks, that
Peloponnesians are the same as Spartans, seeing that
'Peloponnesian' is not any one person nor yet 'Spartan'; it only
follows that the one must be included under the other as
'Spartans' are under 'Peloponnesians': for otherwise, if the one
490
class be not included under the other, each will be better than
the other. For then the Peloponnesians are bound to be better
than the Spartans, seeing that the one class is not included
under the other; for they are better than anybody else. Likewise
also the Spartans must perforce be better than the
Peloponnesians; for they too are better than anybody else; each
then is better than the other! Clearly therefore what is styled
'best' and 'greatest' must be a single thing, if it is to be proved to
be 'the same' as another. This also is why Xenocrates fails to
prove his case: for the happy life is not numerically single, nor
yet the good life, so that it does not follow that, because they are
both the most desirable, they are therefore the same, but only
that the one falls under the other.
Again, look and see if, supposing the one to be the same as
something, the other also is the same as it: for if they be not
both the same as the same thing, clearly neither are they the
same as one another.
Moreover, examine them in the light of their accidents or of the
things of which they are accidents: for any accident belonging
to the one must belong also to the other, and if the one belong
to anything as an accident, so must the other also. If in any of
these respects there is a discrepancy, clearly they are not the
same.
See further whether, instead of both being found in one class of
predicates, the one signifies a quality and the other a quantity
or relation. Again, see if the genus of each be not the same, the
one being 'good' and the other evil', or the one being 'virtue' and
the other 'knowledge': or see if, though the genus is the same,
the differentiae predicted of either be not the same, the one
(e.g.) being distinguished as a 'speculative' science, the other as
a 'practical' science. Likewise also in other cases.
491
Moreover, from the point of view of 'degrees', see if the one
admits an increase of degree but not the other, or if though both
admit it, they do not admit it at the same time; just as it is not
the case that a man desires intercourse more intensely, the
more intensely he is in love, so that love and the desire for
intercourse are not the same.
Moreover, examine them by means of an addition, and see
whether the addition of each to the same thing fails to make
the same whole; or if the subtraction of the same thing from
each leaves a different remainder. Suppose (e.g.) that he has
declared 'double a half to be the same as 'a multiple of a half:
then, subtracting the words 'a half from each, the remainders
ought to have signified the same thing: but they do not; for
'double' and 'a multiple of do not signify the same thing.
Inquire also not only if some impossible consequence results
directly from the statement made, that A and B are the same,
but also whether it is possible for a supposition to bring it
about; as happens to those who assert that 'empty' is the same
as 'full of air': for clearly if the air be exhausted, the vessel will
not be less but more empty, though it will no longer be full of
air. So that by a supposition, which may be true or may be false
(it makes no difference which), the one character is annulled
and not the other, showing that they are not the same.
Speaking generally, one ought to be on the look-out for any
discrepancy anywhere in any sort of predicate of each term, and
in the things of which they are predicated. For all that is
predicated of the one should be predicated also of the other,
and of whatever the one is a predicate, the other should be a
predicate of it as well.
Moreover, as 'sameness' is a term used in many senses, see
whether things that are the same in one way are the same also
in a different way. For there is either no necessity or even no
492
possibility that things that are the same specifically or
generically should be numerically the same, and it is with the
question whether they are or are not the same in that sense
that we are concerned.
Moreover, see whether the one can exist without the other; for,
if so, they could not be the same.
Such is the number of the commonplace rules that relate to
'sameness'. It is clear from what has been said that all the
destructive commonplaces relating to sameness are useful also
in questions of definition, as was said before:' for if what is
signified by the term and by the expression be not the same,
clearly the expression rendered could not be a definition. None
of the constructive commonplaces, on the other hand, helps in
the matter of definition; for it is not enough to show the
sameness of content between the expression and the term, in
order to establish that the former is a definition, but a definition
must have also all the other characters already announced.
This then is the way, and these the arguments, whereby the
attempt to demolish a definition should always be made. If, on
the other hand, we desire to establish one, the first thing to
observe is that few if any who engage in discussion arrive at a
definition by reasoning: they always assume something of the
kind as their starting points - both in geometry and in
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arithmetic and the other studies of that kind. In the second
place, to say accurately what a definition is, and how it should
be given, belongs to another inquiry. At present it concerns us
only so far as is required for our present purpose, and
accordingly we need only make the bare statement that to
reason to a thing's definition and essence is quite possible. For if
a definition is an expression signifying the essence of the thing
and the predicates contained therein ought also to be the only
ones which are predicated of the thing in the category of
essence; and genera and differentiae are so predicated in that
category: it is obvious that if one were to get an admission that
so and so are the only attributes predicated in that category, the
expression containing so and so would of necessity be a
definition; for it is impossible that anything else should be a
definition, seeing that there is not anything else predicated of
the thing in the category of essence.
That a definition may thus be reached by a process of reasoning
is obvious. The means whereby it should be established have
been more precisely defined elsewhere, but for the purposes of
the inquiry now before us the same commonplace rules serve.
For we have to examine into the contraries and other opposites
of the thing, surveying the expressions used both as wholes and
in detail: for if the opposite definition defines that opposite
term, the definition given must of necessity be that of the term
before us. Seeing, however, that contraries may be conjoined in
more than one way, we have to select from those contraries the
one whose contrary definition seems most obvious. The
expressions, then, have to be examined each as a whole in the
way we have said, and also in detail as follows. First of all, see
that the genus rendered is correctly rendered; for if the contrary
thing be found in the contrary genus to that stated in the
definition, and the thing before you is not in that same genus,
then it would clearly be in the contrary genus: for contraries
must of necessity be either in the same genus or in contrary
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genera. The differentiae, too, that are predicated of contraries
we expect to be contrary, e.g. those of white and black, for the
one tends to pierce the vision, while the other tends to
compress it. So that if contrary differentiae to those in the
definition are predicated of the contrary term, then those
rendered in the definition would be predicated of the term
before us. Seeing, then, that both the genus and the differentiae
have been rightly rendered, clearly the expression given must
be the right definition. It might be replied that there is no
necessity why contrary differentiae should be predicated of
contraries, unless the contraries be found within the same
genus: of things whose genera are themselves contraries it may
very well be that the same differentia is used of both, e.g. of
justice and injustice; for the one is a virtue and the other a vice
of the soul: 'of the soul', therefore, is the differentia in both
cases, seeing that the body as well has its virtue and vice. But
this much at least is true, that the differentiae of contraries are
either contrary or else the same. If, then, the contrary
differentia to that given be predicated of the contrary term and
not of the one in hand, clearly the differentia stated must be
predicated of the latter. Speaking generally, seeing that the
definition consists of genus and differentiae, if the definition of
the contrary term be apparent, the definition of the term before
you will be apparent also: for since its contrary is found either
in the same genus or in the contrary genus, and likewise also
the differentiae predicated of opposites are either contrary to, or
the same as, each other, clearly of the term before you there will
be predicated either the same genus as of its contrary, while, of
its differentiae, either all are contrary to those of its contrary, or
at least some of them are so while the rest remain the same; or,
vice versa, the differentiae will be the same and the genera
contrary; or both genera and differentiae will be contrary. And
that is all; for that both should be the same is not possible; else
contraries will have the same definition.
495
Moreover, look at it from the point of view of its inflexions and
coordinates. For genera and definitions are bound to correspond
in either case. Thus if forgetfulness be the loss of knowledge, to
forget is to lose knowledge, and to have forgotten is to have lost
knowledge. If, then, any one whatever of these is agreed to, the
others must of necessity be agreed to as well. Likewise, also, if
destruction is the decomposition of the thing's essence, then to
be destroyed is to have its essence decomposed, and
'destructively' means 'in such a way as to decompose its
essence'; if again 'destructive' means 'apt to decompose
something's essence', then also 'destruction' means 'the
decomposition of its essence'. Likewise also with the rest: an
admission of any one of them whatever, and all the rest are
admitted too.
Moreover, look at it from the point of view of things that stand
in relations that are like each other. For if 'healthy' means
'productive of health', 'vigorous' too will mean 'productive of
vigour', and 'useful' will mean 'productive of good.' For each of
these things is related in like manner to its own peculiar end, so
that if one of them is defined as 'productive of that end, this
will also be the definition of each of the rest as well.
Moreover, look at it from the point of and like degrees, in all the
ways in which it is possible to establish a result by comparing
two and two together. Thus if A defines a better than B defines
and B is a definition of so too is A of a. Further, if As claim to
define a is like B's to define B, and B defines B, then A too
defines a. This examination from the point of view of greater
degrees is of no use when a single definition is compared with
two things, or two definitions with one thing; for there cannot
possibly be one definition of two things or two of the same
thing.
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The most handy of all the commonplace arguments are those
just mentioned and those from co-ordinates and inflexions, and
these therefore are those which it is most important to master
and to have ready to hand: for they are the most useful on the
greatest number of occasions. Of the rest, too, the most
important are those of most general application: for these are
the most effective, e.g. that you should examine the individual
cases, and then look to see in the case of their various species
whether the definition applies. For the species is synonymous
with its individuals. This sort of inquiry is of service against
those who assume the existence of Ideas, as has been said
before.' Moreover see if a man has used a term metaphorically,
or predicated it of itself as though it were something different.
So too if any other of the commonplace rules is of general
application and effective, it should be employed.
That it is more difficult to establish than to overthrow a
definition, is obvious from considerations presently to be urged.
For to see for oneself, and to secure from those whom one is
questioning, an admission of premisses of this sort is no simple
matter, e.g. that of the elements of the definition rendered the
one is genus and the other differentia, and that only the genus
and differentiae are predicated in the category of essence. Yet
without these premisses it is impossible to reason to a
definition; for if any other things as well are predicated of the
thing in the category of essence, there is no telling whether the
formula stated or some other one is its definition, for a
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definition is an expression indicating the essence of a thing. The
point is clear also from the following: It is easier to draw one
conclusion than many. Now in demolishing a definition it is
sufficient to argue against one point only (for if we have
overthrown any single point whatsoever, we shall have
demolished the definition); whereas in establishing a definition,
one is bound to bring people to the view that everything
contained in the definition is attributable. Moreover, in
establishing a case, the reasoning brought forward must be
universal: for the definition put forward must be predicated of
everything of which the term is predicated, and must moreover
be convertible, if the definition rendered is to be peculiar to the
subject. In overthrowing a view, on the other hand, there is no
longer any necessity to show one's point universally: for it is
enough to show that the formula is untrue of any one of the
things embraced under the term.
Further, even supposing it should be necessary to overthrow
something by a universal proposition, not even so is there any
need to prove the converse of the proposition in the process of
overthrowing the definition. For merely to show that the
definition fails to be predicated of every one of the things of
which the term is predicated, is enough to overthrow it
universally: and there is no need to prove the converse of this in
order to show that the term is predicated of things of which the
expression is not predicated. Moreover, even if it applies to
everything embraced under the term, but not to it alone, the
definition is thereby demolished.
The case stands likewise in regard to the property and genus of
a term also. For in both cases it is easier to overthrow than to
establish. As regards the property this is clear from what has
been said: for as a rule the property is rendered in a complex
phrase, so that to overthrow it, it is only necessary to demolish
one of the terms used, whereas to establish it is necessary to
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reason to them all. Then, too, nearly all the other rules that
apply to the definition will apply also to the property of a thing.
For in establishing a property one has to show that it is true of
everything included under the term in question, whereas to
overthrow one it is enough to show in a single case only that it
fails to belong: further, even if it belongs to everything falling
under the term, but not to that only, it is overthrown in this case
as well, as was explained in the case of the definition. In regard
to the genus, it is clear that you are bound to establish it in one
way only, viz. by showing that it belongs in every case, while of
overthrowing it there are two ways: for if it has been shown that
it belongs either never or not in a certain case, the original
statement has been demolished. Moreover, in establishing a
genus it is not enough to show that it belongs, but also that it
belongs as genus has to be shown; whereas in overthrowing it,
it is enough to show its failure to belong either in some
particular case or in every case. It appears, in fact, as though,
just as in other things to destroy is easier than to create, so in
these matters too to overthrow is easier than to establish.
In the case of an accidental attribute the universal proposition
is easier to overthrow than to establish; for to establish it, one
has to show that it belongs in every case, whereas to overthrow
it, it is enough to show that it does not belong in one single
case. The particular proposition is, on the contrary, easier to
establish than to overthrow: for to establish it, it is enough to
show that it belongs in a particular instance, whereas to
overthrow it, it has to be shown that it never belongs at all.
It is clear also that the easiest thing of all is to overthrow a
definition. For on account of the number of statements involved
we are presented in the definition with the greatest number of
points for attack, and the more plentiful the material, the
quicker an argument comes: for there is more likelihood of a
mistake occurring in a large than in a small number of things.
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Moreover, the other rules too may be used as means for
attacking a definition: for if either the formula be not peculiar,
or the genus rendered be the wrong one, or something included
in the formula fail to belong, the definition is thereby
demolished. On the other hand, against the others we cannot
bring all of the arguments drawn from definitions, nor yet of the
rest: for only those relating to accidental attributes apply
generally to all the aforesaid kinds of attribute. For while each
of the aforesaid kinds of attribute must belong to the thing in
question, yet the genus may very well not belong as a property
without as yet being thereby demolished. Likewise also the
property need not belong as a genus, nor the accident as a
genus or property, so long as they do belong. So that it is
impossible to use one set as a basis of attack upon the other
except in the case of definition. Clearly, then, it is the easiest of
all things to demolish a definition, while to establish one is the
hardest. For there one both has to establish all those other
points by reasoning (i.e. that the attributes stated belong, and
that the genus rendered is the true genus, and that the formula
is peculiar to the term), and moreover, besides this, that the
formula indicates the essence of the thing; and this has to be
done correctly.
Of the rest, the property is most nearly of this kind: for it is
easier to demolish, because as a rule it contains several terms;
while it is the hardest to establish, both because of the number
of things that people must be brought to accept, and, besides
this, because it belongs to its subject alone and is predicated
convertibly with its subject.
The easiest thing of all to establish is an accidental predicate:
for in other cases one has to show not only that the predicate
belongs, but also that it belongs in such and such a particular
way: whereas in the case of the accident it is enough to show
merely that it belongs. On the other hand, an accidental
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predicate is the hardest thing to overthrow, because it affords
the least material: for in stating accident a man does not add
how the predicate belongs; and accordingly, while in other cases
it is possible to demolish what is said in two ways, by showing
either that the predicate does not belong, or that it does not
belong in the particular way stated, in the case of an accidental
predicate the only way to demolish it is to show that it does not
belong at all.
The commonplace arguments through which we shall be well
supplied with lines of argument with regard to our several
problems have now been enumerated at about sufficient length.
Book VIII
Next there fall to be discussed the problems of arrangement
and method in pitting questions. Any one who intends to frame
questions must, first of all, select the ground from which he
should make his attack; secondly, he must frame them and
arrange them one by one to himself; thirdly and lastly, he must
proceed actually to put them to the other party. Now so far as
the selection of his ground is concerned the problem is one
alike for the philosopher and the dialectician; but how to go on
to arrange his points and frame his questions concerns the
dialectician only: for in every problem of that kind a reference
to another party is involved. Not so with the philosopher, and
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the man who is investigating by himself: the premisses of his
reasoning, although true and familiar, may be refused by the
answerer because they lie too near the original statement and
so he foresees what will follow if he grants them: but for this
the philosopher does not care. Nay, he may possibly be even
anxious to secure axioms as familiar and as near to the
question in hand as possible: for these are the bases on which
scientific reasonings are built up.
The sources from which one's commonplace arguments should
be drawn have already been described:' we have now to discuss
the arrangement and formation of questions and first to
distinguish the premisses, other than the necessary premisses,
which have to be adopted. By necessary premisses are meant
those through which the actual reasoning is constructed. Those
which are secured other than these are of four kinds; they serve
either inductively to secure the universal premiss being granted,
or to lend weight to the argument, or to conceal the conclusion,
or to render the argument more clear. Beside these there is no
other premiss which need be secured: these are the ones
whereby you should try to multiply and formulate your
questions. Those which are used to conceal the conclusion
serve a controversial purpose only; but inasmuch as an
undertaking of this sort is always conducted against another
person, we are obliged to employ them as well.
The necessary premisses through which the reasoning is
effected, ought not to be propounded directly in so many words.
Rather one should soar as far aloof from them as possible. Thus
if one desires to secure an admission that the knowledge of
contraries is one, one should ask him to admit it not of
contraries, but of opposites: for, if he grants this, one will then
argue that the knowledge of contraries is also the same, seeing
that contraries are opposites; if he does not, one should secure
the admission by induction, by formulating a proposition to that
502
effect in the case of some particular pair of contraries. For one
must secure the necessary premisses either by reasoning or by
induction, or else partly by one and partly by the other,
although any propositions which are too obvious to be denied
may be formulated in so many words. This is because the
coming conclusion is less easily discerned at the greater
distance and in the process of induction, while at the same
time, even if one cannot reach the required premisses in this
way, it is still open to one to formulate them in so many words.
The premisses, other than these, that were mentioned above,
must be secured with a view to the latter. The way to employ
them respectively is as follows: Induction should proceed from
individual cases to the universal and from the known to the
unknown; and the objects of perception are better known, to
most people if not invariably. Concealment of one's plan is
obtained by securing through prosyllogisms the premisses
through which the proof of the original proposition is going to
be constructed - and as many of them as possible. This is likely
to be effected by making syllogisms to prove not only the
necessary premisses but also some of those which are required
to establish them. Moreover, do not state the conclusions of
these premisses but draw them later one after another; for this
is likely to keep the answerer at the greatest possible distance
from the original proposition. Speaking generally, a man who
desires to get information by a concealed method should so put
his questions that when he has put his whole argument and
has stated the conclusion, people still ask 'Well, but why is
that?' This result will be secured best of all by the method above
described: for if one states only the final conclusion, it is
unclear how it comes about; for the answerer does not foresee
on what grounds it is based, because the previous syllogisms
have not been made articulate to him: while the final syllogism,
showing the conclusion, is likely to be kept least articulate if we
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lay down not the secured propositions on which it is based, but
only the grounds on which we reason to them.
It is a useful rule, too, not to secure the admissions claimed as
the bases of the syllogisms in their proper order, but alternately
those that conduce to one conclusion and those that conduce to
another; for, if those which go together are set side by side, the
conclusion that will result from them is more obvious in
advance.
One should also, wherever possible, secure the universal
premiss by a definition relating not to the precise terms
themselves but to their co-ordinates; for people deceive
themselves, whenever the definition is taken in regard to a co-
ordinate, into thinking that they are not making the admission
universally. An instance would be, supposing one had to secure
the admission that the angry man desires vengeance on
account of an apparent slight, and were to secure this, that
'anger' is a desire for vengeance on account of an apparent
slight: for, clearly, if this were secured, we should have
universally what we intend. If, on the other hand, people
formulate propositions relating to the actual terms themselves,
they often find that the answerer refuses to grant them because
on the actual term itself he is readier with his objection, e.g.
that the 'angry man' does not desire vengeance, because we
become angry with our parents, but we do not desire vengeance
on them. Very likely the objection is not valid; for upon some
people it is vengeance enough to cause them pain and make
them sorry; but still it gives a certain plausibility and air of
reasonableness to the denial of the proposition. In the case,
however, of the definition of 'anger' it is not so easy to find an
objection.
Moreover, formulate your proposition as though you did so not
for its own sake, but in order to get at something else: for people
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are shy of granting what an opponent's case really requires.
Speaking generally, a questioner should leave it as far as
possible doubtful whether he wishes to secure an admission of
his proposition or of its opposite: for if it be uncertain what
their opponent's argument requires, people are more ready to
say what they themselves think.
Moreover, try to secure admissions by means of likeness: for
such admissions are plausible, and the universal involved is less
patent; e.g. make the other person admit that as knowledge and
ignorance of contraries is the same, so too perception of
contraries is the same; or vice versa, that since the perception is
the same, so is the knowledge also. This argument resembles
induction, but is not the same thing; for in induction it is the
universal whose admission is secured from the particulars,
whereas in arguments from likeness, what is secured is not the
universal under which all the like cases fall.
It is a good rule also, occasionally to bring an objection against
oneself: for answerers are put off their guard against those who
appear to be arguing impartially. It is useful too, to add that 'So
and so is generally held or commonly said'; for people are shy of
upsetting the received opinion unless they have some positive
objection to urge: and at the same time they are cautious about
upsetting such things because they themselves too find them
useful. Moreover, do not be insistent, even though you really
require the point: for insistence always arouses the more
opposition. Further, formulate your premiss as though it were a
mere illustration: for people admit the more readily a
proposition made to serve some other purpose, and not
required on its own account. Moreover, do not formulate the
very proposition you need to secure, but rather something from
which that necessarily follows: for people are more willing to
admit the latter, because it is not so clear from this what the
result will be, and if the one has been secured, the other has
505
been secured also. Again, one should put last the point which
one most wishes to have conceded; for people are specially
inclined to deny the first questions put to them, because most
people in asking questions put first the points which they are
most eager to secure. On the other hand, in dealing with some
people propositions of this sort should be put forward first: for
ill-tempered men admit most readily what comes first, unless
the conclusion that will result actually stares them in the face,
while at the close of an argument they show their ill-temper.
Likewise also with those who consider themselves smart at
answering: for when they have admitted most of what you want
they finally talk clap-trap to the effect that the conclusion does
not follow from their admissions: yet they say 'Yes' readily,
confident in their own character, and imagining that they
cannot suffer any reverse. Moreover, it is well to expand the
argument and insert things that it does not require at all, as do
those who draw false geometrical figures: for in the multitude
of details the whereabouts of the fallacy is obscured. For this
reason also a questioner sometimes evades observation as he
adds in a corner what, if he formulated it by itself, would not be
granted.
For concealment, then, the rules which should be followed are
the above. Ornament is attained by induction and distinction of
things closely akin. What sort of process induction is obvious: as
for distinction, an instance of the kind of thing meant is the
distinction of one form of knowledge as better than another by
being either more accurate, or concerned with better objects; or
the distinction of sciences into speculative, practical, and
productive. For everything of this kind lends additional
ornament to the argument, though there is no necessity to say
them, so far as the conclusion goes.
For clearness, examples and comparisons should be adduced,
and let the illustrations be relevant and drawn from things that
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we know, as in Homer and not as in Choerilus; for then the
proposition is likely to become clearer.
In dialectics, syllogism should be employed in reasoning against
dialecticians rather than against the crowd: induction, on the
other hand, is most useful against the crowd. This point has
been treated previously as well.' In induction, it is possible in
some cases to ask the question in its universal form, but in
others this is not easy, because there is no established general
term that covers all the resemblances: in this case, when people
need to secure the universal, they use the phrase 'in all cases of
this sort'. But it is one of the very hardest things to distinguish
which of the things adduced are 'of this sort', and which are
not: and in this connexion people often throw dust in each
others' eyes in their discussion, the one party asserting the
likeness of things that are not alike, and the other disputing the
likeness of things that are. One ought, therefore, to try oneself
to coin a word to cover all things of the given sort, so as to leave
no opportunity either to the answerer to dispute, and say that
the thing advanced does not answer to a like description, or to
the questioner to suggest falsely that it does answer to a like
description, for many things appear to answer to like
descriptions that do not really do so.
If one has made an induction on the strength of several cases
and yet the answerer refuses to grant the universal proposition,
then it is fair to demand his objection. But until one has oneself
stated in what cases it is so, it is not fair to demand that he
shall say in what cases it is not so: for one should make the
induction first, and then demand the objection. One ought,
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moreover, to claim that the objections should not be brought in
reference to the actual subject of the proposition, unless that
subject happen to be the one and only thing of the kind, as for
instance two is the one prime number among the even
numbers: for, unless he can say that this subject is unique of its
kind, the objector ought to make his objection in regard to some
other. People sometimes object to a universal proposition, and
bring their objection not in regard to the thing itself, but in
regard to some homonym of it: thus they argue that a man can
very well have a colour or a foot or a hand other than his own,
for a painter may have a colour that is not his own, and a cook
may have a foot that is not his own. To meet them, therefore,
you should draw the distinction before putting your question in
such cases: for so long as the ambiguity remains undetected, so
long will the objection to the proposition be deemed valid. If,
however, he checks the series of questions by an objection in
regard not to some homonym, but to the actual thing asserted,
the questioner should withdraw the point objected to, and form
the remainder into a universal proposition, until he secures
what he requires; e.g. in the case of forgetfulness and having
forgotten: for people refuse to admit that the man who has lost
his knowledge of a thing has forgotten it, because if the thing
alters, he has lost knowledge of it, but he has not forgotten it.
Accordingly the thing to do is to withdraw the part objected to,
and assert the remainder, e.g. that if a person have lost
knowledge of a thing while it still remains, he then has
forgotten it. One should similarly treat those who object to the
statement that 'the greater the good, the greater the evil that is
its opposite': for they allege that health, which is a less good
thing than vigour, has a greater evil as its opposite: for disease
is a greater evil than debility. In this case too, therefore, we have
to withdraw the point objected to; for when it has been
withdrawn, the man is more likely to admit the proposition, e.g.
that 'the greater good has the greater evil as its opposite, unless
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the one good involves the other as well', as vigour involves
health. This should be done not only when he formulates an
objection, but also if, without so doing, he refuses to admit the
point because he foresees something of the kind: for if the point
objected to be withdrawn, he will be forced to admit the
proposition because he cannot foresee in the rest of it any case
where it does not hold true: if he refuse to admit it, then when
asked for an objection he certainly will be unable to render one.
Propositions that are partly false and partly true are of this type:
for in the case of these it is possible by withdrawing a part to
leave the rest true. If, however, you formulate the proposition on
the strength of many cases and he has no objection to bring,
you may claim that he shall admit it: for a premiss is valid in
dialectics which thus holds in several instances and to which
no objection is forthcoming.
Whenever it is possible to reason to the same conclusion either
through or without a reduction per impossibile, if one is
demonstrating and not arguing dialectically it makes no
difference which method of reasoning be adopted, but in
argument with another reasoning per impossibile should be
avoided. For where one has reasoned without the reduction per
impossibile, no dispute can arise; if, on the other hand, one does
reason to an impossible conclusion, unless its falsehood is too
plainly manifest, people deny that it is impossible, so that the
questioners do not get what they want.
One should put forward all propositions that hold true of
several cases, and to which either no objection whatever
appears or at least not any on the surface: for when people
cannot see any case in which it is not so, they admit it for true.
The conclusion should not be put in the form of a question; if it
be, and the man shakes his head, it looks as if the reasoning
had failed. For often, even if it be not put as a question but
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advanced as a consequence, people deny it, and then those who
do not see that it follows upon the previous admissions do not
realize that those who deny it have been refuted: when, then,
the one man merely asks it as a question without even saying
that it so follows, and the other denies it, it looks altogether as if
the reasoning had failed.
Not every universal question can form a dialectical proposition
as ordinarily understood, e.g. 'What is man?' or 'How many
meanings has «the good»?' For a dialectical premiss must be of
a form to which it is possible to reply 'Yes' or 'No', whereas to
the aforesaid it is not possible. For this reason questions of this
kind are not dialectical unless the questioner himself draws
distinctions or divisions before expressing them, e.g. 'Good
means this, or this, does it not?' For questions of this sort are
easily answered by a Yes or a No. Hence one should endeavour
to formulate propositions of this kind in this form. It is at the
same time also perhaps fair to ask the other man how many
meanings of 'the good' there are, whenever you have yourself
distinguished and formulated them, and he will not admit them
at all.
Any one who keeps on asking one thing for a long time is a bad
inquirer. For if he does so though the person questioned keeps
on answering the questions, clearly he asks a large number of
questions, or else asks the same question a large number of
times: in the one case he merely babbles, in the other he fails to
reason: for reasoning always consists of a small number of
premisses. If, on the other hand, he does it because the person
questioned does not answer the questions, he is at fault in not
taking him to task or breaking off the discussion.
510
There are certain hypotheses upon which it is at once difficult
to bring, and easy to stand up to, an argument. Such (e.g.) are
those things which stand first and those which stand last in the
order of nature. For the former require definition, while the
latter have to be arrived at through many steps if one wishes to
secure a continuous proof from first principles, or else all
discussion about them wears the air of mere sophistry: for to
prove anything is impossible unless one begins with the
appropriate principles, and connects inference with inference
till the last are reached. Now to define first principles is just
what answerers do not care to do, nor do they pay any attention
if the questioner makes a definition: and yet until it is clear
what it is that is proposed, it is not easy to discuss it. This sort
of thing happens particularly in the case of the first principles:
for while the other propositions are shown through these, these
cannot be shown through anything else: we are obliged to
understand every item of that sort by a definition. The
inferences, too, that lie too close to the first principle are hard to
treat in argument: for it is not possible to bring many arguments
in regard to them, because of the small number of those steps,
between the conclusion and the principle, whereby the
succeeding propositions have to be shown. The hardest,
however, of all definitions to treat in argument are those that
employ terms about which, in the first place, it is uncertain
whether they are used in one sense or several, and, further,
whether they are used literally or metaphorically by the definer.
For because of their obscurity, it is impossible to argue upon
such terms; and because of the impossibility of saying whether
this obscurity is due to their being used metaphorically, it is
impossible to refute them.
In general, it is safe to suppose that, whenever any problem
proves intractable, it either needs definition or else bears either
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several senses, or a metaphorical sense, or it is not far removed
from the first principles; or else the reason is that we have yet
to discover in the first place just this - in which of the aforesaid
directions the source of our difficulty lies: when we have made
this clear, then obviously our business must be either to define
or to distinguish, or to supply the intermediate premisses: for it
is through these that the final conclusions are shown.
It often happens that a difficulty is found in discussing or
arguing a given position because the definition has not been
correctly rendered: e.g. 'Has one thing one contrary or many?':
here when the term 'contraries' has been properly defined, it is
easy to bring people to see whether it is possible for the same
thing to have several contraries or not: in the same way also
with other terms requiring definition. It appears also in
mathematics that the difficulty in using a figure is sometimes
due to a defect in definition; e.g. in proving that the line which
cuts the plane parallel to one side divides similarly both the line
which it cuts and the area; whereas if the definition be given,
the fact asserted becomes immediately clear: for the areas have
the same fraction subtracted from them as have the sides: and
this is the definition of 'the same ratio'. The most primary of the
elementary principles are without exception very easy to show,
if the definitions involved, e.g. the nature of a line or of a circle,
be laid down; only the arguments that can be brought in regard
to each of them are not many, because there are not many
intermediate steps. If, on the other hand, the definition of the
starting-points be not laid down, to show them is difficult and
may even prove quite impossible. The case of the significance of
verbal expressions is like that of these mathematical
conceptions.
One may be sure then, whenever a position is hard to discuss,
that one or other of the aforesaid things has happened to it.
Whenever, on the other hand, it is a harder task to argue to the
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point claimed, i.e. the premiss, than to the resulting position, a
doubt may arise whether such claims should be admitted or
not: for if a man is going to refuse to admit it and claim that you
shall argue to it as well, he will be giving the signal for a harder
undertaking than was originally proposed: if, on the other hand,
he grants it, he will be giving the original thesis credence on the
strength of what is less credible than itself. If, then, it is
essential not to enhance the difficulty of the problem, he had
better grant it; if, on the other hand, it be essential to reason
through premisses that are better assured, he had better refuse.
In other words, in serious inquiry he ought not to grant it,
unless he be more sure about it than about the conclusion;
whereas in a dialectical exercise he may do so if he is merely
satisfied of its truth. Clearly, then, the circumstances under
which such admissions should be claimed are different for a
mere questioner and for a serious teacher.
As to the formulation, then, and arrangement of one's
questions, about enough has been said.
With regard to the giving of answers, we must first define what
is the business of a good answerer, as of a good questioner. The
business of the questioner is so to develop the argument as to
make the answerer utter the most extrvagant paradoxes that
necessarily follow because of his position: while that of the
answerer is to make it appear that it is not he who is
responsible for the absurdity or paradox, but only his position:
for one may, perhaps, distinguish between the mistake of taking
up a wrong position to start with, and that of not maintaining it
properly, when once taken up.
513
Inasmuch as no rules are laid down for those who argue for the
sake of training and of examination: - and the aim of those
engaged in teaching or learning is quite different from that of
those engaged in a competition; as is the latter from that of
those who discuss things together in the spirit of inquiry: for a
learner should always state what he thinks: for no one is even
trying to teach him what is false; whereas in a competition the
business of the questioner is to appear by all means to produce
an effect upon the other, while that of the answerer is to appear
unaffected by him; on the other hand, in an assembly of
disputants discussing in the spirit not of a competition but of
an examination and inquiry, there are as yet no articulate rules
about what the answerer should aim at, and what kind of things
he should and should not grant for the correct or incorrect
defence of his position: - inasmuch, then, as we have no
tradition bequeathed to us by others, let us try to say something
upon the matter for ourselves.
The thesis laid down by the answerer before facing the
questioner's argument is bound of necessity to be one that is
either generally accepted or generally rejected or else is neither:
and moreover is so accepted or rejected either absolutely or else
with a restriction, e.g. by some given person, by the speaker or
by some one else. The manner, however, of its acceptance or
rejection, whatever it be, makes no difference: for the right way
to answer, i.e. to admit or to refuse to admit what has been
asked, will be the same in either case. If, then, the statement
laid down by the answerer be generally rejected, the conclusion
aimed at by the questioner is bound to be one generally
accepted, whereas if the former be generally accepted, the latter
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is generally rejected: for the conclusion which the questioner
tries to draw is always the opposite of the statement laid down.
If, on the other hand, what is laid down is generally neither
rejected nor accepted, the conclusion will be of the same type
as well. Now since a man who reasons correctly demonstrates
his proposed conclusion from premisses that are more
generally accepted, and more familiar, it is clear that (1) where
the view laid down by him is one that generally is absolutely
rejected, the answerer ought not to grant either what is thus
absolutely not accepted at all, or what is accepted indeed, but
accepted less generally than the questioner's conclusion. For if
the statement laid down by the answerer be generally rejected,
the conclusion aimed at by the questioner will be one that is
generally accepted, so that the premisses secured by the
questioner should all be views generally accepted, and more
generally accepted than his proposed conclusion, if the less
familiar is to be inferred through the more familiar.
Consequently, if any of the questions put to him be not of this
character, the answerer should not grant them. (2) If, on the
other hand, the statement laid down by the answerer be
generally accepted without qualification, clearly the conclusion
sought by the questioner will be one generally rejected without
qualification. Accordingly, the answerer should admit all views
that are generally accepted and, of those that are not generally
accepted, all that are less generally rejected than the conclusion
sought by the questioner. For then he will probably be thought
to have argued sufficiently well. (3) Likewise, too, if the
statement laid down by the answerer be neither rejected
generally nor generally accepted; for then, too, anything that
appears to be true should be granted, and, of the views not
generally accepted, any that are more generally accepted than
the questioner's conclusion; for in that case the result will be
that the arguments will be more generally accepted. If, then, the
view laid down by the answerer be one that is generally
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accepted or rejected without qualification, then the views that
are accepted absolutely must be taken as the standard of
comparison: whereas if the view laid down be one that is not
generally accepted or rejected, but only by the answerer, then
the standard whereby the latter must judge what is generally
accepted or not, and must grant or refuse to grant the point
asked, is himself. If, again, the answerer be defending some one
else's opinion, then clearly it will be the latter's judgement to
which he must have regard in granting or denying the various
points. This is why those, too, who introduce other's opinions,
e.g. that 'good and evil are the same thing, as Heraclitus says,'
refuse to admit the impossibility of contraries belonging at the
same time to the same thing; not because they do not
themselves believe this, but because on Heraclitus' principles
one has to say so. The same thing is done also by those who
take on the defence of one another's positions; their aim being
to speak as would the man who stated the position.
It is clear, then, what the aims of the answerer should be,
whether the position he lays down be a view generally accepted
without qualification or accepted by some definite person. Now
every question asked is bound to involve some view that is
either generally held or generally rejected or neither, and is also
bound to be either relevant to the argument or irrelevant: if
then it be a view generally accepted and irrelevant, the
answerer should grant it and remark that it is the accepted
view: if it be a view not generally accepted and irrelevant, he
should grant it but add a comment that it is not generally
accepted, in order to avoid the appearance of being a simpleton.
If it be relevant and also be generally accepted, he should admit
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that it is the view generally accepted but say that it lies too
close to the original proposition, and that if it be granted the
problem proposed collapses. If what is claimed by the
questioner be relevant but too generally rejected, the answerer,
while admitting that if it be granted the conclusion sought
follows, should yet protest that the proposition is too absurd to
be admitted. Suppose, again, it be a view that is neither rejected
generally nor generally accepted, then, if it be irrelevant to the
argument, it may be granted without restriction; if, however, it
be relevant, the answerer should add the comment that, if it be
granted, the original problem collapses. For then the answerer
will not be held to be personally accountable for what happens
to him, if he grants the several points with his eyes open, and
also the questioner will be able to draw his inference, seeing
that all the premisses that are more generally accepted than the
conclusion are granted him. Those who try to draw an inference
from premisses more generally rejected than the conclusion
clearly do not reason correctly: hence, when men ask these
things, they ought not to be granted.
The questioner should be met in a like manner also in the case
of terms used obscurely, i.e. in several senses. For the answerer,
if he does not understand, is always permitted to say 'I do not
understand': he is not compelled to reply 'Yes' or 'No' to a
question which may mean different things. Clearly, then, in the
first place, if what is said be not clear, he ought not to hesitate
to say that he does not understand it; for often people
encounter some difficulty from assenting to questions that are
not clearly put. If he understands the question and yet it covers
many senses, then supposing what it says to be universally true
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or false, he should give it an unqualified assent or denial: if, on
the other hand, it be partly true and partly false, he should add
a comment that it bears different senses, and also that in one it
is true, in the other false: for if he leave this distinction till later,
it becomes uncertain whether originally as well he perceived
the ambiguity or not. If he does not foresee the ambiguity, but
assents to the question having in view the one sense of the
words, then, if the questioner takes it in the other sense, he
should say, 'That was not what I had in view when I admitted it;
I meant the other sense': for if a term or expression covers more
than one thing, it is easy to disagree. If, however, the question is
both clear and simple, he should answer either 'Yes' or 'No'.
8
A premiss in reasoning always either is one of the constituent
elements in the reasoning, or else goes to establish one of these:
(and you can always tell when it is secured in order to establish
something else by the fact of a number of similar questions
being put: for as a rule people secure their universal by means
either of induction or of likeness): - accordingly the particular
propositions should all be admitted, if they are true and
generally held. On the other hand, against the universal one
should try to bring some negative instance; for to bring the
argument to a standstill without a negative instance, either real
or apparent, shows ill-temper. If, then, a man refuses to grant
the universal when supported by many instances, although he
has no negative instance to show, he obviously shows ill-
temper. If, moreover, he cannot even attempt a counter-proof
that it is not true, far more likely is he to be thought ill-
tempered - although even counter-proof is not enough: for we
often hear arguments that are contrary to common opinions,
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whose solution is yet difficult, e.g. the argument of Zeno that it
is impossible to move or to traverse the stadium; - but still, this
is no reason for omitting to assert the opposites of these views.
If, then, a man refuses to admit the proposition without having
either a negative instance or some counter-argument to bring
against it, clearly he is ill-tempered: for ill-temper in argument
consists in answering in ways other than the above, so as to
wreck the reasoning.
Before maintaining either a thesis or a definition the answerer
should try his hand at attacking it by himself; for clearly his
business is to oppose those positions from which questioners
demolish what he has laid down.
He should beware of maintaining a hypothesis that is generally
rejected: and this it may be in two ways: for it may be one
which results in absurd statements, e.g. suppose any one were
to say that everything is in motion or that nothing is; and also
there are all those which only a bad character would choose,
and which are implicitly opposed to men's wishes, e.g. that
pleasure is the good, and that to do injustice is better than to
suffer it. For people then hate him, supposing him to maintain
them not for the sake of argument but because he really thinks
them.
10
Of all arguments that reason to a false conclusion the right
solution is to demolish the point on which the fallacy that
occurs depends: for the demolition of any random point is no
solution, even though the point demolished be false. For the
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argument may contain many falsehoods, e.g. suppose some one
to secure the premisses, 'He who sits, writes' and 'Socrates is
sitting': for from these it follows that 'Socrates is writing'. Now
we may demolish the proposition 'Socrates is sitting', and still
be no nearer a solution of the argument; it may be true that the
point claimed is false; but it is not on that that fallacy of the
argument depends: for supposing that any one should happen
to be sitting and not writing, it would be impossible in such a
case to apply the same solution. Accordingly, it is not this that
needs to be demolished, but rather that 'He who sits, writes': for
he who sits does not always write. He, then, who has
demolished the point on which the fallacy depends, has given
the solution of the argument completely. Any one who knows
that it is on such and such a point that the argument depends,
knows the solution of it, just as in the case of a figure falsely
drawn. For it is not enough to object, even if the point
demolished be a falsehood, but the reason of the fallacy should
also be proved: for then it would be clear whether the man
makes his objection with his eyes open or not.
There are four possible ways of preventing a man from working
his argument to a conclusion. It can be done either by
demolishing the point on which the falsehood that comes about
depends, or by stating an objection directed against the
questioner: for often when a solution has not as a matter of fact
been brought, yet the questioner is rendered thereby unable to
pursue the argument any farther. Thirdly, one may object to the
questions asked: for it may happen that what the questioner
wants does not follow from the questions he has asked because
he has asked them badly, whereas if something additional be
granted the conclusion comes about. If, then, the questioner be
unable to pursue his argument farther, the objection would
properly be directed against the questioner; if he can do so, then
it would be against his questions. The fourth and worst kind of
objection is that which is directed to the time allowed for
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discussion: for some people bring objections of a kind which
would take longer to answer than the length of the discussion
in hand.
There are then, as we said, four ways of making objections: but
of them the first alone is a solution: the others are just
hindrances and stumbling-blocks to prevent the conclusions.
11
Adverse criticism of an argument on its own merits, and of it
when presented in the form of questions, are two different
things. For often the failure to carry through the argument
correctly in discussion is due to the person questioned, because
he will not grant the steps of which a correct argument might
have been made against his position: for it is not in the power of
the one side only to effect properly a result that depends on
both alike. Accordingly it sometimes becomes necessary to
attack the speaker and not his position, when the answerer lies
in wait for the points that are contrary to the questioner and
becomes abusive as well: when people lose their tempers in this
way, their argument becomes a contest, not a discussion.
Moreover, since arguments of this kind are held not for the sake
of instruction but for purposes of practice and examination,
clearly one has to reason not only to true conclusions, but also
to false ones, and not always through true premisses, but
sometimes through false as well. For often, when a true
proposition is put forward, the dialectician is compelled to
demolish it: and then false propositions have to be formulated.
Sometimes also when a false proposition is put forward, it has
to be demolished by means of false propositions: for it is
possible for a given man to believe what is not the fact more
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firmly than the truth. Accordingly, if the argument be made to
depend on something that he holds, it will be easier to persuade
or help him. He, however, who would rightly convert any one to
a different opinion should do so in a dialectical and not in a
contentious manner, just as a geometrician should reason
geometrically, whether his conclusion be false or true: what
kind of syllogisms are dialectical has already been said. The
principle that a man who hinders the common business is a
bad partner, clearly applies to an argument as well; for in
arguments as well there is a common aim in view, except with
mere contestants, for these cannot both reach the same goal;
for more than one cannot possibly win. It makes no difference
whether he effects this as answerer or as questioner: for both
he who asks contentious questions is a bad dialectician, and
also he who in answering fails to grant the obvious answer or to
understand the point of the questioner's inquiry. What has been
said, then, makes it clear that adverse criticism is not to be
passed in a like strain upon the argument on its own merits,
and upon the questioner: for it may very well be that the
argument is bad, but that the questioner has argued with the
answerer in the best possible way: for when men lose their
tempers, it may perhaps be impossible to make one's inferences
straight-forwardly as one would wish: we have to do as we can.
Inasmuch as it is indeterminate when people are claiming the
admission of contrary things, and when they are claiming what
originally they set out to prove - for often when they are talking
by themselves they say contrary things, and admit afterwards
what they have previously denied; for which reason they often
assent, when questioned, to contrary things and to what
originally had to be proved - the argument is sure to become
vitiated. The responsibility, however, for this rests with the
answerer, because while refusing to grant other points, he does
grant points of that kind. It is, then, clear that adverse criticism
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is not to be passed in a like manner upon questioners and upon
their arguments.
In itself an argument is liable to five kinds of adverse criticism:
(1) The first is when neither the proposed conclusion nor indeed
any conclusion at all is drawn from the questions asked, and
when most, if not all, of the premisses on which the conclusion
rests are false or generally rejected, when, moreover, neither
any withdrawals nor additions nor both together can bring the
conclusions about.
(2) The second is, supposing the reasoning, though constructed
from the premisses, and in the manner, described above, were
to be irrelevant to the original position.
(3) The third is, supposing certain additions would bring an
inference about but yet these additions were to be weaker than
those that were put as questions and less generally held than
the conclusion.
(4) Again, supposing certain withdrawals could effect the same:
for sometimes people secure more premisses than are
necessary, so that it is not through them that the inference
comes about.
(5) Moreover, suppose the premisses be less generally held and
less credible than the conclusion, or if, though true, they require
more trouble to prove than the proposed view.
One must not claim that the reasoning to a proposed view shall
in every case equally be a view generally accepted and
convincing: for it is a direct result of the nature of things that
some subjects of inquiry shall be easier and some harder, so
that if a man brings people to accept his point from opinions
that are as generally received as the case admits, he has argued
his case correctly. Clearly, then, not even the argument itself is
523
open to the same adverse criticism when taken in relation to
the proposed conclusion and when taken by itself. For there is
nothing to prevent the argument being open to reproach in
itself, and yet commendable in relation to the proposed
conclusion, or again, vice versa, being commendable in itself,
and yet open to reproach in relation to the proposed conclusion,
whenever there are many propositions both generally held and
also true whereby it could easily be proved. It is possible also
that an argument, even though brought to a conclusion, may
sometimes be worse than one which is not so concluded,
whenever the premisses of the former are silly, while its
conclusion is not so; whereas the latter, though requiring
certain additions, requires only such as are generally held and
true, and moreover does not rest as an argument on these
additions. With those which bring about a true conclusion by
means of false premisses, it is not fair to find fault: for a false
conclusion must of necessity always be reached from a false
premiss, but a true conclusion may sometimes be drawn even
from false premisses; as is clear from the Analytics.
Whenever by the argument stated something is demonstrated,
but that something is other than what is wanted and has no
bearing whatever on the conclusion, then no inference as to the
latter can be drawn from it: and if there appears to be, it will be
a sophism, not a proof. A philosopheme is a demonstrative
inference: an epichireme is a dialectical inference: a sophism is
a contentious inference: an aporeme is an inference that
reasons dialectically to a contradiction.
If something were to be shown from premisses, both of which
are views generally accepted, but not accepted with like
conviction, it may very well be that the conclusion shown is
something held more strongly than either. If, on the other hand,
general opinion be for the one and neither for nor against the
other, or if it be for the one and against the other, then, if the
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pro and con be alike in the case of the premisses, they will be
alike for the conclusion also: if, on the other hand, the one
preponderates, the conclusion too will follow suit.
It is also a fault in reasoning when a man shows something
through a long chain of steps, when he might employ fewer
steps and those already included in his argument: suppose him
to be showing (e.g.) that one opinion is more properly so called
than another, and suppose him to make his postulates as
follows: 'x-in-itself is more fully x than anything else': 'there
genuinely exists an object of opinion in itself: therefore 'the
object-of-opinion-in-itself is more fully an object of opinion
than the particular objects of opinion'. Now 'a relative term is
more fully itself when its correlate is more fully itself: and
'there exists a genuine opinion-in-itself, which will be «opinion»
in a more accurate sense than the particular opinions': and it
has been postulated both that 'a genuine opinion-in-itself
exists', and that 'x-in-itself is more fully x than anything else':
therefore 'this will be opinion in a more accurate sense'.
Wherein lies the viciousness of the reasoning? Simply in that it
conceals the ground on which the argument depends.
12
An argument is clear in one, and that the most ordinary, sense,
if it be so brought to a conclusion as to make no further
questions necessary: in another sense, and this is the type most
usually advanced, when the propositions secured are such as
compel the conclusion, and the argument is concluded through
premisses that are themselves conclusions: moreover, it is so
also if some step is omitted that generally is firmly accepted.
525
An argument is called fallacious in four senses: (1) when it
appears to be brought to a conclusion, and is not really so -
what is called 'contentious' reasoning: (2) when it comes to a
conclusion but not to the conclusion proposed - which happens
principally in the case of reductiones ad impossibile: (3) when it
comes to the proposed conclusion but not according to the
mode of inquiry appropriate to the case, as happens when a
non-medical argument is taken to be a medical one, or one
which is not geometrical for a geometrical argument, or one
which is not dialectical for dialectical, whether the result
reached be true or false: (4) if the conclusion be reached through
false premisses: of this type the conclusion is sometimes false,
sometimes true: for while a false conclusion is always the result
of false premisses, a true conclusion may be drawn even from
premisses that are not true, as was said above as well.
Fallacy in argument is due to a mistake of the arguer rather
than of the argument: yet it is not always the fault of the arguer
either, but only when he is not aware of it: for we often accept
on its merits in preference to many true ones an argument
which demolishes some true proposition if it does so from
premisses as far as possible generally accepted. For an
argument of that kind does demonstrate other things that are
true: for one of the premisses laid down ought never to be there
at all, and this will then be demonstrated. If, however, a true
conclusion were to be reached through premisses that are false
and utterly childish, the argument is worse than many
arguments that lead to a false conclusion, though an argument
which leads to a false conclusion may also be of this type.
Clearly then the first thing to ask in regard to the argument in
itself is, 'Has it a conclusion?'; the second, 'Is the conclusion
true or false?'; the third, 'Of what kind of premisses does it
consist?': for if the latter, though false, be generally accepted,
the argument is dialectical, whereas if, though true, they be
generally rejected, it is bad: if they be both false and also
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entirely contrary to general opinion, clearly it is bad, either
altogether or else in relation to the particular matter in hand.
13
Of the ways in which a questioner may beg the original
question and also beg contraries the true account has been
given in the Analytics:' but an account on the level of general
opinion must be given now.
People appear to beg their original question in five ways: the
first and most obvious being if any one begs the actual point
requiring to be shown: this is easily detected when put in so
many words; but it is more apt to escape detection in the case
of different terms, or a term and an expression, that mean the
same thing. A second way occurs whenever any one begs
universally something which he has to demonstrate in a
particular case: suppose (e.g.) he were trying to prove that the
knowledge of contraries is one and were to claim that the
knowledge of opposites in general is one: for then he is
generally thought to be begging, along with a number of other
things, that which he ought to have shown by itself. A third way
is if any one were to beg in particular cases what he undertakes
to show universally: e.g. if he undertook to show that the
knowledge of contraries is always one, and begged it of certain
pairs of contraries: for he also is generally considered to be
begging independently and by itself what, together with a
number of other things, he ought to have shown. Again, a man
begs the question if he begs his conclusion piecemeal:
supposing e.g. that he had to show that medicine is a science of
what leads to health and to disease, and were to claim first the
one, then the other; or, fifthly, if he were to beg the one or the
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other of a pair of statements that necessarily involve one other;
e.g. if he had to show that the diagonal is incommensurable
with the side, and were to beg that the side is incommensurable
with the diagonal.
The ways in which people assume contraries are equal in
number to those in which they beg their original question. For it
would happen, firstly, if any one were to beg an opposite
affirmation and negation; secondly, if he were to beg the
contrary terms of an antithesis, e.g. that the same thing is good
and evil; thirdly, suppose any one were to claim something
universally and then proceed to beg its contradictory in some
particular case, e.g. if having secured that the knowledge of
contraries is one, he were to claim that the knowledge of what
makes for health or for disease is different; or, fourthly, suppose
him, after postulating the latter view, to try to secure universally
the contradictory statement. Again, fifthly, suppose a man begs
the contrary of the conclusion which necessarily comes about
through the premisses laid down; and this would happen
suppose, even without begging the opposites in so many words,
he were to beg two premisses such that this contradictory
statement that is opposite to the first conclusion will follow
from them. The securing of contraries differs from begging the
original question in this way: in the latter case the mistake lies
in regard to the conclusion; for it is by a glance at the
conclusion that we tell that the original question has been
begged: whereas contrary views lie in the premisses, viz. in a
certain relation which they bear to one another.
528
14
The best way to secure training and practice in arguments of
this kind is in the first place to get into the habit of converting
the arguments. For in this way we shall be better equipped for
dealing with the proposition stated, and after a few attempts we
shall know several arguments by heart. For by 'conversion' of an
argument is meant the taking the reverse of the conclusion
together with the remaining propositions asked and so
demolishing one of those that were conceded: for it follows
necessarily that if the conclusion be untrue, some one of the
premisses is demolished, seeing that, given all the premisses,
the conclusion was bound to follow. Always, in dealing with any
proposition, be on the look-out for a line of argument both pro
and con: and on discovering it at once set about looking for the
solution of it: for in this way you will soon find that you have
trained yourself at the same time in both asking questions and
answering them. If we cannot find any one else to argue with,
we should argue with ourselves. Select, moreover, arguments
relating to the same thesis and range them side by side: for this
produces a plentiful supply of arguments for carrying a point by
sheer force, and in refutation also it is of great service,
whenever one is well stocked with arguments pro and con: for
then you find yourself on your guard against contrary
statements to the one you wish to secure. Moreover, as
contributing to knowledge and to philosophic wisdom the
power of discerning and holding in one view the results of
either of two hypotheses is no mean instrument; for it then
only remains to make a right choice of one of them. For a task of
this kind a certain natural ability is required: in fact real natural
ability just is the power right to choose the true and shun the
false. Men of natural ability can do this; for by a right liking or
disliking for whatever is proposed to them they rightly select
what is best.
529
It is best to know by heart arguments upon those questions
which are of most frequent occurrence, and particularly in
regard to those propositions which are ultimate: for in
discussing these answerers frequently give up in despair.
Moreover, get a good stock of definitions: and have those of
familiar and primary ideas at your fingers' ends: for it is
through these that reasonings are effected. You should try,
moreover, to master the heads under which other arguments
mostly tend to fall. For just as in geometry it is useful to be
practised in the elements, and in arithmetic to have the
multiplication table up to ten at one's fingers' ends - and indeed
it makes a great difference in one's knowledge of the multiples
of other numbers too - likewise also in arguments it is a great
advantage to be well up in regard to first principles, and to have
a thorough knowledge of premisses at the tip of one's tongue.
For just as in a person with a trained memory, a memory of
things themselves is immediately caused by the mere mention
of their loci, so these habits too will make a man readier in
reasoning, because he has his premisses classified before his
mind's eye, each under its number. It is better to commit to
memory a premiss of general application than an argument: for
it is difficult to be even moderately ready with a first principle,
or hypothesis.
Moreover, you should get into the habit of turning one
argument into several, and conceal your procedure as darkly as
you can: this kind of effect is best produced by keeping as far as
possible away from topics akin to the subject of the argument.
This can be done with arguments that are entirely universal, e.g.
the statement that 'there cannot be one knowledge of more
than one thing': for that is the case with both relative terms and
contraries and co-ordinates.
Records of discussions should be made in a universal form,
even though one has argued only some particular case: for this
530
will enable one to turn a single rule into several. A like rule
applies in Rhetoric as well to enthymemes. For yourself,
however, you should as far as possible avoid universalizing your
reasonings. You should, moreover, always examine arguments
to see whether they rest on principles of general application: for
all particular arguments really reason universally, as well, i.e. a
particular demonstration always contains a universal
demonstration, because it is impossible to reason at all without
using universals.
You should display your training in inductive reasoning against
a young man, in deductive against an expert. You should try,
moreover, to secure from those skilled in deduction their
premisses, from inductive reasoners their parallel cases; for this
is the thing in which they are respectively trained. In general,
too, from your exercises in argumentation you should try to
carry away either a syllogism on some subject or a refutation or
a proposition or an objection, or whether some one put his
question properly or improperly (whether it was yourself or
some one else) and the point which made it the one or the
other. For this is what gives one ability, and the whole object of
training is to acquire ability, especially in regard to propositions
and objections. For it is the skilled propounder and objector
who is, speaking generally, a dialectician. To formulate a
proposition is to form a number of things into one - for the
conclusion to which the argument leads must be taken
generally, as a single thing - whereas to formulate an objection
is to make one thing into many; for the objector either
distinguishes or demolishes, partly granting, partly denying the
statements proposed.
Do not argue with every one, nor practise upon the man in the
street: for there are some people with whom any argument is
bound to degenerate. For against any one who is ready to try all
means in order to seem not to be beaten, it is indeed fair to try
531
all means of bringing about one's conclusion: but it is not good
form. Wherefore the best rule is, not lightly to engage with
casual acquaintances, or bad argument is sure to result. For you
see how in practising together people cannot refrain from
contentious argument.
It is best also to have ready-made arguments relating to those
questions in which a very small stock will furnish us with
arguments serviceable on a very large number of occasions.
These are those that are universal, and those in regard to which
it is rather difficult to produce points for ourselves from matters
of everyday experience.
532
Aristotle - On Sophistical Refutations
[Translated by W. A. Pickard-Cambridge]
Let us now discuss sophistic refutations, i.e. what appear to be
refutations but are really fallacies instead. We will begin in the
natural order with the first.
That some reasonings are genuine, while others seem to be so
but are not, is evident. This happens with arguments, as also
elsewhere, through a certain likeness between the genuine and
the sham. For physically some people are in a vigorous
condition, while others merely seem to be so by blowing and
rigging themselves out as the tribesmen do their victims for
sacrifice; and some people are beautiful thanks to their beauty,
while others seem to be so, by dint of embellishing themselves.
So it is, too, with inanimate things; for of these, too, some are
really silver and others gold, while others are not and merely
seem to be such to our sense; e.g. things made of litharge and
tin seem to be of silver, while those made of yellow metal look
golden. In the same way both reasoning and refutation are
sometimes genuine, sometimes not, though inexperience may
make them appear so: for inexperienced people obtain only, as
it were, a distant view of these things. For reasoning rests on
certain statements such that they involve necessarily the
assertion of something other than what has been stated,
through what has been stated: refutation is reasoning involving
the contradictory of the given conclusion. Now some of them do
not really achieve this, though they seem to do so for a number
of reasons; and of these the most prolific and usual domain is
533
the argument that turns upon names only. It is impossible in a
discussion to bring in the actual things discussed: we use their
names as symbols instead of them; and therefore we suppose
that what follows in the names, follows in the things as well,
just as people who calculate suppose in regard to their counters.
But the two cases (names and things) are not alike. For names
are finite and so is the sum-total of formulae, while things are
infinite in number. Inevitably, then, the same formulae, and a
single name, have a number of meanings. Accordingly just as, in
counting, those who are not clever in manipulating their
counters are taken in by the experts, in the same way in
arguments too those who are not well acquainted with the force
of names misreason both in their own discussions and when
they listen to others. For this reason, then, and for others to be
mentioned later, there exists both reasoning and refutation that
is apparent but not real. Now for some people it is better worth
while to seem to be wise, than to be wise without seeming to be
(for the art of the sophist is the semblance of wisdom without
the reality, and the sophist is one who makes money from an
apparent but unreal wisdom); for them, then, it is clearly
essential also to seem to accomplish the task of a wise man
rather than to accomplish it without seeming to do so. To
reduce it to a single point of contrast it is the business of one
who knows a thing, himself to avoid fallacies in the subjects
which he knows and to be able to show up the man who makes
them; and of these accomplishments the one depends on the
faculty to render an answer, and the other upon the securing of
one. Those, then, who would be sophists are bound to study the
class of arguments aforesaid: for it is worth their while: for a
faculty of this kind will make a man seem to be wise, and this is
the purpose they happen to have in view.
Clearly, then, there exists a class of arguments of this kind, and
it is at this kind of ability that those aim whom we call sophists.
Let us now go on to discuss how many kinds there are of
534
sophistical arguments, and how many in number are the
elements of which this faculty is composed, and how many
branches there happen to be of this inquiry, and the other
factors that contribute to this art.
Of arguments in dialogue form there are four classes:
Didactic, Dialectical, Examination-arguments, and Contentious
arguments. Didactic arguments are those that reason from the
principles appropriate to each subject and not from the
opinions held by the answerer (for the learner should take
things on trust): dialectical arguments are those that reason
from premisses generally accepted, to the contradictory of a
given thesis: examination-arguments are those that reason
from premisses which are accepted by the answerer and which
any one who pretends to possess knowledge of the subject is
bound to know-in what manner, has been defined in another
treatise: contentious arguments are those that reason or appear
to reason to a conclusion from premisses that appear to be
generally accepted but are not so. The subject, then, of
demonstrative arguments has been discussed in the Analytics,
while that of dialectic arguments and examination-arguments
has been discussed elsewhere: let us now proceed to speak of
the arguments used in competitions and contests.
535
First we must grasp the number of aims entertained by those
who argue as competitors and rivals to the death. These are five
in number, refutation, fallacy, paradox, solecism, and fifthly to
reduce the opponent in the discussion to babbling - i.e. to
constrain him to repeat himself a number of times: or it is to
produce the appearance of each of these things without the
reality. For they choose if possible plainly to refute the other
party, or as the second best to show that he is committing some
fallacy, or as a third best to lead him into paradox, or fourthly to
reduce him to solecism, i.e. to make the answerer, in
consequence of the argument, to use an ungrammatical
expression; or, as a last resort, to make him repeat himself.
There are two styles of refutation: for some depend on the
language used, while some are independent of language. Those
ways of producing the false appearance of an argument which
depend on language are six in number: they are ambiguity,
amphiboly, combination, division of words, accent, form of
expression. Of this we may assure ourselves both by induction,
and by syllogistic proof based on this - and it may be on other
assumptions as well - that this is the number of ways in which
we might fall to mean the same thing by the same names or
expressions. Arguments such as the following depend upon
ambiguity. 'Those learn who know: for it is those who know
their letters who learn the letters dictated to them'. For to
'learn' is ambiguous; it signifies both 'to understand' by the use
of knowledge, and also 'to acquire knowledge'. Again, 'Evils are
good: for what needs to be is good, and evils must needs be'. For
536
'what needs to be' has a double meaning: it means what is
inevitable, as often is the case with evils, too (for evil of some
kind is inevitable), while on the other hand we say of good
things as well that they 'need to be'. Moreover, 'The same man
is both seated and standing and he is both sick and in health:
for it is he who stood up who is standing, and he who is
recovering who is in health: but it is the seated man who stood
up, and the sick man who was recovering'. For 'The sick man
does so and so', or 'has so and so done to him' is not single in
meaning: sometimes it means 'the man who is sick or is seated
now', sometimes 'the man who was sick formerly'. Of course,
the man who was recovering was the sick man, who really was
sick at the time: but the man who is in health is not sick at the
same time: he is 'the sick man' in the sense not that he is sick
now, but that he was sick formerly. Examples such as the
following depend upon amphiboly: 'I wish that you the enemy
may capture'. Also the thesis, 'There must be knowledge of
what one knows': for it is possible by this phrase to mean that
knowledge belongs to both the knower and the known. Also,
'There must be sight of what one sees: one sees the pillar: ergo
the pillar has sight'. Also, 'What you profess to-be, that you
profess to-be: you profess a stone to-be: ergo you profess-to-be
a stone'. Also, 'Speaking of the silent is possible': for 'speaking of
the silent' also has a double meaning: it may mean that the
speaker is silent or that the things of which he speaks are so.
There are three varieties of these ambiguities and amphibolies:
(1) When either the expression or the name has strictly more
than one meaning, e.g. aetos and the 'dog'; (2) when by custom
we use them so; (3) when words that have a simple sense taken
alone have more than one meaning in combination; e.g.
'knowing letters'. For each word, both 'knowing' and 'letters',
possibly has a single meaning: but both together have more
than one - either that the letters themselves have knowledge or
that someone else has it of them.
537
Amphiboly and ambiguity, then, depend on these modes of
speech. Upon the combination of words there depend instances
such as the following: 'A man can walk while sitting, and can
write while not writing'. For the meaning is not the same if one
divides the words and if one combines them in saying that 'it is
possible to walk-while-sitting' and write while not writing. The
same applies to the latter phrase, too, if one combines the
words 'to write-while-not-writing': for then it means that he has
the power to write and not to write at once; whereas if one does
not combine them, it means that when he is not writing he has
the power to write. Also, 'He now if he has learnt his letters'.
Moreover, there is the saying that 'One single thing if you can
carry a crowd you can carry too'.
Upon division depend the propositions that 5 is 2 and 3, and
odd, and that the greater is equal: for it is that amount and
more besides. For the same phrase would not be thought always
to have the same meaning when divided and when combined,
e.g. 'I made thee a slave once a free man', and 'God-like Achilles
left fifty a hundred men'.
An argument depending upon accent it is not easy to construct
in unwritten discussion; in written discussions and in poetry it
is easier. Thus (e.g.) some people emend Homer against those
who criticize as unnatural his expression to men ou
kataputhetai ombro. For they solve the difficulty by a change of
accent, pronouncing the ou with an acuter accent. Also, in the
passage about Agamemnon's dream, they say that Zeus did not
himself say 'We grant him the fulfilment of his prayer', but that
he bade the dream grant it. Instances such as these, then, turn
upon the accentuation.
Others come about owing to the form of expression used, when
what is really different is expressed in the same form, e.g. a
masculine thing by a feminine termination, or a feminine thing
538
by a masculine, or a neuter by either a masculine or a feminine;
or, again, when a quality is expressed by a termination proper to
quantity or vice versa, or what is active by a passive word, or a
state by an active word, and so forth with the other divisions
previously' laid down. For it is possible to use an expression to
denote what does not belong to the class of actions at all as
though it did so belong. Thus (e.g.) 'flourishing' is a word which
in the form of its expression is like 'cutting' or 'building': yet the
one denotes a certain quality - i.e. a certain condition - while
the other denotes a certain action. In the same manner also in
the other instances.
Refutations, then, that depend upon language are drawn from
these common-place rules. Of fallacies, on the other hand, that
are independent of language there are seven kinds:
(1) that which depends upon Accident:
(2) the use of an expression absolutely or not absolutely but
with some qualification of respect or place, or time, or relation:
(3) that which depends upon ignorance of what 'refutation' is:
(4) that which depends upon the consequent:
(5) that which depends upon assuming the original conclusion:
(6) stating as cause what is not the cause:
(7) the making of more than one question into one.
Fallacies, then, that depend on Accident occur whenever any
attribute is claimed to belong in like manner to a thing and to
539
its accident. For since the same thing has many accidents there
is no necessity that all the same attributes should belong to all
of a thing's predicates and to their subject as well. Thus (e.g.), 'If
Coriscus be different from «man», he is different from himself:
for he is a man': or 'If he be different from Socrates, and
Socrates be a man, then', they say, 'he has admitted that
Coriscus is different from a man, because it so happens (accidit)
that the person from whom he said that he (Coriscus) is
different is a man'.
Those that depend on whether an expression is used absolutely
or in a certain respect and not strictly, occur whenever an
expression used in a particular sense is taken as though it were
used absolutely, e.g. in the argument 'If what is not is the object
of an opinion, then what is not is': for it is not the same thing
'to be x' and 'to be' absolutely. Or again, 'What is, is not, if it is
not a particular kind of being, e.g. if it is not a man.' For it is not
the same thing 'not to be x' and 'not to be' at all: it looks as if it
were, because of the closeness of the expression, i.e. because 'to
be x' is but little different from 'to be', and 'not to be x' from 'not
to be'. Likewise also with any argument that turns upon the
point whether an expression is used in a certain respect or used
absolutely. Thus e.g. 'Suppose an Indian to be black all over, but
white in respect of his teeth; then he is both white and not
white.' Or if both characters belong in a particular respect, then,
they say, 'contrary attributes belong at the same time'. This kind
of thing is in some cases easily seen by any one, e.g. suppose a
man were to secure the statement that the Ethiopian is black,
and were then to ask whether he is white in respect of his
teeth; and then, if he be white in that respect, were to suppose
at the conclusion of his questions that therefore he had proved
dialectically that he was both white and not white. But in some
cases it often passes undetected, viz. in all cases where,
whenever a statement is made of something in a certain
respect, it would be generally thought that the absolute
540
statement follows as well; and also in all cases where it is not
easy to see which of the attributes ought to be rendered strictly.
A situation of this kind arises, where both the opposite
attributes belong alike: for then there is general support for the
view that one must agree absolutely to the assertion of both, or
of neither: e.g. if a thing is half white and half black, is it white
or black?
Other fallacies occur because the terms 'proof or 'refutation'
have not been defined, and because something is left out in
their definition. For to refute is to contradict one and the same
attribute - not merely the name, but the reality - and a name
that is not merely synonymous but the same name - and to
confute it from the propositions granted, necessarily, without
including in the reckoning the original point to be proved, in the
same respect and relation and manner and time in which it was
asserted. A 'false assertion' about anything has to be defined in
the same way. Some people, however, omit some one of the said
conditions and give a merely apparent refutation, showing (e.g.)
that the same thing is both double and not double: for two is
double of one, but not double of three. Or, it may be, they show
that it is both double and not double of the same thing, but not
that it is so in the same respect: for it is double in length but not
double in breadth. Or, it may be, they show it to be both double
and not double of the same thing and in the same respect and
manner, but not that it is so at the same time: and therefore
their refutation is merely apparent. One might, with some
violence, bring this fallacy into the group of fallacies dependent
on language as well.
Those that depend on the assumption of the original point to be
proved, occur in the same way, and in as many ways, as it is
possible to beg the original point; they appear to refute because
men lack the power to keep their eyes at once upon what is the
same and what is different.
541
The refutation which depends upon the consequent arises
because people suppose that the relation of consequence is
convertible. For whenever, suppose A is, B necessarily is, they
then suppose also that if B is, A necessarily is. This is also the
source of the deceptions that attend opinions based on sense-
perception. For people often suppose bile to be honey because
honey is attended by a yellow colour: also, since after rain the
ground is wet in consequence, we suppose that if the ground is
wet, it has been raining; whereas that does not necessarily
follow. In rhetoric proofs from signs are based on consequences.
For when rhetoricians wish to show that a man is an adulterer,
they take hold of some consequence of an adulterous life, viz.
that the man is smartly dressed, or that he is observed to
wander about at night. There are, however, many people of
whom these things are true, while the charge in question is
untrue. It happens like this also in real reasoning; e.g. Melissus'
argument, that the universe is eternal, assumes that the
universe has not come to be (for from what is not nothing could
possibly come to be) and that what has come to be has done so
from a first beginning. If, therefore, the universe has not come
to be, it has no first beginning, and is therefore eternal. But this
does not necessarily follow: for even if what has come to be
always has a first beginning, it does not also follow that what
has a first beginning has come to be; any more than it follows
that if a man in a fever be hot, a man who is hot must be in a
fever.
The refutation which depends upon treating as cause what is
not a cause, occurs whenever what is not a cause is inserted in
the argument, as though the refutation depended upon it. This
kind of thing happens in arguments that reason ad impossible:
for in these we are bound to demolish one of the premisses. If,
then, the false cause be reckoned in among the questions that
are necessary to establish the resulting impossibility, it will
often be thought that the refutation depends upon it, e.g. in the
542
proof that the 'soul' and 'life' are not the same: for if coming-to-
be be contrary to perishing, then a particular form of perishing
will have a particular form of coming-to-be as its contrary: now
death is a particular form of perishing and is contrary to life:
life, therefore, is a coming to-be, and to live is to come-to-be. But
this is impossible: accordingly, the 'soul' and 'life' are not the
same. Now this is not proved: for the impossibility results all
the same, even if one does not say that life is the same as the
soul, but merely says that life is contrary to death, which is a
form of perishing, and that perishing has 'coming-to-be' as its
contrary. Arguments of that kind, then, though not inconclusive
absolutely, are inconclusive in relation to the proposed
conclusion. Also even the questioners themselves often fail
quite as much to see a point of that kind.
Such, then, are the arguments that depend upon the
consequent and upon false cause. Those that depend upon the
making of two questions into one occur whenever the plurality
is undetected and a single answer is returned as if to a single
question. Now, in some cases, it is easy to see that there is more
than one, and that an answer is not to be given, e.g. 'Does the
earth consist of sea, or the sky?' But in some cases it is less
easy, and then people treat the question as one, and either
confess their defeat by failing to answer the question, or are
exposed to an apparent refutation. Thus 'Is A and is B a man?'
'Yes.' 'Then if any one hits A and B, he will strike a man'
(singular), 'not men' (plural). Or again, where part is good and
part bad, 'is the whole good or bad?' For whichever he says, it is
possible that he might be thought to expose himself to an
apparent refutation or to make an apparently false statement:
for to say that something is good which is not good, or not good
which is good, is to make a false statement. Sometimes,
however, additional premisses may actually give rise to a
genuine refutation; e.g. suppose a man were to grant that the
descriptions 'white' and 'naked' and 'blind' apply to one thing
543
and to a number of things in a like sense. For if 'blind' describes
a thing that cannot see though nature designed it to see, it will
also describe things that cannot see though nature designed
them to do so. Whenever, then, one thing can see while another
cannot, they will either both be able to see or else both be blind;
which is impossible.
The right way, then, is either to divide apparent proofs and
refutations as above, or else to refer them all to ignorance of
what 'refutation' is, and make that our starting-point: for it is
possible to analyse all the aforesaid modes of fallacy into
breaches of the definition of a refutation. In the first place, we
may see if they are inconclusive: for the conclusion ought to
result from the premisses laid down, so as to compel us
necessarily to state it and not merely to seem to compel us.
Next we should also take the definition bit by bit, and try the
fallacy thereby. For of the fallacies that consist in language,
some depend upon a double meaning, e.g. ambiguity of words
and of phrases, and the fallacy of like verbal forms (for we
habitually speak of everything as though it were a particular
substance) - while fallacies of combination and division and
accent arise because the phrase in question or the term as
altered is not the same as was intended. Even this, however,
should be the same, just as the thing signified should be as well,
if a refutation or proof is to be effected; e.g. if the point concerns
a doublet, then you should draw the conclusion of a 'doublet',
not of a 'cloak'. For the former conclusion also would be true,
but it has not been proved; we need a further question to show
that 'doublet' means the same thing, in order to satisfy any one
who asks why you think your point proved.
544
Fallacies that depend on Accident are clear cases of ignoratio
elenchi when once 'proof has been defined. For the same
definition ought to hold good of 'refutation' too, except that a
mention of 'the contradictory' is here added: for a refutation is a
proof of the contradictory. If, then, there is no proof as regards
an accident of anything, there is no refutation. For supposing,
when A and B are, C must necessarily be, and C is white, there is
no necessity for it to be white on account of the syllogism. So, if
the triangle has its angles equal to two right-angles, and it
happens to be a figure, or the simplest element or starting
point, it is not because it is a figure or a starting point or
simplest element that it has this character. For the
demonstration proves the point about it not qua figure or qua
simplest element, but qua triangle. Likewise also in other cases.
If, then, refutation is a proof, an argument which argued per
accidens could not be a refutation. It is, however, just in this
that the experts and men of science generally suffer refutation
at the hand of the unscientific: for the latter meet the scientists
with reasonings constituted per accidens; and the scientists for
lack of the power to draw distinctions either say 'Yes' to their
questions, or else people suppose them to have said 'Yes',
although they have not.
Those that depend upon whether something is said in a certain
respect only or said absolutely, are clear cases of ignoratio
elenchi because the affirmation and the denial are not
concerned with the same point. For of 'white in a certain
respect' the negation is 'not white in a certain respect', while of
'white absolutely' it is 'not white, absolutely'. If, then, a man
treats the admission that a thing is 'white in a certain respect'
as though it were said to be white absolutely, he does not effect
a refutation, but merely appears to do so owing to ignorance of
what refutation is.
545
The clearest cases of all, however, are those that were
previously described' as depending upon the definition of a
'refutation': and this is also why they were called by that name.
For the appearance of a refutation is produced because of the
omission in the definition, and if we divide fallacies in the
above manner, we ought to set 'Defective definition' as a
common mark upon them all.
Those that depend upon the assumption of the original point
and upon stating as the cause what is not the cause, are clearly
shown to be cases of ignoratio elenchi through the definition
thereof. For the conclusion ought to come about 'because these
things are so', and this does not happen where the premisses
are not causes of it: and again it should come about without
taking into account the original point, and this is not the case
with those arguments which depend upon begging the original
point.
Those that depend upon the assumption of the original point
and upon stating as the cause what is not the cause, are clearly
shown to be cases of ignoratio elenchi through the definition
thereof. For the conclusion ought to come about 'because these
things are so', and this does not happen where the premisses
are not causes of it: and again it should come about without
taking into account the original point, and this is not the case
with those arguments which depend upon begging the original
point.
Those that depend upon the consequent are a branch of
Accident: for the consequent is an accident, only it differs from
the accident in this, that you may secure an admission of the
accident in the case of one thing only (e.g. the identity of a
yellow thing and honey and of a white thing and swan),
whereas the consequent always involves more than one thing:
for we claim that things that are the same as one and the same
546
thing are also the same as one another, and this is the ground of
a refutation dependent on the consequent. It is, however, not
always true, e.g. suppose that and B are the same as C per
accidens; for both 'snow' and the 'swan' are the same as
something white'. Or again, as in Melissus' argument, a man
assumes that to 'have been generated' and to 'have a beginning'
are the same thing, or to 'become equal' and to 'assume the
same magnitude'. For because what has been generated has a
beginning, he claims also that what has a beginning has been
generated, and argues as though both what has been generated
and what is finite were the same because each has a beginning.
Likewise also in the case of things that are made equal he
assumes that if things that assume one and the same
magnitude become equal, then also things that become equal
assume one magnitude: i.e. he assumes the consequent.
Inasmuch, then, as a refutation depending on accident consists
in ignorance of what a refutation is, clearly so also does a
refutation depending on the consequent. We shall have further
to examine this in another way as well.
Those fallacies that depend upon the making of several
questions into one consist in our failure to dissect the definition
of 'proposition'. For a proposition is a single statement about a
single thing. For the same definition applies to 'one single thing
only' and to the 'thing', simply, e.g. to 'man' and to 'one single
man only' and likewise also in other cases. If, then, a 'single
proposition' be one which claims a single thing of a single thing,
a 'proposition', simply, will also be the putting of a question of
that kind. Now since a proof starts from propositions and
refutation is a proof, refutation, too, will start from propositions.
If, then, a proposition is a single statement about a single thing,
it is obvious that this fallacy too consists in ignorance of what a
refutation is: for in it what is not a proposition appears to be
one. If, then, the answerer has returned an answer as though to
a single question, there will be a refutation; while if he has
547
returned one not really but apparently, there will be an
apparent refutation of his thesis. All the types of fallacy, then,
fall under ignorance of what a refutation is, some of them
because the contradiction, which is the distinctive mark of a
refutation, is merely apparent, and the rest failing to conform to
the definition of a proof.
The deception comes about in the case of arguments that
depend on ambiguity of words and of phrases because we are
unable to divide the ambiguous term (for some terms it is not
easy to divide, e.g. 'unity', 'being', and 'sameness'), while in
those that depend on combination and division, it is because we
suppose that it makes no difference whether the phrase be
combined or divided, as is indeed the case with most phrases.
Likewise also with those that depend on accent: for the
lowering or raising of the voice upon a phrase is thought not to
alter its meaning - with any phrase, or not with many. With
those that depend on the of expression it is because of the
likeness of expression. For it is hard to distinguish what kind of
things are signified by the same and what by different kinds of
expression: for a man who can do this is practically next door to
the understanding of the truth. A special reason why a man is
liable to be hurried into assent to the fallacy is that we suppose
every predicate of everything to be an individual thing, and we
understand it as being one with the thing: and we therefore
treat it as a substance: for it is to that which is one with a thing
or substance, as also to substance itself, that 'individually' and
'being' are deemed to belong in the fullest sense. For this
reason, too, this type of fallacy is to be ranked among those that
depend on language; in the first place, because the deception is
548
effected the more readily when we are inquiring into a problem
in company with others than when we do so by ourselves (for
an inquiry with another person is carried on by means of
speech, whereas an inquiry by oneself is carried on quite as
much by means of the object itself); secondly a man is liable to
be deceived, even when inquiring by himself, when he takes
speech as the basis of his inquiry: moreover the deception
arises out of the likeness (of two different things), and the
likeness arises out of the language. With those fallacies that
depend upon Accident, deception comes about because we
cannot distinguish the sameness and otherness of terms, i.e.
their unity and multiplicity, or what kinds of predicate have all
the same accidents as their subject. Likewise also with those
that depend on the Consequent: for the consequent is a branch
of Accident. Moreover, in many cases appearances point to this
- and the claim is made that if is inseparable from B, so also is B
from With those that depend upon an imperfection in the
definition of a refutation, and with those that depend upon the
difference between a qualified and an absolute statement, the
deception consists in the smallness of the difference involved;
for we treat the limitation to the particular thing or respect or
manner or time as adding nothing to the meaning, and so grant
the statement universally. Likewise also in the case of those
that assume the original point, and those of false cause, and all
that treat a number of questions as one: for in all of them the
deception lies in the smallness of the difference: for our failure
to be quite exact in our definition of 'premiss' and of 'proof is
due to the aforesaid reason.
549
8
Since we know on how many points apparent syllogisms
depend, we know also on how many sophistical syllogisms and
refutations may depend. By a sophistical refutation and
syllogism I mean not only a syllogism or refutation which
appears to be valid but is not, but also one which, though it is
valid, only appears to be appropriate to the thing in question.
These are those which fail to refute and prove people to be
ignorant according to the nature of the thing in question, which
was the function of the art of examination. Now the art of
examining is a branch of dialectic: and this may prove a false
conclusion because of the ignorance of the answerer. Sophistic
refutations on the other hand, even though they prove the
contradictory of his thesis, do not make clear whether he is
ignorant: for sophists entangle the scientist as well with these
arguments.
That we know them by the same line of inquiry is clear: for the
same considerations which make it appear to an audience that
the points required for the proof were asked in the questions
and that the conclusion was proved, would make the answerer
think so as well, so that false proof will occur through all or
some of these means: for what a man has not been asked but
thinks he has granted, he would also grant if he were asked. Of
course, in some cases the moment we add the missing
question, we also show up its falsity, e.g. in fallacies that depend
on language and on solecism. If then, fallacious proofs of the
contradictory of a thesis depend on their appearing to refute, it
is clear that the considerations on which both proofs of false
conclusions and an apparent refutation depend must be the
same in number. Now an apparent refutation depends upon the
elements involved in a genuine one: for the failure of one or
other of these must make the refutation merely apparent, e.g.
that which depends on the failure of the conclusion to follow
550
from the argument (the argument ad impossible) and that
which treats two questions as one and so depends upon a flaw
in the premiss, and that which depends on the substitution of
an accident for an essential attribute, and - a branch of the last
- that which depends upon the consequent: more over, the
conclusion may follow not in fact but only verbally: then,
instead of proving the contradictory universally and in the same
respect and relation and manner, the fallacy may be dependent
on some limit of extent or on one or other of these
qualifications: moreover, there is the assumption of the original
point to be proved, in violation of the clause 'without reckoning
in the original point'. Thus we should have the number of
considerations on which the fallacious proofs depend: for they
could not depend on more, but all will depend on the points
aforesaid.
A sophistical refutation is a refutation not absolutely but
relatively to some one: and so is a proof, in the same way. For
unless that which depends upon ambiguity assumes that the
ambiguous term has a single meaning, and that which depends
on like verbal forms assumes that substance is the only
category, and the rest in the same way, there will be neither
refutations nor proofs, either absolutely or relatively to the
answerer: whereas if they do assume these things, they will
stand, relatively to the answerer; but absolutely they will not
stand: for they have not secured a statement that does have a
single meaning, but only one that appears to have, and that
only from this particular man.
551
The number of considerations on which depend the refutations
of those who are refuted, we ought not to try to grasp without a
knowledge of everything that is. This, however, is not the
province of any special study: for possibly the sciences are
infinite in number, so that obviously demonstrations may be
infinite too. Now refutations may be true as well as false: for
whenever it is possible to demonstrate something, it is also
possible to refute the man who maintains the contradictory of
the truth; e.g. if a man has stated that the diagonal is
commensurate with the side of the square, one might refute
him by demonstrating that it is incommensurate. Accordingly,
to exhaust all possible refutations we shall have to have
scientific knowledge of everything: for some refutations depend
upon the principles that rule in geometry and the conclusions
that follow from these, others upon those that rule in medicine,
and others upon those of the other sciences. For the matter of
that, the false refutations likewise belong to the number of the
infinite: for according to every art there is false proof, e.g.
according to geometry there is false geometrical proof, and
according to medicine there is false medical proof. By 'according
to the art', I mean 'according to the principles of it'. Clearly,
then, it is not of all refutations, but only of those that depend
upon dialectic that we need to grasp the common-place rules:
for these stand in a common relation to every art and faculty.
And as regards the refutation that is according to one or other
of the particular sciences it is the task of that particular
scientist to examine whether it is merely apparent without
being real, and, if it be real, what is the reason for it: whereas it
is the business of dialecticians so to examine the refutation that
proceeds from the common first principles that fall under no
particular special study. For if we grasp the startingpoints of the
accepted proofs on any subject whatever we grasp those of the
refutations current on that subject. For a refutation is the proof
552
of the contradictory of a given thesis, so that either one or two
proofs of the contradictory constitute a refutation. We grasp,
then, the number of considerations on which all such depend:
if, however, we grasp this, we also grasp their solutions as well;
for the objections to these are the solutions of them. We also
grasp the number of considerations on which those refutations
depend, that are merely apparent - apparent, I mean, not to
everybody, but to people of a certain stamp; for it is an
indefinite task if one is to inquire how many are the
considerations that make them apparent to the man in the
street. Accordingly it is clear that the dialectician's business is
to be able to grasp on how many considerations depends the
formation, through the common first principles, of a refutation
that is either real or apparent, i.e. either dialectical or
apparently dialectical, or suitable for an examination.
10
It is no true distinction between arguments which some people
draw when they say that some arguments are directed against
the expression, and others against the thought expressed: for it
is absurd to suppose that some arguments are directed against
the expression and others against the thought, and that they
are not the same. For what is failure to direct an argument
against the thought except what occurs whenever a man does
not in using the expression think it to be used in his question in
the same sense in which the person questioned granted it? And
this is the same thing as to direct the argument against the
expression. On the other hand, it is directed against the thought
whenever a man uses the expression in the same sense which
the answerer had in mind when he granted it. If now any (i.e.
both the questioner and the person questioned), in dealing with
553
an expression with more than one meaning, were to suppose it
to have one meaning - as e.g. it may be that 'Being' and 'One'
have many meanings, and yet both the answerer answers and
the questioner puts his question supposing it to be one, and the
argument is to the effect that 'All things are one' - will this
discussion be directed any more against the expression than
against the thought of the person questioned? If, on the other
hand, one of them supposes the expression to have many
meanings, it is clear that such a discussion will not be directed
against the thought. Such being the meanings of the phrases in
question, they clearly cannot describe two separate classes of
argument. For, in the first place, it is possible for any such
argument as bears more than one meaning to be directed
against the expression and against the thought, and next it is
possible for any argument whatsoever; for the fact of being
directed against the thought consists not in the nature of the
argument, but in the special attitude of the answerer towards
the points he concedes. Next, all of them may be directed to the
expression. For 'to be directed against the expression' means in
this doctrine 'not to be directed against the thought'. For if not
all are directed against either expression or thought, there will
be certain other arguments directed neither against the
expression nor against the thought, whereas they say that all
must be one or the other, and divide them all as directed either
against the expression or against the thought, while others
(they say) there are none. But in point of fact those that depend
on mere expression are only a branch of those syllogisms that
depend on a multiplicity of meanings. For the absurd statement
has actually been made that the description 'dependent on
mere expression' describes all the arguments that depend on
language: whereas some of these are fallacies not because the
answerer adopts a particular attitude towards them, but
because the argument itself involves the asking of a question
such as bears more than one meaning.
554
It is, too, altogether absurd to discuss Refutation without first
discussing Proof: for a refutation is a proof, so that one ought to
discuss proof as well before describing false refutation: for a
refutation of that kind is a merely apparent proof of the
contradictory of a thesis. Accordingly, the reason of the falsity
will be either in the proof or in the contradiction (for mention of
the 'contradiction' must be added), while sometimes it is in
both, if the refutation be merely apparent. In the argument that
speaking of the silent is possible it lies in the contradiction, not
in the proof; in the argument that one can give what one does
not possess, it lies in both; in the proof that Homer's poem is a
figure through its being a cycle it lies in the proof. An argument
that does not fail in either respect is a true proof.
But, to return to the point whence our argument digressed, are
mathematical reasonings directed against the thought, or not?
And if any one thinks 'triangle' to be a word with many
meanings, and granted it in some different sense from the
figure which was proved to contain two right angles, has the
questioner here directed his argument against the thought of
the former or not?
Moreover, if the expression bears many senses, while the
answerer does not understand or suppose it to have them,
surely the questioner here has directed his argument against
his thought! Or how else ought he to put his question except by
suggesting a distinction - suppose one's question to be speaking
of the silent possible or not? - as follows, 'Is the answer «No» in
one sense, but «Yes» in another?' If, then, any one were to
answer that it was not possible in any sense and the other were
to argue that it was, has not his argument been directed against
the thought of the answerer? Yet his argument is supposed to
be one of those that depend on the expression. There is not,
then, any definite kind of arguments that is directed against the
thought. Some arguments are, indeed, directed against the
555
expression: but these are not all even apparent refutations, let
alone all refutations. For there are also apparent refutations
which do not depend upon language, e.g. those that depend
upon accident, and others.
If, however, any one claims that one should actually draw the
distinction, and say, 'By «speaking of the silent» I mean, in one
sense this and in the other sense that', surely to claim this is in
the first place absurd (for sometimes the questioner does not
see the ambiguity of his question, and he cannot possibly draw
a distinction which he does not think to be there): in the second
place, what else but this will didactic argument be? For it will
make manifest the state of the case to one who has never
considered, and does not know or suppose that there is any
other meaning but one. For what is there to prevent the same
thing also happening to us in cases where there is no double
meaning? 'Are the units in four equal to the twos? Observe that
the twos are contained in four in one sense in this way, in
another sense in that'. Also, 'Is the knowledge of contraries one
or not? Observe that some contraries are known, while others
are unknown'. Thus the man who makes this claim seems to be
unaware of the difference between didactic and dialectical
argument, and of the fact that while he who argues didactically
should not ask questions but make things clear himself, the
other should merely ask questions.
11
Moreover, to claim a 'Yes' or 'No' answer is the business not of a
man who is showing something, but of one who is holding an
examination. For the art of examining is a branch of dialectic
and has in view not the man who has knowledge, but the
556
ignorant pretender. He, then, is a dialectician who regards the
common principles with their application to the particular
matter in hand, while he who only appears to do this is a
sophist. Now for contentious and sophistical reasoning: (1) one
such is a merely apparent reasoning, on subjects on which
dialectical reasoning is the proper method of examination, even
though its conclusion be true: for it misleads us in regard to the
cause: also (2) there are those misreasonings which do not
conform to the line of inquiry proper to the particular subject,
but are generally thought to conform to the art in question. For
false diagrams of geometrical figures are not contentious (for
the resulting fallacies conform to the subject of the art) - any
more than is any false diagram that may be offered in proof of a
truth - e.g. Hippocrates' figure or the squaring of the circle by
means of the lunules. But Bryson's method of squaring the
circle, even if the circle is thereby squared, is still sophistical
because it does not conform to the subject in hand. So, then,
any merely apparent reasoning about these things is a
contentious argument, and any reasoning that merely appears
to conform to the subject in hand, even though it be genuine
reasoning, is a contentious argument: for it is merely apparent
in its conformity to the subject-matter, so that it is deceptive
and plays foul. For just as a foul in a race is a definite type of
fault, and is a kind of foul fighting, so the art of contentious
reasoning is foul fighting in disputation: for in the former case
those who are resolved to win at all costs snatch at everything,
and so in the latter case do contentious reasoners. Those, then,
who do this in order to win the mere victory are generally
considered to be contentious and quarrelsome persons, while
those who do it to win a reputation with a view to making
money are sophistical. For the art of sophistry is, as we said,' a
kind of art of money-making from a merely apparent wisdom,
and this is why they aim at a merely apparent demonstration:
and quarrelsome persons and sophists both employ the same
557
arguments, but not with the same motives: and the same
argument will be sophistical and contentious, but not in the
same respect; rather, it will be contentious in so far as its aim is
an apparent victory, while in so far as its aim is an apparent
wisdom, it will be sophistical: for the art of sophistry is a certain
appearance of wisdom without the reality. The contentious
argument stands in somewhat the same relation to the
dialectical as the drawer of false diagrams to the geometrician;
for it beguiles by misreasoning from the same principles as
dialectic uses, just as the drawer of a false diagram beguiles the
geometrician. But whereas the latter is not a contentious
reasoner, because he bases his false diagram on the principles
and conclusions that fall under the art of geometry, the
argument which is subordinate to the principles of dialectic will
yet clearly be contentious as regards other subjects. Thus, e.g.
though the squaring of the circle by means of the lunules is not
contentious, Bryson's solution is contentious: and the former
argument cannot be adapted to any subject except geometry,
because it proceeds from principles that are peculiar to
geometry, whereas the latter can be adapted as an argument
against all the number of people who do not know what is or is
not possible in each particular context: for it will apply to them
all. Or there is the method whereby Antiphon squared the circle.
Or again, an argument which denied that it was better to take a
walk after dinner, because of Zeno's argument, would not be a
proper argument for a doctor, because Zeno's argument is of
general application. If, then, the relation of the contentious
argument to the dialectical were exactly like that of the drawer
of false diagrams to the geometrician, a contentious argument
upon the aforesaid subjects could not have existed. But, as it is,
the dialectical argument is not concerned with any definite kind
of being, nor does it show anything, nor is it even an argument
such as we find in the general philosophy of being. For all
beings are not contained in any one kind, nor, if they were,
558
could they possibly fall under the same principles. Accordingly,
no art that is a method of showing the nature of anything
proceeds by asking questions: for it does not permit a man to
grant whichever he likes of the two alternatives in the question:
for they will not both of them yield a proof. Dialectic, on the
other hand, does proceed by questioning, whereas if it were
concerned to show things, it would have refrained from putting
questions, even if not about everything, at least about the first
principles and the special principles that apply to the particular
subject in hand. For suppose the answerer not to grant these, it
would then no longer have had any grounds from which to
argue any longer against the objection. Dialectic is at the same
time a mode of examination as well. For neither is the art of
examination an accomplishment of the same kind as geometry,
but one which a man may possess, even though he has not
knowledge. For it is possible even for one without knowledge to
hold an examination of one who is without knowledge, if also
the latter grants him points taken not from thing that he knows
or from the special principles of the subject under discussion
but from all that range of consequences attaching to the subject
which a man may indeed know without knowing the theory of
the subject, but which if he do not know, he is bound to be
ignorant of the theory. So then clearly the art of examining does
not consist in knowledge of any definite subject. For this reason,
too, it deals with everything: for every 'theory' of anything
employs also certain common principles. Hence everybody,
including even amateurs, makes use in a way of dialectic and
the practice of examining: for all undertake to some extent a
rough trial of those who profess to know things. What serves
them here is the general principles: for they know these of
themselves just as well as the scientist, even if in what they say
they seem to the latter to go wildly astray from them. All, then,
are engaged in refutation; for they take a hand as amateurs in
the same task with which dialectic is concerned professionally;
559
and he is a dialectician who examines by the help of a theory of
reasoning. Now there are many identical principles which are
true of everything, though they are not such as to constitute a
particular nature, i.e. a particular kind of being, but are like
negative terms, while other principles are not of this kind but
are special to particular subjects; accordingly it is possible from
these general principles to hold an examination on everything,
and that there should be a definite art of so doing, and,
moreover, an art which is not of the same kind as those which
demonstrate. This is why the contentious reasoner does not
stand in the same condition in all respects as the drawer of a
false diagram: for the contentious reasoner will not be given to
misreasoning from any definite class of principles, but will deal
with every class.
These, then, are the types of sophistical refutations: and that it
belongs to the dialectician to study these, and to be able to
effect them, is not difficult to see: for the investigation of
premisses comprises the whole of this study.
12
So much, then, for apparent refutations. As for showing that the
answerer is committing some fallacy, and drawing his argument
into paradox - for this was the second item of the sophist's
programme - in the first place, then, this is best brought about
by a certain manner of questioning and through the question.
For to put the question without framing it with reference to any
definite subject is a good bait for these purposes: for people are
more inclined to make mistakes when they talk at large, and
they talk at large when they have no definite subject before
them. Also the putting of several questions, even though the
560
position against which one is arguing be quite definite, and the
claim that he shall say only what he thinks, create abundant
opportunity for drawing him into paradox or fallacy, and also,
whether to any of these questions he replies 'Yes' or replies 'No',
of leading him on to statements against which one is well off
for a line of attack. Nowadays, however, men are less able to
play foul by these means than they were formerly: for people
rejoin with the question, 'What has that to do with the original
subject?' It is, too, an elementary rule for eliciting some fallacy
or paradox that one should never put a controversial question
straight away, but say that one puts it from the wish for
information: for the process of inquiry thus invited gives room
for an attack.
A rule specially appropriate for showing up a fallacy is the
sophistic rule, that one should draw the answerer on to the kind
of statements against which one is well supplied with
arguments: this can be done both properly and improperly, as
was said before.' Again, to draw a paradoxical statement, look
and see to what school of philosophers the person arguing with
you belongs, and then question him as to some point wherein
their doctrine is paradoxical to most people: for with every
school there is some point of that kind. It is an elementary rule
in these matters to have a collection of the special 'theses' of
the various schools among your propositions. The solution
recommended as appropriate here, too, is to point out that the
paradox does not come about because of the argument:
whereas this is what his opponent always really wants.
Moreover, argue from men's wishes and their professed
opinions. For people do not wish the same things as they say
they wish: they say what will look best, whereas they wish what
appears to be to their interest: e.g. they say that a man ought to
die nobly rather than to live in pleasure, and to live in honest
poverty rather than in dishonourable riches; but they wish the
561
opposite. Accordingly, a man who speaks according to his
wishes must be led into stating the professed opinions of
people, while he who speaks according to these must be led into
admitting those that people keep hidden away: for in either
case they are bound to introduce a paradox; for they will speak
contrary either to men's professed or to their hidden opinions.
The widest range of common-place argument for leading men
into paradoxical statement is that which depends on the
standards of Nature and of the Law: it is so that both Callicles is
drawn as arguing in the Gorgias, and that all the men of old
supposed the result to come about: for nature (they said) and
law are opposites, and justice is a fine thing by a legal standard,
but not by that of nature. Accordingly, they said, the man whose
statement agrees with the standard of nature you should meet
by the standard of the law, but the man who agrees with the law
by leading him to the facts of nature: for in both ways
paradoxical statements may be committed. In their view the
standard of nature was the truth, while that of the law was the
opinion held by the majority. So that it is clear that they, too,
used to try either to refute the answerer or to make him make
paradoxical statements, just as the men of to-day do as well.
Some questions are such that in both forms the answer is
paradoxical; e.g. 'Ought one to obey the wise or one's father?'
and 'Ought one to do what is expedient or what is just?' and 'Is
it preferable to suffer injustice or to do an injury?' You should
lead people, then, into views opposite to the majority and to the
philosophers; if any one speaks as do the expert reasoners, lead
him into opposition to the majority, while if he speaks as do the
majority, then into opposition to the reasoners. For some say
that of necessity the happy man is just, whereas it is
paradoxical to the many that a king should be happy. To lead a
man into paradoxes of this sort is the same as to lead him into
the opposition of the standards of nature and law: for the law
562
represents the opinion of the majority, whereas philosophers
speak according to the standard of nature and the truth.
13
Paradoxes, then, you should seek to elicit by means of these
common-place rules. Now as for making any one babble, we
have already said what we mean by 'to babble'. This is the object
in view in all arguments of the following kind: If it is all the
same to state a term and to state its definition, the 'double' and
'double of half are the same: if then 'double' be the 'double of
half, it will be the 'double of half of half. And if, instead of
'double', 'double of half be again put, then the same expression
will be repeated three times, 'double of half of half of half. Also
'desire is of the pleasant, isn't it?' desire is conation for the
pleasant: accordingly, 'desire' is 'conation for the pleasant for
the pleasant'.
All arguments of this kind occur in dealing (1) with any relative
terms which not only have relative genera, but are also
themselves relative, and are rendered in relation to one and the
same thing, as e.g. conation is conation for something, and
desire is desire of something, and double is double of
something, i.e. double of half: also in dealing (2) with any terms
which, though they be not relative terms at all, yet have their
substance, viz. the things of which they are the states or
affections or what not, indicated as well in their definition, they
being predicated of these things. Thus e.g. 'odd' is a 'number
containing a middle': but there is an 'odd number': therefore
there is a 'number-containing-a-middle number'. Also, if
snubness be a concavity of the nose, and there be a snub nose,
there is therefore a 'concave-nose nose'.
563
People sometimes appear to produce this result, without really
producing it, because they do not add the question whether the
expression 'double', just by itself, has any meaning or no, and if
so, whether it has the same meaning, or a different one; but
they draw their conclusion straight away. Still it seems,
inasmuch as the word is the same, to have the same meaning
as well.
14
We have said before what kind of thing 'solecism' is.' It is
possible both to commit it, and to seem to do so without doing
so, and to do so without seeming to do so. Suppose, as
Protagoras used to say that menis ('wrath') and pelex ('helmet')
are masculine: according to him a man who calls wrath a
'destructress' (oulomenen) commits a solecism, though he does
not seem to do so to other people, where he who calls it a
'destructor' (oulomenon) commits no solecism though he
seems to do so. It is clear, then, that any one could produce this
effect by art as well: and for this reason many arguments seem
to lead to solecism which do not really do so, as happens in the
case of refutations.
Almost all apparent solecisms depend upon the word 'this'
(tode), and upon occasions when the inflection denotes neither
a masculine nor a feminine object but a neuter. For 'he' (outos)
signifies a masculine, and 'she' (aute) feminine; but 'this'
(touto), though meant to signify a neuter, often also signifies
one or other of the former: e.g. 'What is this?' 'It is Calliope'; 'it
is a log'; 'it is Coriscus'. Now in the masculine and feminine the
inflections are all different, whereas in the neuter some are and
some are not. Often, then, when 'this' (touto) has been granted,
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people reason as if 'him' (touton) had been said: and likewise
also they substitute one inflection for another. The fallacy
comes about because 'this' (touto) is a common form of several
inflections: for 'this' signifies sometimes 'he' (outos) and
sometimes 'him' (touton). It should signify them alternately;
when combined with 'is' (esti) it should be 'he', while with
'being' it should be 'him': e.g. 'Coriscus (Kopiskos) is', but 'being
Coriscus' (Kopiskon). It happens in the same way in the case of
feminine nouns as well, and in the case of the so-called
'chattels' that have feminine or masculine designations. For
only those names which end in o and n, have the designation
proper to a chattel, e.g. xulon ('log'), schoinion ('rope'); those
which do not end so have that of a masculine or feminine
object, though some of them we apply to chattels: e.g. askos
('wineskin') is a masculine noun, and kline ('bed') a feminine.
For this reason in cases of this kind as well there will be a
difference of the same sort between a construction with 'is'
(esti) or with 'being' (to einai). Also, Solecism resembles in a
certain way those refutations which are said to depend on the
like expression of unlike things. For, just as there we come upon
a material solecism, so here we come upon a verbal: for 'man' is
both a 'matter' for expression and also a 'word': and so is white'.
It is clear, then, that for solecisms we must try to construct our
argument out of the aforesaid inflections.
These, then, are the types of contentious arguments, and the
subdivisions of those types, and the methods for conducting
them aforesaid. But it makes no little difference if the materials
for putting the question be arranged in a certain manner with a
view to concealment, as in the case of dialectics. Following then
upon what we have said, this must be discussed first.
565
15
With a view then to refutation, one resource is length - for it is
difficult to keep several things in view at once; and to secure
length the elementary rules that have been stated before should
be employed. One resource, on the other hand, is speed; for
when people are left behind they look ahead less. Moreover,
there is anger and contentiousness, for when agitated
everybody is less able to take care of himself. Elementary rules
for producing anger are to make a show of the wish to play foul,
and to be altogether shameless. Moreover, there is the putting
of one's questions alternately, whether one has more than one
argument leading to the same conclusion, or whether one has
arguments to show both that something is so, and that it is not
so: for the result is that he has to be on his guard at the same
time either against more than one line, or against contrary
lines, of argument. In general, all the methods described before
of producing concealment are useful also for purposes of
contentious argument: for the object of concealment is to avoid
detection, and the object of this is to deceive.
To counter those who refuse to grant whatever they suppose to
help one's argument, one should put the question negatively, as
though desirous of the opposite answer, or at any rate as though
one put the question without prejudice; for when it is obscure
what answer one wants to secure, people are less refractory.
Also when, in dealing with particulars, a man grants the
individual case, when the induction is done you should often
not put the universal as a question, but take it for granted and
use it: for sometimes people themselves suppose that they have
granted it, and also appear to the audience to have done so, for
they remember the induction and assume that the questions
could not have been put for nothing. In cases where there is no
term to indicate the universal, still you should avail yourself of
the resemblance of the particulars to suit your purpose; for
566
resemblance often escapes detection. Also, with a view to
obtaining your premiss, you ought to put it in your question
side by side with its contrary. E.g. if it were necessary to secure
the admission that 'A man should obey his father in everything',
ask 'Should a man obey his parents in everything, or disobey
them in everything?'; and to secure that 'A number multiplied
by a large number is a large number', ask 'Should one agree that
it is a large number or a small one?' For then, if compelled to
choose, one will be more inclined to think it a large one: for the
placing of their contraries close beside them makes things look
big to men, both relatively and absolutely, and worse and better.
A strong appearance of having been refuted is often produced
by the most highly sophistical of all the unfair tricks of
questioners, when without proving anything, instead of putting
their final proposition as a question, they state it as a
conclusion, as though they had proved that 'Therefore so-and-
so is not true'.
It is also a sophistical trick, when a paradox has been laid down,
first to propose at the start some view that is generally
accepted, and then claim that the answerer shall answer what
he thinks about it, and to put one's question on matters of that
kind in the form 'Do you think that...?' For then, if the question
be taken as one of the premisses of one's argument, either a
refutation or a paradox is bound to result; if he grants the view,
a refutation; if he refuses to grant it or even to admit it as the
received opinion, a paradox; if he refuses to grant it, but admits
that it is the received opinion, something very like a refutation,
results.
Moreover, just as in rhetorical discourses, so also in those aimed
at refutation, you should examine the discrepancies of the
answerer's position either with his own statements, or with
those of persons whom he admits to say and do aright,
567
moreover with those of people who are generally supposed to
bear that kind of character, or who are like them, or with those
of the majority or of all men. Also just as answerers, too, often,
when they are in process of being confuted, draw a distinction,
if their confutation is just about to take place, so questioners
also should resort to this from time to time to counter objectors,
pointing out, supposing that against one sense of the words the
objection holds, but not against the other, that they have taken
it in the latter sense, as e.g. Cleophon does in the Mandrobulus.
They should also break off their argument and cut down their
other lines of attack, while in answering, if a man perceives this
being done beforehand, he should put in his objection and have
his say first. One should also lead attacks sometimes against
positions other than the one stated, on the understood
condition that one cannot find lines of attack against the view
laid down, as Lycophron did when ordered to deliver a eulogy
upon the lyre. To counter those who demand 'Against what are
you directing your effort?', since one is generally thought bound
to state the charge made, while, on the other hand, some ways
of stating it make the defence too easy, you should state as your
aim only the general result that always happens in refutations,
namely the contradiction of his thesis - viz. that your effort is to
deny what he has affirmed, or to affirm what he denied: don't
say that you are trying to show that the knowledge of contraries
is, or is not, the same. One must not ask one's conclusion in the
form of a premiss, while some conclusions should not even be
put as questions at all; one should take and use it as granted.
16
We have now therefore dealt with the sources of questions, and
the methods of questioning in contentious disputations: next
568
we have to speak of answering, and of how solutions should be
made, and of what requires them, and of what use is served by
arguments of this kind.
The use of them, then, is, for philosophy, twofold. For in the first
place, since for the most part they depend upon the expression,
they put us in a better condition for seeing in how many senses
any term is used, and what kind of resemblances and what kind
of differences occur between things and between their names.
In the second place they are useful for one's own personal
researches; for the man who is easily committed to a fallacy by
some one else, and does not perceive it, is likely to incur this
fate of himself also on many occasions. Thirdly and lastly, they
further contribute to one's reputation, viz. the reputation of
being well trained in everything, and not inexperienced in
anything: for that a party to arguments should find fault with
them, if he cannot definitely point out their weakness, creates a
suspicion, making it seem as though it were not the truth of the
matter but merely inexperience that put him out of temper.
Answerers may clearly see how to meet arguments of this kind,
if our previous account was right of the sources whence
fallacies came, and also our distinctions adequate of the forms
of dishonesty in putting questions. But it is not the same thing
take an argument in one's hand and then to see and solve its
faults, as it is to be able to meet it quickly while being subjected
to questions: for what we know, we often do not know in a
different context. Moreover, just as in other things speed is
enhanced by training, so it is with arguments too, so that
supposing we are unpractised, even though a point be clear to
us, we are often too late for the right moment. Sometimes too it
happens as with diagrams; for there we can sometimes analyse
the figure, but not construct it again: so too in refutations,
though we know the thing on which the connexion of the
569
argument depends, we still are at a loss to split the argument
apart.
17
First then, just as we say that we ought sometimes to choose to
prove something in the general estimation rather than in truth,
so also we have sometimes to solve arguments rather in the
general estimation than according to the truth. For it is a
general rule in fighting contentious persons, to treat them not
as refuting, but as merely appearing to refute: for we say that
they don't really prove their case, so that our object in
correcting them must be to dispel the appearance of it. For if
refutation be an unambiguous contradiction arrived at from
certain views, there could be no need to draw distinctions
against amphiboly and ambiguity: they do not effect a proof.
The only motive for drawing further distinctions is that the
conclusion reached looks like a refutation. What, then, we have
to beware of, is not being refuted, but seeming to be, because of
course the asking of amphibolies and of questions that turn
upon ambiguity, and all the other tricks of that kind, conceal
even a genuine refutation, and make it uncertain who is refuted
and who is not. For since one has the right at the end, when the
conclusion is drawn, to say that the only denial made of One's
statement is ambiguous, no matter how precisely he may have
addressed his argument to the very same point as oneself, it is
not clear whether one has been refuted: for it is not clear
whether at the moment one is speaking the truth. If, on the
other hand, one had drawn a distinction, and questioned him
on the ambiguous term or the amphiboly, the refutation would
not have been a matter of uncertainty. Also what is incidentally
the object of contentious arguers, though less so nowadays than
570
formerly, would have been fulfilled, namely that the person
questioned should answer either 'Yes' or 'No': whereas
nowadays the improper forms in which questioners put their
questions compel the party questioned to add something to his
answer in correction of the faultiness of the proposition as put:
for certainly, if the questioner distinguishes his meaning
adequately, the answerer is bound to reply either 'Yes' or 'No'.
If any one is going to suppose that an argument which turns
upon ambiguity is a refutation, it will be impossible for an
answerer to escape being refuted in a sense: for in the case of
visible objects one is bound of necessity to deny the term one
has asserted, and to assert what one has denied. For the remedy
which some people have for this is quite unavailing. They say,
not that Coriscus is both musical and unmusical, but that this
Coriscus is musical and this Coriscus unmusical. But this will
not do, for to say 'this Coriscus is unmusical', or 'musical', and
to say 'this Coriscus' is so, is to use the same expression: and
this he is both affirming and denying at once. 'But perhaps they
do not mean the same.' Well, nor did the simple name in the
former case: so where is the difference? If, however, he is to
ascribe to the one person the simple title 'Coriscus', while to the
other he is to add the prefix 'one' or 'this', he commits an
absurdity: for the latter is no more applicable to the one than to
the other: for to whichever he adds it, it makes no difference.
All the same, since if a man does not distinguish the senses of
an amphiboly, it is not clear whether he has been confuted or
has not been confuted, and since in arguments the right to
distinguish them is granted, it is evident that to grant the
question simply without drawing any distinction is a mistake,
so that, even if not the man himself, at any rate his argument
looks as though it had been refuted. It often happens, however,
that, though they see the amphiboly, people hesitate to draw
such distinctions, because of the dense crowd of persons who
571
propose questions of the kind, in order that they may not be
thought to be obstructionists at every turn: then, though they
would never have supposed that that was the point on which
the argument turned, they often find themselves faced by a
paradox. Accordingly, since the right of drawing the distinction
is granted, one should not hesitate, as has been said before.
If people never made two questions into one question, the
fallacy that turns upon ambiguity and amphiboly would not
have existed either, but either genuine refutation or none. For
what is the difference between asking 'Are Callias and
Themistocles musical?' and what one might have asked if they,
being different, had had one name? For if the term applied
means more than one thing, he has asked more than one
question. If then it be not right to demand simply to be given a
single answer to two questions, it is evident that it is not proper
to give a simple answer to any ambiguous question, not even if
the predicate be true of all the subjects, as some claim that one
should. For this is exactly as though he had asked Are Coriscus
and Callias at home or not at home?', supposing them to be
both in or both out: for in both cases there is a number of
propositions: for though the simple answer be true, that does
not make the question one. For it is possible for it to be true to
answer even countless different questions when put to one, all
together with either a 'Yes' or a 'No': but still one should not
answer them with a single answer: for that is the death of
discussion. Rather, the case is like as though different things
has actually had the same name applied to them. If then, one
should not give a single answer to two questions, it is evident
that we should not say simply 'Yes' or 'No' in the case of
ambiguous terms either: for the remark is simply a remark, not
an answer at all, although among disputants such remarks are
loosely deemed to be answers, because they do not see what the
consequence is.
572
As we said, then, inasmuch as certain refutations are generally
taken for such, though not such really, in the same way also
certain solutions will be generally taken for solutions, though
not really such. Now these, we say, must sometimes be
advanced rather than the true solutions in contentious
reasonings and in the encounter with ambiguity. The proper
answer in saying what one thinks is to say 'Granted'; for in that
way the likelihood of being refuted on a side issue is minimized.
If, on the other hand, one is compelled to say something
paradoxical, one should then be most careful to add that 'it
seems' so: for in that way one avoids the impression of being
either refuted or paradoxical. Since it is clear what is meant by
'begging the original question', and people think that they must
at all costs overthrow the premisses that lie near the
conclusion, and plead in excuse for refusing to grant him some
of them that he is begging the original question, so whenever
any one claims from us a point such as is bound to follow as a
consequence from our thesis, but is false or paradoxical, we
must plead the same: for the necessary consequences are
generally held to be a part of the thesis itself. Moreover,
whenever the universal has been secured not under a definite
name, but by a comparison of instances, one should say that the
questioner assumes it not in the sense in which it was granted
nor in which he proposed it in the premiss: for this too is a
point upon which a refutation often depends.
If one is debarred from these defences one must pass to the
argument that the conclusion has not been properly shown,
approaching it in the light of the aforesaid distinction between
the different kinds of fallacy.
In the case, then, of names that are used literally one is bound
to answer either simply or by drawing a distinction: the tacit
understandings implied in our statements, e.g. in answer to
questions that are not put clearly but elliptically - it is upon this
573
that the consequent refutation depends. For example, 'Is what
belongs to Athenians the property of Athenians?' Yes. And so it
is likewise in other cases. But observe; man belongs to the
animal kingdom, doesn't he?' Yes. 'Then man is the property of
the animal kingdom.' But this is a fallacy: for we say that man
'belongs to' the animal kingdom because he is an animal, just
as we say that Lysander 'belongs to' the Spartans, because he is
a Spartan. It is evident, then, that where the premiss put
forward is not clear, one must not grant it simply.
Whenever of two things it is generally thought that if the one is
true the other is true of necessity, whereas, if the other is true,
the first is not true of necessity, one should, if asked which of
them is true, grant the smaller one: for the larger the number of
premisses, the harder it is to draw a conclusion from them. If,
again, the sophist tries to secure that has a contrary while B has
not, suppose what he says is true, you should say that each has
a contrary, only for the one there is no established name.
Since, again, in regard to some of the views they express, most
people would say that any one who did not admit them was
telling a falsehood, while they would not say this in regard to
some, e.g. to any matters whereon opinion is divided (for most
people have no distinct view whether the soul of animals is
destructible or immortal), accordingly (1) it is uncertain in
which of two senses the premiss proposed is usually meant -
whether as maxims are (for people call by the name of 'maxims'
both true opinions and general assertions) or like the doctrine
'the diagonal of a square is incommensurate with its side': and
moreover (2) whenever opinions are divided as to the truth, we
then have subjects of which it is very easy to change the
terminology undetected. For because of the uncertainty in
which of the two senses the premiss contains the truth, one will
not be thought to be playing any trick, while because of the
division of opinion, one will not be thought to be telling a
574
falsehood. Change the terminology therefore, for the change
will make the position irrefutable.
Moreover, whenever one foresees any question coming, one
should put in one's objection and have one's say beforehand: for
by doing so one is likely to embarrass the questioner most
effectually.
18
Inasmuch as a proper solution is an exposure of false reasoning,
showing on what kind of question the falsity depends, and
whereas 'false reasoning' has a double meaning - for it is used
either if a false conclusion has been proved, or if there is only
an apparent proof and no real one - there must be both the kind
of solution just described, and also the correction of a merely
apparent proof, so as to show upon which of the questions the
appearance depends. Thus it comes about that one solves
arguments that are properly reasoned by demolishing them,
whereas one solves merely apparent arguments by drawing
distinctions. Again, inasmuch as of arguments that are properly
reasoned some have a true and others a false conclusion, those
that are false in respect of their conclusion it is possible to solve
in two ways; for it is possible both by demolishing one of the
premisses asked, and by showing that the conclusion is not the
real state of the case: those, on the other hand, that are false in
respect of the premisses can be solved only by a demolition of
one of them; for the conclusion is true. So that those who wish
to solve an argument should in the first place look and see if it
is properly reasoned, or is unreasoned; and next, whether the
conclusion be true or false, in order that we may effect the
solution either by drawing some distinction or by demolishing
575
something, and demolishing it either in this way or in that, as
was laid down before. There is a very great deal of difference
between solving an argument when being subjected to
questions and when not: for to foresee traps is difficult,
whereas to see them at one's leisure is easier.
19
Of the refutations, then, that depend upon ambiguity and
amphiboly some contain some question with more than one
meaning, while others contain a conclusion bearing a number
of senses: e.g. in the proof that 'speaking of the silent' is
possible, the conclusion has a double meaning, while in the
proof that 'he who knows does not understand what he knows'
one of the questions contains an amphiboly. Also the double-
edged saying is true in one context but not in another: it means
something that is and something that is not.
Whenever, then, the many senses lie in the conclusion no
refutation takes place unless the sophist secures as well the
contradiction of the conclusion he means to prove; e.g. in the
proof that 'seeing of the blind' is possible: for without the
contradiction there was no refutation. Whenever, on the other
hand, the many senses lie in the questions, there is no necessity
to begin by denying the double-edged premiss: for this was not
the goal of the argument but only its support. At the start, then,
one should reply with regard to an ambiguity, whether of a term
or of a phrase, in this manner, that 'in one sense it is so, and in
another not so', as e.g. that 'speaking of the silent' is in one
sense possible but in another not possible: also that in one
sense 'one should do what must needs be done', but not in
another: for 'what must needs be' bears a number of senses. If,
576
however, the ambiguity escapes one, one should correct it at the
end by making an addition to the question: 'Is speaking of the
silent possible?' 'No, but to speak of while he is silent is
possible.' Also, in cases which contain the ambiguity in their
premisses, one should reply in like manner: 'Do people then not
understand what they know? 'Yes, but not those who know it in
the manner described': for it is not the same thing to say that
'those who know cannot understand what they know', and to
say that 'those who know something in this particular manner
cannot do so'. In general, too, even though he draws his
conclusion in a quite unambiguous manner, one should
contend that what he has negated is not the fact which one has
asserted but only its name; and that therefore there is no
refutation.
20
It is evident also how one should solve those refutations that
depend upon the division and combination of words: for if the
expression means something different when divided and when
combined, as soon as one's opponent draws his conclusion one
should take the expression in the contrary way. All such
expressions as the following depend upon the combination or
division of the words: 'Was X being beaten with that with which
you saw him being beaten?' and 'Did you see him being beaten
with that with which he was being beaten?' This fallacy has also
in it an element of amphiboly in the questions, but it really
depends upon combination. For the meaning that depends
upon the division of the words is not really a double meaning
(for the expression when divided is not the same), unless also
the word that is pronounced, according to its breathing, as eros
and eros is a case of double meaning. (In writing, indeed, a word
577
is the same whenever it is written of the same letters and in the
same manner - and even there people nowadays put marks at
the side to show the pronunciation - but the spoken words are
not the same.) Accordingly an expression that depends upon
division is not an ambiguous one. It is evident also that not all
refutations depend upon ambiguity as some people say they do.
The answerer, then, must divide the expression: for 'I-saw-a-
man-being-beaten with my eyes' is not the same as to say 'I saw
a man being-beaten-with-my-eyes'. Also there is the argument
of Euthydemus proving 'Then you know now in Sicily that there
are triremes in Piraeus': and again, 'Can a good man who is a
cobbler be bad?' 'No.' 'But a good man may be a bad cobbler:
therefore a good cobbler will be bad.' Again, 'Things the
knowledge of which is good, are good things to learn, aren't
they?' 'Yes.' 'The knowledge, however, of evil is good: therefore
evil is a good thing to know.' 'Yes. But, you see, evil is both evil
and a thing-to-learn, so that evil is an evil-thing-to-learn,
although the knowledge of evils is good.' Again, 'Is it true to say
in the present moment that you are born?' 'Yes.' 'Then you are
born in the present moment.' 'No; the expression as divided has
a different meaning: for it is true to say-in-the-present-moment
that «you are born», but not «You are born-in-the-present-
moment».' Again, 'Could you do what you can, and as you can?'
'Yes.' 'But when not harping, you have the power to harp: and
therefore you could harp when not harping.' 'No: he has not the
power to harp-while-not-harping; merely, when he is not doing
it, he has the power to do it.' Some people solve this last
refutation in another way as well. For, they say, if he has granted
that he can do anything in the way he can, still it does not
follow that he can harp when not harping: for it has not been
granted that he will do anything in every way in which he can;
and it is not the same thing' to do a thing in the way he can'
and 'to do it in every way in which he can'. But evidently they
do not solve it properly: for of arguments that depend upon the
578
same point the solution is the same, whereas this will not fit all
cases of the kind nor yet all ways of putting the questions: it is
valid against the questioner, but not against his argument.
21
Accentuation gives rise to no fallacious arguments, either as
written or as spoken, except perhaps some few that might be
made up; e.g. the following argument. 'Is ou katalueis a house?'
'Yes.' 'Is then ou katalueis the negation of katalueis?' 'Yes.' 'But
you said that ou katalueis is a house: therefore the house is a
negation.' How one should solve this, is clear: for the word does
not mean the same when spoken with an acuter and when
spoken with a graver accent.
22
It is clear also how one must meet those fallacies that depend
on the identical expressions of things that are not identical,
seeing that we are in possession of the kinds of predications.
For the one man, say, has granted, when asked, that a term
denoting a substance does not belong as an attribute, while the
other has shown that some attribute belongs which is in the
Category of Relation or of Quantity, but is usually thought to
denote a substance because of its expression; e.g. in the
following argument: 'Is it possible to be doing and to have done
the same thing at the same time?' 'No.' 'But, you see, it is surely
possible to be seeing and to have seen the same thing at the
same time, and in the same aspect.' Again, 'Is any mode of
579
passivity a mode of activity?' 'No.' 'Then «he is cut», «he is
burnt», «he is struck by some sensible object» are alike in
expression and all denote some form of passivity, while again
«to say», «to run», «to see» are like one like one another in
expression: but, you see, «to see» is surely a form of being struck
by a sensible object; therefore it is at the same time a form of
passivity and of activity.' Suppose, however, that in that case
any one, after granting that it is not possible to do and to have
done the same thing in the same time, were to say that it is
possible to see and to have seen it, still he has not yet been
refuted, suppose him to say that 'to see' is not a form of 'doing'
(activity) but of 'passivity': for this question is required as well,
though he is supposed by the listener to have already granted it,
when he granted that 'to cut' is a form of present, and 'to have
cut' a form of past, activity, and so on with the other things that
have a like expression. For the listener adds the rest by himself,
thinking the meaning to be alike: whereas really the meaning is
not alike, though it appears to be so because of the expression.
The same thing happens here as happens in cases of ambiguity:
for in dealing with ambiguous expressions the tyro in argument
supposes the sophist to have negated the fact which he (the
tyro) affirmed, and not merely the name: whereas there still
wants the question whether in using the ambiguous term he
had a single meaning in view: for if he grants that that was so,
the refutation will be effected.
Like the above are also the following arguments. It is asked if a
man has lost what he once had and afterwards has not: for a
man will no longer have ten dice even though he has only lost
one die. No: rather it is that he has lost what he had before and
has not now; but there is no necessity for him to have lost as
much or as many things as he has not now. So then, he asks the
questions as to what he has, and draws the conclusion as to the
whole number that he has: for ten is a number. If then he had
asked to begin with, whether a man no longer having the
580
number of things he once had has lost the whole number, no
one would have granted it, but would have said 'Either the
whole number or one of them'. Also there is the argument that
'a man may give what he has not got': for he has not got only
one die. No: rather it is that he has given not what he had not
got, but in a manner in which he had not got it, viz. just the one.
For the word 'only' does not signify a particular substance or
quality or number, but a manner relation, e.g. that it is not
coupled with any other. It is therefore just as if he had asked
'Could a man give what he has not got?' and, on being given the
answer 'No', were to ask if a man could give a thing quickly
when he had not got it quickly, and, on this being granted, were
to conclude that 'a man could give what he had not got'. It is
quite evident that he has not proved his point: for to 'give
quickly' is not to give a thing, but to give in a certain manner;
and a man could certainly give a thing in a manner in which he
has not got it, e.g. he might have got it with pleasure and give it
with pain.
Like these are also all arguments of the following kind: 'Could a
man strike a blow with a hand which he has not got, or see with
an eye which he has not got?' For he has not got only one eye.
Some people solve this case, where a man has more than one
eye, or more than one of anything else, by saying also that he
has only one. Others also solve it as they solve the refutation of
the view that 'what a man has, he has received': for A gave only
one vote; and certainly B, they say, has only one vote from A.
Others, again, proceed by demolishing straight away the
proposition asked, and admitting that it is quite possible to
have what one has not received; e.g. to have received sweet
wine, but then, owing to its going bad in the course of receipt, to
have it sour. But, as was said also above,' all these persons direct
their solutions against the man, not against his argument. For if
this were a genuine solution, then, suppose any one to grant the
opposite, he could find no solution, just as happens in other
581
cases; e.g. suppose the true solution to be 'So-and-so is partly
true and partly not', then, if the answerer grants the expression
without any qualification, the sophist's conclusion follows. If, on
the other hand, the conclusion does not follow, then that could
not be the true solution: and what we say in regard to the
foregoing examples is that, even if all the sophist's premisses be
granted, still no proof is effected.
Moreover, the following too belong to this group of arguments.
'If something be in writing did some one write it?' 'Yes.' 'But it is
now in writing that you are seated - a false statement, though it
was true at the time when it was written: therefore the
statement that was written is at the same time false and true.'
But this is fallacious, for the falsity or truth of a statement or
opinion indicates not a substance but a quality: for the same
account applies to the case of an opinion as well. Again, 'Is what
a learner learns what he learns?' 'Yes.' 'But suppose some one
learns «slow» quick'. Then his (the sophist's) words denote not
what the learner learns but how he learns it. Also, 'Does a man
tread upon what he walks through? 'Yes.' 'But X walks through a
whole day.' No, rather the words denote not what he walks
through, but when he walks; just as when any one uses the
words 'to drink the cup' he denotes not what he drinks, but the
vessel out of which he drinks. Also, 'Is it either by learning or by
discovery that a man knows what he knows?' 'Yes.' 'But suppose
that of a pair of things he has discovered one and learned the
other, the pair is not known to him by either method.' No: 'what'
he knows, means' every single thing' he knows, individually; but
this does not mean 'all the things' he knows, collectively. Again,
there is the proof that there is a 'third man' distinct from Man
and from individual men. But that is a fallacy, for 'Man', and
indeed every general predicate, denotes not an individual
substance, but a particular quality, or the being related to
something in a particular manner, or something of that sort.
Likewise also in the case of 'Coriscus' and 'Coriscus the
582
musician' there is the problem, Are they the same or different?'
For the one denotes an individual substance and the other a
quality, so that it cannot be isolated; though it is not the
isolation which creates the 'third man', but the admission that
it is an individual substance. For 'Man' cannot be an individual
substance, as Callias is. Nor is the case improved one whit even
if one were to call the clement he has isolated not an individual
substance but a quality: for there will still be the one beside the
many, just as 'Man' was. It is evident then that one must not
grant that what is a common predicate applying to a class
universally is an individual substance, but must say that
denotes either a quality, or a relation, or a quantity, or
something of that kind.
23
It is a general rule in dealing with arguments that depend on
language that the solution always follows the opposite of the
point on which the argument turns: e.g. if the argument
depends upon combination, then the solution consists in
division; if upon division, then in combination. Again, if it
depends on an acute accent, the solution is a grave accent; if on
a grave accent, it is an acute. If it depends on ambiguity, one can
solve it by using the opposite term; e.g. if you find yourself
calling something inanimate, despite your previous denial that
it was so, show in what sense it is alive: if, on the other hand,
one has declared it to be inanimate and the sophist has proved
it to be animate, say how it is inanimate. Likewise also in a case
of amphiboly. If the argument depends on likeness of
expression, the opposite will be the solution. 'Could a man give
what he has not got? 'No, not what he has not got; but he could
give it in a way in which he has not got it, e.g. one die by itself.'
583
Does a man know either by learning or by discovery each thing
that he knows, singly? but not the things that he knows,
collectively.' Also a man treads, perhaps, on any thing he walks
through, but not on the time he walks through. Likewise also in
the case of the other examples.
24
In dealing with arguments that depend on Accident, one and
the same solution meets all cases. For since it is indeterminate
when an attribute should be ascribed to a thing, in cases where
it belongs to the accident of the thing, and since in some cases
it is generally agreed and people admit that it belongs, while in
others they deny that it need belong, we should therefore, as
soon as the conclusion has been drawn, say in answer to them
all alike, that there is no need for such an attribute to belong.
One must, however, be prepared to adduce an example of the
kind of attribute meant. All arguments such as the following
depend upon Accident. 'Do you know what I am going to ask
you? you know the man who is approaching', or 'the man in the
mask'? 'Is the statue your work of art?' or 'Is the dog your
father?' 'Is the product of a small number with a small number
a small number?' For it is evident in all these cases that there is
no necessity for the attribute which is true of the thing's
accident to be true of the thing as well. For only to things that
are indistinguishable and one in essence is it generally agreed
that all the same attributes belong; whereas in the case of a
good thing, to be good is not the same as to be going to be the
subject of a question; nor in the case of a man approaching, or
wearing a mask, is 'to be approaching' the same thing as 'to be
Coriscus', so that suppose I know Coriscus, but do not know the
man who is approaching, it still isn't the case that I both know
584
and do not know the same man; nor, again, if this is mine and is
also a work of art, is it therefore my work of art, but my property
or thing or something else. (The solution is after the same
manner in the other cases as well.)
Some solve these refutations by demolishing the original
proposition asked: for they say that it is possible to know and
not to know the same thing, only not in the same respect:
accordingly, when they don't know the man who is coming
towards them, but do know Corsicus, they assert that they do
know and don't know the same object, but not in the same
respect. Yet, as we have already remarked, the correction of
arguments that depend upon the same point ought to be the
same, whereas this one will not stand if one adopts the same
principle in regard not to knowing something, but to being, or to
being is a in a certain state, e.g. suppose that X is father, and is
also yours: for if in some cases this is true and it is possible to
know and not to know the same thing, yet with that case the
solution stated has nothing to do. Certainly there is nothing to
prevent the same argument from having a number of flaws; but
it is not the exposition of any and every fault that constitutes a
solution: for it is possible for a man to show that a false
conclusion has been proved, but not to show on what it
depends, e.g. in the case of Zeno's argument to prove that
motion is impossible. So that even if any one were to try to
establish that this doctrine is an impossible one, he still is
mistaken, and even if he proved his case ten thousand times
over, still this is no solution of Zeno's argument: for the solution
was all along an exposition of false reasoning, showing on what
its falsity depends. If then he has not proved his case, or is
trying to establish even a true proposition, or a false one, in a
false manner, to point this out is a true solution. Possibly,
indeed, the present suggestion may very well apply in some
cases: but in these cases, at any rate, not even this would be
generally agreed: for he knows both that Coriscus is Coriscus
585
and that the approaching figure is approaching. To know and
not to know the same thing is generally thought to be possible,
when e.g. one knows that X is white, but does not realize that
he is musical: for in that way he does know and not know the
same thing, though not in the same respect. But as to the
approaching figure and Coriscus he knows both that it is
approaching and that he is Coriscus.
A like mistake to that of those whom we have mentioned is that
of those who solve the proof that every number is a small
number: for if, when the conclusion is not proved, they pass this
over and say that a conclusion has been proved and is true, on
the ground that every number is both great and small, they
make a mistake.
Some people also use the principle of ambiguity to solve the
aforesaid reasonings, e.g. the proof that 'X is your father', or
'son', or 'slave'. Yet it is evident that if the appearance a proof
depends upon a plurality of meanings, the term, or the
expression in question, ought to bear a number of literal senses,
whereas no one speaks of A as being 'B's child' in the literal
sense, if B is the child's master, but the combination depends
upon Accident. 'Is A yours?' 'Yes.' 'And is A a child?' 'Yes.' 'Then
the child A is yours,' because he happens to be both yours and a
child; but he is not 'your child'.
There is also the proof that 'something «of evils» is good'; for
wisdom is a 'knowledge «of evils»'. But the expression that this
is 'of so-and-so' (='so-and-so's') has not a number of meanings:
it means that it is 'so-and-so's property'. We may suppose of
course, on the other hand, that it has a number of meanings -
for we also say that man is 'of the animals', though not their
property; and also that any term related to 'evils' in a way
expressed by a genitive case is on that account a so-and-so 'of
evils', though it is not one of the evils - but in that case the
586
apparently different meanings seem to depend on whether the
term is used relatively or absolutely. 'Yet it is conceivably
possible to find a real ambiguity in the phrase «Something of
evils is good».' Perhaps, but not with regard to the phrase in
question. It would occur more nearly, suppose that 'A servant is
good of the wicked'; though perhaps it is not quite found even
there: for a thing may be 'good' and be 'X's' without being at the
same time 'X's good'. Nor is the saying that 'Man is of the
animals' a phrase with a number of meanings: for a phrase does
not become possessed of a number of meanings merely
suppose we express it elliptically: for we express 'Give me the
Iliad' by quoting half a line of it, e.g. 'Give me «Sing, goddess, of
the wrath. ..»'
25
Those arguments which depend upon an expression that is
valid of a particular thing, or in a particular respect, or place, or
manner, or relation, and not valid absolutely, should be solved
by considering the conclusion in relation to its contradictory, to
see if any of these things can possibly have happened to it. For
it is impossible for contraries and opposites and an affirmative
and a negative to belong to the same thing absolutely; there is,
however, nothing to prevent each from belonging in a particular
respect or relation or manner, or to prevent one of them from
belonging in a particular respect and the other absolutely. So
that if this one belongs absolutely and that one in a particular
respect, there is as yet no refutation. This is a feature one has to
find in the conclusion by examining it in comparison with its
contradictory.
587
All arguments of the following kind have this feature: 'Is it
possible for what is-not to be? «No.» But, you see, it is
something, despite its not being.' Likewise also, Being will not
be; for it will not he some particular form of being. Is it possible
for the same man at the same time to be a keeper and a breaker
of his oath?' 'Can the same man at the same time both obey
and disobey the same man?' Or isn't it the case that being
something in particular and Being are not the same? On the
other hand, Not-being, even if it be something, need not also
have absolute 'being' as well. Nor if a man keeps his oath in this
particular instance or in this particular respect, is he bound also
to be a keeper of oaths absolutely, but he who swears that he
will break his oath, and then breaks it, keeps this particular
oath only; he is not a keeper of his oath: nor is the disobedient
man 'obedient', though he obeys one particular command. The
argument is similar, also, as regards the problem whether the
same man can at the same time say what is both false and true:
but it appears to be a troublesome question because it is not
easy to see in which of the two connexions the word
'absolutely' is to be rendered - with 'true' or with 'false'. There
is, however, nothing to prevent it from being false absolutely,
though true in some particular respect or relation, i.e. being true
in some things, though not 'true' absolutely. Likewise also in
cases of some particular relation and place and time. For all
arguments of the following kind depend upon this.' Is health, or
wealth, a good thing?' 'Yes.' 'But to the fool who does not use it
aright it is not a good thing: therefore it is both good and not
good.' 'Is health, or political power, a good thing?' 'Yes. «But
sometimes it is not particularly good: therefore the same thing
is both good and not good to the same man.' Or rather there is
nothing to prevent a thing, though good absolutely, being not
good to a particular man, or being good to a particular man, and
yet not good or here. 'Is that which the prudent man would not
wish, an evil?' 'Yes.' 'But to get rid of, he would not wish the
588
good: therefore the good is an evil.' But that is a mistake; for it is
not the same thing to say 'The good is an evil' and 'to get rid of
the good is an evil'. Likewise also the argument of the thief is
mistaken. For it is not the case that if the thief is an evil thing,
acquiring things is also evil: what he wishes, therefore, is not
what is evil but what is good; for to acquire something good is
good. Also, disease is an evil thing, but not to get rid of disease.
'Is the just preferable to the unjust, and what takes place justly
to what takes place unjustly? 'Yes.' 'But to to be put to death
unjustly is preferable.' 'Is it just that each should have his own?'
'Yes.' 'But whatever decisions a man comes to on the strength of
his personal opinion, even if it be a false opinion, are valid in
law: therefore the same result is both just and unjust.' Also,
should one decide in favour of him who says what is unjust?'
'The former.' 'But you see, it is just for the injured party to say
fully the things he has suffered; and these are fallacies. For
because to suffer a thing unjustly is preferable, unjust ways are
not therefore preferable, though in this particular case the
unjust may very well be better than the just. Also, to have one's
own is just, while to have what is another's is not just: all the
same, the decision in question may very well be a just decision,
whatever it be that the opinion of the man who gave the
decision supports: for because it is just in this particular case or
in this particular manner, it is not also just absolutely. Likewise
also, though things are unjust, there is nothing to prevent the
speaking of them being just: for because to speak of things is
just, there is no necessity that the things should be just, any
more than because to speak of things be of use, the things need
be of use. Likewise also in the case of what is just. So that it is
not the case that because the things spoken of are unjust, the
victory goes to him who speaks unjust things: for he speaks of
things that are just to speak of, though absolutely, i.e. to suffer,
they are unjust.
589
26
Refutations that depend on the definition of a refutation must,
according to the plan sketched above, be met by comparing
together the conclusion with its contradictory, and seeing that it
shall involve the same attribute in the same respect and
relation and manner and time. If this additional question be put
at the start, you should not admit that it is impossible for the
same thing to be both double and not double, but grant that it is
possible, only not in such a way as was agreed to constitute a
refutation of your case. All the following arguments depend
upon a point of that kind. 'Does a man who knows A to be A,
know the thing called A?' and in the same way, 'is one who is
ignorant that A is A ignorant of the thing called A?' 'Yes.' 'But
one who knows that Coriscus is Coriscus might be ignorant of
the fact that he is musical, so that he both knows and is
ignorant of the same thing.' Is a thing four cubits long greater
than a thing three cubits long?' 'Yes.' 'But a thing might grow
from three to four cubits in length; 'now what is 'greater' is
greater than a 'less': accordingly the thing in question will be
both greater and less than itself in the same respect.
27
As to refutations that depend on begging and assuming the
original point to be proved, suppose the nature of the question
to be obvious, one should not grant it, even though it be a view
generally held, but should tell him the truth. Suppose, however,
that it escapes one, then, thanks to the badness of arguments of
that kind, one should make one's error recoil upon the
questioner, and say that he has brought no argument: for a
590
refutation must be proved independently of the original point.
Secondly, one should say that the point was granted under the
impression that he intended not to use it as a premiss, but to
reason against it, in the opposite way from that adopted in
refutations on side issues.
28
Also, those refutations that bring one to their conclusion
through the consequent you should show up in the course of
the argument itself. The mode in which consequences follow is
twofold. For the argument either is that as the universal follows
on its particular - as (e.g.) 'animal' follows from 'man' - so does
the particular on its universal: for the claim is made that if A is
always found with B, then B also is always found with A. Or else
it proceeds by way of the opposites of the terms involved: for if
A follows B, it is claimed that A's opposite will follow B's
opposite. On this latter claim the argument of Melissus also
depends: for he claims that because that which has come to be
has a beginning, that which has not come to be has none, so
that if the heaven has not come to be, it is also eternal. But that
is not so; for the sequence is vice versa.
29
In the case of any refutations whose reasoning depends on
some addition, look and see if upon its subtraction the
absurdity follows none the less: and then if so, the answerer
should point this out, and say that he granted the addition not
591
because he really thought it, but for the sake of the argument,
whereas the questioner has not used it for the purpose of his
argument at all.
30
To meet those refutations which make several questions into
one, one should draw a distinction between them straight away
at the start. For a question must be single to which there is a
single answer, so that one must not affirm or deny several
things of one thing, nor one thing of many, but one of one. But
just as in the case of ambiguous terms, an attribute belongs to a
term sometimes in both its senses, and sometimes in neither,
so that a simple answer does one, as it happens, no harm
despite the fact that the question is not simple, so it is in these
cases of double questions too. Whenever, then, the several
attributes belong to the one subject, or the one to the many, the
man who gives a simple answer encounters no obstacle even
though he has committed this mistake: but whenever an
attribute belongs to one subject but not to the other, or there is
a question of a number of attributes belonging to a number of
subjects and in one sense both belong to both, while in another
sense, again, they do not, then there is trouble, so that one must
beware of this. Thus (e.g.) in the following arguments:
Supposing to be good and B evil, you will, if you give a single
answer about both, be compelled to say that it is true to call
these good, and that it is true to call them evil and likewise to
call them neither good nor evil (for each of them has not each
character), so that the same thing will be both good and evil and
neither good nor evil. Also, since everything is the same as itself
and different from anything else, inasmuch as the man who
answers double questions simply can be made to say that
592
several things are 'the same' not as other things but 'as
themselves', and also that they are different from themselves, it
follows that the same things must be both the same as and
different from themselves. Moreover, if what is good becomes
evil while what is evil is good, then they must both become two.
So of two unequal things each being equal to itself, it will follow
that they are both equal and unequal to themselves.
Now these refutations fall into the province of other solutions
as well: for 'both' and 'all' have more than one meaning, so that
the resulting affirmation and denial of the same thing does not
occur, except verbally: and this is not what we meant by a
refutation. But it is clear that if there be not put a single
question on a number of points, but the answerer has affirmed
or denied one attribute only of one subject only, the absurdity
will not come to pass.
31
With regard to those who draw one into repeating the same
thing a number of times, it is clear that one must not grant that
predications of relative terms have any meaning in abstraction
by themselves, e.g. that 'double' is a significant term apart from
the whole phrase 'double of half merely on the ground that it
figures in it. For ten figures in 'ten minus one' and in 'not do',
and generally the affirmation in the negation; but for all that,
suppose any one were to say, 'This is not white', he does not say
that it is white. The bare word 'double', one may perhaps say,
has not even any meaning at all, any more than has 'the' in 'the
half: and even if it has a meaning, yet it has not the same
meaning as in the combination. Nor is 'knowledge' the same
thing in a specific branch of it (suppose it, e.g. to be 'medical
593
knowledge') as it is in general: for in general it was the
'knowledge of the knowable'. In the case of terms that are
predicated of the terms through which they are defined, you
should say the same thing, that the term defined is not the
same in abstraction as it is in the whole phrase. For 'concave'
has a general meaning which is the same in the case of a snub
nose, and of a bandy leg, but when added to either substantive
nothing prevents it from differentiating its meaning; in fact it
bears one sense as applied to the nose, and another as applied
to the leg: for in the former connexion it means 'snub' and in
the latter 'bandyshaped'; i.e. it makes no difference whether you
say 'a snub nose' or 'a concave nose'. Moreover, the expression
must not be granted in the nominative case: for it is a
falsehood. For snubness is not a concave nose but something
(e.g. an affection) belonging to a nose: hence, there is no
absurdity in supposing that the snub nose is a nose possessing
the concavity that belongs to a nose.
32
With regard to solecisms, we have previously said what it is that
appears to bring them about; the method of their solution will
be clear in the course of the arguments themselves. Solecism is
the result aimed at in all arguments of the following kind: 'Is a
thing truly that which you truly call it?' 'Yes'. 'But, speaking of a
stone, you call him real: therefore of a stone it follows that «him
is real».' No: rather, talking of a stone means not saying which'
but 'whom', and not 'that' but 'him'. If, then, any one were to
ask, 'Is a stone him whom you truly call him?' he would be
generally thought not to be speaking good Greek, any more than
if he were to ask, 'Is he what you call her?' Speak in this way of
a 'stick' or any neuter word, and the difference does not break
594
out. For this reason, also, no solecism is incurred, suppose any-
one asks, 'Is a thing what you say it to be?' 'Yes'. 'But, speaking
of a stick, you call it real: therefore, of a stick it follows that it is
real.' 'Stone', however, and 'he' have masculine designations.
Now suppose some one were to ask, 'Can «he» be a «she» (a
female)?', and then again, 'Well, but is not he Coriscus?' and
then were to say, 'Then he is a «she»,' he has not proved the
solecism, even if the name 'Coriscus' does signify a 'she', if, on
the other hand, the answerer does not grant this: this point
must be put as an additional question: while if neither is it the
fact nor does he grant it, then the sophist has not proved his
case either in fact or as against the person he has been
questioning. In like manner, then, in the above instance as well
it must be definitely put that 'he' means the stone. If, however,
this neither is so nor is granted, the conclusion must not be
stated: though it follows apparently, because the case (the
accusative), that is really unlike, appears to be like the
nominative. 'Is it true to say that this object is what you call it
by name?' 'Yes'. 'But you call it by the name of a shield: this
object therefore is «of a shield».' No: not necessarily, because the
meaning of 'this object' is not 'of a shield' but 'a shield': 'of a
shield' would be the meaning of 'this object's'. Nor again if 'He is
what you call him by name', while 'the name you call him by is
Cleon's', is he therefore 'Cleon's': for he is not 'Cleon's', for what
was said was that 'He, not his, is what I call him by name'. For
the question, if put in the latter way, would not even be Greek.
'Do you know this?' 'Yes.' 'But this is he: therefore you know he'.
No: rather 'this' has not the same meaning in 'Do you know
this?' as in 'This is a stone'; in the first it stands for an
accusative, in the second for a nominative case. 'When you have
understanding of anything, do you understand it?' 'Yes.' 'But
you have understanding of a stone: therefore you understand of
a stone.' No: the one phrase is in the genitive, 'of a stone', while
the other is in the accusative, 'a stone': and what was granted
595
was that 'you understand that, not of that, of which you have
understanding', so that you understand not 'of a stone', but 'the
stone'.
Thus that arguments of this kind do not prove solecism but
merely appear to do so, and both why they so appear and how
you should meet them, is clear from what has been said.
33
We must also observe that of all the arguments aforesaid it is
easier with some to see why and where the reasoning leads the
hearer astray, while with others it is more difficult, though often
they are the same arguments as the former. For we must call an
argument the same if it depends upon the same point; but the
same argument is apt to be thought by some to depend on
diction, by others on accident, and by others on something else,
because each of them, when worked with different terms, is not
so clear as it was. Accordingly, just as in fallacies that depend
on ambiguity, which are generally thought to be the silliest form
of fallacy, some are clear even to the man in the street (for
humorous phrases nearly all depend on diction; e.g. 'The man
got the cart down from the stand'; and 'Where are you bound?'
'To the yard arm'; and 'Which cow will calve afore?' 'Neither, but
both behind;' and 'Is the North wind clear?' 'No, indeed; for it
has murdered the beggar and the merchant. » Is he a Good
enough-King?' 'No, indeed; a Rob-son': and so with the great
majority of the rest as well), while others appear to elude the
most expert (and it is a symptom of this that they often fight
about their terms, e.g. whether the meaning of 'Being' and 'One'
is the same in all their applications or different; for some think
that 'Being' and 'One' mean the same; while others solve the
596
argument of Zeno and Parmenides by asserting that 'One' and
'Being' are used in a number of senses), likewise also as regards
fallacies of Accident and each of the other types, some of the
arguments will be easier to see while others are more difficult;
also to grasp to which class a fallacy belongs, and whether it is a
refutation or not a refutation, is not equally easy in all cases.
An incisive argument is one which produces the greatest
perplexity: for this is the one with the sharpest fang. Now
perplexity is twofold, one which occurs in reasoned arguments,
respecting which of the propositions asked one is to demolish,
and the other in contentious arguments, respecting the manner
in which one is to assent to what is propounded. Therefore it is
in syllogistic arguments that the more incisive ones produce the
keenest heart-searching. Now a syllogistic argument is most
incisive if from premisses that are as generally accepted as
possible it demolishes a conclusion that is accepted as generally
as possible. For the one argument, if the contradictory is
changed about, makes all the resulting syllogisms alike in
character: for always from premisses that are generally
accepted it will prove a conclusion, negative or positive as the
case may be, that is just as generally accepted; and therefore
one is bound to feel perplexed. An argument, then, of this kind
is the most incisive, viz. the one that puts its conclusion on all
fours with the propositions asked; and second comes the one
that argues from premisses, all of which are equally convincing:
for this will produce an equal perplexity as to what kind of
premiss, of those asked, one should demolish. Herein is a
difficulty: for one must demolish something, but what one must
demolish is uncertain. Of contentious arguments, on the other
hand, the most incisive is the one which, in the first place, is
characterized by an initial uncertainty whether it has been
properly reasoned or not; and also whether the solution
depends on a false premiss or on the drawing of a distinction;
while, of the rest, the second place is held by that whose
597
solution clearly depends upon a distinction or a demolition, and
yet it does not reveal clearly which it is of the premisses asked,
whose demolition, or the drawing of a distinction within it, will
bring the solution about, but even leaves it vague whether it is
on the conclusion or on one of the premisses that the deception
depends.
Now sometimes an argument which has not been properly
reasoned is silly, supposing the assumptions required to be
extremely contrary to the general view or false; but sometimes
it ought not to be held in contempt. For whenever some
question is left out, of the kind that concerns both the subject
and the nerve of the argument, the reasoning that has both
failed to secure this as well, and also failed to reason properly, is
silly; but when what is omitted is some extraneous question,
then it is by no means to be lightly despised, but the argument
is quite respectable, though the questioner has not put his
questions well.
Just as it is possible to bring a solution sometimes against the
argument, at others against the questioner and his mode of
questioning, and at others against neither of these, likewise also
it is possible to marshal one's questions and reasoning both
against the thesis, and against the answerer and against the
time, whenever the solution requires a longer time to examine
than the period available.
34
As to the number, then, and kind of sources whence fallacies
arise in discussion, and how we are to show that our opponent
is committing a fallacy and make him utter paradoxes;
moreover, by the use of what materials solescism is brought
598
about, and how to question and what is the way to arrange the
questions; moreover, as to the question what use is served by all
arguments of this kind, and concerning the answerer's part,
both as a whole in general, and in particular how to solve
arguments and solecisms - on all these things let the foregoing
discussion suffice. It remains to recall our original proposal and
to bring our discussion to a close with a few words upon it.
Our programme was, then, to discover some faculty of
reasoning about any theme put before us from the most
generally accepted premisses that there are. For that is the
essential task of the art of discussion (dialectic) and of
examination (peirastic). Inasmuch, however, as it is annexed to
it, on account of the near presence of the art of sophistry
(sophistic), not only to be able to conduct an examination
dialectically but also with a show of knowledge, we therefore
proposed for our treatise not only the aforesaid aim of being
able to exact an account of any view, but also the aim of
ensuring that in standing up to an argument we shall defend
our thesis in the same manner by means of views as generally
held as possible. The reason of this we have explained; for this,
too, was why Socrates used to ask questions and not to answer
them; for he used to confess that he did not know. We have
made clear, in the course of what precedes, the number both of
the points with reference to which, and of the materials from
which, this will be accomplished, and also from what sources
we can become well supplied with these: we have shown,
moreover, how to question or arrange the questioning as a
whole, and the problems concerning the answers and solutions
to be used against the reasonings of the questioner. We have
also cleared up the problems concerning all other matters that
belong to the same inquiry into arguments. In addition to this
we have been through the subject of Fallacies, as we have
already stated above.
599
That our programme, then, has been adequately completed is
clear. But we must not omit to notice what has happened in
regard to this inquiry. For in the case of all discoveries the
results of previous labours that have been handed down from
others have been advanced bit by bit by those who have taken
them on, whereas the original discoveries generally make
advance that is small at first though much more useful than the
development which later springs out of them. For it may be that
in everything, as the saying is, 'the first start is the main part':
and for this reason also it is the most difficult; for in proportion
as it is most potent in its influence, so it is smallest in its
compass and therefore most difficult to see: whereas when this
is once discovered, it is easier to add and develop the remainder
in connexion with it. This is in fact what has happened in
regard to rhetorical speeches and to practically all the other
arts: for those who discovered the beginnings of them advanced
them in all only a little way, whereas the celebrities of to-day
are the heirs (so to speak) of a long succession of men who have
advanced them bit by bit, and so have developed them to their
present form, Tisias coming next after the first founders, then
Thrasymachus after Tisias, and Theodorus next to him, while
several people have made their several contributions to it: and
therefore it is not to be wondered at that the art has attained
considerable dimensions. Of this inquiry, on the other hand, it
was not the case that part of the work had been thoroughly
done before, while part had not. Nothing existed at all. For the
training given by the paid professors of contentious arguments
was like the treatment of the matter by Gorgias. For they used
to hand out speeches to be learned by heart, some rhetorical,
others in the form of question and answer, each side supposing
that their arguments on either side generally fall among them.
And therefore the teaching they gave their pupils was ready but
rough. For they used to suppose that they trained people by
imparting to them not the art but its products, as though any
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one professing that he would impart a form of knowledge to
obviate any pain in the feet, were then not to teach a man the
art of shoe-making or the sources whence he can acquire
anything of the kind, but were to present him with several kinds
of shoes of all sorts: for he has helped him to meet his need, but
has not imparted an art to him. Moreover, on the subject of
Rhetoric there exists much that has been said long ago, whereas
on the subject of reasoning we had nothing else of an earlier
date to speak of at all, but were kept at work for a long time in
experimental researches. If, then, it seems to you after
inspection that, such being the situation as it existed at the
start, our investigation is in a satisfactory condition compared
with the other inquiries that have been developed by tradition,
there must remain for all of you, or for our students, the task of
extending us your pardon for the shortcomings of the inquiry,
and for the discoveries thereof your warm thanks.
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Aristotle - Physics
[Translated by R. P. Hardie and R. K. Gaye]
Book I
When the objects of an inquiry, in any department, have
principles, conditions, or elements, it is through acquaintance
with these that knowledge, that is to say scientific knowledge, is
attained. For we do not think that we know a thing until we are
acquainted with its primary conditions or first principles, and
have carried our analysis as far as its simplest elements. Plainly
therefore in the science of Nature, as in other branches of study,
our first task will be to try to determine what relates to its
principles.
The natural way of doing this is to start from the things which
are more knowable and obvious to us and proceed towards
those which are clearer and more knowable by nature; for the
same things are not 'knowable relatively to us' and 'knowable'
without qualification. So in the present inquiry we must follow
this method and advance from what is more obscure by nature,
but clearer to us, towards what is more clear and more
knowable by nature.
Now what is to us plain and obvious at first is rather confused
masses, the elements and principles of which become known to
us later by analysis. Thus we must advance from generalities to
particulars; for it is a whole that is best known to sense-
perception, and a generality is a kind of whole, comprehending
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many things within it, like parts. Much the same thing happens
in the relation of the name to the formula. A name, e.g. 'round',
means vaguely a sort of whole: its definition analyses this into
its particular senses. Similarly a child begins by calling all men
'father', and all women 'mother', but later on distinguishes each
of them.
The principles in question must be either (a) one or (b) more
than one. If (a) one, it must be either (i) motionless, as
Parmenides and Melissus assert, or (ii) in motion, as the
physicists hold, some declaring air to be the first principle,
others water. If (b) more than one, then either (i) a finite or (ii)
an infinite plurality. If (i) finite (but more than one), then either
two or three or four or some other number. If (ii) infinite, then
either as Democritus believed one in kind, but differing in shape
or form; or different in kind and even contrary.
A similar inquiry is made by those who inquire into the number
of existents: for they inquire whether the ultimate constituents
of existing things are one or many, and if many, whether a finite
or an infinite plurality. So they too are inquiring whether the
principle or element is one or many.
Now to investigate whether Being is one and motionless is not a
contribution to the science of Nature. For just as the geometer
has nothing more to say to one who denies the principles of his
science - this being a question for a different science or for or
common to all - so a man investigating principles cannot argue
with one who denies their existence. For if Being is just one, and
one in the way mentioned, there is a principle no longer, since a
principle must be the principle of some thing or things.
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To inquire therefore whether Being is one in this sense would be
like arguing against any other position maintained for the sake
of argument (such as the Heraclitean thesis, or such a thesis as
that Being is one man) or like refuting a merely contentious
argument - a description which applies to the arguments both
of Melissus and of Parmenides: their premisses are false and
their conclusions do not follow. Or rather the argument of
Melissus is gross and palpable and offers no difficulty at all:
accept one ridiculous proposition and the rest follows - a simple
enough proceeding.
We physicists, on the other hand, must take for granted that the
things that exist by nature are, either all or some of them, in
motion which is indeed made plain by induction. Moreover, no
man of science is bound to solve every kind of difficulty that
may be raised, but only as many as are drawn falsely from the
principles of the science: it is not our business to refute those
that do not arise in this way: just as it is the duty of the
geometer to refute the squaring of the circle by means of
segments, but it is not his duty to refute Antiphon's proof. At
the same time the holders of the theory of which we are
speaking do incidentally raise physical questions, though
Nature is not their subject: so it will perhaps be as well to spend
a few words on them, especially as the inquiry is not without
scientific interest.
The most pertinent question with which to begin will be this: In
what sense is it asserted that all things are one? For 'is' is used
in many senses. Do they mean that all things 'are' substance or
quantities or qualities? And, further, are all things one
substance - one man, one horse, or one soul - or quality and
that one and the same - white or hot or something of the kind?
These are all very different doctrines and all impossible to
maintain.
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For if both substance and quantity and quality are, then,
whether these exist independently of each other or not, Being
will be many.
If on the other hand it is asserted that all things are quality or
quantity, then, whether substance exists or not, an absurdity
results, if the impossible can properly be called absurd. For none
of the others can exist independently: substance alone is
independent: for everything is predicated of substance as
subject. Now Melissus says that Being is infinite. It is then a
quantity. For the infinite is in the category of quantity, whereas
substance or quality or affection cannot be infinite except
through a concomitant attribute, that is, if at the same time
they are also quantities. For to define the infinite you must use
quantity in your formula, but not substance or quality. If then
Being is both substance and quantity, it is two, not one: if only
substance, it is not infinite and has no magnitude; for to have
that it will have to be a quantity.
Again, 'one' itself, no less than 'being', is used in many senses,
so we must consider in what sense the word is used when it is
said that the All is one.
Now we say that (a) the continuous is one or that (b) the
indivisible is one, or (c) things are said to be 'one', when their
essence is one and the same, as 'liquor' and 'drink'.
If (a) their One is one in the sense of continuous, it is many, for
the continuous is divisible ad infinitum.
There is, indeed, a difficulty about part and whole, perhaps not
relevant to the present argument, yet deserving consideration
on its own account - namely, whether the part and the whole
are one or more than one, and how they can be one or many,
and, if they are more than one, in what sense they are more
than one. (Similarly with the parts of wholes which are not
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continuous.) Further, if each of the two parts is indivisibly one
with the whole, the difficulty arises that they will be indivisibly
one with each other also.
But to proceed: If (b) their One is one as indivisible, nothing will
have quantity or quality, and so the one will not be infinite, as
Melissus says - nor, indeed, limited, as Parmenides says, for
though the limit is indivisible, the limited is not.
But if (c) all things are one in the sense of having the same
definition, like 'raiment' and 'dress', then it turns out that they
are maintaining the Heraclitean doctrine, for it will be the same
thing 'to be good' and 'to be bad', and 'to be good' and 'to be not
good', and so the same thing will be 'good' and 'not good', and
man and horse; in fact, their view will be, not that all things are
one, but that they are nothing; and that 'to be of such-and-such
a quality' is the same as 'to be of such-and-such a size'.
Even the more recent of the ancient thinkers were in a pother
lest the same thing should turn out in their hands both one and
many. So some, like Lycophron, were led to omit 'is', others to
change the mode of expression and say 'the man has been
whitened' instead of 'is white', and 'walks' instead of 'is
walking', for fear that if they added the word 'is' they should be
making the one to be many - as if 'one' and 'being' were always
used in one and the same sense. What 'is' may be many either
in definition (for example 'to be white' is one thing, 'to be
musical' another, yet the same thing be both, so the one is
many) or by division, as the whole and its parts. On this point,
indeed, they were already getting into difficulties and admitted
that the one was many - as if there was any difficulty about the
same thing being both one and many, provided that these are
not opposites; for 'one' may mean either 'potentially one' or
'actually one'.
606
If, then, we approach the thesis in this way it seems impossible
for all things to be one. Further, the arguments they use to prove
their position are not difficult to expose. For both of them
reason contentiously - I mean both Melissus and Parmenides.
[Their premisses are false and their conclusions do not follow.
Or rather the argument of Melissus is gross and palpable and
offers no difficulty at all: admit one ridiculous proposition and
the rest follows - a simple enough proceeding.] The fallacy of
Melissus is obvious. For he supposes that the assumption 'what
has come into being always has a beginning' justifies the
assumption 'what has not come into being has no beginning'.
Then this also is absurd, that in every case there should be a
beginning of the thing - not of the time and not only in the case
of coming to be in the full sense but also in the case of coming
to have a quality - as if change never took place suddenly.
Again, does it follow that Being, if one, is motionless? Why
should it not move, the whole of it within itself, as parts of it do
which are unities, e.g. this water? Again, why is qualitative
change impossible? But, further, Being cannot be one in form,
though it may be in what it is made of. (Even some of the
physicists hold it to be one in the latter way, though not in the
former.) Man obviously differs from horse in form, and
contraries from each other.
The same kind of argument holds good against Parmenides
also, besides any that may apply specially to his view: the
answer to him being that 'this is not true' and 'that does not
follow'. His assumption that one is used in a single sense only is
false, because it is used in several. His conclusion does not
follow, because if we take only white things, and if 'white' has a
single meaning, none the less what is white will be many and
not one. For what is white will not be one either in the sense
that it is continuous or in the sense that it must be defined in
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only one way. 'Whiteness' will be different from 'what has
whiteness'. Nor does this mean that there is anything that can
exist separately, over and above what is white. For 'whiteness'
and 'that which is white' differ in definition, not in the sense
that they are things which can exist apart from each other. But
Parmenides had not come in sight of this distinction.
It is necessary for him, then, to assume not only that 'being' has
the same meaning, of whatever it is predicated, but further that
it means (1) what just is and (2) what is just one.
It must be so, for (1) an attribute is predicated of some subject,
so that the subject to which 'being' is attributed will not be, as it
is something different from 'being'. Something, therefore, which
is not will be. Hence 'substance' will not be a predicate of
anything else. For the subject cannot be a being, unless 'being'
means several things, in such a way that each is something. But
ex hypothesi 'being' means only one thing.
If, then, 'substance' is not attributed to anything, but other
things are attributed to it, how does 'substance' mean what is
rather than what is not? For suppose that 'substance' is also
'white'. Since the definition of the latter is different (for being
cannot even be attributed to white, as nothing is which is not
'substance'), it follows that 'white' is not-being - and that not in
the sense of a particular not-being, but in the sense that it is not
at all. Hence 'substance' is not; for it is true to say that it is
white, which we found to mean not-being. If to avoid this we
say that even 'white' means substance, it follows that 'being'
has more than one meaning.
In particular, then, Being will not have magnitude, if it is
substance. For each of the two parts must he in a different
sense.
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(2) Substance is plainly divisible into other substances, if we
consider the mere nature of a definition. For instance, if 'man' is
a substance, 'animal' and 'biped' must also be substances. For if
not substances, they must be attributes - and if attributes,
attributes either of (a) man or of (b) some other subject. But
neither is possible.
(a) An attribute is either that which may or may not belong to
the subject or that in whose definition the subject of which it is
an attribute is involved. Thus 'sitting' is an example of a
separable attribute, while 'snubness' contains the definition of
'nose', to which we attribute snubness. Further, the definition of
the whole is not contained in the definitions of the contents or
elements of the definitory formula; that of 'man' for instance in
'biped', or that of 'white man' in 'white'. If then this is so, and if
'biped' is supposed to be an attribute of 'man', it must be either
separable, so that 'man' might possibly not be 'biped', or the
definition of 'man' must come into the definition of 'biped' -
which is impossible, as the converse is the case.
(b) If, on the other hand, we suppose that 'biped' and 'animal'
are attributes not of man but of something else, and are not
each of them a substance, then 'man' too will be an attribute of
something else. But we must assume that substance is not the
attribute of anything, that the subject of which both 'biped' and
'animal' and each separately are predicated is the subject also
of the complex 'biped animal'.
Are we then to say that the All is composed of indivisible
substances? Some thinkers did, in point of fact, give way to both
arguments. To the argument that all things are one if being
means one thing, they conceded that not-being is; to that from
bisection, they yielded by positing atomic magnitudes. But
obviously it is not true that if being means one thing, and
cannot at the same time mean the contradictory of this, there
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will be nothing which is not, for even if what is not cannot be
without qualification, there is no reason why it should not be a
particular not-being. To say that all things will be one, if there is
nothing besides Being itself, is absurd. For who understands
'being itself to be anything but a particular substance? But if
this is so, there is nothing to prevent there being many beings,
as has been said.
It is, then, clearly impossible for Being to be one in this sense.
The physicists on the other hand have two modes of
explanation.
The first set make the underlying body one either one of the
three or something else which is denser than fire and rarer than
air then generate everything else from this, and obtain
multiplicity by condensation and rarefaction. Now these are
contraries, which may be generalized into 'excess and defect'.
(Compare Plato's 'Great and Small' - except that he make these
his matter, the one his form, while the others treat the one
which underlies as matter and the contraries as differentiae, i.e.
forms).
The second set assert that the contrarieties are contained in the
one and emerge from it by segregation, for example
Anaximander and also all those who assert that 'what is' is one
and many, like Empedocles and Anaxagoras; for they too
produce other things from their mixture by segregation. These
differ, however, from each other in that the former imagines a
cycle of such changes, the latter a single series. Anaxagoras
again made both his 'homceomerous' substances and his
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contraries infinite in multitude, whereas Empedocles posits
only the so-called elements.
The theory of Anaxagoras that the principles are infinite in
multitude was probably due to his acceptance of the common
opinion of the physicists that nothing comes into being from
not-being. For this is the reason why they use the phrase 'all
things were together' and the coming into being of such and
such a kind of thing is reduced to change of quality, while some
spoke of combination and separation. Moreover, the fact that
the contraries proceed from each other led them to the
conclusion. The one, they reasoned, must have already existed
in the other; for since everything that comes into being must
arise either from what is or from what is not, and it is
impossible for it to arise from what is not (on this point all the
physicists agree), they thought that the truth of the alternative
necessarily followed, namely that things come into being out of
existent things, i.e. out of things already present, but
imperceptible to our senses because of the smallness of their
bulk. So they assert that everything has been mixed in every,
thing, because they saw everything arising out of everything.
But things, as they say, appear different from one another and
receive different names according to the nature of the particles
which are numerically predominant among the innumerable
constituents of the mixture. For nothing, they say, is purely and
entirely white or black or sweet, bone or flesh, but the nature of
a thing is held to be that of which it contains the most.
Now (1) the infinite qua infinite is unknowable, so that what is
infinite in multitude or size is unknowable in quantity, and
what is infinite in variety of kind is unknowable in quality. But
the principles in question are infinite both in multitude and in
kind. Therefore it is impossible to know things which are
composed of them; for it is when we know the nature and
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quantity of its components that we suppose we know a
complex.
Further (2) if the parts of a whole may be of any size in the
direction either of greatness or of smallness (by 'parts' I mean
components into which a whole can be divided and which are
actually present in it), it is necessary that the whole thing itself
may be of any size. Clearly, therefore, since it is impossible for
an animal or plant to be indefinitely big or small, neither can its
parts be such, or the whole will be the same. But flesh, bone,
and the like are the parts of animals, and the fruits are the parts
of plants. Hence it is obvious that neither flesh, bone, nor any
such thing can be of indefinite size in the direction either of the
greater or of the less.
Again (3) according to the theory all such things are already
present in one another and do not come into being but are
constituents which are separated out, and a thing receives its
designation from its chief constituent. Further, anything may
come out of anything - water by segregation from flesh and
flesh from water. Hence, since every finite body is exhausted by
the repeated abstraction of a finite body, it seems obviously to
follow that everything cannot subsist in everything else. For let
flesh be extracted from water and again more flesh be produced
from the remainder by repeating the process of separation:
then, even though the quantity separated out will continually
decrease, still it will not fall below a certain magnitude. If,
therefore, the process comes to an end, everything will not be in
everything else (for there will be no flesh in the remaining
water); if on the other hand it does not, and further extraction is
always possible, there will be an infinite multitude of finite
equal particles in a finite quantity - which is impossible.
Another proof may be added: Since every body must diminish in
size when something is taken from it, and flesh is quantitatively
definite in respect both of greatness and smallness, it is clear
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that from the minimum quantity of flesh no body can be
separated out; for the flesh left would be less than the
minimum of flesh.
Lastly (4) in each of his infinite bodies there would be already
present infinite flesh and blood and brain - having a distinct
existence, however, from one another, and no less real than the
infinite bodies, and each infinite: which is contrary to reason.
The statement that complete separation never will take place is
correct enough, though Anaxagoras is not fully aware of what it
means. For affections are indeed inseparable. If then colours
and states had entered into the mixture, and if separation took
place, there would be a 'white' or a 'healthy' which was nothing
but white or healthy, i.e. was not the predicate of a subject. So
his 'Mind' is an absurd person aiming at the impossible, if he is
supposed to wish to separate them, and it is impossible to do
so, both in respect of quantity and of quality - of quantity,
because there is no minimum magnitude, and of quality,
because affections are inseparable.
Nor is Anaxagoras right about the coming to be of homogeneous
bodies. It is true there is a sense in which clay is divided into
pieces of clay, but there is another in which it is not. Water and
air are, and are generated 'from' each other, but not in the way
in which bricks come 'from' a house and again a house 'from'
bricks; and it is better to assume a smaller and finite number of
principles, as Empedocles does.
All thinkers then agree in making the contraries principles, both
those who describe the All as one and unmoved (for even
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Parmenides treats hot and cold as principles under the names
of fire and earth) and those too who use the rare and the dense.
The same is true of Democritus also, with his plenum and void,
both of which exist, be says, the one as being, the other as not-
being. Again he speaks of differences in position, shape, and
order, and these are genera of which the species are contraries,
namely, of position, above and below, before and behind; of
shape, angular and angle-less, straight and round.
It is plain then that they all in one way or another identify the
contraries with the principles. And with good reason. For first
principles must not be derived from one another nor from
anything else, while everything has to be derived from them.
But these conditions are fulfilled by the primary contraries,
which are not derived from anything else because they are
primary, nor from each other because they are contraries.
But we must see how this can be arrived at as a reasoned result,
as well as in the way just indicated.
Our first presupposition must be that in nature nothing acts on,
or is acted on by, any other thing at random, nor may anything
come from anything else, unless we mean that it does so in
virtue of a concomitant attribute. For how could 'white' come
from 'musical', unless 'musical' happened to be an attribute of
the not-white or of the black? No, 'white' comes from 'not-
white' - and not from any 'not-white', but from black or some
intermediate colour. Similarly, 'musical' comes to be from 'not-
musical', but not from any thing other than musical, but from
'unmusical' or any intermediate state there may be.
Nor again do things pass into the first chance thing; 'white'
does not pass into 'musical' (except, it may be, in virtue of a
concomitant attribute), but into 'not-white' - and not into any
chance thing which is not white, but into black or an
intermediate colour; 'musical' passes into 'not-musical' - and
614
not into any chance thing other than musical, but into
'unmusical' or any intermediate state there may be.
The same holds of other things also: even things which are not
simple but complex follow the same principle, but the opposite
state has not received a name, so we fail to notice the fact. What
is in tune must come from what is not in tune, and vice versa;
the tuned passes into untunedness - and not into any
untunedness, but into the corresponding opposite. It does not
matter whether we take attunement, order, or composition for
our illustration; the principle is obviously the same in all, and in
fact applies equally to the production of a house, a statue, or
any other complex. A house comes from certain things in a
certain state of separation instead of conjunction, a statue (or
any other thing that has been shaped) from shapelessness -
each of these objects being partly order and partly composition.
If then this is true, everything that comes to be or passes away
from, or passes into, its contrary or an intermediate state. But
the intermediates are derived from the contraries - colours, for
instance, from black and white. Everything, therefore, that
comes to be by a natural process is either a contrary or a
product of contraries.
Up to this point we have practically had most of the other
writers on the subject with us, as I have said already: for all of
them identify their elements, and what they call their
principles, with the contraries, giving no reason indeed for the
theory, but contrained as it were by the truth itself. They differ,
however, from one another in that some assume contraries
which are more primary, others contraries which are less so:
some those more knowable in the order of explanation, others
those more familiar to sense. For some make hot and cold, or
again moist and dry, the conditions of becoming; while others
615
make odd and even, or again Love and Strife; and these differ
from each other in the way mentioned.
Hence their principles are in one sense the same, in another
different; different certainly, as indeed most people think, but
the same inasmuch as they are analogous; for all are taken from
the same table of columns, some of the pairs being wider,
others narrower in extent. In this way then their theories are
both the same and different, some better, some worse; some, as
I have said, take as their contraries what is more knowable in
the order of explanation, others what is more familiar to sense.
(The universal is more knowable in the order of explanation, the
particular in the order of sense: for explanation has to do with
the universal, sense with the particular.) 'The great and the
small', for example, belong to the former class, 'the dense and
the rare' to the latter.
It is clear then that our principles must be contraries.
The next question is whether the principles are two or three or
more in number.
One they cannot be, for there cannot be one contrary. Nor can
they be innumerable, because, if so, Being will not be knowable:
and in any one genus there is only one contrariety, and
substance is one genus: also a finite number is sufficient, and a
finite number, such as the principles of Empedocles, is better
than an infinite multitude; for Empedocles professes to obtain
from his principles all that Anaxagoras obtains from his
innumerable principles. Lastly, some contraries are more
primary than others, and some arise from others - for example
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sweet and bitter, white and black - whereas the principles must
always remain principles.
This will suffice to show that the principles are neither one nor
innumerable.
Granted, then, that they are a limited number, it is plausible to
suppose them more than two. For it is difficult to see how either
density should be of such a nature as to act in any way on rarity
or rarity on density. The same is true of any other pair of
contraries; for Love does not gather Strife together and make
things out of it, nor does Strife make anything out of Love, but
both act on a third thing different from both. Some indeed
assume more than one such thing from which they construct
the world of nature.
Other objections to the view that it is not necessary to assume a
third principle as a substratum may be added. (1) We do not find
that the contraries constitute the substance of any thing. But
what is a first principle ought not to be the predicate of any
subject. If it were, there would be a principle of the supposed
principle: for the subject is a principle, and prior presumably to
what is predicated of it. Again (2) we hold that a substance is
not contrary to another substance. How then can substance be
derived from what are not substances? Or how can non-
substances be prior to substance?
If then we accept both the former argument and this one, we
must, to preserve both, assume a third somewhat as the
substratum of the contraries, such as is spoken of by those who
describe the All as one nature - water or fire or what is
intermediate between them. What is intermediate seems
preferable; for fire, earth, air, and water are already involved
with pairs of contraries. There is, therefore, much to be said for
those who make the underlying substance different from these
four; of the rest, the next best choice is air, as presenting
617
sensible differences in a less degree than the others; and after
air, water. All, however, agree in this, that they differentiate their
One by means of the contraries, such as density and rarity and
more and less, which may of course be generalized, as has
already been said into excess and defect. Indeed this doctrine
too (that the One and excess and defect are the principles of
things) would appear to be of old standing, though in different
forms; for the early thinkers made the two the active and the
one the passive principle, whereas some of the more recent
maintain the reverse.
To suppose then that the elements are three in number would
seem, from these and similar considerations, a plausible view,
as I said before. On the other hand, the view that they are more
than three in number would seem to be untenable.
For the one substratum is sufficient to be acted on; but if we
have four contraries, there will be two contrarieties, and we
shall have to suppose an intermediate nature for each pair
separately. If, on the other hand, the contrarieties, being two,
can generate from each other, the second contrariety will be
superfluous. Moreover, it is impossible that there should be
more than one primary contrariety. For substance is a single
genus of being, so that the principles can differ only as prior
and posterior, not in genus; in a single genus there is always a
single contrariety, all the other contrarieties in it being held to
be reducible to one.
It is clear then that the number of elements is neither one nor
more than two or three; but whether two or three is, as I said, a
question of considerable difficulty.
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We will now give our own account, approaching the question
first with reference to becoming in its widest sense: for we shall
be following the natural order of inquiry if we speak first of
common characteristics, and then investigate the
characteristics of special cases.
We say that one thing comes to be from another thing, and one
sort of thing from another sort of thing, both in the case of
simple and of complex things. I mean the following. We can say
(1) 'man becomes musical', (2) what is 'not-musical becomes
musical', or (3), the 'not-musical man becomes a musical man'.
Now what becomes in (1) and (2) - 'man' and 'not musical' - I
call simple, and what each becomes - 'musical' - simple also.
But when (3) we say the 'not-musical man becomes a musical
man', both what becomes and what it becomes are complex.
As regards one of these simple 'things that become' we say not
only 'this becomes so-and-so', but also 'from being this, comes
to be so-and-so', as 'from being not-musical comes to be
musical'; as regards the other we do not say this in all cases, as
we do not say (1) 'from being a man he came to be musical' but
only 'the man became musical'.
When a 'simple' thing is said to become something, in one case
(1) it survives through the process, in the other (2) it does not.
For man remains a man and is such even when he becomes
musical, whereas what is not musical or is unmusical does not
continue to exist, either simply or combined with the subject.
These distinctions drawn, one can gather from surveying the
various cases of becoming in the way we are describing that, as
we say, there must always be an underlying something, namely
that which becomes, and that this, though always one
numerically, in form at least is not one. (By that I mean that it
619
can be described in different ways.) For 'to be man' is not the
same as 'to be unmusical'. One part survives, the other does
not: what is not an opposite survives (for 'man' survives), but
'not-musical' or 'unmusical' does not survive, nor does the
compound of the two, namely 'unmusical man'.
We speak of 'becoming that from this' instead of 'this becoming
that' more in the case of what does not survive the change -
'becoming musical from unmusical', not 'from man' - but there
are exceptions, as we sometimes use the latter form of
expression even of what survives; we speak of 'a statue coming
to be from bronze', not of the 'bronze becoming a statue'. The
change, however, from an opposite which does not survive is
described indifferently in both ways, 'becoming that from this'
or 'this becoming that'. We say both that 'the unmusical
becomes musical', and that 'from unmusical he becomes
musical'. And so both forms are used of the complex, 'becoming
a musical man from an unmusical man', and unmusical man
becoming a musical man'.
But there are different senses of 'coming to be'. In some cases
we do not use the expression 'come to be', but 'come to be so-
and-so'. Only substances are said to 'come to be' in the
unqualified sense.
Now in all cases other than substance it is plain that there must
be some subject, namely, that which becomes. For we know that
when a thing comes to be of such a quantity or quality or in
such a relation, time, or place, a subject is always presupposed,
since substance alone is not predicated of another subject, but
everything else of substance.
But that substances too, and anything else that can be said 'to
be' without qualification, come to be from some substratum,
will appear on examination. For we find in every case
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something that underlies from which proceeds that which
comes to be; for instance, animals and plants from seed.
Generally things which come to be, come to be in different
ways: (1) by change of shape, as a statue; (2) by addition, as
things which grow; (3) by taking away, as the Hermes from the
stone; (4) by putting together, as a house; (5) by alteration, as
things which 'turn' in respect of their material substance.
It is plain that these are all cases of coming to be from a
substratum.
Thus, clearly, from what has been said, whatever comes to be is
always complex. There is, on the one hand, (a) something which
comes into existence, and again (b) something which becomes
that - the latter (b) in two senses, either the subject or the
opposite. By the 'opposite' I mean the 'unmusical', by the
'subject' 'man', and similarly I call the absence of shape or form
or order the 'opposite', and the bronze or stone or gold the
'subject'.
Plainly then, if there are conditions and principles which
constitute natural objects and from which they primarily are or
have come to be - have come to be, I mean, what each is said to
be in its essential nature, not what each is in respect of a
concomitant attribute - plainly, I say, everything comes to be
from both subject and form. For 'musical man' is composed (in a
way) of 'man' and 'musical': you can analyse it into the
definitions of its elements. It is clear then that what comes to
be will come to be from these elements.
Now the subject is one numerically, though it is two in form.
(For it is the man, the gold - the 'matter' generally - that is
counted, for it is more of the nature of a 'this', and what comes
to be does not come from it in virtue of a concomitant attribute;
the privation, on the other hand, and the contrary are incidental
621
in the process.) And the positive form is one - the order, the
acquired art of music, or any similar predicate.
There is a sense, therefore, in which we must declare the
principles to be two, and a sense in which they are three; a
sense in which the contraries are the principles - say for
example the musical and the unmusical, the hot and the cold,
the tuned and the untuned - and a sense in which they are not,
since it is impossible for the contraries to be acted on by each
other. But this difficulty also is solved by the fact that the
substratum is different from the contraries, for it is itself not a
contrary. The principles therefore are, in a way, not more in
number than the contraries, but as it were two, nor yet precisely
two, since there is a difference of essential nature, but three. For
'to be man' is different from 'to be unmusical', and 'to be
unformed' from 'to be bronze'.
We have now stated the number of the principles of natural
objects which are subject to generation, and how the number is
reached: and it is clear that there must be a substratum for the
contraries, and that the contraries must be two. (Yet in another
way of putting it this is not necessary, as one of the contraries
will serve to effect the change by its successive absence and
presence.)
The underlying nature is an object of scientific knowledge, by
an analogy. For as the bronze is to the statue, the wood to the
bed, or the matter and the formless before receiving form to any
thing which has form, so is the underlying nature to substance,
i.e. the 'this' or existent.
This then is one principle (though not one or existent in the
same sense as the 'this'), and the definition was one as we
agreed; then further there is its contrary, the privation. In what
sense these are two, and in what sense more, has been stated
above. Briefly, we explained first that only the contraries were
622
principles, and later that a substratum was indispensable, and
that the principles were three; our last statement has elucidated
the difference between the contraries, the mutual relation of
the principles, and the nature of the substratum. Whether the
form or the substratum is the essential nature of a physical
object is not yet clear. But that the principles are three, and in
what sense, and the way in which each is a principle, is clear.
So much then for the question of the number and the nature of
the principles.
8
We will now proceed to show that the difficulty of the early
thinkers, as well as our own, is solved in this way alone.
The first of those who studied science were misled in their
search for truth and the nature of things by their inexperience,
which as it were thrust them into another path. So they say that
none of the things that are either comes to be or passes out of
existence, because what comes to be must do so either from
what is or from what is not, both of which are impossible. For
what is cannot come to be (because it is already), and from what
is not nothing could have come to be (because something must
be present as a substratum). So too they exaggerated the
consequence of this, and went so far as to deny even the
existence of a plurality of things, maintaining that only Being
itself is. Such then was their opinion, and such the reason for its
adoption.
Our explanation on the other hand is that the phrases
'something comes to be from what is or from what is not', 'what
is not or what is does something or has something done to it or
623
becomes some particular thing', are to be taken (in the first way
of putting our explanation) in the same sense as 'a doctor does
something or has something done to him', 'is or becomes
something from being a doctor.' These expressions may be
taken in two senses, and so too, clearly, may 'from being', and
'being acts or is acted on'. A doctor builds a house, not qua
doctor, but qua housebuilder, and turns gray, not qua doctor, but
qua dark-haired. On the other hand he doctors or fails to doctor
qua doctor. But we are using words most appropriately when we
say that a doctor does something or undergoes something, or
becomes something from being a doctor, if he does, undergoes,
or becomes qua doctor. Clearly then also 'to come to be so-and-
so from not-being' means 'qua not-being'.
It was through failure to make this distinction that those
thinkers gave the matter up, and through this error that they
went so much farther astray as to suppose that nothing else
comes to be or exists apart from Being itself, thus doing away
with all becoming.
We ourselves are in agreement with them in holding that
nothing can be said without qualification to come from what is
not. But nevertheless we maintain that a thing may 'come to be
from what is not' - that is, in a qualified sense. For a thing
comes to be from the privation, which in its own nature is not-
being, - this not surviving as a constituent of the result. Yet this
causes surprise, and it is thought impossible that something
should come to be in the way described from what is not.
In the same way we maintain that nothing comes to be from
being, and that being does not come to be except in a qualified
sense. In that way, however, it does, just as animal might come
to be from animal, and an animal of a certain kind from an
animal of a certain kind. Thus, suppose a dog to come to be
from a horse. The dog would then, it is true, come to be from
624
animal (as well as from an animal of a certain kind) but not as
animal, for that is already there. But if anything is to become an
animal, not in a qualified sense, it will not be from animal: and
if being, not from being - nor from not-being either, for it has
been explained that by 'from not being' we mean from not-
being qua not-being.
Note further that we do not subvert the principle that
everything either is or is not.
This then is one way of solving the difficulty. Another consists
in pointing out that the same things can be explained in terms
of potentiality and actuality. But this has been done with
greater precision elsewhere. So, as we said, the difficulties
which constrain people to deny the existence of some of the
things we mentioned are now solved. For it was this reason
which also caused some of the earlier thinkers to turn so far
aside from the road which leads to coming to be and passing
away and change generally. If they had come in sight of this
nature, all their ignorance would have been dispelled.
Others, indeed, have apprehended the nature in question, but
not adequately.
In the first place they allow that a thing may come to be
without qualification from not being, accepting on this point
the statement of Parmenides. Secondly, they think that if the
substratum is one numerically, it must have also only a single
potentiality - which is a very different thing.
625
Now we distinguish matter and privation, and hold that one of
these, namely the matter, is not-being only in virtue of an
attribute which it has, while the privation in its own nature is
not-being; and that the matter is nearly, in a sense is, substance,
while the privation in no sense is. They, on the other hand,
identify their Great and Small alike with not being, and that
whether they are taken together as one or separately. Their triad
is therefore of quite a different kind from ours. For they got so
far as to see that there must be some underlying nature, but
they make it one - for even if one philosopher makes a dyad of
it, which he calls Great and Small, the effect is the same, for he
overlooked the other nature. For the one which persists is a
joint cause, with the form, of what comes to be - a mother, as it
were. But the negative part of the contrariety may often seem, if
you concentrate your attention on it as an evil agent, not to
exist at all.
For admitting with them that there is something divine, good,
and desirable, we hold that there are two other principles, the
one contrary to it, the other such as of its own nature to desire
and yearn for it. But the consequence of their view is that the
contrary desires its wtextinction. Yet the form cannot desire
itself, for it is not defective; nor can the contrary desire it, for
contraries are mutually destructive. The truth is that what
desires the form is matter, as the female desires the male and
the ugly the beautiful - only the ugly or the female not per se
but per accidens.
The matter comes to be and ceases to be in one sense, while in
another it does not. As that which contains the privation, it
ceases to be in its own nature, for what ceases to be - the
privation - is contained within it. But as potentiality it does not
cease to be in its own nature, but is necessarily outside the
sphere of becoming and ceasing to be. For if it came to be,
something must have existed as a primary substratum from
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which it should come and which should persist in it; but this is
its own special nature, so that it will be before coming to be. (For
my definition of matter is just this-the primary substratum of
each thing, from which it comes to be without qualification, and
which persists in the result.) And if it ceases to be it will pass
into that at the last, so it will have ceased to be before ceasing
to be.
The accurate determination of the first principle in respect of
form, whether it is one or many and what it is or what they are,
is the province of the primary type of science; so these
questions may stand over till then. But of the natural, i.e.
perishable, forms we shall speak in the expositions which
follow.
The above, then, may be taken as sufficient to establish that
there are principles and what they are and how many there are.
Now let us make a fresh start and proceed.
Book II
Of things that exist, some exist by nature, some from other
causes.
627
'By nature' the animals and their parts exist, and the plants and
the simple bodies (earth, fire, air, water) - for we say that these
and the like exist 'by nature'.
All the things mentioned present a feature in which they differ
from things which are not constituted by nature. Each of them
has within itself a principle of motion and of stationariness (in
respect of place, or of growth and decrease, or by way of
alteration). On the other hand, a bed and a coat and anything
else of that sort, qua receiving these designations i.e. in so far as
they are products of art - have no innate impulse to change. But
in so far as they happen to be composed of stone or of earth or
of a mixture of the two, they do have such an impulse, and just
to that extent which seems to indicate that nature is a source or
cause of being moved and of being at rest in that to which it
belongs primarily, in virtue of itself and not in virtue of a
concomitant attribute.
I say 'not in virtue of a concomitant attribute', because (for
instance) a man who is a doctor might cure himself.
Nevertheless it is not in so far as he is a patient that he
possesses the art of medicine: it merely has happened that the
same man is doctor and patient - and that is why these
attributes are not always found together. So it is with all other
artificial products. None of them has in itself the source of its
own production. But while in some cases (for instance houses
and the other products of manual labour) that principle is in
something else external to the thing, in others those which may
cause a change in themselves in virtue of a concomitant
attribute - it lies in the things themselves (but not in virtue of
what they are).
'Nature' then is what has been stated. Things 'have a
nature'which have a principle of this kind. Each of them is a
628
substance; for it is a subject, and nature always implies a
subject in which it inheres.
The term 'according to nature' is applied to all these things and
also to the attributes which belong to them in virtue of what
they are, for instance the property of fire to be carried upwards
- which is not a 'nature' nor 'has a nature' but is 'by nature' or
'according to nature'.
What nature is, then, and the meaning of the terms 'by nature'
and 'according to nature', has been stated. That nature exists, it
would be absurd to try to prove; for it is obvious that there are
many things of this kind, and to prove what is obvious by what
is not is the mark of a man who is unable to distinguish what is
self-evident from what is not. (This state of mind is clearly
possible. A man blind from birth might reason about colours.
Presumably therefore such persons must be talking about words
without any thought to correspond.)
Some identify the nature or substance of a natural object with
that immediate constituent of it which taken by itself is without
arrangement, e.g. the wood is the 'nature' of the bed, and the
bronze the 'nature' of the statue.
As an indication of this Antiphon points out that if you planted
a bed and the rotting wood acquired the power of sending up a
shoot, it would not be a bed that would come up, but wood -
which shows that the arrangement in accordance with the rules
of the art is merely an incidental attribute, whereas the real
nature is the other, which, further, persists continuously
through the process of making.
But if the material of each of these objects has itself the same
relation to something else, say bronze (or gold) to water, bones
(or wood) to earth and so on, that (they say) would be their
nature and essence. Consequently some assert earth, others fire
629
or air or water or some or all of these, to be the nature of the
things that are. For whatever any one of them supposed to have
this character - whether one thing or more than one thing - this
or these he declared to be the whole of substance, all else being
its affections, states, or dispositions. Every such thing they held
to be eternal (for it could not pass into anything else), but other
things to come into being and cease to be times without
number.
This then is one account of 'nature', namely that it is the
immediate material substratum of things which have in
themselves a principle of motion or change.
Another account is that 'nature' is the shape or form which is
specified in the definition of the thing.
For the word 'nature' is applied to what is according to nature
and the natural in the same way as 'art' is applied to what is
artistic or a work of art. We should not say in the latter case that
there is anything artistic about a thing, if it is a bed only
potentially, not yet having the form of a bed; nor should we call
it a work of art. The same is true of natural compounds. What is
potentially flesh or bone has not yet its own 'nature', and does
not exist until it receives the form specified in the definition,
which we name in defining what flesh or bone is. Thus in the
second sense of 'nature' it would be the shape or form (not
separable except in statement) of things which have in
themselves a source of motion. (The combination of the two,
e.g. man, is not 'nature' but 'by nature' or 'natural'.)
The form indeed is 'nature' rather than the matter; for a thing is
more properly said to be what it is when it has attained to
fulfilment than when it exists potentially. Again man is born
from man, but not bed from bed. That is why people say that
the figure is not the nature of a bed, but the wood is - if the bed
sprouted not a bed but wood would come up. But even if the
630
figure is art, then on the same principle the shape of man is his
nature. For man is born from man.
We also speak of a thing's nature as being exhibited in the
process of growth by which its nature is attained. The 'nature' in
this sense is not like 'doctoring', which leads not to the art of
doctoring but to health. Doctoring must start from the art, not
lead to it. But it is not in this way that nature (in the one sense)
is related to nature (in the other). What grows qua growing
grows from something into something. Into what then does it
grow? Not into that from which it arose but into that to which it
tends. The shape then is nature.
'Shape' and 'nature', it should be added, are in two senses. For
the privation too is in a way form. But whether in unqualified
coming to be there is privation, i.e. a contrary to what comes to
be, we must consider later.
We have distinguished, then, the different ways in which the
term 'nature' is used.
The next point to consider is how the mathematician differs
from the physicist. Obviously physical bodies contain surfaces
and volumes, lines and points, and these are the subject-matter
of mathematics.
Further, is astronomy different from physics or a department of
it? It seems absurd that the physicist should be supposed to
know the nature of sun or moon, but not to know any of their
essential attributes, particularly as the writers on physics
631
obviously do discuss their shape also and whether the earth
and the world are spherical or not.
Now the mathematician, though he too treats of these things,
nevertheless does not treat of them as the limits of a physical
body; nor does he consider the attributes indicated as the
attributes of such bodies. That is why he separates them; for in
thought they are separable from motion, and it makes no
difference, nor does any falsity result, if they are separated. The
holders of the theory of Forms do the same, though they are not
aware of it; for they separate the objects of physics, which are
less separable than those of mathematics. This becomes plain if
one tries to state in each of the two cases the definitions of the
things and of their attributes. 'Odd' and 'even', 'straight' and
'curved', and likewise 'number', 'line', and 'figure', do not
involve motion; not so 'flesh' and 'bone' and 'man' - these are
defined like 'snub nose', not like 'curved'.
Similar evidence is supplied by the more physical of the
branches of mathematics, such as optics, harmonics, and
astronomy. These are in a way the converse of geometry. While
geometry investigates physical lines but not qua physical, optics
investigates mathematical lines, but qua physical, not qua
mathematical.
Since 'nature' has two senses, the form and the matter, we must
investigate its objects as we would the essence of snubness.
That is, such things are neither independent of matter nor can
be defined in terms of matter only. Here too indeed one might
raise a difficulty. Since there are two natures, with which is the
physicist concerned? Or should he investigate the combination
of the two? But if the combination of the two, then also each
severally. Does it belong then to the same or to different
sciences to know each severally?
632
If we look at the ancients, physics would to be concerned with
the matter. (It was only very slightly that Empedocles and
Democritus touched on the forms and the essence.)
But if on the other hand art imitates nature, and it is the part of
the same discipline to know the form and the matter up to a
point (e.g. the doctor has a knowledge of health and also of bile
and phlegm, in which health is realized, and the builder both of
the form of the house and of the matter, namely that it is bricks
and beams, and so forth): if this is so, it would be the part of
physics also to know nature in both its senses.
Again, 'that for the sake of which', or the end, belongs to the
same department of knowledge as the means. But the nature is
the end or 'that for the sake of which'. For if a thing undergoes a
continuous change and there is a stage which is last, this stage
is the end or 'that for the sake of which'. (That is why the poet
was carried away into making an absurd statement when he
said 'he has the end for the sake of which he was born'. For not
every stage that is last claims to be an end, but only that which
is best.)
For the arts make their material (some simply 'make' it, others
make it serviceable), and we use everything as if it was there for
our sake. (We also are in a sense an end. 'That for the sake of
which' has two senses: the distinction is made in our work On
Philosophy.) The arts, therefore, which govern the matter and
have knowledge are two, namely the art which uses the product
and the art which directs the production of it. That is why the
using art also is in a sense directive; but it differs in that it
knows the form, whereas the art which is directive as being
concerned with production knows the matter. For the
helmsman knows and prescribes what sort of form a helm
should have, the other from what wood it should be made and
by means of what operations. In the products of art, however,
633
we make the material with a view to the function, whereas in
the products of nature the matter is there all along.
Again, matter is a relative term: to each form there corresponds
a special matter. How far then must the physicist know the
form or essence? Up to a point, perhaps, as the doctor must
know sinew or the smith bronze (i.e. until he understands the
purpose of each): and the physicist is concerned only with
things whose forms are separable indeed, but do not exist apart
from matter. Man is begotten by man and by the sun as well.
The mode of existence and essence of the separable it is the
business of the primary type of philosophy to define.
Now that we have established these distinctions, we must
proceed to consider causes, their character and number.
Knowledge is the object of our inquiry, and men do not think
they know a thing till they have grasped the 'why' of (which is
to grasp its primary cause). So clearly we too must do this as
regards both coming to be and passing away and every kind of
physical change, in order that, knowing their principles, we may
try to refer to these principles each of our problems.
In one sense, then, (1) that out of which a thing comes to be and
which persists, is called 'cause', e.g. the bronze of the statue, the
silver of the bowl, and the genera of which the bronze and the
silver are species.
In another sense (2) the form or the archetype, i.e. the
statement of the essence, and its genera, are called 'causes' (e.g.
of the octave the relation of 2:1, and generally number), and the
parts in the definition.
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Again (3) the primary source of the change or coming to rest;
e.g. the man who gave advice is a cause, the father is cause of
the child, and generally what makes of what is made and what
causes change of what is changed.
Again (4) in the sense of end or 'that for the sake of which' a
thing is done, e.g. health is the cause of walking about. ('Why is
he walking about?' we say. 'To be healthy', and, having said that,
we think we have assigned the cause.) The same is true also of
all the intermediate steps which are brought about through the
action of something else as means towards the end, e.g.
reduction of flesh, purging, drugs, or surgical instruments are
means towards health. All these things are 'for the sake of the
end, though they differ from one another in that some are
activities, others instruments.
This then perhaps exhausts the number of ways in which the
term 'cause' is used.
As the word has several senses, it follows that there are several
causes of the same thing not merely in virtue of a concomitant
attribute), e.g. both the art of the sculptor and the bronze are
causes of the statue. These are causes of the statue qua statue,
not in virtue of anything else that it may be - only not in the
same way, the one being the material cause, the other the cause
whence the motion comes. Some things cause each other
reciprocally, e.g. hard work causes fitness and vice versa, but
again not in the same way, but the one as end, the other as the
origin of change. Further the same thing is the cause of contrary
results. For that which by its presence brings about one result is
sometimes blamed for bringing about the contrary by its
absence. Thus we ascribe the wreck of a ship to the absence of
the pilot whose presence was the cause of its safety.
All the causes now mentioned fall into four familiar divisions.
The letters are the causes of syllables, the material of artificial
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products, fire, &c, of bodies, the parts of the whole, and the
premisses of the conclusion, in the sense of 'that from which'.
Of these pairs the one set are causes in the sense of substratum,
e.g. the parts, the other set in the sense of essence - the whole
and the combination and the form. But the seed and the doctor
and the adviser, and generally the maker, are all sources
whence the change or stationariness originates, while the
others are causes in the sense of the end or the good of the rest;
for 'that for the sake of which' means what is best and the end
of the things that lead up to it. (Whether we say the 'good itself
or the 'apparent good' makes no difference.)
Such then is the number and nature of the kinds of cause.
Now the modes of causation are many, though when brought
under heads they too can be reduced in number. For 'cause' is
used in many senses and even within the same kind one may
be prior to another (e.g. the doctor and the expert are causes of
health, the relation 2:1 and number of the octave), and always
what is inclusive to what is particular. Another mode of
causation is the incidental and its genera, e.g. in one way
'Polyclitus', in another 'sculptor' is the cause of a statue,
because 'being Polyclitus' and 'sculptor' are incidentally
conjoined. Also the classes in which the incidental attribute is
included; thus 'a man' could be said to be the cause of a statue
or, generally, 'a living creature'. An incidental attribute too may
be more or less remote, e.g. suppose that 'a pale man' or 'a
musical man' were said to be the cause of the statue.
All causes, both proper and incidental, may be spoken of either
as potential or as actual; e.g. the cause of a house being built is
either 'house-builder' or 'house-builder building'.
Similar distinctions can be made in the things of which the
causes are causes, e.g. of 'this statue' or of 'statue' or of 'image'
generally, of 'this bronze' or of 'bronze' or of 'material' generally.
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So too with the incidental attributes. Again we may use a
complex expression for either and say, e.g. neither 'Polyclitus'
nor 'sculptor' but 'Polyclitus, sculptor'.
All these various uses, however, come to six in number, under
each of which again the usage is twofold. Cause means either
what is particular or a genus, or an incidental attribute or a
genus of that, and these either as a complex or each by itself;
and all six either as actual or as potential. The difference is this
much, that causes which are actually at work and particular
exist and cease to exist simultaneously with their effect, e.g.
this healing person with this being-healed person and that
house-building man with that being-built house; but this is not
always true of potential causes - the house and the
housebuilder do not pass away simultaneously.
In investigating the cause of each thing it is always necessary to
seek what is most precise (as also in other things): thus man
builds because he is a builder, and a builder builds in virtue of
his art of building. This last cause then is prior: and so generally.
Further, generic effects should be assigned to generic causes,
particular effects to particular causes, e.g. statue to sculptor,
this statue to this sculptor; and powers are relative to possible
effects, actually operating causes to things which are actually
being effected.
This must suffice for our account of the number of causes and
the modes of causation.
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But chance also and spontaneity are reckoned among causes:
many things are said both to be and to come to be as a result of
chance and spontaneity. We must inquire therefore in what
manner chance and spontaneity are present among the causes
enumerated, and whether they are the same or different, and
generally what chance and spontaneity are.
Some people even question whether they are real or not. They
say that nothing happens by chance, but that everything which
we ascribe to chance or spontaneity has some definite cause,
e.g. coming 'by chance' into the market and finding there a man
whom one wanted but did not expect to meet is due to one's
wish to go and buy in the market. Similarly in other cases of
chance it is always possible, they maintain, to find something
which is the cause; but not chance, for if chance were real, it
would seem strange indeed, and the question might be raised,
why on earth none of the wise men of old in speaking of the
causes of generation and decay took account of chance; whence
it would seem that they too did not believe that anything is by
chance. But there is a further circumstance that is surprising.
Many things both come to be and are by chance and
spontaneity, and although know that each of them can be
ascribed to some cause (as the old argument said which denied
chance), nevertheless they speak of some of these things as
happening by chance and others not. For this reason also they
ought to have at least referred to the matter in some way or
other.
Certainly the early physicists found no place for chance among
the causes which they recognized - love, strife, mind, fire, or the
like. This is strange, whether they supposed that there is no
such thing as chance or whether they thought there is but
omitted to mention it - and that too when they sometimes used
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it, as Empedocles does when he says that the air is not always
separated into the highest region, but 'as it may chance'. At any
rate he says in his cosmogony that 'it happened to run that way
at that time, but it often ran otherwise.' He tells us also that
most of the parts of animals came to be by chance.
There are some too who ascribe this heavenly sphere and all
the worlds to spontaneity. They say that the vortex arose
spontaneously, i.e. the motion that separated and arranged in
its present order all that exists. This statement might well cause
surprise. For they are asserting that chance is not responsible
for the existence or generation of animals and plants, nature or
mind or something of the kind being the cause of them (for it is
not any chance thing that comes from a given seed but an olive
from one kind and a man from another); and yet at the same
time they assert that the heavenly sphere and the divinest of
visible things arose spontaneously, having no such cause as is
assigned to animals and plants. Yet if this is so, it is a fact which
deserves to be dwelt upon, and something might well have been
said about it. For besides the other absurdities of the statement,
it is the more absurd that people should make it when they see
nothing coming to be spontaneously in the heavens, but much
happening by chance among the things which as they say are
not due to chance; whereas we should have expected exactly
the opposite.
Others there are who, indeed, believe that chance is a cause, but
that it is inscrutable to human intelligence, as being a divine
thing and full of mystery.
Thus we must inquire what chance and spontaneity are,
whether they are the same or different, and how they fit into
our division of causes.
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First then we observe that some things always come to pass in
the same way, and others for the most part. It is clearly of
neither of these that chance is said to be the cause, nor can the
'effect of chance' be identified with any of the things that come
to pass by necessity and always, or for the most part. But as
there is a third class of events besides these two - events which
all say are 'by chance' - it is plain that there is such a thing as
chance and spontaneity; for we know that things of this kind
are due to chance and that things due to chance are of this
kind.
But, secondly, some events are for the sake of something, others
not. Again, some of the former class are in accordance with
deliberate intention, others not, but both are in the class of
things which are for the sake of something. Hence it is clear
that even among the things which are outside the necessary
and the normal, there are some in connexion withwhich the
phrase 'for the sake of something' is applicable. (Events that are
for the sake of something include whatever may be done as a
result of thought or of nature.) Things of this kind, then, when
they come to pass incidental are said to be 'by chance'. For just
as a thing is something either in virtue of itself or incidentally,
so may it be a cause. For instance, the housebuilding faculty is
in virtue of itself the cause of a house, whereas the pale or the
musical is the incidental cause. That which is per se cause of
the effect is determinate, but the incidental cause is
indeterminable, for the possible attributes of an individual are
innumerable. To resume then; when a thing of this kind comes
to pass among events which are for the sake of something, it is
said to be spontaneous or by chance. (The distinction between
the two must be made later - for the present it is sufficient if it
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is plain that both are in the sphere of things done for the sake
of something.)
Example: A man is engaged in collecting subscriptions for a
feast. He would have gone to such and such a place for the
purpose of getting the money, if he had known. He actually
went there for another purpose and it was only incidentally that
he got his money by going there; and this was not due to the
fact that he went there as a rule or necessarily, nor is the end
effected (getting the money) a cause present in himself - it
belongs to the class of things that are intentional and the result
of intelligent deliberation. It is when these conditions are
satisfied that the man is said to have gone 'by chance'. If he had
gone of deliberate purpose and for the sake of this - if he always
or normally went there when he was collecting payments - he
would not be said to have gone 'by chance'.
It is clear then that chance is an incidental cause in the sphere
of those actions for the sake of something which involve
purpose. Intelligent reflection, then, and chance are in the same
sphere, for purpose implies intelligent reflection.
It is necessary, no doubt, that the causes of what comes to pass
by chance be indefinite; and that is why chance is supposed to
belong to the class of the indefinite and to be inscrutable to
man, and why it might be thought that, in a way, nothing occurs
by chance. For all these statements are correct, because they are
well grounded. Things do, in a way, occur by chance, for they
occur incidentally and chance is an incidental cause. But strictly
it is not the cause - without qualification - of anything; for
instance, a housebuilder is the cause of a house; incidentally, a
fluteplayer may be so.
And the causes of the man's coming and getting the money
(when he did not come for the sake of that) are innumerable. He
may have wished to see somebody or been following somebody
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or avoiding somebody, or may have gone to see a spectacle.
Thus to say that chance is a thing contrary to rule is correct. For
'rule' applies to what is always true or true for the most part,
whereas chance belongs to a third type of event. Hence, to
conclude, since causes of this kind are indefinite, chance too is
indefinite. (Yet in some cases one might raise the question
whether any incidental fact might be the cause of the chance
occurrence, e.g. of health the fresh air or the sun's heat may be
the cause, but having had one's hair cut cannot; for some
incidental causes are more relevant to the effect than others.)
Chance or fortune is called 'good' when the result is good, 'evil'
when it is evil. The terms 'good fortune' and 'ill fortune' are
used when either result is of considerable magnitude. Thus one
who comes within an ace of some great evil or great good is
said to be fortunate or unfortunate. The mind affirms the
essence of the attribute, ignoring the hair's breadth of
difference. Further, it is with reason that good fortune is
regarded as unstable; for chance is unstable, as none of the
things which result from it can be invariable or normal.
Both are then, as I have said, incidental causes - both chance
and spontaneity - in the sphere of things which are capable of
coming to pass not necessarily, nor normally, and with
reference to such of these as might come to pass for the sake of
something.
They differ in that 'spontaneity' is the wider term. Every result
of chance is from what is spontaneous, but not everything that
is from what is spontaneous is from chance.
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Chance and what results from chance are appropriate to agents
that are capable of good fortune and of moral action generally.
Therefore necessarily chance is in the sphere of moral actions.
This is indicated by the fact that good fortune is thought to be
the same, or nearly the same, as happiness, and happiness to be
a kind of moral action, since it is well-doing. Hence what is not
capable of moral action cannot do anything by chance. Thus an
inanimate thing or a lower animal or a child cannot do anything
by chance, because it is incapable of deliberate intention; nor
can 'good fortune' or 'ill fortune' be ascribed to them, except
metaphorically, as Protarchus, for example, said that the stones
of which altars are made are fortunate because they are held in
honour, while their fellows are trodden under foot. Even these
things, however, can in a way be affected by chance, when one
who is dealing with them does something to them by chance,
but not otherwise.
The spontaneous on the other hand is found both in the lower
animals and in many inanimate objects. We say, for example,
that the horse came 'spontaneously', because, though his
coming saved him, he did not come for the sake of safety. Again,
the tripod fell 'of itself, because, though when it fell it stood on
its feet so as to serve for a seat, it did not fall for the sake of
that.
Hence it is clear that events which (1) belong to the general
class of things that may come to pass for the sake of something,
(2) do not come to pass for the sake of what actually results, and
(3) have an external cause, may be described by the phrase
'from spontaneity'. These 'spontaneous' events are said to be
'from chance' if they have the further characteristics of being
the objects of deliberate intention and due to agents capable of
that mode of action. This is indicated by the phrase 'in vain',
which is used when A which is for the sake of B, does not result
in B. For instance, taking a walk is for the sake of evacuation of
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the bowels; if this does not follow after walking, we say that we
have walked 'in vain' and that the walking was 'vain'. This
implies that what is naturally the means to an end is 'in vain',
when it does not effect the end towards which it was the
natural means - for it would be absurd for a man to say that he
had bathed in vain because the sun was not eclipsed, since the
one was not done with a view to the other. Thus the
spontaneous is even according to its derivation the case in
which the thing itself happens in vain. The stone that struck the
man did not fall for the purpose of striking him; therefore it fell
spontaneously, because it might have fallen by the action of an
agent and for the purpose of striking. The difference between
spontaneity and what results by chance is greatest in things
that come to be by nature; for when anything comes to be
contrary to nature, we do not say that it came to be by chance,
but by spontaneity. Yet strictly this too is different from the
spontaneous proper; for the cause of the latter is external, that
of the former internal.
We have now explained what chance is and what spontaneity
is, and in what they differ from each other. Both belong to the
mode of causation 'source of change', for either some natural or
some intelligent agent is always the cause; but in this sort of
causation the number of possible causes is infinite.
Spontaneity and chance are causes of effects which though they
might result from intelligence or nature, have in fact been
caused by something incidentally. Now since nothing which is
incidental is prior to what is per se, it is clear that no incidental
cause can be prior to a cause per se. Spontaneity and chance,
therefore, are posterior to intelligence and nature. Hence,
however true it may be that the heavens are due to spontaneity,
it will still be true that intelligence and nature will be prior
causes of this All and of many things in it besides.
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It is clear then that there are causes, and that the number of
them is what we have stated. The number is the same as that of
the things comprehended under the question 'why'. The 'why' is
referred ultimately either (1), in things which do not involve
motion, e.g. in mathematics, to the 'what' (to the definition of
'straight line' or 'commensurable', &c), or (2) to what initiated a
motion, e.g. 'why did they go to war? - because there had been a
raid'; or (3) we are inquiring 'for the sake of what?' - 'that they
may rule'; or (4), in the case of things that come into being, we
are looking for the matter. The causes, therefore, are these and
so many in number.
Now, the causes being four, it is the business of the physicist to
know about them all, and if he refers his problems back to all of
them, he will assign the 'why' in the way proper to his science -
the matter, the form, the mover, 'that for the sake of which'. The
last three often coincide; for the 'what' and 'that for the sake of
which' are one, while the primary source of motion is the same
in species as these (for man generates man), and so too, in
general, are all things which cause movement by being
themselves moved; and such as are not of this kind are no
longer inside the province of physics, for they cause motion not
by possessing motion or a source of motion in themselves, but
being themselves incapable of motion. Hence there are three
branches of study, one of things which are incapable of motion,
the second of things in motion, but indestructible, the third of
destructible things.
The question 'why', then, is answered by reference to the
matter, to the form, and to the primary moving cause. For in
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respect of coming to be it is mostly in this last way that causes
are investigated - 'what comes to be after what? what was the
primary agent or patient?' and so at each step of the series.
Now the principles which cause motion in a physical way are
two, of which one is not physical, as it has no principle of
motion in itself. Of this kind is whatever causes movement, not
being itself moved, such as (1) that which is completely
unchangeable, the primary reality, and (2) the essence of that
which is coming to be, i.e. the form; for this is the end or 'that
for the sake of which'. Hence since nature is for the sake of
something, we must know this cause also. We must explain the
'why' in all the senses of the term, namely, (1) that from this
that will necessarily result ('from this' either without
qualification or in most cases); (2) that 'this must be so if that is
to be so' (as the conclusion presupposes the premisses); (3) that
this was the essence of the thing; and (4) because it is better
thus (not without qualification, but with reference to the
essential nature in each case).
8
We must explain then (1) that Nature belongs to the class of
causes which act for the sake of something; (2) about the
necessary and its place in physical problems, for all writers
ascribe things to this cause, arguing that since the hot and the
cold, &c, are of such and such a kind, therefore certain things
necessarily are and come to be - and if they mention any other
cause (one his 'friendship and strife', another his 'mind'), it is
only to touch on it, and then good-bye to it.
A difficulty presents itself: why should not nature work, not for
the sake of something, nor because it is better so, but just as the
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sky rains, not in order to make the corn grow, but of necessity?
What is drawn up must cool, and what has been cooled must
become water and descend, the result of this being that the
corn grows. Similarly if a man's crop is spoiled on the threshing-
floor, the rain did not fall for the sake of this - in order that the
crop might be spoiled - but that result just followed. Why then
should it not be the same with the parts in nature, e.g. that our
teeth should come up of necessity - the front teeth sharp, fitted
for tearing, the molars broad and useful for grinding down the
food - since they did not arise for this end, but it was merely a
coincident result; and so with all other parts in which we
suppose that there is purpose? Wherever then all the parts
came about just what they would have been if they had come be
for an end, such things survived, being organized spontaneously
in a fitting way; whereas those which grew otherwise perished
and continue to perish, as Empedocles says his 'man-faced ox-
progeny' did.
Such are the arguments (and others of the kind) which may
cause difficulty on this point. Yet it is impossible that this
should be the true view. For teeth and all other natural things
either invariably or normally come about in a given way; but of
not one of the results of chance or spontaneity is this true. We
do not ascribe to chance or mere coincidence the frequency of
rain in winter, but frequent rain in summer we do; nor heat in
the dog-days, but only if we have it in winter. If then, it is agreed
that things are either the result of coincidence or for an end,
and these cannot be the result of coincidence or spontaneity, it
follows that they must be for an end; and that such things are
all due to nature even the champions of the theory which is
before us would agree. Therefore action for an end is present in
things which come to be and are by nature.
Further, where a series has a completion, all the preceding steps
are for the sake of that. Now surely as in intelligent action, so in
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nature; and as in nature, so it is in each action, if nothing
interferes. Now intelligent action is for the sake of an end;
therefore the nature of things also is so. Thus if a house, e.g. had
been a thing made by nature, it would have been made in the
same way as it is now by art; and if things made by nature were
made also by art, they would come to be in the same way as by
nature. Each step then in the series is for the sake of the next;
and generally art partly completes what nature cannot bring to
a finish, and partly imitates her. If, therefore, artificial products
are for the sake of an end, so clearly also are natural products.
The relation of the later to the earlier terms of the series is the
same in both. This is most obvious in the animals other than
man: they make things neither by art nor after inquiry or
deliberation. Wherefore people discuss whether it is by
intelligence or by some other faculty that these creatures
work.spiders, ants, and the like. By gradual advance in this
direction we come to see clearly that in plants too that is
produced which is conducive to the end-leaves, e.g. grow to
provide shade for the fruit. If then it is both by nature and for an
end that the swallow makes its nest and the spider its web, and
plants grow leaves for the sake of the fruit and send their roots
down (not up) for the sake of nourishment, it is plain that this
kind of cause is operative in things which come to be and are by
nature. And since 'nature' means two things, the matter and the
form, of which the latter is the end, and since all the rest is for
the sake of the end, the form must be the cause in the sense of
'that for the sake of which'.
Now mistakes come to pass even in the operations of art: the
grammarian makes a mistake in writing and the doctor pours
out the wrong dose. Hence clearly mistakes are possible in the
operations of nature also. If then in art there are cases in which
what is rightly produced serves a purpose, and if where
mistakes occur there was a purpose in what was attempted,
only it was not attained, so must it be also in natural products,
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and monstrosities will be failures in the purposive effort. Thus
in the original combinations the 'ox-progeny' if they failed to
reach a determinate end must have arisen through the
corruption of some principle corresponding to what is now the
seed.
Further, seed must have come into being first, and not
straightway the animals: the words 'whole-natured first...' must
have meant seed.
Again, in plants too we find the relation of means to end,
though the degree of organization is less. Were there then in
plants also 'olive-headed vine-progeny', like the 'man-headed
ox-progeny', or not? An absurd suggestion; yet there must have
been, if there were such things among animals.
Moreover, among the seeds anything must have come to be at
random. But the person who asserts this entirely does away
with 'nature' and what exists 'by nature'. For those things are
natural which, by a continuous movement originated from an
internal principle, arrive at some completion: the same
completion is not reached from every principle; nor any chance
completion, but always the tendency in each is towards the
same end, if there is no impediment.
The end and the means towards it may come about by chance.
We say, for instance, that a stranger has come by chance, paid
the ransom, and gone away, when he does so as if he had come
for that purpose, though it was not for that that he came. This is
incidental, for chance is an incidental cause, as I remarked
before. But when an event takes place always or for the most
part, it is not incidental or by chance. In natural products the
sequence is invariable, if there is no impediment.
It is absurd to suppose that purpose is not present because we
do not observe the agent deliberating. Art does not deliberate. If
649
the ship-building art were in the wood, it would produce the
same results by nature. If, therefore, purpose is present in art, it
is present also in nature. The best illustration is a doctor
doctoring himself: nature is like that.
It is plain then that nature is a cause, a cause that operates for a
purpose.
As regards what is 'of necessity', we must ask whether the
necessity is 'hypothetical', or 'simple' as well. The current view
places what is of necessity in the process of production, just as
if one were to suppose that the wall of a house necessarily
comes to be because what is heavy is naturally carried
downwards and what is light to the top, wherefore the stones
and foundations take the lowest place, with earth above
because it is lighter, and wood at the top of all as being the
lightest. Whereas, though the wall does not come to be without
these, it is not due to these, except as its material cause: it
comes to be for the sake of sheltering and guarding certain
things. Similarly in all other things which involve production for
an end; the product cannot come to be without things which
have a necessary nature, but it is not due to these (except as its
material); it comes to be for an end. For instance, why is a saw
such as it is? To effect so-and-so and for the sake of so-and-so.
This end, however, cannot be realized unless the saw is made of
iron. It is, therefore, necessary for it to be of iron, it we are to
have a saw and perform the operation of sawing. What is
necessary then, is necessary on a hypothesis; it is not a result
necessarily determined by antecedents. Necessity is in the
matter, while 'that for the sake of which' is in the definition.
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Necessity in mathematics is in a way similar to necessity in
things which come to be through the operation of nature. Since
a straight line is what it is, it is necessary that the angles of a
triangle should equal two right angles. But not conversely;
though if the angles are not equal to two right angles, then the
straight line is not what it is either. But in things which come to
be for an end, the reverse is true. If the end is to exist or does
exist, that also which precedes it will exist or does exist;
otherwise just as there, if - the conclusion is not true, the
premiss will not be true, so here the end or 'that for the sake of
which' will not exist. For this too is itself a starting-point, but of
the reasoning, not of the action; while in mathematics the
starting-point is the starting-point of the reasoning only, as
there is no action. If then there is to be a house, such-and-such
things must be made or be there already or exist, or generally
the matter relative to the end, bricks and stones if it is a house.
But the end is not due to these except as the matter, nor will it
come to exist because of them. Yet if they do not exist at all,
neither will the house, or the saw - the former in the absence of
stones, the latter in the absence of iron - just as in the other
case the premisses will not be true, if the angles of the triangle
are not equal to two right angles.
The necessary in nature, then, is plainly what we call by the
name of matter, and the changes in it. Both causes must be
stated by the physicist, but especially the end; for that is the
cause of the matter, not vice versa; and the end is 'that for the
sake of which', and the beginning starts from the definition or
essence; as in artificial products, since a house is of such-and-
such a kind, certain things must necessarily come to be or be
there already, or since health is this, these things must
necessarily come to be or be there already. Similarly if man is
this, then these; if these, then those. Perhaps the necessary is
present also in the definition. For if one defines the operation of
sawing as being a certain kind of dividing, then this cannot
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come about unless the saw has teeth of a certain kind; and
these cannot be unless it is of iron. For in the definition too
there are some parts that are, as it were, its matter.
Book III
Nature has been defined as a 'principle of motion and change',
and it is the subject of our inquiry. We must therefore see that
we understand the meaning of 'motion'; for if it were unknown,
the meaning of 'nature' too would be unknown.
When we have determined the nature of motion, our next task
will be to attack in the same way the terms which are involved
in it. Now motion is supposed to belong to the class of things
which are continuous; and the infinite presents itself first in the
continuous - that is how it comes about that 'infinite' is often
used in definitions of the continuous ('what is infinitely
divisible is continuous'). Besides these, place, void, and time are
thought to be necessary conditions of motion.
Clearly, then, for these reasons and also because the attributes
mentioned are common to, and coextensive with, all the objects
of our science, we must first take each of them in hand and
discuss it. For the investigation of special attributes comes after
that of the common attributes.
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To begin then, as we said, with motion.
We may start by distinguishing (1) what exists in a state of
fulfilment only, (2) what exists as potential, (3) what exists as
potential and also in fulfilment - one being a 'this', another 'so
much', a third 'such', and similarly in each of the other modes
of the predication of being.
Further, the word 'relative' is used with reference to (1) excess
and defect, (2) agent and patient and generally what can move
and what can be moved. For 'what can cause movement' is
relative to 'what can be moved', and vice versa.
Again, there is no such thing as motion over and above the
things. It is always with respect to substance or to quantity or to
quality or to place that what changes changes. But it is
impossible, as we assert, to find anything common to these
which is neither 'this' nor quantum nor quale nor any of the
other predicates. Hence neither will motion and change have
reference to something over and above the things mentioned,
for there is nothing over and above them.
Now each of these belongs to all its subjects in either of two
ways: namely (1) substance - the one is positive form, the other
privation; (2) in quality, white and black; (3) in quantity,
complete and incomplete; (4) in respect of locomotion, upwards
and downwards or light and heavy. Hence there are as many
types of motion or change as there are meanings of the word
'is'.
We have now before us the distinctions in the various classes of
being between what is full real and what is potential.
Def. The fulfilment of what exists potentially, in so far as it
exists potentially, is motion - namely, of what is alterable qua
alterable, alteration: of what can be increased and its opposite
what can be decreased (there is no common name), increase
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and decrease: of what can come to be and can pass away,
coming to he and passing away: of what can be carried along,
locomotion.
Examples will elucidate this definition of motion. When the
buildable, in so far as it is just that, is fully real, it is being built,
and this is building. Similarly, learning, doctoring, rolling,
leaping, ripening, ageing.
The same thing, if it is of a certain kind, can be both potential
and fully real, not indeed at the same time or not in the same
respect, but e.g. potentially hot and actually cold. Hence at once
such things will act and be acted on by one another in many
ways: each of them will be capable at the same time of causing
alteration and of being altered. Hence, too, what effects motion
as a physical agent can be moved: when a thing of this kind
causes motion, it is itself also moved. This, indeed, has led some
people to suppose that every mover is moved. But this question
depends on another set of arguments, and the truth will be
made clear later, is possible for a thing to cause motion, though
it is itself incapable of being moved.
It is the fulfilment of what is potential when it is already fully
real and operates not as itself but as movable, that is motion.
What I mean by 'as' is this: Bronze is potentially a statue. But it
is not the fulfilment of bronze as bronze which is motion. For 'to
be bronze' and 'to be a certain potentiality' are not the same.
If they were identical without qualification, i.e. in definition, the
fulfilment of bronze as bronze would have been motion. But
they are not the same, as has been said. (This is obvious in
contraries. 'To be capable of health' and 'to be capable of illness'
are not the same, for if they were there would be no difference
between being ill and being well. Yet the subject both of health
and of sickness - whether it is humour or blood - is one and the
same.)
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We can distinguish, then, between the two - just as, to give
another example, 'colour' and visible' are different - and clearly
it is the fulfilment of what is potential as potential that is
motion. So this, precisely, is motion.
Further it is evident that motion is an attribute of a thing just
when it is fully real in this way, and neither before nor after. For
each thing of this kind is capable of being at one time actual, at
another not. Take for instance the buildable as buildable. The
actuality of the buildable as buildable is the process of building.
For the actuality of the buildable must be either this or the
house. But when there is a house, the buildable is no longer
buildable. On the other hand, it is the buildable which is being
built. The process then of being built must be the kind of
actuality required But building is a kind of motion, and the
same account will apply to the other kinds also.
The soundness of this definition is evident both when we
consider the accounts of motion that the others have given, and
also from the difficulty of defining it otherwise.
One could not easily put motion and change in another genus -
this is plain if we consider where some people put it; they
identify motion with or 'inequality' or 'not being'; but such
things are not necessarily moved, whether they are 'different' or
'unequal' or 'non-existent'; Nor is change either to or from
these rather than to or from their opposites.
The reason why they put motion into these genera is that it is
thought to be something indefinite, and the principles in the
second column are indefinite because they are privative: none
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of them is either 'this' or 'such' or comes under any of the other
modes of predication. The reason in turn why motion is thought
to be indefinite is that it cannot be classed simply as a
potentiality or as an actuality - a thing that is merely capable of
having a certain size is not undergoing change, nor yet a thing
that is actually of a certain size, and motion is thought to be a
sort of actuality, but incomplete, the reason for this view being
that the potential whose actuality it is is incomplete. This is
why it is hard to grasp what motion is. It is necessary to class it
with privation or with potentiality or with sheer actuality, yet
none of these seems possible. There remains then the suggested
mode of definition, namely that it is a sort of actuality, or
actuality of the kind described, hard to grasp, but not incapable
of existing.
The mover too is moved, as has been said - every mover, that is,
which is capable of motion, and whose immobility is rest -
when a thing is subject to motion its immobility is rest. For to
act on the movable as such is just to move it. But this it does by
contact, so that at the same time it is also acted on. Hence we
can define motion as the fulfilment of the movable qua
movable, the cause of the attribute being contact with what can
move so that the mover is also acted on. The mover or agent
will always be the vehicle of a form, either a 'this' or 'such',
which, when it acts, will be the source and cause of the change,
e.g. the full-formed man begets man from what is potentially
man.
The solution of the difficulty that is raised about the motion -
whether it is in the movable - is plain. It is the fulfilment of this
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potentiality, and by the action of that which has the power of
causing motion; and the actuality of that which has the power
of causing motion is not other than the actuality of the
movable, for it must be the fulfilment of both. A thing is capable
of causing motion because it can do this, it is a mover because it
actually does it. But it is on the movable that it is capable of
acting. Hence there is a single actuality of both alike, just as one
to two and two to one are the same interval, and the steep
ascent and the steep descent are one - for these are one and the
same, although they can be described in different ways. So it is
with the mover and the moved.
This view has a dialectical difficulty. Perhaps it is necessary that
the actuality of the agent and that of the patient should not be
the same. The one is 'agency' and the other 'patiency'; and the
outcome and completion of the one is an 'action', that of the
other a 'passion'. Since then they are both motions, we may ask:
in what are they, if they are different? Either (a) both are in what
is acted on and moved, or (b) the agency is in the agent and the
patiency in the patient. (If we ought to call the latter also
'agency', the word would be used in two senses.)
Now, in alternative (b), the motion will be in the mover, for the
same statement will hold of 'mover' and 'moved'. Hence either
every mover will be moved, or, though having motion, it will not
be moved.
If on the other hand (a) both are in what is moved and acted on
- both the agency and the patiency (e.g. both teaching and
learning, though they are two, in the learner), then, first, the
actuality of each will not be present in each, and, a second
absurdity, a thing will have two motions at the same time. How
will there be two alterations of quality in one subject towards
one definite quality? The thing is impossible: the actualization
will be one.
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But (some one will say) it is contrary to reason to suppose that
there should be one identical actualization of two things which
are different in kind. Yet there will be, if teaching and learning
are the same, and agency and patiency. To teach will be the
same as to learn, and to act the same as to be acted on - the
teacher will necessarily be learning everything that he teaches,
and the agent will be acted on. One may reply:
(1) It is not absurd that the actualization of one thing should be
in another. Teaching is the activity of a person who can teach,
yet the operation is performed on some patient - it is not cut
adrift from a subject, but is of A on B.
(2) There is nothing to prevent two things having one and the
same actualization, provided the actualizations are not
described in the same way, but are related as what can act to
what is acting.
(3) Nor is it necessary that the teacher should learn, even if to
act and to be acted on are one and the same, provided they are
not the same in definition (as 'raiment' and 'dress'), but are the
same merely in the sense in which the road from Thebes to
Athens and the road from Athens to Thebes are the same, as
has been explained above. For it is not things which are in a way
the same that have all their attributes the same, but only such
as have the same definition. But indeed it by no means follows
from the fact that teaching is the same as learning, that to learn
is the same as to teach, any more than it follows from the fact
that there is one distance between two things which are at a
distance from each other, that the two vectors AB and BA, are
one and the same. To generalize, teaching is not the same as
learning, or agency as patiency, in the full sense, though they
belong to the same subject, the motion; for the 'actualization of
X in Y' and the 'actualization ofY through the action of X' differ
in definition.
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What then Motion is, has been stated both generally and
particularly. It is not difficult to see how each of its types will be
defined - alteration is the fulfillment of the alterable qua
alterable (or, more scientifically, the fulfilment of what can act
and what can be acted on, as such) - generally and again in
each particular case, building, healing, &c. A similar definition
will apply to each of the other kinds of motion.
The science of nature is concerned with spatial magnitudes and
motion and time, and each of these at least is necessarily
infinite or finite, even if some things dealt with by the science
are not, e.g. a quality or a point - it is not necessary perhaps
that such things should be put under either head. Hence it is
incumbent on the person who specializes in physics to discuss
the infinite and to inquire whether there is such a thing or not,
and, if there is, what it is.
The appropriateness to the science of this problem is clearly
indicated. All who have touched on this kind of science in a way
worth considering have formulated views about the infinite, and
indeed, to a man, make it a principle of things.
(1) Some, as the Pythagoreans and Plato, make the infinite a
principle in the sense of a self-subsistent substance, and not as
a mere attribute of some other thing. Only the Pythagoreans
place the infinite among the objects of sense (they do not regard
number as separable from these), and assert that what is
outside the heaven is infinite. Plato, on the other hand, holds
that there is no body outside (the Forms are not outside because
they are nowhere), yet that the infinite is present not only in the
objects of sense but in the Forms also.
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Further, the Pythagoreans identify the infinite with the even. For
this, they say, when it is cut off and shut in by the odd, provides
things with the element of infinity. An indication of this is what
happens with numbers. If the gnomons are placed round the
one, and without the one, in the one construction the figure
that results is always different, in the other it is always the
same. But Plato has two infinites, the Great and the Small.
The physicists, on the other hand, all of them, always regard the
infinite as an attribute of a substance which is different from it
and belongs to the class of the so-called elements - water or air
or what is intermediate between them. Those who make them
limited in number never make them infinite in amount. But
those who make the elements infinite in number, as
Anaxagoras and Democritus do, say that the infinite is
continuous by contact - compounded of the homogeneous parts
according to the one, of the seed-mass of the atomic shapes
according to the other.
Further, Anaxagoras held that any part is a mixture in the same
way as the All, on the ground of the observed fact that anything
comes out of anything. For it is probably for this reason that he
maintains that once upon a time all things were together. (This
flesh and this bone were together, and so of any thing: therefore
all things: and at the same time too.) For there is a beginning of
separation, not only for each thing, but for all. Each thing that
comes to be comes from a similar body, and there is a coming to
be of all things, though not, it is true, at the same time. Hence
there must also be an origin of coming to be. One such source
there is which he calls Mind, and Mind begins its work of
thinking from some starting-point. So necessarily all things
must have been together at a certain time, and must have
begun to be moved at a certain time.
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Democritus, for his part, asserts the contrary, namely that no
element arises from another element. Nevertheless for him the
common body is a source of all things, differing from part to
part in size and in shape.
It is clear then from these considerations that the inquiry
concerns the physicist. Nor is it without reason that they all
make it a principle or source. We cannot say that the infinite
has no effect, and the only effectiveness which we can ascribe
to it is that of a principle. Everything is either a source or
derived from a source. But there cannot be a source of the
infinite or limitless, for that would be a limit of it. Further, as it
is a beginning, it is both uncreatable and indestructible. For
there must be a point at which what has come to be reaches
completion, and also a termination of all passing away. That is
why, as we say, there is no principle of this, but it is this which
is held to be the principle of other things, and to encompass all
and to steer all, as those assert who do not recognize, alongside
the infinite, other causes, such as Mind or Friendship. Further
they identify it with the Divine, for it is 'deathless and
imperishable' as Anaximander says, with the majority of the
physicists.
Belief in the existence of the infinite comes mainly from five
considerations:
(1) From the nature of time - for it is infinite.
(2) From the division of magnitudes - for the mathematicians
also use the notion of the infinite.
(3) If coming to be and passing away do not give out, it is only
because that from which things come to be is infinite.
(4) Because the limited always finds its limit in something, so
that there must be no limit, if everything is always limited by
something different from itself.
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(5) Most of all, a reason which is peculiarly appropriate and
presents the difficulty that is felt by everybody - not only
number but also mathematical magnitudes and what is outside
the heaven are supposed to be infinite because they never give
out in our thought.
The last fact (that what is outside is infinite) leads people to
suppose that body also is infinite, and that there is an infinite
number of worlds. Why should there be body in one part of the
void rather than in another? Grant only that mass is anywhere
and it follows that it must be everywhere. Also, if void and place
are infinite, there must be infinite body too, for in the case of
eternal things what may be must be. But the problem of the
infinite is difficult: many contradictions result whether we
suppose it to exist or not to exist. If it exists, we have still to ask
how it exists; as a substance or as the essential attribute of
some entity? Or in neither way, yet none the less is there
something which is infinite or some things which are infinitely
many?
The problem, however, which specially belongs to the physicist
is to investigate whether there is a sensible magnitude which is
infinite.
We must begin by distinguishing the various senses in which
the term 'infinite' is used.
(1) What is incapable of being gone through, because it is not in
its nature to be gone through (the sense in which the voice is
'invisible').
(2) What admits of being gone through, the process however
having no termination, or what scarcely admits of being gone
through.
(3) What naturally admits of being gone through, but is not
actually gone through or does not actually reach an end.
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Further, everything that is infinite may be so in respect of
addition or division or both.
Now it is impossible that the infinite should be a thing which is
itself infinite, separable from sensible objects. If the infinite is
neither a magnitude nor an aggregate, but is itself a substance
and not an attribute, it will be indivisible; for the divisible must
be either a magnitude or an aggregate. But if indivisible, then
not infinite, except in the sense (1) in which the voice is
'invisible'. But this is not the sense in which it is used by those
who say that the infinite exists, nor that in which we are
investigating it, namely as (2) 'that which cannot be gone
through'. But if the infinite exists as an attribute, it would not
be, qua infinite an element in substances, any more than the
invisible would be an element of speech, though the voice is
invisible.
Further, how can the infinite be itself any thing, unless both
number and magnitude, of which it is an essential attribute,
exist in that way? If they are not substances, a fortiori the
infinite is not.
It is plain, too, that the infinite cannot be an actual thing and a
substance and principle. For any part of it that is taken will be
infinite, if it has parts: for 'to be infinite' and 'the infinite' are
the same, if it is a substance and not predicated of a subject.
Hence it will be either indivisible or divisible into infinites. But
the same thing cannot be many infinites. (Yet just as part of air
is air, so a part of the infinite would be infinite, if it is supposed
to be a substance and principle.) Therefore the infinite must be
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without parts and indivisible. But this cannot be true of what is
infinite in full completion: for it must be a definite quantity.
Suppose then that infinity belongs to substance as an attribute.
But, if so, it cannot, as we have said, be described as a principle,
but rather that of which it is an attribute - the air or the even
number.
Thus the view of those who speak after the manner of the
Pythagoreans is absurd. With the same breath they treat the
infinite as substance, and divide it into parts.
This discussion, however, involves the more general question
whether the infinite can be present in mathematical objects
and things which are intelligible and do not have extension, as
well as among sensible objects. Our inquiry (as physicists) is
limited to its special subject-matter, the objects of sense, and
we have to ask whether there is or is not among them a body
which is infinite in the direction of increase.
We may begin with a dialectical argument and show as follows
that there is no such thing. If 'bounded by a surface' is the
definition of body there cannot be an infinite body either
intelligible or sensible. Nor can number taken in abstraction be
infinite, for number or that which has number is numerable. If
then the numerable can be numbered, it would also be possible
to go through the infinite.
If, on the other hand, we investigate the question more in
accordance with principles appropriate to physics, we are led as
follows to the same result.
The infinite body must be either (1) compound, or (2) simple; yet
neither alternative is possible.
(1) Compound the infinite body will not be, if the elements are
finite in number. For they must be more than one, and the
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contraries must always balance, and no one of them can be
infinite. If one of the bodies falls in any degree short of the
other in potency - suppose fire is finite in amount while air is
infinite and a given quantity of fire exceeds in power the same
amount of air in any ratio provided it is numerically definite -
the infinite body will obviously prevail over and annihilate the
finite body. On the other hand, it is impossible that each should
be infinite. 'Body' is what has extension in all directions and the
infinite is what is boundlessly extended, so that the infinite
body would be extended in all directions ad infinitum.
Nor (2) can the infinite body be one and simple, whether it is, as
some hold, a thing over and above the elements (from which
they generate the elements) or is not thus qualified.
(a) We must consider the former alternative; for there are some
people who make this the infinite, and not air or water, in order
that the other elements may not be annihilated by the element
which is infinite. They have contrariety with each other - air is
cold, water moist, fire hot; if one were infinite, the others by
now would have ceased to be. As it is, they say, the infinite is
different from them and is their source.
It is impossible, however, that there should be such a body; not
because it is infinite on that point a general proof can be given
which applies equally to all, air, water, or anything else - but
simply because there is, as a matter of fact, no such sensible
body, alongside the so-called elements. Everything can be
resolved into the elements of which it is composed. Hence the
body in question would have been present in our world here,
alongside air and fire and earth and water: but nothing of the
kind is observed.
(b) Nor can fire or any other of the elements be infinite. For
generally, and apart from the question of how any of them
could be infinite, the All, even if it were limited, cannot either be
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or become one of them, as Heraclitus says that at some time all
things become fire. (The same argument applies also to the one
which the physicists suppose to exist alongside the elements:
for everything changes from contrary to contrary, e.g. from hot
to cold).
The preceding consideration of the various cases serves to show
us whether it is or is not possible that there should be an
infinite sensible body. The following arguments give a general
demonstration that it is not possible.
It is the nature of every kind of sensible body to be somewhere,
and there is a place appropriate to each, the same for the part
and for the whole, e.g. for the whole earth and for a single clod,
and for fire and for a spark.
Suppose (a) that the infinite sensible body is homogeneous.
Then each part will be either immovable or always being carried
along. Yet neither is possible. For why downwards rather than
upwards or in any other direction? I mean, e.g, if you take a
clod, where will it be moved or where will it be at rest? For ex
hypothesi the place of the body akin to it is infinite. Will it
occupy the whole place, then? And how? What then will be the
nature of its rest and of its movement, or where will they be? It
will either be at home everywhere - then it will not be moved;
or it will be moved everywhere - then it will not come to rest.
But if (b) the All has dissimilar parts, the proper places of the
parts will be dissimilar also, and the body of the All will have no
unity except that of contact. Then, further, the parts will be
either finite or infinite in variety of kind, (i) Finite they cannot
be, for if the All is to be infinite, some of them would have to be
infinite, while the others were not, e.g. fire or water will be
infinite. But, as we have seen before, such an element would
destroy what is contrary to it. (This indeed is the reason why
none of the physicists made fire or earth the one infinite body,
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but either water or air or what is intermediate between them,
because the abode of each of the two was plainly determinate,
while the others have an ambiguous place between up and
down.)
But (ii) if the parts are infinite in number and simple, their
proper places too will be infinite in number, and the same will
be true of the elements themselves. If that is impossible, and
the places are finite, the whole too must be finite; for the place
and the body cannot but fit each other. Neither is the whole
place larger than what can be filled by the body (and then the
body would no longer be infinite), nor is the body larger than
the place; for either there would be an empty space or a body
whose nature it is to be nowhere.
Anaxagoras gives an absurd account of why the infinite is at
rest. He says that the infinite itself is the cause of its being
fixed. This because it is in itself, since nothing else contains it -
on the assumption that wherever anything is, it is there by its
own nature. But this is not true: a thing could be somewhere by
compulsion, and not where it is its nature to be.
Even if it is true as true can be that the whole is not moved (for
what is fixed by itself and is in itself must be immovable), yet
we must explain why it is not its nature to be moved. It is not
enough just to make this statement and then decamp. Anything
else might be in a state of rest, but there is no reason why it
should not be its nature to be moved. The earth is not carried
along, and would not be carried along if it were infinite,
provided it is held together by the centre. But it would not be
because there was no other region in which it could be carried
along that it would remain at the centre, but because this is its
nature. Yet in this case also we may say that it fixes itself. If
then in the case of the earth, supposed to be infinite, it is at rest,
not because it is infinite, but because it has weight and what is
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heavy rests at the centre and the earth is at the centre, similarly
the infinite also would rest in itself, not because it is infinite
and fixes itself, but owing to some other cause.
Another difficulty emerges at the same time. Any part of the
infinite body ought to remain at rest. Just as the infinite
remains at rest in itself because it fixes itself, so too any part of
it you may take will remain in itself. The appropriate places of
the whole and of the part are alike, e.g. of the whole earth and
of a clod the appropriate place is the lower region; of fire as a
whole and of a spark, the upper region. If, therefore, to be in
itself is the place of the infinite, that also will be appropriate to
the part. Therefore it will remain in itself.
In general, the view that there is an infinite body is plainly
incompatible with the doctrine that there is necessarily a
proper place for each kind of body, if every sensible body has
either weight or lightness, and if a body has a natural
locomotion towards the centre if it is heavy, and upwards if it is
light. This would need to be true of the infinite also. But neither
character can belong to it: it cannot be either as a whole, nor
can it be half the one and half the other. For how should you
divide it? or how can the infinite have the one part up and the
other down, or an extremity and a centre?
Further, every sensible body is in place, and the kinds or
differences of place are up-down, before-behind, right-left; and
these distinctions hold not only in relation to us and by
arbitrary agreement, but also in the whole itself. But in the
infinite body they cannot exist. In general, if it is impossible
that there should be an infinite place, and if every body is in
place, there cannot be an infinite body.
Surely what is in a special place is in place, and what is in place
is in a special place. Just, then, as the infinite cannot be quantity
- that would imply that it has a particular quantity, e,g, two or
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three cubits; quantity just means these - so a thing's being in
place means that it is somewhere, and that is either up or down
or in some other of the six differences of position: but each of
these is a limit.
It is plain from these arguments that there is no body which is
actually infinite.
But on the other hand to suppose that the infinite does not
exist in any way leads obviously to many impossible
consequences: there will be a beginning and an end of time, a
magnitude will not be divisible into magnitudes, number will
not be infinite. If, then, in view of the above considerations,
neither alternative seems possible, an arbiter must be called in;
and clearly there is a sense in which the infinite exists and
another in which it does not.
We must keep in mind that the word 'is' means either what
potentially is or what fully is. Further, a thing is infinite either
by addition or by division.
Now, as we have seen, magnitude is not actually infinite. But by
division it is infinite. (There is no difficulty in refuting the
theory of indivisible lines.) The alternative then remains that
the infinite has a potential existence.
But the phrase 'potential existence' is ambiguous. When we
speak of the potential existence of a statue we mean that there
will be an actual statue. It is not so with the infinite. There will
not be an actual infinite. The word 'is' has many senses, and we
say that the infinite 'is' in the sense in which we say 'it is day' or
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'it is the games', because one thing after another is always
coming into existence. For of these things too the distinction
between potential and actual existence holds. We say that there
are Olympic games, both in the sense that they may occur and
that they are actually occurring.
The infinite exhibits itself in different ways - in time, in the
generations of man, and in the division of magnitudes. For
generally the infinite has this mode of existence: one thing is
always being taken after another, and each thing that is taken is
always finite, but always different. Again, 'being' has more than
one sense, so that we must not regard the infinite as a 'this',
such as a man or a horse, but must suppose it to exist in the
sense in which we speak of the day or the games as existing
things whose being has not come to them like that of a
substance, but consists in a process of coming to be or passing
away; definite if you like at each stage, yet always different.
But when this takes place in spatial magnitudes, what is taken
perists, while in the succession of time and of men it takes
place by the passing away of these in such a way that the source
of supply never gives out.
In a way the infinite by addition is the same thing as the infinite
by division. In a finite magnitude, the infinite by addition comes
about in a way inverse to that of the other. For in proportion as
we see division going on, in the same proportion we see
addition being made to what is already marked off. For if we
take a determinate part of a finite magnitude and add another
part determined by the same ratio (not taking in the same
amount of the original whole), and so on, we shall not traverse
the given magnitude. But if we increase the ratio of the part, so
as always to take in the same amount, we shall traverse the
magnitude, for every finite magnitude is exhausted by means of
any determinate quantity however small.
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The infinite, then, exists in no other way, but in this way it does
exist, potentially and by reduction. It exists fully in the sense in
which we say 'it is day' or 'it is the games'; and potentially as
matter exists, not independently as what is finite does.
By addition then, also, there is potentially an infinite, namely,
what we have described as being in a sense the same as the
infinite in respect of division. For it will always be possible to
take something ah extra. Yet the sum of the parts taken will not
exceed every determinate magnitude, just as in the direction of
division every determinate magnitude is surpassed in smallness
and there will be a smaller part.
But in respect of addition there cannot be an infinite which
even potentially exceeds every assignable magnitude, unless it
has the attribute of being actually infinite, as the physicists hold
to be true of the body which is outside the world, whose
essential nature is air or something of the kind. But if there
cannot be in this way a sensible body which is infinite in the
full sense, evidently there can no more be a body which is
potentially infinite in respect of addition, except as the inverse
of the infinite by division, as we have said. It is for this reason
that Plato also made the infinites two in number, because it is
supposed to be possible to exceed all limits and to proceed ad
infinitum in the direction both of increase and of reduction. Yet
though he makes the infinites two, he does not use them. For in
the numbers the infinite in the direction of reduction is not
present, as the monad is the smallest; nor is the infinite in the
direction of increase, for the parts number only up to the decad.
The infinite turns out to be the contrary of what it is said to be.
It is not what has nothing outside it that is infinite, but what
always has something outside it. This is indicated by the fact
that rings also that have no bezel are described as 'endless',
because it is always possible to take a part which is outside a
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given part. The description depends on a certain similarity, but
it is not true in the full sense of the word. This condition alone
is not sufficient: it is necessary also that the next part which is
taken should never be the same. In the circle, the latter
condition is not satisfied: it is only the adjacent part from which
the new part is different.
Our definition then is as follows:
A quantity is infinite if it is such that we can always take a part
outside what has been already taken. On the other hand, what
has nothing outside it is complete and whole. For thus we
define the whole - that from which nothing is wanting, as a
whole man or a whole box. What is true of each particular is
true of the whole as such - the whole is that of which nothing is
outside. On the other hand that from which something is
absent and outside, however small that may be, is not 'all'.
'Whole' and 'complete' are either quite identical or closely akin.
Nothing is complete (teleion) which has no end (telos); and the
end is a limit.
Hence Parmenides must be thought to have spoken better than
Melissus. The latter says that the whole is infinite, but the
former describes it as limited, 'equally balanced from the
middle'. For to connect the infinite with the all and the whole is
not like joining two pieces of string; for it is from this they get
the dignity they ascribe to the infinite - its containing all things
and holding the all in itself - from its having a certain similarity
to the whole. It is in fact the matter of the completeness which
belongs to size, and what is potentially a whole, though not in
the full sense. It is divisible both in the direction of reduction
and of the inverse addition. It is a whole and limited; not,
however, in virtue of its own nature, but in virtue of what is
other than it. It does not contain, but, in so far as it is infinite, is
contained. Consequently, also, it is unknowable, qua infinite; for
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the matter has no form. (Hence it is plain that the infinite
stands in the relation of part rather than of whole. For the
matter is part of the whole, as the bronze is of the bronze
statue.) If it contains in the case of sensible things, in the case
of intelligible things the great and the small ought to contain
them. But it is absurd and impossible to suppose that the
unknowable and indeterminate should contain and determine.
It is reasonable that there should not be held to be an infinite in
respect of addition such as to surpass every magnitude, but that
there should be thought to be such an infinite in the direction of
division. For the matter and the infinite are contained inside
what contains them, while it is the form which contains. It is
natural too to suppose that in number there is a limit in the
direction of the minimum, and that in the other direction every
assigned number is surpassed. In magnitude, on the contrary,
every assigned magnitude is surpassed in the direction of
smallness, while in the other direction there is no infinite
magnitude. The reason is that what is one is indivisible
whatever it may be, e.g. a man is one man, not many. Number
on the other hand is a plurality of 'ones' and a certain quantity
of them. Hence number must stop at the indivisible: for 'two'
and 'three' are merely derivative terms, and so with each of the
other numbers. But in the direction of largeness it is always
possible to think of a larger number: for the number of times a
magnitude can be bisected is infinite. Hence this infinite is
potential, never actual: the number of parts that can be taken
always surpasses any assigned number. But this number is not
separable from the process of bisection, and its infinity is not a
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permanent actuality but consists in a process of coming to be,
like time and the number of time.
With magnitudes the contrary holds. What is continuous is
divided ad infinitum, but there is no infinite in the direction of
increase. For the size which it can potentially be, it can also
actually be. Hence since no sensible magnitude is infinite, it is
impossible to exceed every assigned magnitude; for if it were
possible there would be something bigger than the heavens.
The infinite is not the same in magnitude and movement and
time, in the sense of a single nature, but its secondary sense
depends on its primary sense, i.e. movement is called infinite in
virtue of the magnitude covered by the movement (or alteration
or growth), and time because of the movement. (I use these
terms for the moment. Later I shall explain what each of them
means, and also why every magnitude is divisible into
magnitudes.)
Our account does not rob the mathematicians of their science,
by disproving the actual existence of the infinite in the direction
of increase, in the sense of the untraversable. In point of fact
they do not need the infinite and do not use it. They postulate
only that the finite straight line may be produced as far as they
wish. It is possible to have divided in the same ratio as the
largest quantity another magnitude of any size you like. Hence,
for the purposes of proof, it will make no difference to them to
have such an infinite instead, while its existence will be in the
sphere of real magnitudes.
In the fourfold scheme of causes, it is plain that the infinite is a
cause in the sense of matter, and that its essence is privation,
the subject as such being what is continuous and sensible. All
the other thinkers, too, evidently treat the infinite as matter -
that is why it is inconsistent in them to make it what contains,
and not what is contained.
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8
It remains to dispose of the arguments which are supposed to
support the view that the infinite exists not only potentially but
as a separate thing. Some have no cogency; others can be met
by fresh objections that are valid.
(1) In order that coming to be should not fail, it is not necessary
that there should be a sensible body which is actually infinite.
The passing away of one thing may be the coming to be of
another, the All being limited.
(2) There is a difference between touching and being limited.
The former is relative to something and is the touching of
something (for everything that touches touches something), and
further is an attribute of some one of the things which are
limited. On the other hand, what is limited is not limited in
relation to anything. Again, contact is not necessarily possible
between any two things taken at random.
(3) To rely on mere thinking is absurd, for then the excess or
defect is not in the thing but in the thought. One might think
that one of us is bigger than he is and magnify him ad
infinitum. But it does not follow that he is bigger than the size
we are, just because some one thinks he is, but only because he
is the size he is. The thought is an accident.
(a) Time indeed and movement are infinite, and also thinking, in
the sense that each part that is taken passes in succession out
of existence.
(b) Magnitude is not infinite either in the way of reduction or of
magnification in thought.
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This concludes my account of the way in which the infinite
exists, and of the way in which it does not exist, and of what it
is.
Book IV
The physicist must have a knowledge of Place, too, as well as of
the infinite - namely, whether there is such a thing or not, and
the manner of its existence and what it is - both because all
suppose that things which exist are somewhere (the non-
existent is nowhere - where is the goat-stag or the sphinx?),
and because 'motion' in its most general and primary sense is
change of place, which we call 'locomotion'.
The question, what is place? presents many difficulties. An
examination of all the relevant facts seems to lead to divergent
conclusions. Moreover, we have inherited nothing from previous
thinkers, whether in the way of a statement of difficulties or of
a solution.
The existence of place is held to be obvious from the fact of
mutual replacement. Where water now is, there in turn, when
the water has gone out as from a vessel, air is present. When
therefore another body occupies this same place, the place is
thought to be different from all the bodies which come to be in
it and replace one another. What now contains air formerly
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contained water, so that clearly the place or space into which
and out of which they passed was something different from
both.
Further, the typical locomotions of the elementary natural
bodies - namely, fire, earth, and the like - show not only that
place is something, but also that it exerts a certain influence.
Each is carried to its own place, if it is not hindered, the one up,
the other down. Now these are regions or kinds of place - up
and down and the rest of the six directions. Nor do such
distinctions (up and down and right and left, &c.) hold only in
relation to us. To us they are not always the same but change
with the direction in which we are turned: that is why the same
thing may be both right and left, up and down, before and
behind. But in nature each is distinct, taken apart by itself. It is
not every chance direction which is 'up', but where fire and
what is light are carried; similarly, too, 'down' is not any chance
direction but where what has weight and what is made of earth
are carried - the implication being that these places do not
differ merely in relative position, but also as possessing distinct
potencies. This is made plain also by the objects studied by
mathematics. Though they have no real place, they
nevertheless, in respect of their position relatively to us, have a
right and left as attributes ascribed to them only in
consequence of their relative position, not having by nature
these various characteristics. Again, the theory that the void
exists involves the existence of place: for one would define void
as place bereft of body.
These considerations then would lead us to suppose that place
is something distinct from bodies, and that every sensible body
is in place. Hesiod too might be held to have given a correct
account of it when he made chaos first. At least he says:
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'First of all things came chaos to being, then broad-breasted
earth,' implying that things need to have space first, because he
thought, with most people, that everything is somewhere and in
place. If this is its nature, the potency of place must be a
marvellous thing, and take precedence of all other things. For
that without which nothing else can exist, while it can exist
without the others, must needs be first; for place does not pass
out of existence when the things in it are annihilated.
True, but even if we suppose its existence settled, the question
of its nature presents difficulty - whether it is some sort of
'bulk' of body or some entity other than that, for we must first
determine its genus.
(1) Now it has three dimensions, length, breadth, depth, the
dimensions by which all body also is bounded. But the place
cannot be body; for if it were there would be two bodies in the
same place.
(2) Further, if body has a place and space, clearly so too have
surface and the other limits of body; for the same statement
will apply to them: where the bounding planes of the water
were, there in turn will be those of the air. But when we come to
a point we cannot make a distinction between it and its place.
Hence if the place of a point is not different from the point, no
more will that of any of the others be different, and place will
not be something different from each of them.
(3) What in the world then are we to suppose place to be? If it
has the sort of nature described, it cannot be an element or
composed of elements, whether these be corporeal or
incorporeal: for while it has size, it has not body. But the
elements of sensible bodies are bodies, while nothing that has
size results from a combination of intelligible elements.
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(4) Also we may ask: of what in things is space the cause? None
of the four modes of causation can be ascribed to it. It is neither
in the sense of the matter of existents (for nothing is composed
of it), nor as the form and definition of things, nor as end, nor
does it move existents.
(5) Further, too, if it is itself an existent, where will it be? Zeno's
difficulty demands an explanation: for if everything that exists
has a place, place too will have a place, and so on ad infinitum.
(6) Again, just as every body is in place, so, too, every place has a
body in it. What then shall we say about growing things? It
follows from these premisses that their place must grow with
them, if their place is neither less nor greater than they are.
By asking these questions, then, we must raise the whole
problem about place - not only as to what it is, but even
whether there is such a thing.
We may distinguish generally between predicating B of A
because it (A) is itself, and because it is something else; and
particularly between place which is common and in which all
bodies are, and the special place occupied primarily by each. I
mean, for instance, that you are now in the heavens because
you are in the air and it is in the heavens; and you are in the air
because you are on the earth; and similarly on the earth
because you are in this place which contains no more than you.
Now if place is what primarily contains each body, it would be a
limit, so that the place would be the form or shape of each body
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by which the magnitude or the matter of the magnitude is
defined: for this is the limit of each body.
If, then, we look at the question in this way the place of a thing
is its form. But, if we regard the place as the extension of the
magnitude, it is the matter. For this is different from the
magnitude: it is what is contained and defined by the form, as
by a bounding plane. Matter or the indeterminate is of this
nature; when the boundary and attributes of a sphere are taken
away, nothing but the matter is left.
This is why Plato in the Timaeus says that matter and space are
the same; for the 'participant' and space are identical. (It is true,
indeed, that the account he gives there of the 'participant' is
different from what he says in his so-called 'unwritten
teaching'. Nevertheless, he did identify place and space.) I
mention Plato because, while all hold place to be something, he
alone tried to say what it is.
In view of these facts we should naturally expect to find
difficulty in determining what place is, if indeed it is one of
these two things, matter or form. They demand a very close
scrutiny, especially as it is not easy to recognize them apart.
But it is at any rate not difficult to see that place cannot be
either of them. The form and the matter are not separate from
the thing, whereas the place can be separated. As we pointed
out, where air was, water in turn comes to be, the one replacing
the other; and similarly with other bodies. Hence the place of a
thing is neither a part nor a state of it, but is separable from it.
For place is supposed to be something like a vessel - the vessel
being a transportable place. But the vessel is no part of the
thing.
In so far then as it is separable from the thing, it is not the form:
qua containing, it is different from the matter.
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Also it is held that what is anywhere is both itself something
and that there is a different thing outside it. (Plato of course, if
we may digress, ought to tell us why the form and the numbers
are not in place, if 'what participates' is place - whether what
participates is the Great and the Small or the matter, as he
called it in writing in the Timaeus.)
Further, how could a body be carried to its own place, if place
was the matter or the form? It is impossible that what has no
reference to motion or the distinction of up and down can be
place. So place must be looked for among things which have
these characteristics.
If the place is in the thing (it must be if it is either shape or
matter) place will have a place: for both the form and the
indeterminate undergo change and motion along with the
thing, and are not always in the same place, but are where the
thing is. Hence the place will have a place.
Further, when water is produced from air, the place has been
destroyed, for the resulting body is not in the same place. What
sort of destruction then is that?
This concludes my statement of the reasons why space must be
something, and again of the difficulties that may be raised
about its essential nature.
The next step we must take is to see in how many senses one
thing is said to be 'in' another.
(1) As the finger is 'in' the hand and generally the part 'in' the
whole.
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(2) As the whole is 'in' the parts: for there is no whole over and
above the parts.
(3) As man is 'in' animal and generally species 'in' genus.
(4) As the genus is 'in' the species and generally the part of the
specific form 'in' the definition of the specific form.
(5) As health is 'in' the hot and the cold and generally the form
'in' the matter.
(6) As the affairs of Greece centre 'in' the king, and generally
events centre 'in' their primary motive agent.
(7) As the existence of a thing centres 'in its good and generally
'in' its end, i.e. in 'that for the sake of which' it exists.
(8) In the strictest sense of all, as a thing is 'in' a vessel, and
generally 'in' place.
One might raise the question whether a thing can be in itself, or
whether nothing can be in itself - everything being either
nowhere or in something else.
The question is ambiguous; we may mean the thing qua itself
or qua something else.
When there are parts of a whole - the one that in which a thing
is, the other the thing which is in it - the whole will be
described as being in itself. For a thing is described in terms of
its parts, as well as in terms of the thing as a whole, e.g. a man
is said to be white because the visible surface of him is white, or
to be scientific because his thinking faculty has been trained.
The jar then will not be in itself and the wine will not be in
itself. But the jar of wine will: for the contents and the container
are both parts of the same whole.
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In this sense then, but not primarily, a thing can be in itself,
namely, as 'white' is in body (for the visible surface is in body),
and science is in the mind.
It is from these, which are 'parts' (in the sense at least of being
'in' the man), that the man is called white, &c. But the jar and
the wine in separation are not parts of a whole, though together
they are. So when there are parts, a thing will be in itself, as
'white' is in man because it is in body, and in body because it
resides in the visible surface. We cannot go further and say that
it is in surface in virtue of something other than itself. (Yet it is
not in itself: though these are in a way the same thing,) they
differ in essence, each having a special nature and capacity,
'surface' and 'white'.
Thus if we look at the matter inductively we do not find
anything to be 'in' itself in any of the senses that have been
distinguished; and it can be seen by argument that it is
impossible. For each of two things will have to be both, e.g. the
jar will have to be both vessel and wine, and the wine both wine
and jar, if it is possible for a thing to be in itself; so that,
however true it might be that they were in each other, the jar
will receive the wine in virtue not of its being wine but of the
wine's being wine, and the wine will be in the jar in virtue not
of its being a jar but of the jar's being a jar. Now that they are
different in respect of their essence is evident; for 'that in which
something is' and 'that which is in it' would be differently
defined.
Nor is it possible for a thing to be in itself even incidentally: for
two things would at the same time in the same thing. The jar
would be in itself- if a thing whose nature it is to receive can be
in itself; and that which it receives, namely (if wine) wine, will
be in it.
Obviously then a thing cannot be in itself primarily.
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Zeno's problem - that if Place is something it must be in
something - is not difficult to solve. There is nothing to prevent
the first place from being 'in' something else - not indeed in
that as 'in' place, but as health is 'in' the hot as a positive
determination of it or as the hot is 'in' body as an affection. So
we escape the infinite regress.
Another thing is plain: since the vessel is no part of what is in it
(what contains in the strict sense is different from what is
contained), place could not be either the matter or the form of
the thing contained, but must different - for the latter, both the
matter and the shape, are parts of what is contained.
This then may serve as a critical statement of the difficulties
involved.
What then after all is place? The answer to this question may be
elucidated as follows.
Let us take for granted about it the various characteristics which
are supposed correctly to belong to it essentially. We assume
then-
(1) Place is what contains that of which it is the place.
(2) Place is no part of the thing.
(3) The immediate place of a thing is neither less nor greater
than the thing.
(4) Place can be left behind by the thing and is separable. In
addition:
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(5) All place admits of the distinction of up and down, and each
of the bodies is naturally carried to its appropriate place and
rests there, and this makes the place either up or down.
Having laid these foundations, we must complete the theory.
We ought to try to make our investigation such as will render an
account of place, and will not only solve the difficulties
connected with it, but will also show that the attributes
supposed to belong to it do really belong to it, and further will
make clear the cause of the trouble and of the difficulties about
it. Such is the most satisfactory kind of exposition.
First then we must understand that place would not have been
thought of, if there had not been a special kind of motion,
namely that with respect to place. It is chiefly for this reason
that we suppose the heaven also to be in place, because it is in
constant movement. Of this kind of change there are two
species - locomotion on the one hand and, on the other,
increase and diminution. For these too involve variation of
place: what was then in this place has now in turn changed to
what is larger or smaller.
Again, when we say a thing is 'moved', the predicate either (1)
belongs to it actually, in virtue of its own nature, or (2) in virtue
of something conjoined with it. In the latter case it may be
either (a) something which by its own nature is capable of being
moved, e.g. the parts of the body or the nail in the ship, or (b)
something which is not in itself capable of being moved, but is
always moved through its conjunction with something else, as
'whiteness' or 'science'. These have changed their place only
because the subjects to which they belong do so.
We say that a thing is in the world, in the sense of in place,
because it is in the air, and the air is in the world; and when we
say it is in the air, we do not mean it is in every part of the air,
but that it is in the air because of the outer surface of the air
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which surrounds it; for if all the air were its place, the place of a
thing would not be equal to the thing - which it is supposed to
be, and which the primary place in which a thing is actually is.
When what surrounds, then, is not separate from the thing, but
is in continuity with it, the thing is said to be in what surrounds
it, not in the sense of in place, but as a part in a whole. But
when the thing is separate and in contact, it is immediately 'in'
the inner surface of the surrounding body, and this surface is
neither a part of what is in it nor yet greater than its extension,
but equal to it; for the extremities of things which touch are
coincident.
Further, if one body is in continuity with another, it is not
moved in that but with that. On the other hand it is moved in
that if it is separate. It makes no difference whether what
contains is moved or not.
Again, when it is not separate it is described as a part in a
whole, as the pupil in the eye or the hand in the body: when it is
separate, as the water in the cask or the wine in the jar. For the
hand is moved with the body and the water in the cask.
It will now be plain from these considerations what place is.
There are just four things of which place must be one - the
shape, or the matter, or some sort of extension between the
bounding surfaces of the containing body, or this boundary
itself if it contains no extension over and above the bulk of the
body which comes to be in it.
Three of these it obviously cannot be:
(1) The shape is supposed to be place because it surrounds, for
the extremities of what contains and of what is contained are
coincident. Both the shape and the place, it is true, are
boundaries. But not of the same thing: the form is the boundary
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of the thing, the place is the boundary of the body which
contains it.
(2) The extension between the extremities is thought to be
something, because what is contained and separate may often
be changed while the container remains the same (as water
may be poured from a vessel) - the assumption being that the
extension is something over and above the body displaced. But
there is no such extension. One of the bodies which change
places and are naturally capable of being in contact with the
container falls in whichever it may chance to be.
If there were an extension which were such as to exist
independently and be permanent, there would be an infinity of
places in the same thing. For when the water and the air change
places, all the portions of the two together will play the same
part in the whole which was previously played by all the water
in the vessel; at the same time the place too will be undergoing
change; so that there will be another place which is the place of
the place, and many places will be coincident. There is not a
different place of the part, in which it is moved, when the whole
vessel changes its place: it is always the same: for it is in the
(proximate) place where they are that the air and the water (or
the parts of the water) succeed each other, not in that place in
which they come to be, which is part of the place which is the
place of the whole world.
(3) The matter, too, might seem to be place, at least if we
consider it in what is at rest and is thus separate but in
continuity. For just as in change of quality there is something
which was formerly black and is now white, or formerly soft
and now hard - this is just why we say that the matter exists -
so place, because it presents a similar phenomenon, is thought
to exist - only in the one case we say so because what was air is
now water, in the other because where air formerly was there a
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is now water. But the matter, as we said before, is neither
separable from the thing nor contains it, whereas place has
both characteristics.
Well, then, if place is none of the three - neither the form nor
the matter nor an extension which is always there, different
from, and over and above, the extension of the thing which is
displaced - place necessarily is the one of the four which is left,
namely, the boundary of the containing body at which it is in
contact with the contained body. (By the contained body is
meant what can be moved by way of locomotion.)
Place is thought to be something important and hard to grasp,
both because the matter and the shape present themselves
along with it, and because the displacement of the body that is
moved takes place in a stationary container, for it seems
possible that there should be an interval which is other than the
bodies which are moved. The air, too, which is thought to be
incorporeal, contributes something to the belief: it is not only
the boundaries of the vessel which seem to be place, but also
what is between them, regarded as empty. Just, in fact, as the
vessel is transportable place, so place is a non-portable vessel.
So when what is within a thing which is moved, is moved and
changes its place, as a boat on a river, what contains plays the
part of a vessel rather than that of place. Place on the other
hand is rather what is motionless: so it is rather the whole river
that is place, because as a whole it is motionless.
Hence we conclude that the innermost motionless boundary of
what contains is place.
This explains why the middle of the heaven and the surface
which faces us of the rotating system are held to be 'up' and
'down' in the strict and fullest sense for all men: for the one is
always at rest, while the inner side of the rotating body remains
always coincident with itself. Hence since the light is what is
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naturally carried up, and the heavy what is carried down, the
boundary which contains in the direction of the middle of the
universe, and the middle itself, are down, and that which
contains in the direction of the outermost part of the universe,
and the outermost part itself, are up.
For this reason, too, place is thought to be a kind of surface, and
as it were a vessel, i.e. a container of the thing.
Further, place is coincident with the thing, for boundaries are
coincident with the bounded.
If then a body has another body outside it and containing it, it is
in place, and if not, not. That is why, even if there were to be
water which had not a container, the parts of it, on the one
hand, will be moved (for one part is contained in another),
while, on the other hand, the whole will be moved in one sense,
but not in another. For as a whole it does not simultaneously
change its place, though it will be moved in a circle: for this
place is the place of its parts. (Some things are moved, not up
and down, but in a circle; others up and down, such things
namely as admit of condensation and rarefaction.)
As was explained, some things are potentially in place, others
actually. So, when you have a homogeneous substance which is
continuous, the parts are potentially in place: when the parts
are separated, but in contact, like a heap, they are actually in
place.
Again, (1) some things are per se in place, namely every body
which is movable either by way of locomotion or by way of
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increase is per se somewhere, but the heaven, as has been said,
is not anywhere as a whole, nor in any place, if at least, as we
must suppose, no body contains it. On the line on which it is
moved, its parts have place: for each is contiguous the next.
But (2) other things are in place indirectly, through something
conjoined with them, as the soul and the heaven. The latter is,
in a way, in place, for all its parts are: for on the orb one part
contains another. That is why the upper part is moved in a
circle, while the All is not anywhere. For what is somewhere is
itself something, and there must be alongside it some other
thing wherein it is and which contains it. But alongside the All
or the Whole there is nothing outside the All, and for this
reason all things are in the heaven; for the heaven, we may say,
is the All. Yet their place is not the same as the heaven. It is part
of it, the innermost part of it, which is in contact with the
movable body; and for this reason the earth is in water, and this
in the air, and the air in the aether, and the aether in heaven,
but we cannot go on and say that the heaven is in anything else.
It is clear, too, from these considerations that all the problems
which were raised about place will be solved when it is
explained in this way:
(1) There is no necessity that the place should grow with the
body in it,
(2) Nor that a point should have a place,
(3) Nor that two bodies should be in the same place,
(4) Nor that place should be a corporeal interval: for what is
between the boundaries of the place is any body which may
chance to be there, not an interval in body.
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Further, (5) place is also somewhere, not in the sense of being in
a place, but as the limit is in the limited; for not everything that
is is in place, but only movable body.
Also (6) it is reasonable that each kind of body should be carried
to its own place. For a body which is next in the series and in
contact (not by compulsion) is akin, and bodies which are
united do not affect each other, while those which are in
contact interact on each other.
Nor (7) is it without reason that each should remain naturally in
its proper place. For this part has the same relation to its place,
as a separable part to its whole, as when one moves a part of
water or air: so, too, air is related to water, for the one is like
matter, the other form - water is the matter of air, air as it were
the actuality of water, for water is potentially air, while air is
potentially water, though in another way.
These distinctions will be drawn more carefully later. On the
present occasion it was necessary to refer to them: what has
now been stated obscurely will then be made more clear. If the
matter and the fulfilment are the same thing (for water is both,
the one potentially, the other completely), water will be related
to air in a way as part to whole. That is why these have contact:
it is organic union when both become actually one.
This concludes my account of place - both of its existence and
of its nature.
The investigation of similar questions about the void, also, must
be held to belong to the physicist - namely whether it exists or
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not, and how it exists or what it is - just as about place. The
views taken of it involve arguments both for and against, in
much the same sort of way. For those who hold that the void
exists regard it as a sort of place or vessel which is supposed to
be 'full' when it holds the bulk which it is capable of containing,
'void' when it is deprived of that - as if 'void' and 'full' and
'place' denoted the same thing, though the essence of the three
is different.
We must begin the inquiry by putting down the account given
by those who say that it exists, then the account of those who
say that it does not exist, and third the current view on these
questions.
Those who try to show that the void does not exist do not
disprove what people really mean by it, but only their erroneous
way of speaking; this is true of Anaxagoras and of those who
refute the existence of the void in this way. They merely give an
ingenious demonstration that air is something - by straining
wine-skins and showing the resistance of the air, and by cutting
it off in clepsydras. But people really mean that there is an
empty interval in which there is no sensible body. They hold
that everything which is in body is body and say that what has
nothing in it at all is void (so what is full of air is void). It is not
then the existence of air that needs to be proved, but the non-
existence of an interval, different from the bodies, either
separable or actual - an interval which divides the whole body
so as to break its continuity, as Democritus and Leucippus hold,
and many other physicists - or even perhaps as something
which is outside the whole body, which remains continuous.
These people, then, have not reached even the threshold of the
problem, but rather those who say that the void exists.
(1) They argue, for one thing, that change in place (i.e.
locomotion and increase) would not be. For it is maintained that
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motion would seem not to exist, if there were no void, since
what is full cannot contain anything more. If it could, and there
were two bodies in the same place, it would also be true that
any number of bodies could be together; for it is impossible to
draw a line of division beyond which the statement would
become untrue. If this were possible, it would follow also that
the smallest body would contain the greatest; for 'many a little
makes a mickle': thus if many equal bodies can be together, so
also can many unequal bodies.
Melissus, indeed, infers from these considerations that the All is
immovable; for if it were moved there must, he says, be void,
but void is not among the things that exist.
This argument, then, is one way in which they show that there
is a void.
(2) They reason from the fact that some things are observed to
contract and be compressed, as people say that a cask will hold
the wine which formerly filled it, along with the skins into
which the wine has been decanted, which implies that the
compressed body contracts into the voids present in it.
Again (3) increase, too, is thought to take always by means of
void, for nutriment is body, and it is impossible for two bodies to
be together. A proof of this they find also in what happens to
ashes, which absorb as much water as the empty vessel.
The Pythagoreans, too, (4) held that void exists and that it
enters the heaven itself, which as it were inhales it, from the
infinite air. Further it is the void which distinguishes the
natures of things, as if it were like what separates and
distinguishes the terms of a series. This holds primarily in the
numbers, for the void distinguishes their nature.
These, then, and so many, are the main grounds on which
people have argued for and against the existence of the void.
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As a step towards settling which view is true, we must
determine the meaning of the name.
The void is thought to be place with nothing in it. The reason
for this is that people take what exists to be body, and hold that
while every body is in place, void is place in which there is no
body, so that where there is no body, there must be void.
Every body, again, they suppose to be tangible; and of this
nature is whatever has weight or lightness.
Hence, by a syllogism, what has nothing heavy or light in it, is
void.
This result, then, as I have said, is reached by syllogism. It
would be absurd to suppose that the point is void; for the void
must be place which has in it an interval in tangible body.
But at all events we observe then that in one way the void is
described as what is not full of body perceptible to touch; and
what has heaviness and lightness is perceptible to touch. So we
would raise the question: what would they say of an interval
that has colour or sound - is it void or not? Clearly they would
reply that if it could receive what is tangible it was void, and if
not, not.
In another way void is that in which there is no 'this' or
corporeal substance. So some say that the void is the matter of
the body (they identify the place, too, with this), and in this they
speak incorrectly; for the matter is not separable from the
things, but they are inquiring about the void as about something
separable.
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Since we have determined the nature of place, and void must, if
it exists, be place deprived of body, and we have stated both in
what sense place exists and in what sense it does not, it is plain
that on this showing void does not exist, either unseparated or
separated; the void is meant to be, not body but rather an
interval in body. This is why the void is thought to be
something, viz. because place is, and for the same reasons. For
the fact of motion in respect of place comes to the aid both of
those who maintain that place is something over and above the
bodies that come to occupy it, and of those who maintain that
the void is something. They state that the void is the condition
of movement in the sense of that in which movement takes
place; and this would be the kind of thing that some say place
is.
But there is no necessity for there being a void if there is
movement. It is not in the least needed as a condition of
movement in general, for a reason which, incidentally, escaped
Melissus; viz. that the full can suffer qualitative change.
But not even movement in respect of place involves a void; for
bodies may simultaneously make room for one another, though
there is no interval separate and apart from the bodies that are
in movement. And this is plain even in the rotation of
continuous things, as in that of liquids.
And things can also be compressed not into a void but because
they squeeze out what is contained in them (as, for instance,
when water is compressed the air within it is squeezed out);
and things can increase in size not only by the entrance of
something but also by qualitative change; e.g. if water were to
be transformed into air.
In general, both the argument about increase of size and that
about water poured on to the ashes get in their own way. For
either not any and every part of the body is increased, or bodies
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may be increased otherwise than by the addition of body, or
there may be two bodies in the same place (in which case they
are claiming to solve a quite general difficulty, but are not
proving the existence of void), or the whole body must be void,
if it is increased in every part and is increased by means of void.
The same argument applies to the ashes.
It is evident, then, that it is easy to refute the arguments by
which they prove the existence of the void.
8
Let us explain again that there is no void existing separately, as
some maintain. If each of the simple bodies has a natural
locomotion, e.g. fire upward and earth downward and towards
the middle of the universe, it is clear that it cannot be the void
that is the condition of locomotion. What, then, will the void be
the condition of? It is thought to be the condition of movement
in respect of place, and it is not the condition of this.
Again, if void is a sort of place deprived of body, when there is a
void where will a body placed in it move to? It certainly cannot
move into the whole of the void. The same argument applies as
against those who think that place is something separate, into
which things are carried; viz. how will what is placed in it move,
or rest? Much the same argument will apply to the void as to
the 'up' and 'down' in place, as is natural enough since those
who maintain the existence of the void make it a place.
And in what way will things be present either in place - or in
the void? For the expected result does not take place when a
body is placed as a whole in a place conceived of as separate
and permanent; for a part of it, unless it be placed apart, will
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not be in a place but in the whole. Further, if separate place
does not exist, neither will void.
If people say that the void must exist, as being necessary if
there is to be movement, what rather turns out to be the case, if
one the matter, is the opposite, that not a single thing can be
moved if there is a void; for as with those who for a like reason
say the earth is at rest, so, too, in the void things must be at rest;
for there is no place to which things can move more or less than
to another; since the void in so far as it is void admits no
difference.
The second reason is this: all movement is either compulsory or
according to nature, and if there is compulsory movement there
must also be natural (for compulsory movement is contrary to
nature, and movement contrary to nature is posterior to that
according to nature, so that if each of the natural bodies has not
a natural movement, none of the other movements can exist);
but how can there be natural movement if there is no difference
throughout the void or the infinite? For in so far as it is infinite,
there will be no up or down or middle, and in so far as it is a
void, up differs no whit from down; for as there is no difference
in what is nothing, there is none in the void (for the void seems
to be a non-existent and a privation of being), but natural
locomotion seems to be differentiated, so that the things that
exist by nature must be differentiated. Either, then, nothing has
a natural locomotion, or else there is no void.
Further, in point of fact things that are thrown move though
that which gave them their impulse is not touching them, either
by reason of mutual replacement, as some maintain, or because
the air that has been pushed pushes them with a movement
quicker than the natural locomotion of the projectile wherewith
it moves to its proper place. But in a void none of these things
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can take place, nor can anything be moved save as that which is
carried is moved.
Further, no one could say why a thing once set in motion should
stop anywhere; for why should it stop here rather than here? So
that a thing will either be at rest or must be moved ad
infinitum, unless something more powerful get in its way.
Further, things are now thought to move into the void because it
yields; but in a void this quality is present equally everywhere,
so that things should move in all directions.
Further, the truth of what we assert is plain from the following
considerations. We see the same weight or body moving faster
than another for two reasons, either because there is a
difference in what it moves through, as between water, air, and
earth, or because, other things being equal, the moving body
differs from the other owing to excess of weight or of lightness.
Now the medium causes a difference because it impedes the
moving thing, most of all if it is moving in the opposite
direction, but in a secondary degree even if it is at rest; and
especially a medium that is not easily divided, i.e. a medium
that is somewhat dense. A, then, will move through B in time G,
and through D, which is thinner, in time E (if the length of B is
egual to D), in proportion to the density of the hindering body.
For let B be water and D air; then by so much as air is thinner
and more incorporeal than water, A will move through D faster
than through B. Let the speed have the same ratio to the speed,
then, that air has to water. Then if air is twice as thin, the body
will traverse B in twice the time that it does D, and the time G
will be twice the time E. And always, by so much as the medium
is more incorporeal and less resistant and more easily divided,
the faster will be the movement.
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Now there is no ratio in which the void is exceeded by body, as
there is no ratio of to a number. For if 4 exceeds 3 by 1, and 2
by more than 1, and 1 by still more than it exceeds 2, still there
is no ratio by which it exceeds 0; for that which exceeds must
be divisible into the excess + that which is exceeded, so that will
be what it exceeds by + 0. For this reason, too, a line does not
exceed a point unless it is composed of points! Similarly the
void can bear no ratio to the full, and therefore neither can
movement through the one to movement through the other, but
if a thing moves through the thickest medium such and such a
distance in such and such a time, it moves through the void
with a speed beyond any ratio. For let Z be void, equal in
magnitude to B and to D. Then if A is to traverse and move
through it in a certain time, H, a time less than E, however, the
void will bear this ratio to the full. But in a time equal to H, A
will traverse the part of A. And it will surely also traverse in
that time any substance Z which exceeds air in thickness in the
ratio which the time E bears to the time H. For if the body Z be
as much thinner than D as E exceeds H, A, if it moves through Z,
will traverse it in a time inverse to the speed of the movement,
i.e. in a time equal to H. If, then, there is no body in Z, A will
traverse Z still more quickly. But we supposed that its traverse
of Z when Z was void occupied the time H. So that it will
traverse Z in an equal time whether Z be full or void. But this is
impossible. It is plain, then, that if there is a time in which it
will move through any part of the void, this impossible result
will follow: it will be found to traverse a certain distance,
whether this be full or void, in an equal time; for there will be
some body which is in the same ratio to the other body as the
time is to the time.
To sum the matter up, the cause of this result is obvious, viz.
that between any two movements there is a ratio (for they
occupy time, and there is a ratio between any two times, so long
as both are finite), but there is no ratio of void to full.
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These are the consequences that result from a difference in the
media; the following depend upon an excess of one moving
body over another. We see that bodies which have a greater
impulse either of weight or of lightness, if they are alike in other
respects, move faster over an equal space, and in the ratio
which their magnitudes bear to each other. Therefore they will
also move through the void with this ratio of speed. But that is
impossible; for why should one move faster? (In moving
through plena it must be so; for the greater divides them faster
by its force. For a moving thing cleaves the medium either by its
shape, or by the impulse which the body that is carried along or
is projected possesses.) Therefore all will possess equal velocity.
But this is impossible.
It is evident from what has been said, then, that, if there is a
void, a result follows which is the very opposite of the reason
for which those who believe in a void set it up. They think that if
movement in respect of place is to exist, the void cannot exist,
separated all by itself; but this is the same as to say that place is
a separate cavity; and this has already been stated to be
impossible.
But even if we consider it on its own merits the so-called
vacuum will be found to be really vacuous. For as, if one puts a
cube in water, an amount of water equal to the cube will be
displaced; so too in air; but the effect is imperceptible to sense.
And indeed always in the case of any body that can be
displaced, must, if it is not compressed, be displaced in the
direction in which it is its nature to be displaced - always either
down, if its locomotion is downwards as in the case of earth, or
up, if it is fire, or in both directions - whatever be the nature of
the inserted body. Now in the void this is impossible; for it is not
body; the void must have penetrated the cube to a distance
equal to that which this portion of void formerly occupied in
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the void, just as if the water or air had not been displaced by the
wooden cube, but had penetrated right through it.
But the cube also has a magnitude equal to that occupied by the
void; a magnitude which, if it is also hot or cold, or heavy or
light, is none the less different in essence from all its attributes,
even if it is not separable from them; I mean the volume of the
wooden cube. So that even if it were separated from everything
else and were neither heavy nor light, it will occupy an equal
amount of void, and fill the same place, as the part of place or of
the void equal to itself. How then will the body of the cube differ
from the void or place that is equal to it? And if there can be
two such things, why cannot there be any number coinciding?
This, then, is one absurd and impossible implication of the
theory. It is also evident that the cube will have this same
volume even if it is displaced, which is an attribute possessed
by all other bodies also. Therefore if this differs in no respect
from its place, why need we assume a place for bodies over and
above the volume of each, if their volume be conceived of as
free from attributes? It contributes nothing to the situation if
there is an equal interval attached to it as well. [Further it ought
to be clear by the study of moving things what sort of thing void
is. But in fact it is found nowhere in the world. For air is
something, though it does not seem to be so - nor, for that
matter, would water, if fishes were made of iron; for the
discrimination of the tangible is by touch.]
It is clear, then, from these considerations that there is no
separate void.
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There are some who think that the existence of rarity and
density shows that there is a void. If rarity and density do not
exist, they say, neither can things contract and be compressed.
But if this were not to take place, either there would be no
movement at all, or the universe would bulge, as Xuthus said, or
air and water must always change into equal amounts (e.g. if air
has been made out of a cupful of water, at the same time out of
an equal amount of air a cupful of water must have been made),
or void must necessarily exist; for compression and expansion
cannot take place otherwise.
Now, if they mean by the rare that which has many voids
existing separately, it is plain that if void cannot exist separate
any more than a place can exist with an extension all to itself,
neither can the rare exist in this sense. But if they mean that
there is void, not separately existent, but still present in the
rare, this is less impossible, yet, first, the void turns out not to
be a condition of all movement, but only of movement upwards
(for the rare is light, which is the reason why they say fire is
rare); second, the void turns out to be a condition of movement
not as that in which it takes place, but in that the void carries
things up as skins by being carried up themselves carry up what
is continuous with them. Yet how can void have a local
movement or a place? For thus that into which void moves is till
then void of a void.
Again, how will they explain, in the case of what is heavy, its
movement downwards? And it is plain that if the rarer and
more void a thing is the quicker it will move upwards, if it were
completely void it would move with a maximum speed! But
perhaps even this is impossible, that it should move at all; the
same reason which showed that in the void all things are
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incapable of moving shows that the void cannot move, viz. the
fact that the speeds are incomparable.
Since we deny that a void exists, but for the rest the problem
has been truly stated, that either there will be no movement, if
there is not to be condensation and rarefaction, or the universe
will bulge, or a transformation of water into air will always be
balanced by an equal transformation of air into water (for it is
clear that the air produced from water is bulkier than the
water): it is necessary therefore, if compression does not exist,
either that the next portion will be pushed outwards and make
the outermost part bulge, or that somewhere else there must be
an equal amount of water produced out of air, so that the entire
bulk of the whole may be equal, or that nothing moves. For
when anything is displaced this will always happen, unless it
comes round in a circle; but locomotion is not always circular,
but sometimes in a straight line.
These then are the reasons for which they might say that there
is a void; our statement is based on the assumption that there is
a single matter for contraries, hot and cold and the other
natural contrarieties, and that what exists actually is produced
from a potential existent, and that matter is not separable from
the contraries but its being is different, and that a single matter
may serve for colour and heat and cold.
The same matter also serves for both a large and a small body.
This is evident; for when air is produced from water, the same
matter has become something different, not by acquiring an
addition to it, but has become actually what it was potentially,
and, again, water is produced from air in the same way, the
change being sometimes from smallness to greatness, and
sometimes from greatness to smallness. Similarly, therefore, if
air which is large in extent comes to have a smaller volume, or
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becomes greater from being smaller, it is the matter which is
potentially both that comes to be each of the two.
For as the same matter becomes hot from being cold, and cold
from being hot, because it was potentially both, so too from hot
it can become more hot, though nothing in the matter has
become hot that was not hot when the thing was less hot; just
as, if the arc or curve of a greater circle becomes that of a
smaller, whether it remains the same or becomes a different
curve, convexity has not come to exist in anything that was not
convex but straight (for differences of degree do not depend on
an intermission of the quality); nor can we get any portion of a
flame, in which both heat and whiteness are not present. So too,
then, is the earlier heat related to the later. So that the
greatness and smallness, also, of the sensible volume are
extended, not by the matter's acquiring anything new, but
because the matter is potentially matter for both states; so that
the same thing is dense and rare, and the two qualities have
one matter.
The dense is heavy, and the rare is light. [Again, as the arc of a
circle when contracted into a smaller space does not acquire a
new part which is convex, but what was there has been
contracted; and as any part of fire that one takes will be hot; so,
too, it is all a question of contraction and expansion of the same
matter.] There are two types in each case, both in the dense and
in the rare; for both the heavy and the hard are thought to be
dense, and contrariwise both the light and the soft are rare; and
weight and hardness fail to coincide in the case of lead and
iron.
From what has been said it is evident, then, that void does not
exist either separate (either absolutely separate or as a separate
element in the rare) or potentially, unless one is willing to call
the condition of movement void, whatever it may be. At that
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rate the matter of the heavy and the light, qua matter of them,
would be the void; for the dense and the rare are productive of
locomotion in virtue of this contrariety, and in virtue of their
hardness and softness productive of passivity and impassivity,
i.e. not of locomotion but rather of qualitative change.
So much, then, for the discussion of the void, and of the sense
in which it exists and the sense in which it does not exist.
10
Next for discussion after the subjects mentioned is Time. The
best plan will be to begin by working out the difficulties
connected with it, making use of the current arguments. First,
does it belong to the class of things that exist or to that of
things that do not exist? Then secondly, what is its nature? To
start, then: the following considerations would make one
suspect that it either does not exist at all or barely, and in an
obscure way. One part of it has been and is not, while the other
is going to be and is not yet. Yet time - both infinite time and
any time you like to take - is made up of these. One would
naturally suppose that what is made up of things which do not
exist could have no share in reality.
Further, if a divisible thing is to exist, it is necessary that, when
it exists, all or some of its parts must exist. But of time some
parts have been, while others have to be, and no part of it is
though it is divisible. For what is 'now' is not a part: a part is a
measure of the whole, which must be made up of parts. Time,
on the other hand, is not held to be made up of 'nows'.
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Again, the 'now' which seems to bound the past and the future
- does it always remain one and the same or is it always other
and other? It is hard to say.
(1) If it is always different and different, and if none of the parts
in time which are other and other are simultaneous (unless the
one contains and the other is contained, as the shorter time is
by the longer), and if the 'now' which is not, but formerly was,
must have ceased-to-be at some time, the 'nows' too cannot be
simultaneous with one another, but the prior 'now' must always
have ceased-to-be. But the prior 'now' cannot have ceased-to-be
in itself (since it then existed); yet it cannot have ceased-to-be
in another 'now'. For we may lay it down that one 'now' cannot
be next to another, any more than point to point. If then it did
not cease-to-be in the next 'now' but in another, it would exist
simultaneously with the innumerable 'nows' between the two -
which is impossible.
Yes, but (2) neither is it possible for the 'now' to remain always
the same. No determinate divisible thing has a single
termination, whether it is continuously extended in one or in
more than one dimension: but the 'now' is a termination, and it
is possible to cut off a determinate time. Further, if coincidence
in time (i.e. being neither prior nor posterior) means to be 'in
one and the same «now»', then, if both what is before and what
is after are in this same 'now', things which happened ten
thousand years ago would be simultaneous with what has
happened to-day, and nothing would be before or after anything
else.
This may serve as a statement of the difficulties about the
attributes of time.
As to what time is or what is its nature, the traditional accounts
give us as little light as the preliminary problems which we
have worked through.
706
Some assert that it is (1) the movement of the whole, others
that it is (2) the sphere itself.
(1) Yet part, too, of the revolution is a time, but it certainly is not
a revolution: for what is taken is part of a revolution, not a
revolution. Besides, if there were more heavens than one, the
movement of any of them equally would be time, so that there
would be many times at the same time.
(2) Those who said that time is the sphere of the whole thought
so, no doubt, on the ground that all things are in time and all
things are in the sphere of the whole. The view is too naive for it
to be worth while to consider the impossibilities implied in it.
But as time is most usually supposed to be (3) motion and a
kind of change, we must consider this view.
Now (a) the change or movement of each thing is only in the
thing which changes or where the thing itself which moves or
changes may chance to be. But time is present equally
everywhere and with all things.
Again, (b) change is always faster or slower, whereas time is not:
for 'fast' and 'slow' are defined by time - 'fast' is what moves
much in a short time, 'slow' what moves little in a long time;
but time is not defined by time, by being either a certain
amount or a certain kind of it.
Clearly then it is not movement. (We need not distinguish at
present between 'movement' and 'change'.)
707
11
But neither does time exist without change; for when the state
of our own minds does not change at all, or we have not noticed
its changing, we do not realize that time has elapsed, any more
than those who are fabled to sleep among the heroes in
Sardinia do when they are awakened; for they connect the
earlier 'now' with the later and make them one, cutting out the
interval because of their failure to notice it. So, just as, if the
'now' were not different but one and the same, there would not
have been time, so too when its difference escapes our notice
the interval does not seem to be time. If, then, the non-
realization of the existence of time happens to us when we do
not distinguish any change, but the soul seems to stay in one
indivisible state, and when we perceive and distinguish we say
time has elapsed, evidently time is not independent of
movement and change. It is evident, then, that time is neither
movement nor independent of movement.
We must take this as our starting-point and try to discover -
since we wish to know what time is - what exactly it has to do
with movement.
Now we perceive movement and time together: for even when it
is dark and we are not being affected through the body, if any
movement takes place in the mind we at once suppose that
some time also has elapsed; and not only that but also, when
some time is thought to have passed, some movement also
along with it seems to have taken place. Hence time is either
movement or something that belongs to movement. Since then
it is not movement, it must be the other.
But what is moved is moved from something to something, and
all magnitude is continuous. Therefore the movement goes with
the magnitude. Because the magnitude is continuous, the
movement too must be continuous, and if the movement, then
708
the time; for the time that has passed is always thought to be in
proportion to the movement.
The distinction of 'before' and 'after' holds primarily, then, in
place; and there in virtue of relative position. Since then 'before'
and 'after' hold in magnitude, they must hold also in
movement, these corresponding to those. But also in time the
distinction of 'before' and 'after' must hold, for time and
movement always correspond with each other. The 'before' and
'after' in motion is identical in substratum with motion yet
differs from it in definition, and is not identical with motion.
But we apprehend time only when we have marked motion,
marking it by 'before' and 'after'; and it is only when we have
perceived 'before' and 'after' in motion that we say that time
has elapsed. Now we mark them by judging that A and B are
different, and that some third thing is intermediate to them.
When we think of the extremes as different from the middle
and the mind pronounces that the 'nows' are two, one before
and one after, it is then that we say that there is time, and this
that we say is time. For what is bounded by the 'now' is thought
to be time - we may assume this.
When, therefore, we perceive the 'now' one, and neither as
before and after in a motion nor as an identity but in relation to
a 'before' and an 'after', no time is thought to have elapsed,
because there has been no motion either. On the other hand,
when we do perceive a 'before' and an 'after', then we say that
there is time. For time is just this - number of motion in respect
of 'before' and 'after'.
Hence time is not movement, but only movement in so far as it
admits of enumeration. A proof of this: we discriminate the
more or the less by number, but more or less movement by
time. Time then is a kind of number. (Number, we must note, is
used in two senses - both of what is counted or the countable
709
and also of that with which we count. Time obviously is what is
counted, not that with which we count: there are different kinds
of thing.) Just as motion is a perpetual succession, so also is
time. But every simultaneous time is self-identical; for the 'now'
as a subject is an identity, but it accepts different attributes. The
'now' measures time, in so far as time involves the 'before and
after'.
The 'now' in one sense is the same, in another it is not the
same. In so far as it is in succession, it is different (which is just
what its being was supposed to mean), but its substratum is an
identity: for motion, as was said, goes with magnitude, and
time, as we maintain, with motion. Similarly, then, there
corresponds to the point the body which is carried along, and by
which we are aware of the motion and of the 'before and after'
involved in it. This is an identical substratum (whether a point
or a stone or something else of the kind), but it has different
attributes as the sophists assume that Coriscus' being in the
Lyceum is a different thing from Coriscus' being in the market-
place. And the body which is carried along is different, in so far
as it is at one time here and at another there. But the 'now'
corresponds to the body that is carried along, as time
corresponds to the motion. For it is by means of the body that is
carried along that we become aware of the 'before and after' the
motion, and if we regard these as countable we get the 'now'.
Hence in these also the 'now' as substratum remains the same
(for it is what is before and after in movement), but what is
predicated of it is different; for it is in so far as the 'before and
after' is numerable that we get the 'now'. This is what is most
knowable: for, similarly, motion is known because of that which
is moved, locomotion because of that which is carried, what is
carried is a real thing, the movement is not. Thus what is called
'now' in one sense is always the same; in another it is not the
same: for this is true also of what is carried.
710
Clearly, too, if there were no time, there would be no 'now', and
vice versa, just as the moving body and its locomotion involve
each other mutually, so too do the number of the moving body
and the number of its locomotion. For the number of the
locomotion is time, while the 'now' corresponds to the moving
body, and is like the unit of number.
Time, then, also is both made continuous by the 'now' and
divided at it. For here too there is a correspondence with the
locomotion and the moving body. For the motion or locomotion
is made one by the thing which is moved, because it is one - not
because it is one in its own nature (for there might be pauses in
the movement of such a thing) - but because it is one in
definition: for this determines the movement as 'before' and
'after'. Here, too there is a correspondence with the point; for
the point also both connects and terminates the length - it is
the beginning of one and the end of another. But when you take
it in this way, using the one point as two, a pause is necessary, if
the same point is to be the beginning and the end. The 'now' on
the other hand, since the body carried is moving, is always
different.
Hence time is not number in the sense in which there is
'number' of the same point because it is beginning and end, but
rather as the extremities of a line form a number, and not as the
parts of the line do so, both for the reason given (for we can use
the middle point as two, so that on that analogy time might
stand still), and further because obviously the 'now' is no part of
time nor the section any part of the movement, any more than
the points are parts of the line - for it is two lines that are parts
of one line.
In so far then as the 'now' is a boundary, it is not time, but an
attribute of it; in so far as it numbers, it is number; for
boundaries belong only to that which they bound, but number
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(e.g. ten) is the number of these horses, and belongs also
elsewhere.
It is clear, then, that time is 'number of movement in respect of
the before and after', and is continuous since it is an attribute of
what is continuous.
12
The smallest number, in the strict sense of the word 'number', is
two. But of number as concrete, sometimes there is a minimum,
sometimes not: e.g. of a 'line', the smallest in respect of
multiplicity is two (or, if you like, one), but in respect of size
there is no minimum; for every line is divided ad infinitum.
Hence it is so with time. In respect of number the minimum is
one (or two); in point of extent there is no minimum.
It is clear, too, that time is not described as fast or slow, but as
many or few and as long or short. For as continuous it is long or
short and as a number many or few, but it is not fast or slow -
any more than any number with which we number is fast or
slow.
Further, there is the same time everywhere at once, but not the
same time before and after, for while the present change is one,
the change which has happened and that which will happen
are different. Time is not number with which we count, but the
number of things which are counted, and this according as it
occurs before or after is always different, for the 'nows' are
different. And the number of a hundred horses and a hundred
men is the same, but the things numbered are different - the
horses from the men. Further, as a movement can be one and
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the same again and again, so too can time, e.g. a year or a spring
or an autumn.
Not only do we measure the movement by the time, but also the
time by the movement, because they define each other. The
time marks the movement, since it is its number, and the
movement the time. We describe the time as much or little,
measuring it by the movement, just as we know the number by
what is numbered, e.g. the number of the horses by one horse
as the unit. For we know how many horses there are by the use
of the number; and again by using the one horse as unit we
know the number of the horses itself. So it is with the time and
the movement; for we measure the movement by the time and
vice versa. It is natural that this should happen; for the
movement goes with the distance and the time with the
movement, because they are quanta and continuous and
divisible. The movement has these attributes because the
distance is of this nature, and the time has them because of the
movement. And we measure both the distance by the
movement and the movement by the distance; for we say that
the road is long, if the journey is long, and that this is long, if
the road is long - the time, too, if the movement, and the
movement, if the time.
Time is a measure of motion and of being moved, and it
measures the motion by determining a motion which will
measure exactly the whole motion, as the cubit does the length
by determining an amount which will measure out the whole.
Further 'to be in time' means for movement, that both it and its
essence are measured by time (for simultaneously it measures
both the movement and its essence, and this is what being in
time means for it, that its essence should be measured).
Clearly then 'to be in time' has the same meaning for other
things also, namely, that their being should be measured by
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time. 'To be in time' is one of two things: (1) to exist when time
exists, (2) as we say of some things that they are 'in number'.
The latter means either what is a part or mode of number - in
general, something which belongs to number - or that things
have a number.
Now, since time is number, the 'now' and the 'before' and the
like are in time, just as 'unit' and 'odd' and 'even' are in number,
i.e. in the sense that the one set belongs to number, the other to
time. But things are in time as they are in number. If this is so,
they are contained by time as things in place are contained by
place.
Plainly, too, to be in time does not mean to co-exist with time,
any more than to be in motion or in place means to co-exist
with motion or place. For if 'to be in something' is to mean this,
then all things will be in anything, and the heaven will be in a
grain; for when the grain is, then also is the heaven. But this is a
merely incidental conjunction, whereas the other is necessarily
involved: that which is in time necessarily involves that there is
time when it is, and that which is in motion that there is
motion when it is.
Since what is 'in time' is so in the same sense as what is in
number is so, a time greater than everything in time can be
found. So it is necessary that all the things in time should be
contained by time, just like other things also which are 'in
anything', e.g. the things 'in place' by place.
A thing, then, will be affected by time, just as we are
accustomed to say that time wastes things away, and that all
things grow old through time, and that there is oblivion owing
to the lapse of time, but we do not say the same of getting to
know or of becoming young or fair. For time is by its nature the
cause rather of decay, since it is the number of change, and
change removes what is.
714
Hence, plainly, things which are always are not, as such, in time,
for they are not contained time, nor is their being measured by
time. A proof of this is that none of them is affected by time,
which indicates that they are not in time.
Since time is the measure of motion, it will be the measure of
rest too - indirectly. For all rest is in time. For it does not follow
that what is in time is moved, though what is in motion is
necessarily moved. For time is not motion, but 'number of
motion': and what is at rest, also, can be in the number of
motion. Not everything that is not in motion can be said to be
'at rest' - but only that which can be moved, though it actually
is not moved, as was said above.
'To be in number' means that there is a number of the thing,
and that its being is measured by the number in which it is.
Hence if a thing is 'in time' it will be measured by time. But time
will measure what is moved and what is at rest, the one qua
moved, the other qua at rest; for it will measure their motion
and rest respectively.
Hence what is moved will not be measurable by the time simply
in so far as it has quantity, but in so far as its motion has
quantity. Thus none of the things which are neither moved nor
at rest are in time: for 'to be in time' is 'to be measured by time',
while time is the measure of motion and rest.
Plainly, then, neither will everything that does not exist be in
time, i.e. those non-existent things that cannot exist, as the
diagonal cannot be commensurate with the side.
Generally, if time is directly the measure of motion and
indirectly of other things, it is clear that a thing whose
existence is measured by it will have its existence in rest or
motion. Those things therefore which are subject to perishing
and becoming - generally, those which at one time exist, at
715
another do not - are necessarily in time: for there is a greater
time which will extend both beyond their existence and beyond
the time which measures their existence. Of things which do
not exist but are contained by time some were, e.g. Homer once
was, some will be, e.g. a future event; this depends on the
direction in which time contains them; if on both, they have
both modes of existence. As to such things as it does not
contain in any way, they neither were nor are nor will be. These
are those nonexistents whose opposites always are, as the
incommensurability of the diagonal always is - and this will not
be in time. Nor will the commensurability, therefore; hence this
eternally is not, because it is contrary to what eternally is. A
thing whose contrary is not eternal can be and not be, and it is
of such things that there is coming to be and passing away.
13
The 'now' is the link of time, as has been said (for it connects
past and future time), and it is a limit of time (for it is the
beginning of the one and the end of the other). But this is not
obvious as it is with the point, which is fixed. It divides
potentially, and in so far as it is dividing the 'now' is always
different, but in so far as it connects it is always the same, as it
is with mathematical lines. For the intellect it is not always one
and the same point, since it is other and other when one divides
the line; but in so far as it is one, it is the same in every respect.
So the 'now' also is in one way a potential dividing of time, in
another the termination of both parts, and their unity. And the
dividing and the uniting are the same thing and in the same
reference, but in essence they are not the same.
716
So one kind of 'now' is described in this way: another is when
the time is near this kind of 'now'. 'He will come now' because
he will come to-day; 'he has come now' because he came to-day.
But the things in the Iliad have not happened 'now', nor is the
flood 'now' - not that the time from now to them is not
continuous, but because they are not near.
'At some time' means a time determined in relation to the first
of the two types of 'now', e.g. 'at some time' Troy was taken, and
'at some time' there will be a flood; for it must be determined
with reference to the 'now'. There will thus be a determinate
time from this 'now' to that, and there was such in reference to
the past event. But if there be no time which is not 'sometime',
every time will be determined.
Will time then fail? Surely not, if motion always exists. Is time
then always different or does the same time recur? Clearly time
is, in the same way as motion is. For if one and the same motion
sometimes recurs, it will be one and the same time, and if not,
not.
Since the 'now' is an end and a beginning of time, not of the
same time however, but the end of that which is past and the
beginning of that which is to come, it follows that, as the circle
has its convexity and its concavity, in a sense, in the same thing,
so time is always at a beginning and at an end. And for this
reason it seems to be always different; for the 'now' is not the
beginning and the end of the same thing; if it were, it would be
at the same time and in the same respect two opposites. And
time will not fail; for it is always at a beginning.
'Presently' or 'just' refers to the part of future time which is near
the indivisible present 'now' ('When do you walk? 'Presently',
because the time in which he is going to do so is near), and to
the part of past time which is not far from the 'now' ('When do
you walk?' 'I have just been walking'). But to say that Troy has
717
just been taken - we do not say that, because it is too far from
the 'now'. 'Lately', too, refers to the part of past time which is
near the present 'now'. 'When did you go?' 'Lately', if the time is
near the existing now. 'Long ago' refers to the distant past.
'Suddenly' refers to what has departed from its former
condition in a time imperceptible because of its smallness; but
it is the nature of all change to alter things from their former
condition. In time all things come into being and pass away; for
which reason some called it the wisest of all things, but the
Pythagorean Paron called it the most stupid, because in it we
also forget; and his was the truer view. It is clear then that it
must be in itself, as we said before, the condition of destruction
rather than of coming into being (for change, in itself, makes
things depart from their former condition), and only
incidentally of coming into being, and of being. A sufficient
evidence of this is that nothing comes into being without itself
moving somehow and acting, but a thing can be destroyed even
if it does not move at all. And this is what, as a rule, we chiefly
mean by a thing's being destroyed by time. Still, time does not
work even this change; even this sort of change takes place
incidentally in time.
We have stated, then, that time exists and what it is, and in how
many senses we speak of the 'now', and what 'at some time',
'lately', 'presently' or 'just', 'long ago', and 'suddenly' mean.
14
These distinctions having been drawn, it is evident that every
change and everything that moves is in time; for the distinction
of faster and slower exists in reference to all change, since it is
found in every instance. In the phrase 'moving faster' I refer to
718
that which changes before another into the condition in
question, when it moves over the same interval and with a
regular movement; e.g. in the case of locomotion, if both things
move along the circumference of a circle, or both along a
straight line; and similarly in all other cases. But what is before
is in time; for we say 'before' and 'after' with reference to the
distance from the 'now', and the 'now' is the boundary of the
past and the future; so that since 'nows' are in time, the before
and the after will be in time too; for in that in which the 'now'
is, the distance from the 'now' will also be. But 'before' is used
contrariwise with reference to past and to future time; for in the
past we call 'before' what is farther from the 'now', and 'after'
what is nearer, but in the future we call the nearer 'before' and
the farther 'after'. So that since the 'before' is in time, and every
movement involves a 'before', evidently every change and every
movement is in time.
It is also worth considering how time can be related to the soul;
and why time is thought to be in everything, both in earth and
in sea and in heaven. Is because it is an attribute, or state, or
movement (since it is the number of movement) and all these
things are movable (for they are all in place), and time and
movement are together, both in respect of potentiality and in
respect of actuality?
Whether if soul did not exist time would exist or not, is a
question that may fairly be asked; for if there cannot be some
one to count there cannot be anything that can be counted, so
that evidently there cannot be number; for number is either
what has been, or what can be, counted. But if nothing but soul,
or in soul reason, is qualified to count, there would not be time
unless there were soul, but only that of which time is an
attribute, i.e. if movement can exist without soul, and the before
and after are attributes of movement, and time is these qua
numerable.
719
One might also raise the question what sort of movement time
is the number of. Must we not say 'of any kind? For things both
come into being in time and pass away, and grow, and are
altered in time, and are moved locally; thus it is of each
movement qua movement that time is the number. And so it is
simply the number of continuous movement, not of any
particular kind of it.
But other things as well may have been moved now, and there
would be a number of each of the two movements. Is there
another time, then, and will there be two equal times at once?
Surely not. For a time that is both equal and simultaneous is
one and the same time, and even those that are not
simultaneous are one in kind; for if there were dogs, and horses,
and seven of each, it would be the same number. So, too,
movements that have simultaneous limits have the same time,
yet the one may in fact be fast and the other not, and one may
be locomotion and the other alteration; still the time of the two
changes is the same if their number also is equal and
simultaneous; and for this reason, while the movements are
different and separate, the time is everywhere the same,
because the number of equal and simultaneous movements is
everywhere one and the same.
Now there is such a thing as locomotion, and in locomotion
there is included circular movement, and everything is
measured by some one thing homogeneous with it, units by a
unit, horses by a horse, and similarly times by some definite
time, and, as we said, time is measured by motion as well as
motion by time (this being so because by a motion definite in
time the quantity both of the motion and of the time is
measured): if, then, what is first is the measure of everything
homogeneous with it, regular circular motion is above all else
the measure, because the number of this is the best known.
Now neither alteration nor increase nor coming into being can
720
be regular, but locomotion can be. This also is why time is
thought to be the movement of the sphere, viz. because the
other movements are measured by this, and time by this
movement.
This also explains the common saying that human affairs form
a circle, and that there is a circle in all other things that have a
natural movement and coming into being and passing away.
This is because all other things are discriminated by time, and
end and begin as though conforming to a cycle; for even time
itself is thought to be a circle. And this opinion again is held
because time is the measure of this kind of locomotion and is
itself measured by such. So that to say that the things that
come into being form a circle is to say that there is a circle of
time; and this is to say that it is measured by the circular
movement; for apart from the measure nothing else to be
measured is observed; the whole is just a plurality of measures.
It is said rightly, too, that the number of the sheep and of the
dogs is the same number if the two numbers are equal, but not
the same decad or the same ten; just as the equilateral and the
scalene are not the same triangle, yet they are the same figure,
because they are both triangles. For things are called the same
so-and-so if they do not differ by a differentia of that thing, but
not if they do; e.g. triangle differs from triangle by a differentia
of triangle, therefore they are different triangles; but they do not
differ by a differentia of figure, but are in one and the same
division of it. For a figure of the one kind is a circle and a figure
of another kind of triangle, and a triangle of one kind is
equilateral and a triangle of another kind scalene. They are the
same figure, then, that, triangle, but not the same triangle.
Therefore the number of two groups also - is the same number
(for their number does not differ by a differentia of number), but
it is not the same decad; for the things of which it is asserted
differ; one group are dogs, and the other horses.
721
We have now discussed time - both time itself and the matters
appropriate to the consideration of it.
BookV
Everything which changes does so in one of three senses. It may
change (1) accidentally, as for instance when we say that
something musical walks, that which walks being something in
which aptitude for music is an accident. Again (2) a thing is said
without qualification to change because something belonging to
it changes, i.e. in statements which refer to part of the thing in
question: thus the body is restored to health because the eye or
the chest, that is to say a part of the whole body, is restored to
health. And above all there is (3) the case of a thing which is in
motion neither accidentally nor in respect of something else
belonging to it, but in virtue of being itself directly in motion.
Here we have a thing which is essentially movable: and that
which is so is a different thing according to the particular
variety of motion: for instance it may be a thing capable of
alteration: and within the sphere of alteration it is again a
different thing according as it is capable of being restored to
health or capable of being heated. And there are the same
distinctions in the case of the mover: (1) one thing causes
motion accidentally, (2) another partially (because something
belonging to it causes motion), (3) another of itself directly, as,
722
for instance, the physician heals, the hand strikes. We have,
then, the following factors: (a) on the one hand that which
directly causes motion, and (b) on the other hand that which is
in motion: further, we have (c) that in which motion takes place,
namely time, and (distinct from these three) (d) that from which
and (e) that to which it proceeds: for every motion proceeds
from something and to something, that which is directly in
motion being distinct from that to which it is in motion and
that from which it is in motion: for instance, we may take the
three things 'wood', 'hot', and 'cold', of which the first is that
which is in motion, the second is that to which the motion
proceeds, and the third is that from which it proceeds. This
being so, it is clear that the motion is in the wood, not in its
form: for the motion is neither caused nor experienced by the
form or the place or the quantity. So we are left with a mover, a
moved, and a goal of motion. I do not include the starting-point
of motion: for it is the goal rather than the starting-point of
motion that gives its name to a particular process of change.
Thus 'perishing' is change to not-being, though it is also true
that that that which perishes changes from being: and
'becoming' is change to being, though it is also change from
not-being.
Now a definition of motion has been given above, from which it
will be seen that every goal of motion, whether it be a form, an
affection, or a place, is immovable, as, for instance, knowledge
and heat. Here, however, a difficulty may be raised. Affections, it
may be said, are motions, and whiteness is an affection: thus
there may be change to a motion. To this we may reply that it is
not whiteness but whitening that is a motion. Here also the
same distinctions are to be observed: a goal of motion may be
so accidentally, or partially and with reference to something
other than itself, or directly and with no reference to anything
else: for instance, a thing which is becoming white changes
accidentally to an object of thought, the colour being only
723
accidentally the object of thought; it changes to colour, because
white is a part of colour, or to Europe, because Athens is a part
of Europe; but it changes essentially to white colour. It is now
clear in what sense a thing is in motion essentially, accidentally,
or in respect of something other than itself, and in what sense
the phrase 'itself directly' is used in the case both of the mover
and of the moved: and it is also clear that the motion is not in
the form but in that which is in motion, that is to say 'the
movable in activity'. Now accidental change we may leave out of
account: for it is to be found in everything, at any time, and in
any respect. Change which is not accidental on the other hand
is not to be found in everything, but only in contraries, in things
intermediate contraries, and in contradictories, as may be
proved by induction. An intermediate may be a starting-point of
change, since for the purposes of the change it serves as
contrary to either of two contraries: for the intermediate is in a
sense the extremes. Hence we speak of the intermediate as in a
sense a contrary relatively to the extremes and of either
extreme as a contrary relatively to the intermediate: for
instance, the central note is low relatively to the highest and
high relatively to the lowest, and grey is light relatively to black
and dark relatively to white.
And since every change is from something to something - as
the word itself (metabole) indicates, implying something 'after'
(meta) something else, that is to say something earlier and
something later - that which changes must change in one of
four ways: from subject to subject, from subject to nonsubject,
from non-subject to subject, or from non-subject to non-subject,
where by 'subject' I mean what is affirmatively expressed. So it
follows necessarily from what has been said above that there
are only three kinds of change, that from subject to subject, that
from subject to non-subject, and that from non-subject to
subject: for the fourth conceivable kind, that from non-subject
724
to non-subject, is not change, as in that case there is no
opposition either of contraries or of contradictories.
Now change from non-subject to subject, the relation being that
of contradiction, is 'coming to be' - 'unqualified coming to be'
when the change takes place in an unqualified way, 'particular
coming to be' when the change is change in a particular
character: for instance, a change from not-white to white is a
coming to be of the particular thing, white, while change from
unqualified not-being to being is coming to be in an unqualified
way, in respect of which we say that a thing 'comes to be'
without qualification, not that it 'comes to be' some particular
thing. Change from subject to non-subject is 'perishing' -
'unqualified perishing' when the change is from being to not-
being, 'particular perishing' when the change is to the opposite
negation, the distinction being the same as that made in the
case of coming to be.
Now the expression 'not-being' is used in several senses: and
there can be motion neither of that which 'is not' in respect of
the affirmation or negation of a predicate, nor of that which 'is
not' in the sense that it only potentially 'is', that is to say the
opposite of that which actually 'is' in an unqualified sense: for
although that which is 'not-white' or 'not-good' may
nevertheless he in motion accidentally (for example that which
is 'not-white' might be a man), yet that which is without
qualification 'not-so-and-so' cannot in any sense be in motion:
therefore it is impossible for that which is not to be in motion.
This being so, it follows that 'becoming' cannot be a motion: for
it is that which 'is not' that 'becomes'. For however true it may
be that it accidentally 'becomes', it is nevertheless correct to say
that it is that which 'is not' that in an unqualified sense
'becomes'. And similarly it is impossible for that which 'is not'
to be at rest.
725
There are these difficulties, then, in the way of the assumption
that that which 'is not' can be in motion: and it may be further
objected that, whereas everything which is in motion is in
space, that which 'is not' is not in space: for then it would be
somewhere.
So, too, 'perishing' is not a motion: for a motion has for its
contrary either another motion or rest, whereas 'perishing' is
the contrary of 'becoming'.
Since, then, every motion is a kind of change, and there are only
the three kinds of change mentioned above, and since of these
three those which take the form of 'becoming' and 'perishing',
that is to say those which imply a relation of contradiction, are
not motions: it necessarily follows that only change from
subject to subject is motion. And every such subject is either a
contrary or an intermediate (for a privation may be allowed to
rank as a contrary) and can be affirmatively expressed, as
naked, toothless, or black. If, then, the categories are severally
distinguished as Being, Quality, Place, Time, Relation, Quantity,
and Activity or Passivity, it necessarily follows that there are
three kinds of motion - qualitative, quantitative, and local.
In respect of Substance there is no motion, because Substance
has no contrary among things that are. Nor is there motion in
respect of Relation: for it may happen that when one correlative
changes, the other, although this does not itself change, is no
longer applicable, so that in these cases the motion is
accidental. Nor is there motion in respect of Agent and Patient -
in fact there can never be motion of mover and moved, because
726
there cannot be motion of motion or becoming of becoming or
in general change of change.
For in the first place there are two senses in which motion of
motion is conceivable. (1) The motion of which there is motion
might be conceived as subject; e.g. a man is in motion because
he changes from fair to dark. Can it be that in this sense motion
grows hot or cold, or changes place, or increases or decreases?
Impossible: for change is not a subject. Or (2) can there be
motion of motion in the sense that some other subject changes
from a change to another mode of being, as e.g. a man changes
from falling ill to getting well? Even this is possible only in an
accidental sense. For, whatever the subject may be, movement
is change from one form to another. (And the same holds good
of becoming and perishing, except that in these processes we
have a change to a particular kind of opposite, while the other,
motion, is a change to a different kind.) So, if there is to be
motion of motion, that which is changing from health to
sickness must simultaneously be changing from this very
change to another. It is clear, then, that by the time that it has
become sick, it must also have changed to whatever may be the
other change concerned (for that it should be at rest, though
logically possible, is excluded by the theory). Moreover this
other can never be any casual change, but must be a change
from something definite to some other definite thing. So in this
case it must be the opposite change, viz. convalescence. It is
only accidentally that there can be change of change, e.g. there
is a change from remembering to forgetting only because the
subject of this change changes at one time to knowledge, at
another to ignorance.
In the second place, if there is to be change of change and
becoming of becoming, we shall have an infinite regress. Thus if
one of a series of changes is to be a change of change, the
preceding change must also be so: e.g. if simple becoming was
727
ever in process of becoming, then that which was becoming
simple becoming was also in process of becoming, so that we
should not yet have arrived at what was in process of simple
becoming but only at what was already in process of becoming
in process of becoming. And this again was sometime in process
of becoming, so that even then we should not have arrived at
what was in process of simple becoming. And since in an
infinite series there is no first term, here there will be no first
stage and therefore no following stage either. On this
hypothesis, then, nothing can become or be moved or change.
Thirdly, if a thing is capable of any particular motion, it is also
capable of the corresponding contrary motion or the
corresponding coming to rest, and a thing that is capable of
becoming is also capable of perishing: consequently, if there be
becoming of becoming, that which is in process of becoming is
in process of perishing at the very moment when it has reached
the stage of becoming: since it cannot be in process of perishing
when it is just beginning to become or after it has ceased to
become: for that which is in process of perishing must be in
existence.
Fourthly, there must be a substrate underlying all processes of
becoming and changing. What can this be in the present case?
It is either the body or the soul that undergoes alteration: what
is it that correspondingly becomes motion or becoming? And
again what is the goal of their motion? It must be the motion or
becoming of something from something to something else. But
in what sense can this be so? For the becoming of learning
cannot be learning: so neither can the becoming of becoming be
becoming, nor can the becoming of any process be that process.
Finally, since there are three kinds of motion, the substratum
and the goal of motion must be one or other of these, e.g.
locomotion will have to be altered or to be locally moved.
728
To sum up, then, since everything that is moved is moved in one
of three ways, either accidentally, or partially, or essentially,
change can change only accidentally, as e.g. when a man who is
being restored to health runs or learns: and accidental change
we have long ago decided to leave out of account.
Since, then, motion can belong neither to Being nor to Relation
nor to Agent and Patient, it remains that there can be motion
only in respect of Quality, Quantity, and Place: for with each of
these we have a pair of contraries. Motion in respect of Quality
let us call alteration, a general designation that is used to
include both contraries: and by Quality I do not here mean a
property of substance (in that sense that which constitutes a
specific distinction is a quality) but a passive quality in virtue of
which a thing is said to be acted on or to be incapable of being
acted on. Motion in respect of Quantity has no name that
includes both contraries, but it is called increase or decrease
according as one or the other is designated: that is to say
motion in the direction of complete magnitude is increase,
motion in the contrary direction is decrease. Motion in respect
of Place has no name either general or particular: but we may
designate it by the general name of locomotion, though strictly
the term 'locomotion' is applicable to things that change their
place only when they have not the power to come to a stand,
and to things that do not move themselves locally.
Change within the same kind from a lesser to a greater or from
a greater to a lesser degree is alteration: for it is motion either
from a contrary or to a contrary, whether in an unqualified or in
a qualified sense: for change to a lesser degree of a quality will
be called change to the contrary of that quality, and change to a
greater degree of a quality will be regarded as change from the
contrary of that quality to the quality itself. It makes no
difference whether the change be qualified or unqualified,
except that in the former case the contraries will have to be
729
contrary to one another only in a qualified sense: and a thing's
possessing a quality in a greater or in a lesser degree means the
presence or absence in it of more or less of the opposite quality.
It is now clear, then, that there are only these three kinds of
motion.
The term 'immovable' we apply in the first place to that which
is absolutely incapable of being moved (just as we
correspondingly apply the term invisible to sound); in the
second place to that which is moved with difficulty after a long
time or whose movement is slow at the start - in fact, what we
describe as hard to move; and in the third place to that which is
naturally designed for and capable of motion, but is not in
motion when, where, and as it naturally would be so. This last is
the only kind of immovable thing of which I use the term 'being
at rest': for rest is contrary to motion, so that rest will be
negation of motion in that which is capable of admitting
motion.
The foregoing remarks are sufficient to explain the essential
nature of motion and rest, the number of kinds of change, and
the different varieties of motion.
Let us now proceed to define the terms 'together' and 'apart', 'in
contact', 'between', 'in succession', 'contiguous', and
'continuous', and to show in what circumstances each of these
terms is naturally applicable.
Things are said to be together in place when they are in one
place (in the strictest sense of the word 'place') and to be apart
when they are in different places.
730
Things are said to be in contact when their extremities are
together.
That which a changing thing, if it changes continuously in a
natural manner, naturally reaches before it reaches that to
which it changes last, is between. Thus 'between' implies the
presence of at least three things: for in a process of change it is
the contrary that is 'last': and a thing is moved continuously if it
leaves no gap or only the smallest possible gap in the material -
not in the time (for a gap in the time does not prevent things
having a 'between', while, on the other hand, there is nothing to
prevent the highest note sounding immediately after the
lowest) but in the material in which the motion takes place.
This is manifestly true not only in local changes but in every
other kind as well. (Now every change implies a pair of
opposites, and opposites may be either contraries or
contradictories; since then contradiction admits of no mean
term, it is obvious that 'between' must imply a pair of
contraries) That is locally contrary which is most distant in a
straight line: for the shortest line is definitely limited, and that
which is definitely limited constitutes a measure.
A thing is 'in succession' when it is after the beginning in
position or in form or in some other respect in which it is
definitely so regarded, and when further there is nothing of the
same kind as itself between it and that to which it is in
succession, e.g. a line or lines if it is a line, a unit or units if it is
a unit, a house if it is a house (there is nothing to prevent
something of a different kind being between). For that which is
in succession is in succession to a particular thing, and is
something posterior: for one is not 'in succession' to two, nor is
the first day of the month to be second: in each case the latter is
'in succession' to the former.
731
A thing that is in succession and touches is 'contiguous'. The
'continuous' is a subdivision of the contiguous: things are called
continuous when the touching limits of each become one and
the same and are, as the word implies, contained in each other:
continuity is impossible if these extremities are two. This
definition makes it plain that continuity belongs to things that
naturally in virtue of their mutual contact form a unity. And in
whatever way that which holds them together is one, so too will
the whole be one, e.g. by a rivet or glue or contact or organic
union.
It is obvious that of these terms 'in succession' is first in order
of analysis: for that which touches is necessarily in succession,
but not everything that is in succession touches: and so
succession is a property of things prior in definition, e.g.
numbers, while contact is not. And if there is continuity there is
necessarily contact, but if there is contact, that alone does not
imply continuity: for the extremities of things may be 'together'
without necessarily being one: but they cannot be one without
being necessarily together. So natural junction is last in coming
to be: for the extremities must necessarily come into contact if
they are to be naturally joined: but things that are in contact are
not all naturally joined, while there is no contact clearly there is
no natural junction either. Hence, if as some say 'point' and
'unit' have an independent existence of their own, it is
impossible for the two to be identical: for points can touch
while units can only be in succession. Moreover, there can
always be something between points (for all lines are
intermediate between points), whereas it is not necessary that
there should possibly be anything between units: for there can
be nothing between the numbers one and two.
We have now defined what is meant by 'together' and 'apart',
'contact', 'between' and 'in succession', 'contiguous' and
732
'continuous': and we have shown in what circumstances each
of these terms is applicable.
There are many senses in which motion is said to be 'one': for
we use the term 'one' in many senses.
Motion is one generically according to the different categories to
which it may be assigned: thus any locomotion is one
generically with any other locomotion, whereas alteration is
different generically from locomotion.
Motion is one specifically when besides being one generically it
also takes place in a species incapable of subdivision: e.g. colour
has specific differences: therefore blackening and whitening
differ specifically; but at all events every whitening will be
specifically the same with every other whitening and every
blackening with every other blackening. But white is not further
subdivided by specific differences: hence any whitening is
specifically one with any other whitening. Where it happens
that the genus is at the same time a species, it is clear that the
motion will then in a sense be one specifically though not in an
unqualified sense: learning is an example of this, knowledge
being on the one hand a species of apprehension and on the
other hand a genus including the various knowledges. A
difficulty, however, may be raised as to whether a motion is
specifically one when the same thing changes from the same to
the same, e.g. when one point changes again and again from a
particular place to a particular place: if this motion is
specifically one, circular motion will be the same as rectilinear
motion, and rolling the same as walking. But is not this
difficulty removed by the principle already laid down that if that
733
in which the motion takes place is specifically different (as in
the present instance the circular path is specifically different
from the straight) the motion itself is also different? We have
explained, then, what is meant by saying that motion is one
generically or one specifically.
Motion is one in an unqualified sense when it is one essentially
or numerically: and the following distinctions will make clear
what this kind of motion is. There are three classes of things in
connexion with which we speak of motion, the 'that which', the
'that in which', and the 'that during which'. I mean that there
must he something that is in motion, e.g. a man or gold, and it
must be in motion in something, e.g. a place or an affection, and
during something, for all motion takes place during a time. Of
these three it is the thing in which the motion takes place that
makes it one generically or specifically, it is the thing moved
that makes the motion one in subject, and it is the time that
makes it consecutive: but it is the three together that make it
one without qualification: to effect this, that in which the
motion takes place (the species) must be one and incapable of
subdivision, that during which it takes place (the time) must be
one and unintermittent, and that which is in motion must be
one - not in an accidental sense (i.e. it must be one as the white
that blackens is one or Coriscus who walks is one, not in the
accidental sense in which Coriscus and white may be one), nor
merely in virtue of community of nature (for there might be a
case of two men being restored to health at the same time in
the same way, e.g. from inflammation of the eye, yet this motion
is not really one, but only specifically one).
Suppose, however, that Socrates undergoes an alteration
specifically the same but at one time and again at another: in
this case if it is possible for that which ceased to be again to
come into being and remain numerically the same, then this
motion too will be one: otherwise it will be the same but not
734
one. And akin to this difficulty there is another; viz. is health
one? and generally are the states and affections in bodies
severally one in essence although (as is clear) the things that
contain them are obviously in motion and in flux? Thus if a
person's health at daybreak and at the present moment is one
and the same, why should not this health be numerically one
with that which he recovers after an interval? The same
argument applies in each case. There is, however, we may
answer, this difference: that if the states are two then it follows
simply from this fact that the activities must also in point of
number be two (for only that which is numerically one can give
rise to an activity that is numerically one), but if the state is one,
this is not in itself enough to make us regard the activity also as
one: for when a man ceases walking, the walking no longer is,
but it will again be if he begins to walk again. But, be this as it
may, if in the above instance the health is one and the same,
then it must be possible for that which is one and the same to
come to be and to cease to be many times. However, these
difficulties lie outside our present inquiry.
Since every motion is continuous, a motion that is one in an
unqualified sense must (since every motion is divisible) be
continuous, and a continuous motion must be one. There will
not be continuity between any motion and any other
indiscriminately any more than there is between any two things
chosen at random in any other sphere: there can be continuity
only when the extremities of the two things are one. Now some
things have no extremities at all: and the extremities of others
differ specifically although we give them the same name of
'end': how should e.g. the 'end' of a line and the 'end' of walking
touch or come to be one? Motions that are not the same either
specifically or generically may, it is true, be consecutive (e.g. a
man may run and then at once fall ill of a fever), and again, in
the torch-race we have consecutive but not continuous
locomotion: for according to our definition there can be
735
continuity only when the ends of the two things are one. Hence
motions may be consecutive or successive in virtue of the time
being continuous, but there can be continuity only in virtue of
the motions themselves being continuous, that is when the end
of each is one with the end of the other. Motion, therefore, that
is in an unqualified sense continuous and one must be
specifically the same, of one thing, and in one time. Unity is
required in respect of time in order that there may be no
interval of immobility, for where there is intermission of motion
there must be rest, and a motion that includes intervals of rest
will be not one but many, so that a motion that is interrupted by
stationariness is not one or continuous, and it is so interrupted
if there is an interval of time. And though of a motion that is not
specifically one (even if the time is unintermittent) the time is
one, the motion is specifically different, and so cannot really be
one, for motion that is one must be specifically one, though
motion that is specifically one is not necessarily one in an
unqualified sense. We have now explained what we mean when
we call a motion one without qualification.
Further, a motion is also said to be one generically, specifically,
or essentially when it is complete, just as in other cases
completeness and wholeness are characteristics of what is one:
and sometimes a motion even if incomplete is said to be one,
provided only that it is continuous.
And besides the cases already mentioned there is another in
which a motion is said to be one, viz. when it is regular: for in a
sense a motion that is irregular is not regarded as one, that title
belonging rather to that which is regular, as a straight line is
regular, the irregular being as such divisible. But the difference
would seem to be one of degree. In every kind of motion we may
have regularity or irregularity: thus there may be regular
alteration, and locomotion in a regular path, e.g. in a circle or on
a straight line, and it is the same with regard to increase and
736
decrease. The difference that makes a motion irregular is
sometimes to be found in its path: thus a motion cannot be
regular if its path is an irregular magnitude, e.g. a broken line, a
spiral, or any other magnitude that is not such that any part of
it taken at random fits on to any other that may be chosen.
Sometimes it is found neither in the place nor in the time nor in
the goal but in the manner of the motion: for in some cases the
motion is differentiated by quickness and slowness: thus if its
velocity is uniform a motion is regular, if not it is irregular. So
quickness and slowness are not species of motion nor do they
constitute specific differences of motion, because this
distinction occurs in connexion with all the distinct species of
motion. The same is true of heaviness and lightness when they
refer to the same thing: e.g. they do not specifically distinguish
earth from itself or fire from itself. Irregular motion, therefore,
while in virtue of being continuous it is one, is so in a lesser
degree, as is the case with locomotion in a broken line: and a
lesser degree of something always means an admixture of its
contrary. And since every motion that is one can be both regular
and irregular, motions that are consecutive but not specifically
the same cannot be one and continuous: for how should a
motion composed of alteration and locomotion be regular? If a
motion is to be regular its parts ought to fit one another.
We have further to determine what motions are contrary to
each other, and to determine similarly how it is with rest. And
we have first to decide whether contrary motions are motions
respectively from and to the same thing, e.g. a motion from
health and a motion to health (where the opposition, it would
seem, is of the same kind as that between coming to be and
737
ceasing to be); or motions respectively from contraries, e.g. a
motion from health and a motion from disease; or motions
respectively to contraries, e.g. a motion to health and a motion
to disease; or motions respectively from a contrary and to the
opposite contrary, e.g. a motion from health and a motion to
disease; or motions respectively from a contrary to the opposite
contrary and from the latter to the former, e.g. a motion from
health to disease and a motion from disease to health: for
motions must be contrary to one another in one or more of
these ways, as there is no other way in which they can be
opposed.
Now motions respectively from a contrary and to the opposite
contrary, e.g. a motion from health and a motion to disease, are
not contrary motions: for they are one and the same. (Yet their
essence is not the same, just as changing from health is
different from changing to disease.) Nor are motion respectively
from a contrary and from the opposite contrary contrary
motions, for a motion from a contrary is at the same time a
motion to a contrary or to an intermediate (of this, however, we
shall speak later), but changing to a contrary rather than
changing from a contrary would seem to be the cause of the
contrariety of motions, the latter being the loss, the former the
gain, of contrariness. Moreover, each several motion takes its
name rather from the goal than from the starting-point of
change, e.g. motion to health we call convalescence, motion to
disease sickening. Thus we are left with motions respectively to
contraries, and motions respectively to contraries from the
opposite contraries. Now it would seem that motions to
contraries are at the same time motions from contraries
(though their essence may not be the same; 'to health' is
distinct, I mean, from 'from disease', and 'from health' from 'to
disease').
738
Since then change differs from motion (motion being change
from a particular subject to a particular subject), it follows that
contrary motions are motions respectively from a contrary to
the opposite contrary and from the latter to the former, e.g. a
motion from health to disease and a motion from disease to
health. Moreover, the consideration of particular examples will
also show what kinds of processes are generally recognized as
contrary: thus falling ill is regarded as contrary to recovering
one's health, these processes having contrary goals, and being
taught as contrary to being led into error by another, it being
possible to acquire error, like knowledge, either by one's own
agency or by that of another. Similarly we have upward
locomotion and downward locomotion, which are contrary
lengthwise, locomotion to the right and locomotion to the left,
which are contrary breadthwise, and forward locomotion and
backward locomotion, which too are contraries. On the other
hand, a process simply to a contrary, e.g. that denoted by the
expression 'becoming white', where no starting-point is
specified, is a change but not a motion. And in all cases of a
thing that has no contrary we have as contraries change from
and change to the same thing. Thus coming to be is contrary to
ceasing to be, and losing to gaining. But these are changes and
not motions. And wherever a pair of contraries admit of an
intermediate, motions to that intermediate must be held to be
in a sense motions to one or other of the contraries: for the
intermediate serves as a contrary for the purposes of the
motion, in whichever direction the change may be, e.g. grey in a
motion from grey to white takes the place of black as starting-
point, in a motion from white to grey it takes the place of black
as goal, and in a motion from black to grey it takes the place of
white as goal: for the middle is opposed in a sense to either of
the extremes, as has been said above. Thus we see that two
motions are contrary to each other only when one is a motion
739
from a contrary to the opposite contrary and the other is a
motion from the latter to the former.
But since a motion appears to have contrary to it not only
another motion but also a state of rest, we must determine how
this is so. A motion has for its contrary in the strict sense of the
term another motion, but it also has for an opposite a state of
rest (for rest is the privation of motion and the privation of
anything may be called its contrary), and motion of one kind
has for its opposite rest of that kind, e.g. local motion has local
rest. This statement, however, needs further qualification: there
remains the question, is the opposite of remaining at a
particular place motion from or motion to that place? It is
surely clear that since there are two subjects between which
motion takes place, motion from one of these (A) to its contrary
(B) has for its opposite remaining in A while the reverse motion
has for its opposite remaining in B. At the same time these two
are also contrary to each other: for it would be absurd to
suppose that there are contrary motions and not opposite states
of rest. States of rest in contraries are opposed. To take an
example, a state of rest in health is (1) contrary to a state of rest
in disease, and (2) the motion to which it is contrary is that from
health to disease. For (2) it would be absurd that its contrary
motion should be that from disease to health, since motion to
that in which a thing is at rest is rather a coming to rest, the
coming to rest being found to come into being simultaneously
with the motion; and one of these two motions it must be. And
(1) rest in whiteness is of course not contrary to rest in health.
740
Of all things that have no contraries there are opposite changes
(viz. change from the thing and change to the thing, e.g. change
from being and change to being), but no motion. So, too, of such
things there is no remaining though there is absence of change.
Should there be a particular subject, absence of change in its
being will be contrary to absence of change in its not-being. And
here a difficulty may be raised: if not-being is not a particular
something, what is it, it may be asked, that is contrary to
absence of change in a thing's being? and is this absence of
change a state of rest? If it is, then either it is not true that every
state of rest is contrary to a motion or else coming to be and
ceasing to be are motion. It is clear then that, since we exclude
these from among motions, we must not say that this absence
of change is a state of rest: we must say that it is similar to a
state of rest and call it absence of change. And it will have for its
contrary either nothing or absence of change in the thing's not-
being, or the ceasing to be of the thing: for such ceasing to be is
change from it and the thing's coming to be is change to it.
Again, a further difficulty may be raised. How is it, it may be
asked, that whereas in local change both remaining and moving
may be natural or unnatural, in the other changes this is not so?
e.g. alteration is not now natural and now unnatural, for
convalescence is no more natural or unnatural than falling ill,
whitening no more natural or unnatural than blackening; so,
too, with increase and decrease: these are not contrary to each
other in the sense that either of them is natural while the other
is unnatural, nor is one increase contrary to another in this
sense; and the same account may be given of becoming and
perishing: it is not true that becoming is natural and perishing
unnatural (for growing old is natural), nor do we observe one
becoming to be natural and another unnatural. We answer that
if what happens under violence is unnatural, then violent
perishing is unnatural and as such contrary to natural
perishing. Are there then also some becomings that are violent
741
and not the result of natural necessity, and are therefore
contrary to natural becomings, and violent increases and
decreases, e.g. the rapid growth to maturity of profligates and
the rapid ripening of seeds even when not packed close in the
earth? And how is it with alterations? Surely just the same: we
may say that some alterations are violent while others are
natural, e.g. patients alter naturally or unnaturally according as
they throw off fevers on the critical days or not. But, it may be
objected, then we shall have perishings contrary to one another,
not to becoming. Certainly: and why should not this in a sense
be so? Thus it is so if one perishing is pleasant and another
painful: and so one perishing will be contrary to another not in
an unqualified sense, but in so far as one has this quality and
the other that.
Now motions and states of rest universally exhibit contrariety
in the manner described above, e.g. upward motion and rest
above are respectively contrary to downward motion and rest
below, these being instances of local contrariety; and upward
locomotion belongs naturally to fire and downward to earth, i.e.
the locomotions of the two are contrary to each other. And
again, fire moves up naturally and down unnaturally: and its
natural motion is certainly contrary to its unnatural motion.
Similarly with remaining: remaining above is contrary to
motion from above downwards, and to earth this remaining
comes unnaturally, this motion naturally. So the unnatural
remaining of a thing is contrary to its natural motion, just as we
find a similar contrariety in the motion of the same thing: one
of its motions, the upward or the downward, will be natural, the
other unnatural.
Here, however, the question arises, has every state of rest that is
not permanent a becoming, and is this becoming a coming to a
standstill? If so, there must be a becoming of that which is at
rest unnaturally, e.g. of earth at rest above: and therefore this
742
earth during the time that it was being carried violently upward
was coming to a standstill. But whereas the velocity of that
which comes to a standstill seems always to increase, the
velocity of that which is carried violently seems always to
decrease: so it will he in a state of rest without having become
so. Moreover 'coming to a standstill' is generally recognized to
be identical or at least concomitant with the locomotion of a
thing to its proper place.
There is also another difficulty involved in the view that
remaining in a particular place is contrary to motion from that
place. For when a thing is moving from or discarding something,
it still appears to have that which is being discarded, so that if a
state of rest is itself contrary to the motion from the state of
rest to its contrary, the contraries rest and motion will be
simultaneously predicable of the same thing. May we not say,
however, that in so far as the thing is still stationary it is in a
state of rest in a qualified sense? For, in fact, whenever a thing
is in motion, part of it is at the starting-point while part is at the
goal to which it is changing: and consequently a motion finds
its true contrary rather in another motion than in a state of rest.
With regard to motion and rest, then, we have now explained in
what sense each of them is one and under what conditions they
exhibit contrariety.
[With regard to coming to a standstill the question may be
raised whether there is an opposite state of rest to unnatural as
well as to natural motions. It would be absurd if this were not
the case: for a thing may remain still merely under violence:
thus we shall have a thing being in a non-permanent state of
rest without having become so. But it is clear that it must be the
case: for just as there is unnatural motion, so, too, a thing may
be in an unnatural state of rest. Further, some things have a
natural and an unnatural motion, e.g. fire has a natural upward
743
motion and an unnatural downward motion: is it, then, this
unnatural downward motion or is it the natural downward
motion of earth that is contrary to the natural upward motion?
Surely it is clear that both are contrary to it though not in the
same sense: the natural motion of earth is contrary inasmuch
as the motion of fire is also natural, whereas the upward
motion of fire as being natural is contrary to the downward
motion of fire as being unnatural. The same is true of the
corresponding cases of remaining. But there would seem to be a
sense in which a state of rest and a motion are opposites.]
Book VI
Now if the terms 'continuous', 'in contact', and 'in succession'
are understood as defined above things being 'continuous' if
their extremities are one, 'in contact' if their extremities are
together, and 'in succession' if there is nothing of their own
kind intermediate between them - nothing that is continuous
can be composed 'of indivisibles': e.g. a line cannot be
composed of points, the line being continuous and the point
indivisible. For the extremities of two points can neither be one
(since of an indivisible there can be no extremity as distinct
from some other part) nor together (since that which has no
parts can have no extremity, the extremity and the thing of
which it is the extremity being distinct).
744
Moreover, if that which is continuous is composed of points,
these points must be either continuous or in contact with one
another: and the same reasoning applies in the case of all
indivisibles. Now for the reason given above they cannot be
continuous: and one thing can be in contact with another only
if whole is in contact with whole or part with part or part with
whole. But since indivisibles have no parts, they must be in
contact with one another as whole with whole. And if they are
in contact with one another as whole with whole, they will not
be continuous: for that which is continuous has distinct parts:
and these parts into which it is divisible are different in this
way, i.e. spatially separate.
Nor, again, can a point be in succession to a point or a moment
to a moment in such a way that length can be composed of
points or time of moments: for things are in succession if there
is nothing of their own kind intermediate between them,
whereas that which is intermediate between points is always a
line and that which is intermediate between moments is always
a period of time.
Again, if length and time could thus be composed of
indivisibles, they could be divided into indivisibles, since each is
divisible into the parts of which it is composed. But, as we saw,
no continuous thing is divisible into things without parts. Nor
can there be anything of any other kind intermediate between
the parts or between the moments: for if there could be any
such thing it is clear that it must be either indivisible or
divisible, and if it is divisible, it must be divisible either into
indivisibles or into divisibles that are infinitely divisible, in
which case it is continuous.
Moreover, it is plain that everything continuous is divisible into
divisibles that are infinitely divisible: for if it were divisible into
indivisibles, we should have an indivisible in contact with an
745
indivisible, since the extremities of things that are continuous
with one another are one and are in contact.
The same reasoning applies equally to magnitude, to time, and
to motion: either all of these are composed of indivisibles and
are divisible into indivisibles, or none. This may be made clear
as follows. If a magnitude is composed of indivisibles, the
motion over that magnitude must be composed of
corresponding indivisible motions: e.g. if the magnitude ABG is
composed of the indivisibles A, B, G, each corresponding part of
the motion DEZ of over ABG is indivisible. Therefore, since
where there is motion there must be something that is in
motion, and where there is something in motion there must be
motion, therefore the being-moved will also be composed of
indivisibles. So traversed A when its motion was D, B when its
motion was E, and G similarly when its motion was Z. Now a
thing that is in motion from one place to another cannot at the
moment when it was in motion both be in motion and at the
same time have completed its motion at the place to which it
was in motion: e.g. if a man is walking to Thebes, he cannot be
walking to Thebes and at the same time have completed his
walk to Thebes: and, as we saw, traverses a the partless
section A in virtue of the presence of the motion D.
Consequently, if actually passed through A after being in
process of passing through, the motion must be divisible: for at
the time when was passing through, it neither was at rest nor
had completed its passage but was in an intermediate state:
while if it is passing through and has completed its passage at
the same moment, then that which is walking will at the
moment when it is walking have completed its walk and will be
in the place to which it is walking; that is to say, it will have
completed its motion at the place to which it is in motion. And
if a thing is in motion over the whole KBG and its motion is the
three D, E, and Z, and if it is not in motion at all over the
partless section A but has completed its motion over it, then the
746
motion will consist not of motions but of starts, and will take
place by a thing's having completed a motion without being in
motion: for on this assumption it has completed its passage
through A without passing through it. So it will be possible for a
thing to have completed a walk without ever walking: for on
this assumption it has completed a walk over a particular
distance without walking over that distance. Since, then,
everything must be either at rest or in motion, and is
therefore at rest in each of the sections A, B, and G, it follows
that a thing can be continuously at rest and at the same time in
motion: for, as we saw, is in motion over the whole ABG and
at rest in any part (and consequently in the whole) of it.
Moreover, if the indivisibles composing DEZ are motions, it
would be possible for a thing in spite of the presence in it of
motion to be not in motion but at rest, while if they are not
motions, it would be possible for motion to be composed of
something other than motions.
And if length and motion are thus indivisible, it is neither more
nor less necessary that time also be similarly indivisible, that is
to say be composed of indivisible moments: for if the whole
distance is divisible and an equal velocity will cause a thing to
pass through less of it in less time, the time must also be
divisible, and conversely, if the time in which a thing is carried
over the section A is divisible, this section A must also be
divisible.
And since every magnitude is divisible into magnitudes - for we
have shown that it is impossible for anything continuous to be
composed of indivisible parts, and every magnitude is
747
continuous - it necessarily follows that the quicker of two
things traverses a greater magnitude in an equal time, an equal
magnitude in less time, and a greater magnitude in less time, in
conformity with the definition sometimes given of 'the quicker'.
Suppose that A is quicker than B. Now since of two things that
which changes sooner is quicker, in the time ZH, in which A has
changed from G to D, B will not yet have arrived at D but will be
short of it: so that in an equal time the quicker will pass over a
greater magnitude. More than this, it will pass over a greater
magnitude in less time: for in the time in which A has arrived at
D, B being the slower has arrived, let us say, at E. Then since A
has occupied the whole time ZH in arriving at D, will have
arrived at in less time than this, say ZK. Now the magnitude
GO that A has passed over is greater than the magnitude GE,
and the time ZK is less than the whole time ZH: so that the
quicker will pass over a greater magnitude in less time. And
from this it is also clear that the quicker will pass over an equal
magnitude in less time than the slower. For since it passes over
the greater magnitude in less time than the slower, and
(regarded by itself) passes over LM the greater in more time
than LX the lesser, the time PRh in which it passes over LM will
be more than the time PS, which it passes over LX: so that, the
time PRh being less than the time PCh in which the slower
passes over LX, the time PS will also be less than the time PX:
for it is less than the time PRh, and that which is less than
something else that is less than a thing is also itself less than
that thing. Hence it follows that the quicker will traverse an
equal magnitude in less time than the slower. Again, since the
motion of anything must always occupy either an equal time or
less or more time in comparison with that of another thing, and
since, whereas a thing is slower if its motion occupies more
time and of equal velocity if its motion occupies an equal time,
the quicker is neither of equal velocity nor slower, it follows
that the motion of the quicker can occupy neither an equal time
748
nor more time. It can only be, then, that it occupies less time,
and thus we get the necessary consequence that the quicker
will pass over an equal magnitude (as well as a greater) in less
time than the slower.
And since every motion is in time and a motion may occupy any
time, and the motion of everything that is in motion may be
either quicker or slower, both quicker motion and slower
motion may occupy any time: and this being so, it necessarily
follows that time also is continuous. By continuous I mean that
which is divisible into divisibles that are infinitely divisible: and
if we take this as the definition of continuous, it follows
necessarily that time is continuous. For since it has been shown
that the quicker will pass over an equal magnitude in less time
than the slower, suppose that A is quicker and B slower, and
that the slower has traversed the magnitude GD in the time ZH.
Now it is clear that the quicker will traverse the same
magnitude in less time than this: let us say in the time ZO.
Again, since the quicker has passed over the whole D in the
time ZO, the slower will in the same time pass over GK, say,
which is less than GD. And since B, the slower, has passed over
GK in the time ZO, the quicker will pass over it in less time: so
that the time ZO will again be divided. And if this is divided the
magnitude GK will also be divided just as GD was: and again, if
the magnitude is divided, the time will also be divided. And we
can carry on this process for ever, taking the slower after the
quicker and the quicker after the slower alternately, and using
what has been demonstrated at each stage as a new point of
departure: for the quicker will divide the time and the slower
will divide the length. If, then, this alternation always holds
good, and at every turn involves a division, it is evident that all
time must be continuous. And at the same time it is clear that
all magnitude is also continuous; for the divisions of which time
and magnitude respectively are susceptible are the same and
equal.
749
Moreover, the current popular arguments make it plain that, if
time is continuous, magnitude is continuous also, inasmuch as
a thing asses over half a given magnitude in half the time taken
to cover the whole: in fact without qualification it passes over a
less magnitude in less time; for the divisions of time and of
magnitude will be the same. And if either is infinite, so is the
other, and the one is so in the same way as the other; i.e. if time
is infinite in respect of its extremities, length is also infinite in
respect of its extremities: if time is infinite in respect of
divisibility, length is also infinite in respect of divisibility: and if
time is infinite in both respects, magnitude is also infinite in
both respects.
Hence Zeno's argument makes a false assumption in asserting
that it is impossible for a thing to pass over or severally to come
in contact with infinite things in a finite time. For there are two
senses in which length and time and generally anything
continuous are called 'infinite': they are called so either in
respect of divisibility or in respect of their extremities. So while
a thing in a finite time cannot come in contact with things
quantitatively infinite, it can come in contact with things
infinite in respect of divisibility: for in this sense the time itself
is also infinite: and so we find that the time occupied by the
passage over the infinite is not a finite but an infinite time, and
the contact with the infinites is made by means of moments
not finite but infinite in number.
The passage over the infinite, then, cannot occupy a finite time,
and the passage over the finite cannot occupy an infinite time:
if the time is infinite the magnitude must be infinite also, and if
the magnitude is infinite, so also is the time. This may be shown
as follows. Let AB be a finite magnitude, and let us suppose that
it is traversed in infinite time G, and let a finite period GD of the
time be taken. Now in this period the thing in motion will pass
over a certain segment of the magnitude: let BE be the segment
750
that it has thus passed over. (This will be either an exact
measure of AB or less or greater than an exact measure: it
makes no difference which it is.) Then, since a magnitude equal
to BE will always be passed over in an equal time, and BE
measures the whole magnitude, the whole time occupied in
passing over AB will be finite: for it will be divisible into periods
equal in number to the segments into which the magnitude is
divisible. Moreover, if it is the case that infinite time is not
occupied in passing over every magnitude, but it is possible to
ass over some magnitude, say BE, in a finite time, and if this BE
measures the whole of which it is a part, and if an equal
magnitude is passed over in an equal time, then it follows that
the time like the magnitude is finite. That infinite time will not
be occupied in passing over BE is evident if the time be taken as
limited in one direction: for as the part will be passed over in
less time than the whole, the time occupied in traversing this
part must be finite, the limit in one direction being given. The
same reasoning will also show the falsity of the assumption
that infinite length can be traversed in a finite time. It is
evident, then, from what has been said that neither a line nor a
surface nor in fact anything continuous can be indivisible.
This conclusion follows not only from the present argument but
from the consideration that the opposite assumption implies
the divisibility of the indivisible. For since the distinction of
quicker and slower may apply to motions occupying any period
of time and in an equal time the quicker passes over a greater
length, it may happen that it will pass over a length twice, or
one and a half times, as great as that passed over by the slower:
for their respective velocities may stand to one another in this
proportion. Suppose, then, that the quicker has in the same
time been carried over a length one and a half times as great as
that traversed by the slower, and that the respective magnitudes
are divided, that of the quicker, the magnitude ABGD, into three
indivisibles, and that of the slower into the two indivisibles EZ,
751
ZH. Then the time may also be divided into three indivisibles,
for an equal magnitude will be passed over in an equal time.
Suppose then that it is thus divided into KL, LM, MN. Again,
since in the same time the slower has been carried over EZ, ZH,
the time may also be similarly divided into two. Thus the
indivisible will be divisible, and that which has no parts will be
passed over not in an indivisible but in a greater time. It is
evident, therefore, that nothing continuous is without parts.
The present also is necessarily indivisible - the present, that is,
not in the sense in which the word is applied to one thing in
virtue of another, but in its proper and primary sense; in which
sense it is inherent in all time. For the present is something that
is an extremity of the past (no part of the future being on this
side of it) and also of the future (no part of the past being on the
other side of it): it is, as we have said, a limit of both. And if it is
once shown that it is essentially of this character and one and
the same, it will at once be evident also that it is indivisible.
Now the present that is the extremity of both times must be
one and the same: for if each extremity were different, the one
could not be in succession to the other, because nothing
continuous can be composed of things having no parts: and if
the one is apart from the other, there will be time intermediate
between them, because everything continuous is such that
there is something intermediate between its limits and
described by the same name as itself. But if the intermediate
thing is time, it will be divisible: for all time has been shown to
be divisible. Thus on this assumption the present is divisible.
But if the present is divisible, there will be part of the past in the
752
future and part of the future in the past: for past time will be
marked off from future time at the actual point of division. Also
the present will be a present not in the proper sense but in
virtue of something else: for the division which yields it will not
be a division proper. Furthermore, there will be a part of the
present that is past and a part that is future, and it will not
always be the same part that is past or future: in fact one and
the same present will not be simultaneous: for the time may be
divided at many points. If, therefore, the present cannot
possibly have these characteristics, it follows that it must be the
same present that belongs to each of the two times. But if this is
so it is evident that the present is also indivisible: for if it is
divisible it will be involved in the same implications as before. It
is clear, then, from what has been said that time contains
something indivisible, and this is what we call a present.
We will now show that nothing can be in motion in a present.
For if this is possible, there can be both quicker and slower
motion in the present. Suppose then that in the present N the
quicker has traversed the distance AB. That being so, the slower
will in the same present traverse a distance less than AB, say
AG. But since the slower will have occupied the whole present
in traversing AG, the quicker will occupy less than this in
traversing it. Thus we shall have a division of the present,
whereas we found it to be indivisible. It is impossible, therefore,
for anything to be in motion in a present.
Nor can anything be at rest in a present: for, as we were saying,
only can be at rest which is naturally designed to be in motion
but is not in motion when, where, or as it would naturally be so:
since, therefore, nothing is naturally designed to be in motion in
a present, it is clear that nothing can be at rest in a present
either.
753
Moreover, inasmuch as it is the same present that belongs to
both the times, and it is possible for a thing to be in motion
throughout one time and to be at rest throughout the other, and
that which is in motion or at rest for the whole of a time will be
in motion or at rest as the case may be in any part of it in which
it is naturally designed to be in motion or at rest: this being so,
the assumption that there can be motion or rest in a present
will carry with it the implication that the same thing can at the
same time be at rest and in motion: for both the times have the
same extremity, viz. the present.
Again, when we say that a thing is at rest, we imply that its
condition in whole and in part is at the time of speaking
uniform with what it was previously: but the present contains
no 'previously': consequently, there can be no rest in it.
It follows then that the motion of that which is in motion and
the rest of that which is at rest must occupy time.
Further, everything that changes must be divisible. For since
every change is from something to something, and when a
thing is at the goal of its change it is no longer changing, and
when both it itself and all its parts are at the starting-point of
its change it is not changing (for that which is in whole and in
part in an unvarying condition is not in a state of change); it
follows, therefore, that part of that which is changing must be
at the starting-point and part at the goal: for as a whole it
cannot be in both or in neither. (Here by 'goal of change' I mean
that which comes first in the process of change: e.g. in a process
of change from white the goal in question will be grey, not
black: for it is not necessary that that that which is changing
754
should be at either of the extremes.) It is evident, therefore, that
everything that changes must be divisible.
Now motion is divisible in two senses. In the first place it is
divisible in virtue of the time that it occupies. In the second
place it is divisible according to the motions of the several parts
of that which is in motion: e.g. if the whole AG is in motion,
there will be a motion of AB and a motion of BG. That being so,
let DE be the motion of the part AB and EZ the motion of the
part BG. Then the whole DZ must be the motion of AG: for DZ
must constitute the motion of AG inasmuch as DE and EZ
severally constitute the motions of each of its parts. But the
motion of a thing can never be constituted by the motion of
something else: consequently the whole motion is the motion
of the whole magnitude.
Again, since every motion is a motion of something, and the
whole motion DZ is not the motion of either of the parts (for
each of the parts DE, EZ is the motion of one of the parts AB, BG)
or of anything else (for, the whole motion being the motion of a
whole, the parts of the motion are the motions of the parts of
that whole: and the parts of DZ are the motions of AB, BG and of
nothing else: for, as we saw, a motion that is one cannot be the
motion of more things than one): since this is so, the whole
motion will be the motion of the magnitude ABG.
Again, if there is a motion of the whole other than DZ, say the
the of each of the arts may be subtracted from it: and these
motions will be equal to DE, EZ respectively: for the motion of
that which is one must be one. So if the whole motion 01 may
be divided into the motions of the parts, 01 will be equal to DZ:
if on the other hand there is any remainder, say KI, this will be a
motion of nothing: for it can be the motion neither of the whole
nor of the parts (as the motion of that which is one must be
one) nor of anything else: for a motion that is continuous must
755
be the motion of things that are continuous. And the same
result follows if the division of 01 reveals a surplus on the side
of the motions of the parts. Consequently, if this is impossible,
the whole motion must be the same as and equal to DZ.
This then is what is meant by the division of motion according
to the motions of the parts: and it must be applicable to
everything that is divisible into parts.
Motion is also susceptible of another kind of division, that
according to time. For since all motion is in time and all time is
divisible, and in less time the motion is less, it follows that
every motion must be divisible according to time. And since
everything that is in motion is in motion in a certain sphere and
for a certain time and has a motion belonging to it, it follows
that the time, the motion, the being-in-motion, the thing that is
in motion, and the sphere of the motion must all be susceptible
of the same divisions (though spheres of motion are not all
divisible in a like manner: thus quantity is essentially, quality
accidentally divisible). For suppose that A is the time occupied
by the motion B. Then if all the time has been occupied by the
whole motion, it will take less of the motion to occupy half the
time, less again to occupy a further subdivision of the time, and
so on to infinity. Again, the time will be divisible similarly to the
motion: for if the whole motion occupies all the time half the
motion will occupy half the time, and less of the motion again
will occupy less of the time.
In the same way the being-in-motion will also be divisible. For
let G be the whole being-in-motion. Then the being-in-motion
that corresponds to half the motion will be less than the whole
being-in-motion, that which corresponds to a quarter of the
motion will be less again, and so on to infinity. Moreover by
setting out successively the being-in-motion corresponding to
each of the two motions DG (say) and GE, we may argue that the
756
whole being-in-motion will correspond to the whole motion (for
if it were some other being-in-motion that corresponded to the
whole motion, there would be more than one being-in-motion
corresponding to the same motion), the argument being the
same as that whereby we showed that the motion of a thing is
divisible into the motions of the parts of the thing: for if we take
separately the being-in-motion corresponding to each of the
two motions, we shall see that the whole being-in-motion is
continuous.
The same reasoning will show the divisibility of the length, and
in fact of everything that forms a sphere of change (though
some of these are only accidentally divisible because that which
changes is so): for the division of one term will involve the
division of all. So, too, in the matter of their being finite or
infinite, they will all alike be either the one or the other. And we
now see that in most cases the fact that all the terms are
divisible or infinite is a direct consequence of the fact that the
thing that changes is divisible or infinite: for the attributes
'divisible' and 'infinite' belong in the first instance to the thing
that changes. That divisibility does so we have already shown:
that infinity does so will be made clear in what follows?
Since everything that changes changes from something to
something, that which has changed must at the moment when
it has first changed be in that to which it has changed. For that
which changes retires from or leaves that from which it
changes: and leaving, if not identical with changing, is at any
rate a consequence of it. And if leaving is a consequence of
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changing, having left is a consequence of having changed: for
there is a like relation between the two in each case.
One kind of change, then, being change in a relation of
contradiction, where a thing has changed from not-being to
being it has left not-being. Therefore it will be in being: for
everything must either be or not be. It is evident, then, that in
contradictory change that which has changed must be in that to
which it has changed. And if this is true in this kind of change,
it will be true in all other kinds as well: for in this matter what
holds good in the case of one will hold good likewise in the case
of the rest.
Moreover, if we take each kind of change separately, the truth of
our conclusion will be equally evident, on the ground that that
that which has changed must be somewhere or in something.
For, since it has left that from which it has changed and must be
somewhere, it must be either in that to which it has changed or
in something else. If, then, that which has changed to B is in
something other than B, say G, it must again be changing from
G to B: for it cannot be assumed that there is no interval
between G and B, since change is continuous. Thus we have the
result that the thing that has changed, at the moment when it
has changed, is changing to that to which it has changed, which
is impossible: that which has changed, therefore, must be in
that to which it has changed. So it is evident likewise that
which has come to be, at the moment when it has come to be,
will be, and that which has ceased to be will not-be: for what we
have said applies universally to every kind of change, and its
truth is most obvious in the case of contradictory change. It is
clear, then, that that which has changed, at the moment when
it has first changed, is in that to which it has changed.
We will now show that the 'primary when' in which that which
has changed effected the completion of its change must be
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indivisible, where by 'primary' I mean possessing the
characteristics in question of itself and not in virtue of the
possession of them by something else belonging to it. For let AG
be divisible, and let it be divided at B. If then the completion of
change has been effected in AB or again in BG, AG cannot be the
primary thing in which the completion of change has been
effected. If, on the other hand, it has been changing in both AB
and BG (for it must either have changed or be changing in each
of them), it must have been changing in the whole AG: but our
assumption was that AG contains only the completion of the
change. It is equally impossible to suppose that one part of AG
contains the process and the other the completion of the
change: for then we shall have something prior to what is
primary. So that in which the completion of change has been
effected must be indivisible. It is also evident, therefore, that
that that in which that which has ceased to be has ceased to be
and that in which that which has come to be has come to be are
indivisible.
But there are two senses of the expression 'the primary when in
which something has changed'. On the one hand it may mean
the primary when containing the completion of the process of
change - the moment when it is correct to say 'it has changed':
on the other hand it may mean the primary when containing
the beginning of the process of change. Now the primary when
that has reference to the end of the change is something really
existent: for a change may really be completed, and there is
such a thing as an end of change, which we have in fact shown
to be indivisible because it is a limit. But that which has
reference to the beginning is not existent at all: for there is no
such thing as a beginning of a process of change, and the time
occupied by the change does not contain any primary when in
which the change began. For suppose that AD is such a primary
when. Then it cannot be indivisible: for, if it were, the moment
immediately preceding the change and the moment in which
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the change begins would be consecutive (and moments cannot
be consecutive). Again, if the changing thing is at rest in the
whole preceding time GA (for we may suppose that it is at rest),
it is at rest in A also: so if AD is without parts, it will
simultaneously be at rest and have changed: for it is at rest in A
and has changed in D. Since then AD is not without parts, it
must be divisible, and the changing thing must have changed in
every part of it (for if it has changed in neither of the two parts
into which AD is divided, it has not changed in the whole either:
if, on the other hand, it is in process of change in both parts, it
is likewise in process of change in the whole: and if, again, it
has changed in one of the two parts, the whole is not the
primary when in which it has changed: it must therefore have
changed in every part). It is evident, then, that with reference to
the beginning of change there is no primary when in which
change has been effected: for the divisions are infinite.
So, too, of that which has changed there is no primary part that
has changed. For suppose that of AE the primary part that has
changed is AZ (everything that changes having been shown to
be divisible): and let 01 be the time in which DZ has changed. If,
then, in the whole time DZ has changed, in half the time there
will be a part that has changed, less than and therefore prior to
DZ: and again there will be another part prior to this, and yet
another, and so on to infinity. Thus of that which changes there
cannot be any primary part that has changed. It is evident, then,
from what has been said, that neither of that which changes
nor of the time in which it changes is there any primary part.
With regard, however, to the actual subject of change - that is to
say that in respect of which a thing changes - there is a
difference to be observed. For in a process of change we may
distinguish three terms - that which changes, that in which it
changes, and the actual subject of change, e.g. the man, the
time, and the fair complexion. Of these the man and the time
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are divisible: but with the fair complexion it is otherwise
(though they are all divisible accidentally, for that in which the
fair complexion or any other quality is an accident is divisible).
For of actual subjects of change it will be seen that those which
are classed as essentially, not accidentally, divisible have no
primary part. Take the case of magnitudes: let AB be a
magnitude, and suppose that it has moved from B to a primary
'where' G. Then if BG is taken to be indivisible, two things
without parts will have to be contiguous (which is impossible):
if on the other hand it is taken to be divisible, there will be
something prior to G to which the magnitude has changed, and
something else again prior to that, and so on to infinity, because
the process of division may be continued without end. Thus
there can be no primary 'where' to which a thing has changed.
And if we take the case of quantitative change, we shall get a
like result, for here too the change is in something continuous.
It is evident, then, that only in qualitative motion can there be
anything essentially indivisible.
Now everything that changes changes time, and that in two
senses: for the time in which a thing is said to change may be
the primary time, or on the other hand it may have an extended
reference, as e.g. when we say that a thing changes in a
particular year because it changes in a particular day. That being
so, that which changes must be changing in any part of the
primary time in which it changes. This is clear from our
definition of 'primary', in which the word is said to express just
this: it may also, however, be made evident by the following
argument. Let ChRh be the primary time in which that which is
in motion is in motion: and (as all time is divisible) let it be
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divided at K. Now in the time ChK it either is in motion or is not
in motion, and the same is likewise true of the time KRh. Then
if it is in motion in neither of the two parts, it will be at rest in
the whole: for it is impossible that it should be in motion in a
time in no part of which it is in motion. If on the other hand it is
in motion in only one of the two parts of the time, ChRh cannot
be the primary time in which it is in motion: for its motion will
have reference to a time other than ChRh. It must, then, have
been in motion in any part of ChRh.
And now that this has been proved, it is evident that everything
that is in motion must have been in motion before. For if that
which is in motion has traversed the distance KL in the primary
time ChRh, in half the time a thing that is in motion with equal
velocity and began its motion at the same time will have
traversed half the distance. But if this second thing whose
velocity is equal has traversed a certain distance in a certain
time, the original thing that is in motion must have traversed
the same distance in the same time. Hence that which is in
motion must have been in motion before.
Again, if by taking the extreme moment of the time - for it is
the moment that defines the time, and time is that which is
intermediate between moments-we are enabled to say that
motion has taken place in the whole time ChRh or in fact in any
period of it, motion may likewise be said to have taken place in
every other such period. But half the time finds an extreme in
the point of division. Therefore motion will have taken place in
half the time and in fact in any part of it: for as soon as any
division is made there is always a time defined by moments. If,
then, all time is divisible, and that which is intermediate
between moments is time, everything that is changing must
have completed an infinite number of changes.
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Again, since a thing that changes continuously and has not
perished or ceased from its change must either be changing or
have changed in any part of the time of its change, and since it
cannot be changing in a moment, it follows that it must have
changed at every moment in the time: consequently, since the
moments are infinite in number, everything that is changing
must have completed an infinite number of changes.
And not only must that which is changing have changed, but
that which has changed must also previously have been
changing, since everything that has changed from something to
something has changed in a period of time. For suppose that a
thing has changed from A to B in a moment. Now the moment
in which it has changed cannot be the same as that in which it
is at A (since in that case it would be in A and B at once): for we
have shown above that that that which has changed, when it
has changed, is not in that from which it has changed. If, on the
other hand, it is a different moment, there will be a period of
time intermediate between the two: for, as we saw, moments
are not consecutive. Since, then, it has changed in a period of
time, and all time is divisible, in half the time it will have
completed another change, in a quarter another, and so on to
infinity: consequently when it has changed, it must have
previously been changing.
Moreover, the truth of what has been said is more evident in the
case of magnitude, because the magnitude over which what is
changing changes is continuous. For suppose that a thing has
changed from G to D. Then if GD is indivisible, two things
without parts will be consecutive. But since this is impossible,
that which is intermediate between them must be a magnitude
and divisible into an infinite number of segments: consequently,
before the change is completed, the thing changes to those
segments. Everything that has changed, therefore, must
previously have been changing: for the same proof also holds
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good of change with respect to what is not continuous, changes,
that is to say, between contraries and between contradictories.
In such cases we have only to take the time in which a thing
has changed and again apply the same reasoning. So that which
has changed must have been changing and that which is
changing must have changed, and a process of change is
preceded by a completion of change and a completion by a
process: and we can never take any stage and say that it is
absolutely the first. The reason of this is that no two things
without parts can be contiguous, and therefore in change the
process of division is infinite, just as lines may be infinitely
divided so that one part is continually increasing and the other
continually decreasing.
So it is evident also that that that which has become must
previously have been in process of becoming, and that which is
in process of becoming must previously have become,
everything (that is) that is divisible and continuous: though it is
not always the actual thing that is in process of becoming of
which this is true: sometimes it is something else, that is to say,
some part of the thing in question, e.g. the foundation-stone of
a house. So, too, in the case of that which is perishing and that
which has perished: for that which becomes and that which
perishes must contain an element of infiniteness as an
immediate consequence of the fact that they are continuous
things: and so a thing cannot be in process of becoming without
having become or have become without having been in process
of becoming. So, too, in the case of perishing and having
perished: perishing must be preceded by having perished, and
having perished must be preceded by perishing. It is evident,
then, that that which has become must previously have been in
process of becoming, and that which is in process of becoming
must previously have become: for all magnitudes and all
periods of time are infinitely divisible.
764
Consequently no absolutely first stage of change can be
represented by any particular part of space or time which the
changing thing may occupy.
Now since the motion of everything that is in motion occupies a
period of time, and a greater magnitude is traversed in a longer
time, it is impossible that a thing should undergo a finite
motion in an infinite time, if this is understood to mean not
that the same motion or a part of it is continually repeated, but
that the whole infinite time is occupied by the whole finite
motion. In all cases where a thing is in motion with uniform
velocity it is clear that the finite magnitude is traversed in a
finite time. For if we take a part of the motion which shall be a
measure of the whole, the whole motion is completed in as
many equal periods of the time as there are parts of the motion.
Consequently, since these parts are finite, both in size
individually and in number collectively, the whole time must
also be finite: for it will be a multiple of the portion, equal to the
time occupied in completing the aforesaid part multiplied by
the number of the parts.
But it makes no difference even if the velocity is not uniform.
For let us suppose that the line AB represents a finite stretch
over which a thing has been moved in the given time, and let
GD be the infinite time. Now if one part of the stretch must have
been traversed before another part (this is clear, that in the
earlier and in the later part of the time a different part of the
stretch has been traversed: for as the time lengthens a different
part of the motion will always be completed in it, whether the
thing in motion changes with uniform velocity or not: and
765
whether the rate of motion increases or diminishes or remains
stationary this is none the less so), let us then take AE a part of
the whole stretch of motion AB which shall be a measure of AB.
Now this part of the motion occupies a certain period of the
infinite time: it cannot itself occupy an infinite time, for we are
assuming that that is occupied by the whole AB. And if again I
take another part equal to AE, that also must occupy a finite
time in consequence of the same assumption. And if I go on
taking parts in this way, on the one hand there is no part which
will be a measure of the infinite time (for the infinite cannot be
composed of finite parts whether equal or unequal, because
there must be some unity which will be a measure of things
finite in multitude or in magnitude, which, whether they are
equal or unequal, are none the less limited in magnitude); while
on the other hand the finite stretch of motion AB is a certain
multiple of AE: consequently the motion AB must be
accomplished in a finite time. Moreover it is the same with
coming to rest as with motion. And so it is impossible for one
and the same thing to be infinitely in process of becoming or of
perishing. The reasoning he will prove that in a finite time there
cannot be an infinite extent of motion or of coming to rest,
whether the motion is regular or irregular. For if we take a part
which shall be a measure of the whole time, in this part a
certain fraction, not the whole, of the magnitude will be
traversed, because we assume that the traversing of the whole
occupies all the time. Again, in another equal part of the time
another part of the magnitude will be traversed: and similarly in
each part of the time that we take, whether equal or unequal to
the part originally taken. It makes no difference whether the
parts are equal or not, if only each is finite: for it is clear that
while the time is exhausted by the subtraction of its parts, the
infinite magnitude will not be thus exhausted, since the process
of subtraction is finite both in respect of the quantity subtracted
and of the number of times a subtraction is made. Consequently
766
the infinite magnitude will not be traversed in finite time: and it
makes no difference whether the magnitude is infinite in only
one direction or in both: for the same reasoning will hold good.
This having been proved, it is evident that neither can a finite
magnitude traverse an infinite magnitude in a finite time, the
reason being the same as that given above: in part of the time it
will traverse a finite magnitude and in each several part
likewise, so that in the whole time it will traverse a finite
magnitude.
And since a finite magnitude will not traverse an infinite in a
finite time, it is clear that neither will an infinite traverse a
finite in a finite time. For if the infinite could traverse the finite,
the finite could traverse the infinite; for it makes no difference
which of the two is the thing in motion; either case involves the
traversing of the infinite by the finite. For when the infinite
magnitude A is in motion a part of it, say GD, will occupy the
finite and then another, and then another, and so on to infinity.
Thus the two results will coincide: the infinite will have
completed a motion over the finite and the finite will have
traversed the infinite: for it would seem to be impossible for the
motion of the infinite over the finite to occur in any way other
than by the finite traversing the infinite either by locomotion
over it or by measuring it. Therefore, since this is impossible, the
infinite cannot traverse the finite.
Nor again will the infinite traverse the infinite in a finite time.
Otherwise it would also traverse the finite, for the infinite
includes the finite. We can further prove this in the same way
by taking the time as our starting-point.
Since, then, it is established that in a finite time neither will the
finite traverse the infinite, nor the infinite the finite, nor the
infinite the infinite, it is evident also that in a finite time there
cannot be infinite motion: for what difference does it make
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whether we take the motion or the magnitude to be infinite? If
either of the two is infinite, the other must be so likewise: for all
locomotion is in space.
8
Since everything to which motion or rest is natural is in motion
or at rest in the natural time, place, and manner, that which is
coming to a stand, when it is coming to a stand, must be in
motion: for if it is not in motion it must be at rest: but that
which is at rest cannot be coming to rest. From this it evidently
follows that coming to a stand must occupy a period of time: for
the motion of that which is in motion occupies a period of time,
and that which is coming to a stand has been shown to be in
motion: consequently coming to a stand must occupy a period
of time.
Again, since the terms 'quicker' and 'slower' are used only of
that which occupies a period of time, and the process of coming
to a stand may be quicker or slower, the same conclusion
follows.
And that which is coming to a stand must be coming to a stand
in any part of the primary time in which it is coming to a stand.
For if it is coming to a stand in neither of two parts into which
the time may be divided, it cannot be coming to a stand in the
whole time, with the result that that that which is coming to a
stand will not be coming to a stand. If on the other hand it is
coming to a stand in only one of the two parts of the time, the
whole cannot be the primary time in which it is coming to a
stand: for it is coming to a stand in the whole time not primarily
but in virtue of something distinct from itself, the argument
768
being the same as that which we used above about things in
motion.
And just as there is no primary time in which that which is in
motion is in motion, so too there is no primary time in which
that which is coming to a stand is coming to a stand, there
being no primary stage either of being in motion or of coming to
a stand. For let AB be the primary time in which a thing is
coming to a stand. Now AB cannot be without parts: for there
cannot be motion in that which is without parts, because the
moving thing would necessarily have been already moved for
part of the time of its movement: and that which is coming to a
stand has been shown to be in motion. But since AB is therefore
divisible, the thing is coming to a stand in every one of the parts
of AB: for we have shown above that it is coming to a stand in
every one of the parts in which it is primarily coming to a stand.
Since then, that in which primarily a thing is coming to a stand
must be a period of time and not something indivisible, and
since all time is infinitely divisible, there cannot be anything in
which primarily it is coming to a stand.
Nor again can there be a primary time at which the being at rest
of that which is at rest occurred: for it cannot have occurred in
that which has no parts, because there cannot be motion in that
which is indivisible, and that in which rest takes place is the
same as that in which motion takes place: for we defined a
state of rest to be the state of a thing to which motion is natural
but which is not in motion when (that is to say in that in which)
motion would be natural to it. Again, our use of the phrase
'being at rest' also implies that the previous state of a thing is
still unaltered, not one point only but two at least being thus
needed to determine its presence: consequently that in which a
thing is at rest cannot be without parts. Since, then it is
divisible, it must be a period of time, and the thing must be at
769
rest in every one of its parts, as may be shown by the same
method as that used above in similar demonstrations.
So there can be no primary part of the time: and the reason is
that rest and motion are always in a period of time, and a period
of time has no primary part any more than a magnitude or in
fact anything continuous: for everything continuous is divisible
into an infinite number of parts.
And since everything that is in motion is in motion in a period
of time and changes from something to something, when its
motion is comprised within a particular period of time
essentially - that is to say when it fills the whole and not
merely a part of the time in question - it is impossible that in
that time that which is in motion should be over against some
particular thing primarily. For if a thing - itself and each of its
parts - occupies the same space for a definite period of time, it
is at rest: for it is in just these circumstances that we use the
term 'being at rest' - when at one moment after another it can
be said with truth that a thing, itself and its parts, occupies the
same space. So if this is being at rest it is impossible for that
which is changing to be as a whole, at the time when it is
primarily changing, over against any particular thing (for the
whole period of time is divisible), so that in one part of it after
another it will be true to say that the thing, itself and its parts,
occupies the same space. If this is not so and the aforesaid
proposition is true only at a single moment, then the thing will
be over against a particular thing not for any period of time but
only at a moment that limits the time. It is true that at any
moment it is always over against something stationary: but it is
not at rest: for at a moment it is not possible for anything to be
either in motion or at rest. So while it is true to say that that
which is in motion is at a moment not in motion and is
opposite some particular thing, it cannot in a period of time be
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over against that which is at rest: for that would involve the
conclusion that that which is in locomotion is at rest.
Zeno's reasoning, however, is fallacious, when he says that if
everything when it occupies an equal space is at rest, and if that
which is in locomotion is always occupying such a space at any
moment, the flying arrow is therefore motionless. This is false,
for time is not composed of indivisible moments any more than
any other magnitude is composed of indivisibles.
Zeno's arguments about motion, which cause so much
disquietude to those who try to solve the problems that they
present, are four in number. The first asserts the non-existence
of motion on the ground that that which is in locomotion must
arrive at the half-way stage before it arrives at the goal. This we
have discussed above.
The second is the so-called 'Achilles', and it amounts to this,
that in a race the quickest runner can never overtake the
slowest, since the pursuer must first reach the point whence
the pursued started, so that the slower must always hold a lead.
This argument is the same in principle as that which depends
on bisection, though it differs from it in that the spaces with
which we successively have to deal are not divided into halves.
The result of the argument is that the slower is not overtaken:
but it proceeds along the same lines as the bisection-argument
(for in both a division of the space in a certain way leads to the
result that the goal is not reached, though the 'Achilles' goes
further in that it affirms that even the quickest runner in
legendary tradition must fail in his pursuit of the slowest), so
that the solution must be the same. And the axiom that that
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which holds a lead is never overtaken is false: it is not
overtaken, it is true, while it holds a lead: but it is overtaken
nevertheless if it is granted that it traverses the finite distance
prescribed. These then are two of his arguments.
The third is that already given above, to the effect that the flying
arrow is at rest, which result follows from the assumption that
time is composed of moments: if this assumption is not
granted, the conclusion will not follow.
The fourth argument is that concerning the two rows of bodies,
each row being composed of an equal number of bodies of equal
size, passing each other on a race-course as they proceed with
equal velocity in opposite directions, the one row originally
occupying the space between the goal and the middle point of
the course and the other that between the middle point and the
starting-post. This, he thinks, involves the conclusion that half a
given time is equal to double that time. The fallacy of the
reasoning lies in the assumption that a body occupies an equal
time in passing with equal velocity a body that is in motion and
a body of equal size that is at rest; which is false. For instance
(so runs the argument), let A, A.. .be the stationary bodies of
equal size, B, EL.the bodies, equal in number and in size to A,
A..., originally occupying the half of the course from the starting-
post to the middle of the A's, and G, G... those originally
occupying the other half from the goal to the middle of the A's,
equal in number, size, and velocity to B, B....Then three
consequences follow:
First, as the B's and the G's pass one another, the first B reaches
the last G at the same moment as the first G reaches the last B.
Secondly at this moment the first G has passed all the A's,
whereas the first B has passed only half the A's, and has
consequently occupied only half the time occupied by the first
G, since each of the two occupies an equal time in passing each
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A. Thirdly, at the same moment all the B's have passed all the
G's: for the first G and the first B will simultaneously reach the
opposite ends of the course, since (so says Zeno) the time
occupied by the first G in passing each of the B's is equal to that
occupied by it in passing each of the A's, because an equal time
is occupied by both the first B and the first G in passing all the
A's. This is the argument, but it presupposed the aforesaid
fallacious assumption.
Nor in reference to contradictory change shall we find anything
unanswerable in the argument that if a thing is changing from
not-white, say, to white, and is in neither condition, then it will
be neither white nor not-white: for the fact that it is not wholly
in either condition will not preclude us from calling it white or
not-white. We call a thing white or not-white not necessarily
because it is be one or the other, but cause most of its parts or
the most essential parts of it are so: not being in a certain
condition is different from not being wholly in that condition.
So, too, in the case of being and not-being and all other
conditions which stand in a contradictory relation: while the
changing thing must of necessity be in one of the two opposites,
it is never wholly in either.
Again, in the case of circles and spheres and everything whose
motion is confined within the space that it occupies, it is not
true to say the motion can be nothing but rest, on the ground
that such things in motion, themselves and their parts, will
occupy the same position for a period of time, and that
therefore they will be at once at rest and in motion. For in the
first place the parts do not occupy the same position for any
period of time: and in the second place the whole also is always
changing to a different position: for if we take the orbit as
described from a point A on a circumference, it will not be the
same as the orbit as described from B or G or any other point on
the same circumference except in an accidental sense, the
773
sense that is to say in which a musical man is the same as a
man. Thus one orbit is always changing into another, and the
thing will never be at rest. And it is the same with the sphere
and everything else whose motion is confined within the space
that it occupies.
10
Our next point is that that which is without parts cannot be in
motion except accidentally: i.e. it can be in motion only in so far
as the body or the magnitude is in motion and the partless is in
motion by inclusion therein, just as that which is in a boat may
be in motion in consequence of the locomotion of the boat, or a
part may be in motion in virtue of the motion of the whole. (It
must be remembered, however, that by 'that which is without
parts' I mean that which is quantitatively indivisible (and that
the case of the motion of a part is not exactly parallel): for parts
have motions belonging essentially and severally to themselves
distinct from the motion of the whole. The distinction may be
seen most clearly in the case of a revolving sphere, in which the
velocities of the parts near the centre and of those on the
surface are different from one another and from that of the
whole; this implies that there is not one motion but many). As
we have said, then, that which is without parts can be in motion
in the sense in which a man sitting in a boat is in motion when
the boat is travelling, but it cannot be in motion of itself. For
suppose that it is changing from AB to BG - either from one
magnitude to another, or from one form to another, or from
some state to its contradictory - and let D be the primary time
in which it undergoes the change. Then in the time in which it
is changing it must be either in AB or in BG or partly in one and
partly in the other: for this, as we saw, is true of everything that
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is changing. Now it cannot be partly in each of the two: for then
it would be divisible into parts. Nor again can it be in BG: for
then it will have completed the change, whereas the
assumption is that the change is in process. It remains, then,
that in the time in which it is changing, it is in AB. That being
so, it will be at rest: for, as we saw, to be in the same condition
for a period of time is to be at rest. So it is not possible for that
which has no parts to be in motion or to change in any way: for
only one condition could have made it possible for it to have
motion, viz. that time should be composed of moments, in
which case at any moment it would have completed a motion
or a change, so that it would never be in motion, but would
always have been in motion. But this we have already shown
above to be impossible: time is not composed of moments, just
as a line is not composed of points, and motion is not composed
of starts: for this theory simply makes motion consist of
indivisibles in exactly the same way as time is made to consist
of moments or a length of points.
Again, it may be shown in the following way that there can be
no motion of a point or of any other indivisible. That which is in
motion can never traverse a space greater than itself without
first traversing a space equal to or less than itself. That being so,
it is evident that the point also must first traverse a space equal
to or less than itself. But since it is indivisible, there can be no
space less than itself for it to traverse first: so it will have to
traverse a distance equal to itself. Thus the line will be
composed of points, for the point, as it continually traverses a
distance equal to itself, will be a measure of the whole line. But
since this is impossible, it is likewise impossible for the
indivisible to be in motion.
Again, since motion is always in a period of time and never in a
moment, and all time is divisible, for everything that is in
motion there must be a time less than that in which it traverses
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a distance as great as itself. For that in which it is in motion will
be a time, because all motion is in a period of time; and all time
has been shown above to be divisible. Therefore, if a point is in
motion, there must be a time less than that in which it has
itself traversed any distance. But this is impossible, for in less
time it must traverse less distance, and thus the indivisible will
be divisible into something less than itself, just as the time is so
divisible: the fact being that the only condition under which
that which is without parts and indivisible could be in motion
would have been the possibility of the infinitely small being in
motion in a moment: for in the two questions - that of motion
in a moment and that of motion of something indivisible - the
same principle is involved.
Our next point is that no process of change is infinite: for every
change, whether between contradictories or between contraries,
is a change from something to something. Thus in contradictory
changes the positive or the negative, as the case may be, is the
limit, e.g. being is the limit of coming to be and not-being is the
limit of ceasing to be: and in contrary changes the particular
contraries are the limits, since these are the extreme points of
any such process of change, and consequently of every process
of alteration: for alteration is always dependent upon some
contraries. Similarly contraries are the extreme points of
processes of increase and decrease: the limit of increase is to be
found in the complete magnitude proper to the peculiar nature
of the thing that is increasing, while the limit of decrease is the
complete loss of such magnitude. Locomotion, it is true, we
cannot show to be finite in this way, since it is not always
between contraries. But since that which cannot be cut (in the
sense that it is inconceivable that it should be cut, the term
'cannot' being used in several senses) - since it is inconceivable
that that which in this sense cannot be cut should be in process
of being cut, and generally that that which cannot come to be
should be in process of coming to be, it follows that it is
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inconceivable that that which cannot complete a change should
be in process of changing to that to which it cannot complete a
change. If, then, it is to be assumed that that which is in
locomotion is in process of changing, it must be capable of
completing the change. Consequently its motion is not infinite,
and it will not be in locomotion over an infinite distance, for it
cannot traverse such a distance.
It is evident, then, that a process of change cannot be infinite in
the sense that it is not defined by limits. But it remains to be
considered whether it is possible in the sense that one and the
same process of change may be infinite in respect of the time
which it occupies. If it is not one process, it would seem that
there is nothing to prevent its being infinite in this sense; e.g. if
a process of locomotion be succeeded by a process of alteration
and that by a process of increase and that again by a process of
coming to be: in this way there may be motion for ever so far as
the time is concerned, but it will not be one motion, because all
these motions do not compose one. If it is to be one process, no
motion can be infinite in respect of the time that it occupies,
with the single exception of rotatory locomotion.
Book VII
Everything that is in motion must be moved by something. For if
it has not the source of its motion in itself it is evident that it is
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moved by something other than itself, for there must be
something else that moves it. If on the other hand it has the
source of its motion in itself, let AB be taken to represent that
which is in motion essentially of itself and not in virtue of the
fact that something belonging to it is in motion. Now in the first
place to assume that AB, because it is in motion as a whole and
is not moved by anything external to itself, is therefore moved
by itself - this is just as if, supposing that KL is moving LM and
is also itself in motion, we were to deny that KM is moved by
anything on the ground that it is not evident which is the part
that is moving it and which the part that is moved. In the
second place that which is in motion without being moved by
anything does not necessarily cease from its motion because
something else is at rest, but a thing must be moved by
something if the fact of something else having ceased from its
motion causes it to be at rest. Thus, if this is accepted,
everything that is in motion must be moved by something. For
AB, which has been taken to represent that which is in motion,
must be divisible since everything that is in motion is divisible.
Let it be divided, then, at G. Now if GB is not in motion, then AB
will not be in motion: for if it is, it is clear that AG would be in
motion while BG is at rest, and thus AB cannot be in motion
essentially and primarily. But ex hypothesi AB is in motion
essentially and primarily. Therefore if GB is not in motion AB
will be at rest. But we have agreed that that which is at rest if
something else is not in motion must be moved by something.
Consequently, everything that is in motion must be moved by
something: for that which is in motion will always be divisible,
and if a part of it is not in motion the whole must be at rest.
Since everything that is in motion must be moved by
something, let us take the case in which a thing is in
locomotion and is moved by something that is itself in motion,
and that again is moved by something else that is in motion,
and that by something else, and so on continually: then the
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series cannot go on to infinity, but there must be some first
movent. For let us suppose that this is not so and take the series
to be infinite. Let A then be moved by B, B by G, G by D, and so
on, each member of the series being moved by that which
comes next to it. Then since ex hypothesi the movent while
causing motion is also itself in motion, and the motion of the
moved and the motion of the movent must proceed
simultaneously (for the movent is causing motion and the
moved is being moved simultaneously) it is evident that the
respective motions of A, B, G, and each of the other moved
movents are simultaneous. Let us take the motion of each
separately and let E be the motion of A, Z of B, and H and
respectively the motions of G and D: for though they are all
moved severally one by another, yet we may still take the
motion of each as numerically one, since every motion is from
something to something and is not infinite in respect of its
extreme points. By a motion that is numerically one I mean a
motion that proceeds from something numerically one and the
same to something numerically one and the same in a period of
time numerically one and the same: for a motion may be the
same generically, specifically, or numerically: it is generically
the same if it belongs to the same category, e.g. substance or
quality: it is specifically the same if it proceeds from something
specifically the same to something specifically the same, e.g.
from white to black or from good to bad, which is not of a kind
specifically distinct: it is numerically the same if it proceeds
from something numerically one to something numerically one
in the same period of time, e.g. from a particular white to a
particular black, or from a particular place to a particular place,
in a particular period of time: for if the period of time were not
one and the same, the motion would no longer be numerically
one though it would still be specifically one.
We have dealt with this question above. Now let us further take
the time in which A has completed its motion, and let it be
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represented by K. Then since the motion of A is finite the time
will also be finite. But since the movents and the things moved
are infinite, the motion EZHO, i.e. the motion that is composed
of all the individual motions, must be infinite. For the motions
of A, B, and the others may be equal, or the motions of the
others may be greater: but assuming what is conceivable, we
find that whether they are equal or some are greater, in both
cases the whole motion is infinite. And since the motion of A
and that of each of the others are simultaneous, the whole
motion must occupy the same time as the motion of A: but the
time occupied by the motion of A is finite: consequently the
motion will be infinite in a finite time, which is impossible.
It might be thought that what we set out to prove has thus been
shown, but our argument so far does not prove it, because it
does not yet prove that anything impossible results from the
contrary supposition: for in a finite time there may be an
infinite motion, though not of one thing, but of many: and in
the case that we are considering this is so: for each thing
accomplishes its own motion, and there is no impossibility in
many things being in motion simultaneously. But if (as we see
to be universally the case) that which primarily is moved locally
and corporeally must be either in contact with or continuous
with that which moves it, the things moved and the movents
must be continuous or in contact with one another, so that
together they all form a single unity: whether this unity is finite
or infinite makes no difference to our present argument; for in
any case since the things in motion are infinite in number the
whole motion will be infinite, if, as is theoretically possible,
each motion is either equal to or greater than that which
follows it in the series: for we shall take as actual that which is
theoretically possible. If, then, A, B, G, D form an infinite
magnitude that passes through the motion EZHO in the finite
time K, this involves the conclusion that an infinite motion is
passed through in a finite time: and whether the magnitude in
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question is finite or infinite this is in either case impossible.
Therefore the series must come to an end, and there must be a
first movent and a first moved: for the fact that this
impossibility results only from the assumption of a particular
case is immaterial, since the case assumed is theoretically
possible, and the assumption of a theoretically possible case
ought not to give rise to any impossible result.
That which is the first movement of a thing - in the sense that
it supplies not 'that for the sake of which' but the source of the
motion - is always together with that which is moved by it by
'together' I mean that there is nothing intermediate between
them). This is universally true wherever one thing is moved by
another. And since there are three kinds of motion, local,
qualitative, and quantitative, there must also be three kinds of
movent, that which causes locomotion, that which causes
alteration, and that which causes increase or decrease.
Let us begin with locomotion, for this is the primary motion.
Everything that is in locomotion is moved either by itself or by
something else. In the case of things that are moved by
themselves it is evident that the moved and the movent are
together: for they contain within themselves their first movent,
so that there is nothing in between. The motion of things that
are moved by something else must proceed in one of four ways:
for there are four kinds of locomotion caused by something
other than that which is in motion, viz. pulling, pushing,
carrying, and twirling. All forms of locomotion are reducible to
these. Thus pushing on is a form of pushing in which that
which is causing motion away from itself follows up that which
781
it pushes and continues to push it: pushing off occurs when the
movent does not follow up the thing that it has moved:
throwing when the movent causes a motion away from itself
more violent than the natural locomotion of the thing moved,
which continues its course so long as it is controlled by the
motion imparted to it. Again, pushing apart and pushing
together are forms respectively of pushing off and pulling:
pushing apart is pushing off, which may be a motion either
away from the pusher or away from something else, while
pushing together is pulling, which may be a motion towards
something else as well as the puller. We may similarly classify
all the varieties of these last two, e.g. packing and combing: the
former is a form of pushing together, the latter a form of
pushing apart. The same is true of the other processes of
combination and separation (they will all be found to be forms
of pushing apart or of pushing together), except such as are
involved in the processes of becoming and perishing. (At same
time it is evident that there is no other kind of motion but
combination and separation: for they may all be apportioned to
one or other of those already mentioned.) Again, inhaling is a
form of pulling, exhaling a form of pushing: and the same is
true of spitting and of all other motions that proceed through
the body, whether secretive or assimilative, the assimilative
being forms of pulling, the secretive of pushing off. All other
kinds of locomotion must be similarly reduced, for they all fall
under one or other of our four heads. And again, of these four,
carrying and twirling are to pulling and pushing. For carrying
always follows one of the other three methods, for that which is
carried is in motion accidentally, because it is in or upon
something that is in motion, and that which carries it is in
doing so being either pulled or pushed or twirled; thus carrying
belongs to all the other three kinds of motion in common. And
twirling is a compound of pulling and pushing, for that which is
twirling a thing must be pulling one part of the thing and
782
pushing another part, since it impels one part away from itself
and another part towards itself. If, therefore, it can be shown
that that which is pushing and that which is pushing and
pulling are adjacent respectively to that which is being pushed
and that which is being pulled, it will be evident that in all
locomotion there is nothing intermediate between moved and
movent. But the former fact is clear even from the definitions of
pushing and pulling, for pushing is motion to something else
from oneself or from something else, and pulling is motion from
something else to oneself or to something else, when the
motion of that which is pulling is quicker than the motion that
would separate from one another the two things that are
continuous: for it is this that causes one thing to be pulled on
along with the other. (It might indeed be thought that there is a
form of pulling that arises in another way: that wood, e.g. pulls
fire in a manner different from that described above. But it
makes no difference whether that which pulls is in motion or is
stationary when it is pulling: in the latter case it pulls to the
place where it is, while in the former it pulls to the place where
it was.) Now it is impossible to move anything either from
oneself to something else or something else to oneself without
being in contact with it: it is evident, therefore, that in all
locomotion there is nothing intermediate between moved and
movent.
Nor again is there anything intermediate between that which
undergoes and that which causes alteration: this can be proved
by induction: for in every case we find that the respective
extremities of that which causes and that which undergoes
alteration are adjacent. For our assumption is that things that
are undergoing alteration are altered in virtue of their being
affected in respect of their so-called affective qualities, since
that which is of a certain quality is altered in so far as it is
sensible, and the characteristics in which bodies differ from one
another are sensible characteristics: for every body differs from
783
another in possessing a greater or lesser number of sensible
characteristics or in possessing the same sensible
characteristics in a greater or lesser degree. But the alteration of
that which undergoes alteration is also caused by the above-
mentioned characteristics, which are affections of some
particular underlying quality. Thus we say that a thing is altered
by becoming hot or sweet or thick or dry or white: and we make
these assertions alike of what is inanimate and of what is
animate, and further, where animate things are in question, we
make them both of the parts that have no power of sense-
perception and of the senses themselves. For in a way even the
senses undergo alteration, since the active sense is a motion
through the body in the course of which the sense is affected in
a certain way. We see, then, that the animate is capable of every
kind of alteration of which the inanimate is capable: but the
inanimate is not capable of every kind of alteration of which the
animate is capable, since it is not capable of alteration in
respect of the senses: moreover the inanimate is unconscious of
being affected by alteration, whereas the animate is conscious
of it, though there is nothing to prevent the animate also being
unconscious of it when the process of the alteration does not
concern the senses. Since, then, the alteration of that which
undergoes alteration is caused by sensible things, in every case
of such alteration it is evident that the respective extremities of
that which causes and that which undergoes alteration are
adjacent. Thus the air is continuous with that which causes the
alteration, and the body that undergoes alteration is continuous
with the air. Again, the colour is continuous with the light and
the light with the sight. And the same is true of hearing and
smelling: for the primary movent in respect to the moved is the
air. Similarly, in the case of tasting, the flavour is adjacent to the
sense of taste. And it is just the same in the case of things that
are inanimate and incapable of sense-perception. Thus there
784
can be nothing intermediate between that which undergoes and
that which causes alteration.
Nor, again, can there be anything intermediate between that
which suffers and that which causes increase: for the part of
the latter that starts the increase does so by becoming attached
in such a way to the former that the whole becomes one. Again,
the decrease of that which suffers decrease is caused by a part
of the thing becoming detached. So that which causes increase
and that which causes decrease must be continuous with that
which suffers increase and that which suffers decrease
respectively: and if two things are continuous with one another
there can be nothing intermediate between them.
It is evident, therefore, that between the extremities of the
moved and the movent that are respectively first and last in
reference to the moved there is nothing intermediate.
Everything, we say, that undergoes alteration is altered by
sensible causes, and there is alteration only in things that are
said to be essentially affected by sensible things. The truth of
this is to be seen from the following considerations. Of all other
things it would be most natural to suppose that there is
alteration in figures and shapes, and in acquired states and in
the processes of acquiring and losing these: but as a matter of
fact in neither of these two classes of things is there alteration.
In the first place, when a particular formation of a thing is
completed, we do not call it by the name of its material: e.g. we
do not call the statue 'bronze' or the pyramid 'wax' or the bed
'wood', but we use a derived expression and call them 'of
785
bronze', 'waxen', and 'wooden' respectively. But when a thing
has been affected and altered in any way we still call it by the
original name: thus we speak of the bronze or the wax being dry
or fluid or hard or hot.
And not only so: we also speak of the particular fluid or hot
substance as being bronze, giving the material the same name
as that which we use to describe the affection.
Since, therefore, having regard to the figure or shape of a thing
we no longer call that which has become of a certain figure by
the name of the material that exhibits the figure, whereas
having regard to a thing's affections or alterations we still call it
by the name of its material, it is evident that becomings of the
former kind cannot be alterations.
Moreover it would seem absurd even to speak in this way, to
speak, that is to say, of a man or house or anything else that has
come into existence as having been altered. Though it may be
true that every such becoming is necessarily the result of
something's being altered, the result, e.g. of the material's being
condensed or rarefied or heated or cooled, nevertheless it is not
the things that are coming into existence that are altered, and
their becoming is not an alteration.
Again, acquired states, whether of the body or of the soul, are
not alterations. For some are excellences and others are defects,
and neither excellence nor defect is an alteration: excellence is
a perfection (for when anything acquires its proper excellence
we call it perfect, since it is then if ever that we have a thing in
its natural state: e.g. we have a perfect circle when we have one
as good as possible), while defect is a perishing of or departure
from this condition. So as when speaking of a house we do not
call its arrival at perfection an alteration (for it would be absurd
to suppose that the coping or the tiling is an alteration or that
in receiving its coping or its tiling a house is altered and not
786
perfected), the same also holds good in the case of excellences
and defects and of the persons or things that possess or acquire
them: for excellences are perfections of a thing's nature and
defects are departures from it: consequently they are not
alterations.
Further, we say that all excellences depend upon particular
relations. Thus bodily excellences such as health and a good
state of body we regard as consisting in a blending of hot and
cold elements within the body in due proportion, in relation
either to one another or to the surrounding atmosphere: and in
like manner we regard beauty, strength, and all the other bodily
excellences and defects. Each of them exists in virtue of a
particular relation and puts that which possesses it in a good or
bad condition with regard to its proper affections, where by
'proper' affections I mean those influences that from the
natural constitution of a thing tend to promote or destroy its
existence. Since then, relatives are neither themselves
alterations nor the subjects of alteration or of becoming or in
fact of any change whatever, it is evident that neither states nor
the processes of losing and acquiring states are alterations,
though it may be true that their becoming or perishing is
necessarily, like the becoming or perishing of a specific
character or form, the result of the alteration of certain other
things, e.g. hot and cold or dry and wet elements or the
elements, whatever they may be, on which the states primarily
depend. For each several bodily defect or excellence involves a
relation with those things from which the possessor of the
defect or excellence is naturally subject to alteration: thus
excellence disposes its possessor to be unaffected by these
influences or to be affected by those of them that ought to be
admitted, while defect disposes its possessor to be affected by
them or to be unaffected by those of them that ought to be
admitted.
787
And the case is similar in regard to the states of the soul, all of
which (like those of body) exist in virtue of particular relations,
the excellences being perfections of nature and the defects
departures from it: moreover, excellence puts its possessor in
good condition, while defect puts its possessor in a bad
condition, to meet his proper affections. Consequently these
cannot any more than the bodily states be alterations, nor can
the processes of losing and acquiring them be so, though their
becoming is necessarily the result of an alteration of the
sensitive part of the soul, and this is altered by sensible objects:
for all moral excellence is concerned with bodily pleasures and
pains, which again depend either upon acting or upon
remembering or upon anticipating. Now those that depend
upon action are determined by sense-perception, i.e. they are
stimulated by something sensible: and those that depend upon
memory or anticipation are likewise to be traced to sense-
perception, for in these cases pleasure is felt either in
remembering what one has experienced or in anticipating what
one is going to experience. Thus all pleasure of this kind must
be produced by sensible things: and since the presence in any
one of moral defect or excellence involves the presence in him
of pleasure or pain (with which moral excellence and defect are
always concerned), and these pleasures and pains are
alterations of the sensitive part, it is evident that the loss and
acquisition of these states no less than the loss and acquisition
of the states of the body must be the result of the alteration of
something else. Consequently, though their becoming is
accompanied by an alteration, they are not themselves
alterations.
Again, the states of the intellectual part of the soul are not
alterations, nor is there any becoming of them. In the first place
it is much more true of the possession of knowledge that it
depends upon a particular relation. And further, it is evident
that there is no becoming of these states. For that which is
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potentially possessed of knowledge becomes actually possessed
of it not by being set in motion at all itself but by reason of the
presence of something else: i.e. it is when it meets with the
particular object that it knows in a manner the particular
through its knowledge of the universal. (Again, there is no
becoming of the actual use and activity of these states, unless it
is thought that there is a becoming of vision and touching and
that the activity in question is similar to these.) And the original
acquisition of knowledge is not a becoming or an alteration: for
the terms 'knowing' and 'understanding' imply that the intellect
has reached a state of rest and come to a standstill, and there is
no becoming that leads to a state of rest, since, as we have said
above, change at all can have a becoming. Moreover, just as to
say, when any one has passed from a state of intoxication or
sleep or disease to the contrary state, that he has become
possessed of knowledge again is incorrect in spite of the fact
that he was previously incapable of using his knowledge, so, too,
when any one originally acquires the state, it is incorrect to say
that he becomes possessed of knowledge: for the possession of
understanding and knowledge is produced by the soul's settling
down out of the restlessness natural to it. Hence, too, in
learning and in forming judgements on matters relating to their
sense-perceptions children are inferior to adults owing to the
great amount of restlessness and motion in their souls. Nature
itself causes the soul to settle down and come to a state of rest
for the performance of some of its functions, while for the
performance of others other things do so: but in either case the
result is brought about through the alteration of something in
the body, as we see in the case of the use and activity of the
intellect arising from a man's becoming sober or being
awakened. It is evident, then, from the preceding argument that
alteration and being altered occur in sensible things and in the
sensitive part of the soul, and, except accidentally, in nothing
else.
789
A difficulty may be raised as to whether every motion is
commensurable with every other or not. Now if they are all
commensurable and if two things to have the same velocity
must accomplish an equal motion in an equal time, then we
may have a circumference equal to a straight line, or, of course,
the one may be greater or less than the other. Further, if one
thing alters and another accomplishes a locomotion in an equal
time, we may have an alteration and a locomotion equal to one
another: thus an affection will be equal to a length, which is
impossible. But is it not only when an equal motion is
accomplished by two things in an equal time that the velocities
of the two are equal? Now an affection cannot be equal to a
length. Therefore there cannot be an alteration equal to or less
than a locomotion: and consequently it is not the case that
every motion is commensurable with every other.
But how will our conclusion work out in the case of the circle
and the straight line? It would be absurd to suppose that the
motion of one in a circle and of another in a straight line cannot
be similar, but that the one must inevitably move more quickly
or more slowly than the other, just as if the course of one were
downhill and of the other uphill. Moreover it does not as a
matter of fact make any difference to the argument to say that
the one motion must inevitably be quicker or slower than the
other: for then the circumference can be greater or less than the
straight line; and if so it is possible for the two to be equal. For if
in the time A the quicker (B) passes over the distance B' and the
slower (G) passes over the distance G', B' will be greater than G':
for this is what we took 'quicker' to mean: and so quicker
motion also implies that one thing traverses an equal distance
790
in less time than another: consequently there will be a part of A
in which B will pass over a part of the circle equal to G', while G
will occupy the whole of A in passing over G'. None the less, if
the two motions are commensurable, we are confronted with
the consequence stated above, viz. that there may be a straight
line equal to a circle. But these are not commensurable: and so
the corresponding motions are not commensurable either.
But may we say that things are always commensurable if the
same terms are applied to them without equivocation? e.g. a
pen, a wine, and the highest note in a scale are not
commensurable: we cannot say whether any one of them is
sharper than any other: and why is this? they are
incommensurable because it is only equivocally that the same
term 'sharp' is applied to them: whereas the highest note in a
scale is commensurable with the leading-note, because the
term 'sharp' has the same meaning as applied to both. Can it be,
then, that the term 'quick' has not the same meaning as applied
to straight motion and to circular motion respectively? If so, far
less will it have the same meaning as applied to alteration and
to locomotion.
Or shall we in the first place deny that things are always
commensurable if the same terms are applied to them without
equivocation? For the term 'much' has the same meaning
whether applied to water or to air, yet water and air are not
commensurable in respect of it: or, if this illustration is not
considered satisfactory, 'double' at any rate would seem to have
the same meaning as applied to each (denoting in each case the
proportion of two to one), yet water and air are not
commensurable in respect of it. But here again may we not take
up the same position and say that the term 'much' is equivocal?
In fact there are some terms of which even the definitions are
equivocal; e.g. if 'much' were defined as 'so much and more','so
much' would mean something different in different cases:
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'equal' is similarly equivocal; and 'one' again is perhaps
inevitably an equivocal term; and if 'one' is equivocal, so is
'two'. Otherwise why is it that some things are commensurable
while others are not, if the nature of the attribute in the two
cases is really one and the same?
Can it be that the incommensurability of two things in respect
of any attribute is due to a difference in that which is primarily
capable of carrying the attribute? Thus horse and dog are so
commensurable that we may say which is the whiter, since that
which primarily contains the whiteness is the same in both, viz.
the surface: and similarly they are commensurable in respect of
size. But water and speech are not commensurable in respect of
clearness, since that which primarily contains the attribute is
different in the two cases. It would seem, however that we must
reject this solution, since clearly we could thus make all
equivocal attributes univocal and say merely that that contains
each of them is different in different cases: thus 'equality',
'sweetness', and 'whiteness' will severally always be the same,
though that which contains them is different in different cases.
Moreover, it is not any casual thing that is capable of carrying
any attribute: each single attribute can be carried primarily only
by one single thing.
Must we then say that, if two things are to be commensurable in
respect of any attribute, not only must the attribute in question
be applicable to both without equivocation, but there must also
be no specific differences either in the attribute itself or in that
which contains the attribute - that these, I mean, must not be
divisible in the way in which colour is divided into kinds? Thus
in this respect one thing will not be commensurable with
another, i.e. we cannot say that one is more coloured than the
other where only colour in general and not any particular colour
is meant; but they are commensurable in respect of whiteness.
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Similarly in the case of motion: two things are of the same
velocity if they occupy an equal time in accomplishing a certain
equal amount of motion. Suppose, then, that in a certain time
an alteration is undergone by one half of a body's length and a
locomotion is accomplished the other half: can be say that in
this case the alteration is equal to the locomotion and of the
same velocity? That would be absurd, and the reason is that
there are different species of motion. And if in consequence of
this we must say that two things are of equal velocity if they
accomplish locomotion over an equal distance in an equal time,
we have to admit the equality of a straight line and a
circumference. What, then, is the reason of this? Is it that
locomotion is a genus or that line is a genus? (We may leave the
time out of account, since that is one and the same.) If the lines
are specifically different, the locomotions also differ specifically
from one another: for locomotion is specifically differentiated
according to the specific differentiation of that over which it
takes place. (It is also similarly differentiated, it would seem,
accordingly as the instrument of the locomotion is different:
thus if feet are the instrument, it is walking, if wings it is flying;
but perhaps we should rather say that this is not so, and that in
this case the differences in the locomotion are merely
differences of posture in that which is in motion.) We may say,
therefore, that things are of equal velocity in an equal time they
traverse the same magnitude: and when I call it 'the same' I
mean that it contains no specific difference and therefore no
difference in the motion that takes place over it. So we have
now to consider how motion is differentiated: and this
discussion serves to show that the genus is not a unity but
contains a plurality latent in it and distinct from it, and that in
the case of equivocal terms sometimes the different senses in
which they are used are far removed from one another, while
sometimes there is a certain likeness between them, and
sometimes again they are nearly related either generically or
793
analogically, with the result that they seem not to be equivocal
though they really are.
When, then, is there a difference of species? Is an attribute
specifically different if the subject is different while the
attribute is the same, or must the attribute itself be different as
well? And how are we to define the limits of a species? What
will enable us to decide that particular instances of whiteness
or sweetness are the same or different? Is it enough that it
appears different in one subject from what appears in another?
Or must there be no sameness at all? And further, where
alteration is in question, how is one alteration to be of equal
velocity with another? One person may be cured quickly and
another slowly, and cures may also be simultaneous: so that,
recovery of health being an alteration, we have here alterations
of equal velocity, since each alteration occupies an equal time.
But what alteration? We cannot here speak of an 'equal'
alteration: what corresponds in the category of quality to
equality in the category of quantity is 'likeness'. However, let us
say that there is equal velocity where the same change is
accomplished in an equal time. Are we, then, to find the
commensurability in the subject of the affection or in the
affection itself? In the case that we have just been considering it
is the fact that health is one and the same that enables us to
arrive at the conclusion that the one alteration is neither more
nor less than the other, but that both are alike. If on the other
hand the affection is different in the two cases, e.g. when the
alterations take the form of becoming white and becoming
healthy respectively, here there is no sameness or equality or
likeness inasmuch as the difference in the affections at once
makes the alterations specifically different, and there is no
unity of alteration any more than there would be unity of
locomotion under like conditions. So we must find out how
many species there are of alteration and of locomotion
respectively. Now if the things that are in motion - that is to say,
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the things to which the motions belong essentially and not
accidentally - differ specifically, then their respective motions
will also differ specifically: if on the other hand they differ
generically or numerically, the motions also will differ
generically or numerically as the case may be. But there still
remains the question whether, supposing that two alterations
are of equal velocity, we ought to look for this equality in the
sameness (or likeness) of the affections, or in the things altered,
to see e.g. whether a certain quantity of each has become white.
Or ought we not rather to look for it in both? That is to say, the
alterations are the same or different according as the affections
are the same or different, while they are equal or unequal
according as the things altered are equal or unequal.
And now we must consider the same question in the case of
becoming and perishing: how is one becoming of equal velocity
with another? They are of equal velocity if in an equal time
there are produced two things that are the same and
specifically inseparable, e.g. two men (not merely generically
inseparable as e.g. two animals). Similarly one is quicker than
the other if in an equal time the product is different in the two
cases. I state it thus because we have no pair of terms that will
convey this 'difference' in the way in which unlikeness is
conveyed. If we adopt the theory that it is number that
constitutes being, we may indeed speak of a 'greater number'
and a 'lesser number' within the same species, but there is no
common term that will include both relations, nor are there
terms to express each of them separately in the same way as we
indicate a higher degree or preponderance of an affection by
'more', of a quantity by 'greater.'
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Now since wherever there is a movent, its motion always acts
upon something, is always in something, and always extends to
something (by 'is always in something' I mean that it occupies a
time: and by 'extends to something' I mean that it involves the
traversing of a certain amount of distance: for at any moment
when a thing is causing motion, it also has caused motion, so
that there must always be a certain amount of distance that has
been traversed and a certain amount of time that has been
occupied), then, A the movement have moved B a distance G in
a time D, then in the same time the same force A will move 1/2B
twice the distance G, and in 1/2D it will move 1/2B the whole
distance for G: thus the rules of proportion will be observed.
Again if a given force move a given weight a certain distance in
a certain time and half the distance in half the time, half the
motive power will move half the weight the same distance in
the same time. Let E represent half the motive power A and Z
half the weight B: then the ratio between the motive power and
the weight in the one case is similar and proportionate to the
ratio in the other, so that each force will cause the same
distance to be traversed in the same time. But if E move Z a
distance G in a time D, it does not necessarily follow that E can
move twice Z half the distance G in the same time. If, then, A
move B a distance G in a time D, it does not follow that E, being
half of A, will in the time D or in any fraction of it cause B to
traverse a part of G the ratio between which and the whole of G
is proportionate to that between A and E (whatever fraction of
AE may be): in fact it might well be that it will cause no motion
at all; for it does not follow that, if a given motive power causes
a certain amount of motion, half that power will cause motion
either of any particular amount or in any length of time:
otherwise one man might move a ship, since both the motive
power of the ship-haulers and the distance that they all cause
the ship to traverse are divisible into as many parts as there are
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men. Hence Zeno's reasoning is false when he argues that there
is no part of the millet that does not make a sound: for there is
no reason why any such part should not in any length of time
fail to move the air that the whole bushel moves in falling. In
fact it does not of itself move even such a quantity of the air as
it would move if this part were by itself: for no part even exists
otherwise than potentially.
If on the other hand we have two forces each of which
separately moves one of two weights a given distance in a given
time, then the forces in combination will move the combined
weights an equal distance in an equal time: for in this case the
rules of proportion apply.
Then does this hold good of alteration and of increase also?
Surely it does, for in any given case we have a definite thing
that cause increase and a definite thing that suffers increase,
and the one causes and the other suffers a certain amount of
increase in a certain amount of time. Similarly we have a
definite thing that causes alteration and a definite thing that
undergoes alteration, and a certain amount, or rather degree, of
alteration is completed in a certain amount of time: thus in
twice as much time twice as much alteration will be completed
and conversely twice as much alteration will occupy twice as
much time: and the alteration of half of its object will occupy
half as much time and in half as much time half of the object
will be altered: or again, in the same amount of time it will be
altered twice as much.
On the other hand if that which causes alteration or increase
causes a certain amount of increase or alteration respectively in
a certain amount of time, it does not necessarily follow that half
the force will occupy twice the time in altering or increasing the
object, or that in twice the time the alteration or increase will be
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completed by it: it may happen that there will be no alteration
or increase at all, the case being the same as with the weight.
Book VIII
It remains to consider the following question. Was there ever a
becoming of motion before which it had no being, and is it
perishing again so as to leave nothing in motion? Or are we to
say that it never had any becoming and is not perishing, but
always was and always will be? Is it in fact an immortal never-
failing property of things that are, a sort of life as it were to all
naturally constituted things?
Now the existence of motion is asserted by all who have
anything to say about nature, because they all concern
themselves with the construction of the world and study the
question of becoming and perishing, which processes could not
come about without the existence of motion. But those who say
that there is an infinite number of worlds, some of which are in
process of becoming while others are in process of perishing,
assert that there is always motion (for these processes of
becoming and perishing of the worlds necessarily involve
motion), whereas those who hold that there is only one world,
whether everlasting or not, make corresponding assumptions in
regard to motion. If then it is possible that at any time nothing
should be in motion, this must come about in one of two ways:
798
either in the manner described by Anaxagoras, who says that all
things were together and at rest for an infinite period of time,
and that then Mind introduced motion and separated them; or
in the manner described by Empedocles, according to whom the
universe is alternately in motion and at rest-in motion, when
Love is making the one out of many, or Strife is making many
out of one, and at rest in the intermediate periods of time - his
account being as follows:
'Since One hath learned to spring from Manifold,
And One disjoined makes manifold arise,
Thus they Become, nor stable is their life:
But since their motion must alternate be,
Thus have they ever Rest upon their round':
for we must suppose that he means by this that they alternate
from the one motion to the other. We must consider, then, how
this matter stands, for the discovery of the truth about it is of
importance, not only for the study of nature, but also for the
investigation of the First Principle.
Let us take our start from what we have already laid down in
our course on Physics. Motion, we say, is the fulfilment of the
movable in so far as it is movable. Each kind of motion,
therefore, necessarily involves the presence of the things that
are capable of that motion. In fact, even apart from the
definition of motion, every one would admit that in each kind of
motion it is that which is capable of that motion that is in
motion: thus it is that which is capable of alteration that is
altered, and that which is capable of local change that is in
locomotion: and so there must be something capable of being
burned before there can be a process of being burned, and
something capable of burning before there can be a process of
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burning. Moreover, these things also must either have a
beginning before which they had no being, or they must be
eternal. Now if there was a becoming of every movable thing, it
follows that before the motion in question another change or
motion must have taken place in which that which was capable
of being moved or of causing motion had its becoming. To
suppose, on the other hand, that these things were in being
throughout all previous time without there being any motion
appears unreasonable on a moment's thought, and still more
unreasonable, we shall find, on further consideration. For if we
are to say that, while there are on the one hand things that are
movable, and on the other hand things that are motive, there is
a time when there is a first movent and a first moved, and
another time when there is no such thing but only something
that is at rest, then this thing that is at rest must previously
have been in process of change: for there must have been some
cause of its rest, rest being the privation of motion. Therefore,
before this first change there will be a previous change. For
some things cause motion in only one way, while others can
produce either of two contrary motions: thus fire causes heating
but not cooling, whereas it would seem that knowledge may be
directed to two contrary ends while remaining one and the
same. Even in the former class, however, there seems to be
something similar, for a cold thing in a sense causes heating by
turning away and retiring, just as one possessed of knowledge
voluntarily makes an error when he uses his knowledge in the
reverse way. But at any rate all things that are capable
respectively of affecting and being affected, or of causing
motion and being moved, are capable of it not under all
conditions, but only when they are in a particular condition and
approach one another: so it is on the approach of one thing to
another that the one causes motion and the other is moved,
and when they are present under such conditions as rendered
the one motive and the other movable. So if the motion was not
800
always in process, it is clear that they must have been in a
condition not such as to render them capable respectively of
being moved and of causing motion, and one or other of them
must have been in process of change: for in what is relative this
is a necessary consequence: e.g. if one thing is double another
when before it was not so, one or other of them, if not both,
must have been in process of change. It follows then, that there
will be a process of change previous to the first.
(Further, how can there be any 'before' and 'after' without the
existence of time? Or how can there be any time without the
existence of motion? If, then, time is the number of motion or
itself a kind of motion, it follows that, if there is always time,
motion must also be eternal. But so far as time is concerned we
see that all with one exception are in agreement in saying that
it is uncreated: in fact, it is just this that enables Democritus to
show that all things cannot have had a becoming: for time, he
says, is uncreated. Plato alone asserts the creation of time,
saying that it had a becoming together with the universe, the
universe according to him having had a becoming. Now since
time cannot exist and is unthinkable apart from the moment,
and the moment a kind of middle-point, uniting as it does in
itself both a beginning and an end, a beginning of future time
and an end of past time, it follows that there must always be
time: for the extremity of the last period of time that we take
must be found in some moment, since time contains no point
of contact for us except the moment. Therefore, since the
moment is both a beginning and an end, there must always be
time on both sides of it. But if this is true of time, it is evident
that it must also be true of motion, time being a kind of
affection of motion.)
The same reasoning will also serve to show the imperishability
of motion: just as a becoming of motion would involve, as we
saw, the existence of a process of change previous to the first, in
801
the same way a perishing of motion would involve the existence
of a process of change subsequent to the last: for when a thing
ceases to be moved, it does not therefore at the same time cease
to be movable - e.g. the cessation of the process of being burned
does not involve the cessation of the capacity of being burned,
since a thing may be capable of being burned without being in
process of being burned - nor, when a thing ceases to be
movent, does it therefore at the same time cease to a be motive.
Again, the destructive agent will have to be destroyed, after
what it destroys has been destroyed, and then that which has
the capacity of destroying it will have to be destroyed
afterwards, (so that there will be a process of change
subsequent to the last,) for being destroyed also is a kind of
change. If, then, view which we are criticizing involves these
impossible consequences, it is clear that motion is eternal and
cannot have existed at one time and not at another: in fact such
a view can hardly be described as anythling else than fantastic.
And much the same may be said of the view that such is the
ordinance of nature and that this must be regarded as a
principle, as would seem to be the view of Empedocles when he
says that the constitution of the world is of necessity such that
Love and Strife alternately predominate and cause motion,
while in the intermediate period of time there is a state of rest.
Probably also those who like like Anaxagoras, assert a single
principle (of motion) would hold this view. But that which is
produced or directed by nature can never be anything
disorderly: for nature is everywhere the cause of order.
Moreover, there is no ratio in the relation of the infinite to the
infinite, whereas order always means ratio. But if we say that
there is first a state of rest for an infinite time, and then motion
is started at some moment, and that the fact that it is this
rather than a previous moment is of no importance, and
involves no order, then we can no longer say that it is nature's
work: for if anything is of a certain character naturally, it either
802
is so invariably and is not sometimes of this and sometimes of
another character (e.g. fire, which travels upwards naturally,
does not sometimes do so and sometimes not) or there is a ratio
in the variation. It would be better, therefore, to say with
Empedocles and any one else who may have maintained such a
theory as his that the universe is alternately at rest and in
motion: for in a system of this kind we have at once a certain
order. But even here the holder of the theory ought not only to
assert the fact: he ought to explain the cause of it: i.e. he should
not make any mere assumption or lay down any gratuitous
axiom, but should employ either inductive or demonstrative
reasoning. The Love and Strife postulated by Empedocles are not
in themselves causes of the fact in question, nor is it of the
essence of either that it should be so, the essential function of
the former being to unite, of the latter to separate. If he is to go
on to explain this alternate predominance, he should adduce
cases where such a state of things exists, as he points to the
fact that among mankind we have something that unites men,
namely Love, while on the other hand enemies avoid one
another: thus from the observed fact that this occurs in certain
cases comes the assumption that it occurs also in the universe.
Then, again, some argument is needed to explain why the
predominance of each of the two forces lasts for an equal period
of time. But it is a wrong assumption to suppose universally
that we have an adequate first principle in virtue of the fact that
something always is so or always happens so. Thus Democritus
reduces the causes that explain nature to the fact that things
happened in the past in the same way as they happen now: but
he does not think fit to seek for a first principle to explain this
'always': so, while his theory is right in so far as it is applied to
certain individual cases, he is wrong in making it of universal
application. Thus, a triangle always has its angles equal to two
right angles, but there is nevertheless an ulterior cause of the
eternity of this truth, whereas first principles are eternal and
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have no ulterior cause. Let this conclude what we have to say in
support of our contention that there never was a time when
there was not motion, and never will be a time when there will
not be motion.
The arguments that may be advanced against this position are
not difficult to dispose of. The chief considerations that might
be thought to indicate that motion may exist though at one
time it had not existed at all are the following:
First, it may be said that no process of change is eternal: for the
nature of all change is such that it proceeds from something to
something, so that every process of change must be bounded by
the contraries that mark its course, and no motion can go on to
infinity.
Secondly, we see that a thing that neither is in motion nor
contains any motion within itself can be set in motion; e.g.
inanimate things that are (whether the whole or some part is in
question) not in motion but at rest, are at some moment set in
motion: whereas, if motion cannot have a becoming before
which it had no being, these things ought to be either always or
never in motion.
Thirdly, the fact is evident above all in the case of animate
beings: for it sometimes happens that there is no motion in us
and we are quite still, and that nevertheless we are then at
some moment set in motion, that is to say it sometimes
happens that we produce a beginning of motion in ourselves
spontaneously without anything having set us in motion from
without. We see nothing like this in the case of inanimate
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things, which are always set in motion by something else from
without: the animal, on the other hand, we say, moves itself:
therefore, if an animal is ever in a state of absolute rest, we have
a motionless thing in which motion can be produced from the
thing itself, and not from without. Now if this can occur in an
animal, why should not the same be true also of the universe as
a whole? If it can occur in a small world it could also occur in a
great one: and if it can occur in the world, it could also occur in
the infinite; that is, if the infinite could as a whole possibly be in
motion or at rest.
Of these objections, then, the first-mentioned motion to
opposites is not always the same and numerically one a correct
statement; in fact, this may be said to be a necessary
conclusion, provided that it is possible for the motion of that
which is one and the same to be not always one and the same.
(I mean that e.g. we may question whether the note given by a
single string is one and the same, or is different each time the
string is struck, although the string is in the same condition and
is moved in the same way.) But still, however this may be, there
is nothing to prevent there being a motion that is the same in
virtue of being continuous and eternal: we shall have something
to say later that will make this point clearer.
As regards the second objection, no absurdity is involved in the
fact that something not in motion may be set in motion, that
which caused the motion from without being at one time
present, and at another absent. Nevertheless, how this can be so
remains matter for inquiry; how it comes about, I mean, that
the same motive force at one time causes a thing to be in
motion, and at another does not do so: for the difficulty raised
by our objector really amounts to this - why is it that some
things are not always at rest, and the rest always in motion?
805
The third objection may be thought to present more difficulty
than the others, namely, that which alleges that motion arises
in things in which it did not exist before, and adduces in proof
the case of animate things: thus an animal is first at rest and
afterwards walks, not having been set in motion apparently by
anything from without. This, however, is false: for we observe
that there is always some part of the animal's organism in
motion, and the cause of the motion of this part is not the
animal itself, but, it may be, its environment. Moreover, we say
that the animal itself originates not all of its motions but its
locomotion. So it may well be the case - or rather we may
perhaps say that it must necessarily be the case - that many
motions are produced in the body by its environment, and some
of these set in motion the intellect or the appetite, and this
again then sets the whole animal in motion: this is what
happens when animals are asleep: though there is then no
perceptive motion in them, there is some motion that causes
them to wake up again. But we will leave this point also to be
elucidated at a later stage in our discussion.
Our enquiry will resolve itself at the outset into a consideration
of the above-mentioned problem - what can be the reason why
some things in the world at one time are in motion and at
another are at rest again? Now one of three things must be true:
either all things are always at rest, or all things are always in
motion, or some things are in motion and others at rest: and in
this last case again either the things that are in motion are
always in motion and the things that are at rest are always at
rest, or they are all constituted so as to be capable alike of
motion and of rest; or there is yet a third possibility remaining -
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it may be that some things in the world are always motionless,
others always in motion, while others again admit of both
conditions. This last is the account of the matter that we must
give: for herein lies the solution of all the difficulties raised and
the conclusion of the investigation upon which we are engaged.
To maintain that all things are at rest, and to disregard sense-
perception in an attempt to show the theory to be reasonable,
would be an instance of intellectual weakness: it would call in
question a whole system, not a particular detail: moreover, it
would be an attack not only on the physicist but on almost all
sciences and all received opinions, since motion plays a part in
all of them. Further, just as in arguments about mathematics
objections that involve first principles do not affect the
mathematician - and the other sciences are in similar case - so,
too, objections involving the point that we have just raised do
not affect the physicist: for it is a fundamental assumption with
him that motion is ultimately referable to nature herself.
The assertion that all things are in motion we may fairly regard
as equally false, though it is less subversive of physical science:
for though in our course on physics it was laid down that rest
no less than motion is ultimately referable to nature herself,
nevertheless motion is the characteristic fact of nature:
moreover, the view is actually held by some that not merely
some things but all things in the world are in motion and
always in motion, though we cannot apprehend the fact by
sense-perception. Although the supporters of this theory do not
state clearly what kind of motion they mean, or whether they
mean all kinds, it is no hard matter to reply to them: thus we
may point out that there cannot be a continuous process either
of increase or of decrease: that which comes between the two
has to be included. The theory resembles that about the stone
being worn away by the drop of water or split by plants growing
out of it: if so much has been extruded or removed by the drop,
807
it does not follow that half the amount has previously been
extruded or removed in half the time: the case of the hauled
ship is exactly comparable: here we have so many drops setting
so much in motion, but a part of them will not set as much in
motion in any period of time. The amount removed is, it is true,
divisible into a number of parts, but no one of these was set in
motion separately: they were all set in motion together. It is
evident, then, that from the fact that the decrease is divisible
into an infinite number of parts it does not follow that some
part must always be passing away: it all passes away at a
particular moment. Similarly, too, in the case of any alteration
whatever if that which suffers alteration is infinitely divisible it
does not follow from this that the same is true of the alteration
itself, which often occurs all at once, as in freezing. Again, when
any one has fallen ill, there must follow a period of time in
which his restoration to health is in the future: the process of
change cannot take place in an instant: yet the change cannot
be a change to anything else but health. The assertion,
therefore, that alteration is continuous is an extravagant calling
into question of the obvious: for alteration is a change from one
contrary to another. Moreover, we notice that a stone becomes
neither harder nor softer. Again, in the matter of locomotion, it
would be a strange thing if a stone could be falling or resting on
the ground without our being able to perceive the fact. Further,
it is a law of nature that earth and all other bodies should
remain in their proper places and be moved from them only by
violence: from the fact then that some of them are in their
proper places it follows that in respect of place also all things
cannot be in motion. These and other similar arguments, then,
should convince us that it is impossible either that all things are
always in motion or that all things are always at rest.
Nor again can it be that some things are always at rest, others
always in motion, and nothing sometimes at rest and
sometimes in motion. This theory must be pronounced
808
impossible on the same grounds as those previously mentioned:
viz. that we see the above-mentioned changes occurring in the
case of the same things. We may further point out that the
defender of this position is fighting against the obvious, for on
this theory there can be no such thing as increase: nor can there
be any such thing as compulsory motion, if it is impossible that
a thing can be at rest before being set in motion unnaturally.
This theory, then, does away with becoming and perishing.
Moreover, motion, it would seem, is generally thought to be a
sort of becoming and perishing, for that to which a thing
changes comes to be, or occupancy of it comes to be, and that
from which a thing changes ceases to be, or there ceases to be
occupancy of it. It is clear, therefore, that there are cases of
occasional motion and occasional rest.
We have now to take the assertion that all things are sometimes
at rest and sometimes in motion and to confront it with the
arguments previously advanced. We must take our start as
before from the possibilities that we distinguished just above.
Either all things are at rest, or all things are in motion, or some
things are at rest and others in motion. And if some things are
at rest and others in motion, then it must be that either all
things are sometimes at rest and sometimes in motion, or some
things are always at rest and the remainder always in motion,
or some of the things are always at rest and others always in
motion while others again are sometimes at rest and
sometimes in motion. Now we have said before that it is
impossible that all things should be at rest: nevertheless we
may now repeat that assertion. We may point out that, even if it
is really the case, as certain persons assert, that the existent is
infinite and motionless, it certainly does not appear to be so if
we follow sense-perception: many things that exist appear to be
in motion. Now if there is such a thing as false opinion or
opinion at all, there is also motion; and similarly if there is such
a thing as imagination, or if it is the case that anything seems to
809
be different at different times: for imagination and opinion are
thought to be motions of a kind. But to investigate this question
at all - to seek a reasoned justification of a belief with regard to
which we are too well off to require reasoned justification -
implies bad judgement of what is better and what is worse,
what commends itself to belief and what does not, what is
ultimate and what is not. It is likewise impossible that all things
should be in motion or that some things should be always in
motion and the remainder always at rest. We have sufficient
ground for rejecting all these theories in the single fact that we
see some things that are sometimes in motion and sometimes
at rest. It is evident, therefore, that it is no less impossible that
some things should be always in motion and the remainder
always at rest than that all things should be at rest or that all
things should be in motion continuously. It remains, then, to
consider whether all things are so constituted as to be capable
both of being in motion and of being at rest, or whether, while
some things are so constituted, some are always at rest and
some are always in motion: for it is this last view that we have
to show to be true.
Now of things that cause motion or suffer motion, to some the
motion is accidental, to others essential: thus it is accidental to
what merely belongs to or contains as a part a thing that causes
motion or suffers motion, essential to a thing that causes
motion or suffers motion not merely by belonging to such a
thing or containing it as a part.
Of things to which the motion is essential some derive their
motion from themselves, others from something else: and in
810
some cases their motion is natural, in others violent and
unnatural. Thus in things that derive their motion from
themselves, e.g. all animals, the motion is natural (for when an
animal is in motion its motion is derived from itself): and
whenever the source of the motion of a thing is in the thing
itself we say that the motion of that thing is natural. Therefore
the animal as a whole moves itself naturally: but the body of
the animal may be in motion unnaturally as well as naturally: it
depends upon the kind of motion that it may chance to be
suffering and the kind of element of which it is composed. And
the motion of things that derive their motion from something
else is in some cases natural, in other unnatural: e.g. upward
motion of earthy things and downward motion of fire are
unnatural. Moreover the parts of animals are often in motion in
an unnatural way, their positions and the character of the
motion being abnormal. The fact that a thing that is in motion
derives its motion from something is most evident in things
that are in motion unnaturally, because in such cases it is clear
that the motion is derived from something other than the thing
itself. Next to things that are in motion unnaturally those
whose motion while natural is derived from themselves - e.g.
animals - make this fact clear: for here the uncertainty is not as
to whether the motion is derived from something but as to how
we ought to distinguish in the thing between the movent and
the moved. It would seem that in animals, just as in ships and
things not naturally organized, that which causes motion is
separate from that which suffers motion, and that it is only in
this sense that the animal as a whole causes its own motion.
The greatest difficulty, however, is presented by the remaining
case of those that we last distinguished. Where things derive
their motion from something else we distinguished the cases in
which the motion is unnatural: we are left with those that are
to be contrasted with the others by reason of the fact that the
motion is natural. It is in these cases that difficulty would be
811
experienced in deciding whence the motion is derived, e.g. in
the case of light and heavy things. When these things are in
motion to positions the reverse of those they would properly
occupy, their motion is violent: when they are in motion to their
proper positions - the light thing up and the heavy thing down -
their motion is natural; but in this latter case it is no longer
evident, as it is when the motion is unnatural, whence their
motion is derived. It is impossible to say that their motion is
derived from themselves: this is a characteristic of life and
peculiar to living things. Further, if it were, it would have been
in their power to stop themselves (I mean that if e.g. a thing can
cause itself to walk it can also cause itself not to walk), and so,
since on this supposition fire itself possesses the power of
upward locomotion, it is clear that it should also possess the
power of downward locomotion. Moreover if things move
themselves, it would be unreasonable to suppose that in only
one kind of motion is their motion derived from themselves.
Again, how can anything of continuous and naturally connected
substance move itself? In so far as a thing is one and
continuous not merely in virtue of contact, it is impassive: it is
only in so far as a thing is divided that one part of it is by nature
active and another passive. Therefore none of the things that we
are now considering move themselves (for they are of naturally
connected substance), nor does anything else that is
continuous: in each case the movent must be separate from the
moved, as we see to be the case with inanimate things when an
animate thing moves them. It is the fact that these things also
always derive their motion from something: what it is would
become evident if we were to distinguish the different kinds of
cause.
The above-mentioned distinctions can also be made in the case
of things that cause motion: some of them are capable of
causing motion unnaturally (e.g. the lever is not naturally
capable of moving the weight), others naturally (e.g. what is
812
actually hot is naturally capable of moving what is potentially
hot): and similarly in the case of all other things of this kind.
In the same way, too, what is potentially of a certain quality or
of a certain quantity in a certain place is naturally movable
when it contains the corresponding principle in itself and not
accidentally (for the same thing may be both of a certain quality
and of a certain quantity, but the one is an accidental, not an
essential property of the other). So when fire or earth is moved
by something the motion is violent when it is unnatural, and
natural when it brings to actuality the proper activities that
they potentially possess. But the fact that the term 'potentially'
is used in more than one sense is the reason why it is not
evident whence such motions as the upward motion of fire and
the downward motion of earth are derived. One who is learning
a science potentially knows it in a different sense from one who
while already possessing the knowledge is not actually
exercising it. Wherever we have something capable of acting
and something capable of being correspondingly acted on, in
the event of any such pair being in contact what is potential
becomes at times actual: e.g. the learner becomes from one
potential something another potential something: for one who
possesses knowledge of a science but is not actually exercising
it knows the science potentially in a sense, though not in the
same sense as he knew it potentially before he learnt it. And
when he is in this condition, if something does not prevent him,
he actively exercises his knowledge: otherwise he would be in
the contradictory state of not knowing. In regard to natural
bodies also the case is similar. Thus what is cold is potentially
hot: then a change takes place and it is fire, and it burns, unless
something prevents and hinders it. So, too, with heavy and
light: light is generated from heavy, e.g. air from water (for
water is the first thing that is potentially light), and air is
actually light, and will at once realize its proper activity as such
unless something prevents it. The activity of lightness consists
813
in the light thing being in a certain situation, namely high up:
when it is in the contrary situation, it is being prevented from
rising. The case is similar also in regard to quantity and quality.
But, be it noted, this is the question we are trying to answer -
how can we account for the motion of light things and heavy
things to their proper situations? The reason for it is that they
have a natural tendency respectively towards a certain position:
and this constitutes the essence of lightness and heaviness, the
former being determined by an upward, the latter by a
downward, tendency. As we have said, a thing may be
potentially light or heavy in more senses than one. Thus not
only when a thing is water is it in a sense potentially light, but
when it has become air it may be still potentially light: for it
may be that through some hindrance it does not occupy an
upper position, whereas, if what hinders it is removed, it
realizes its activity and continues to rise higher. The process
whereby what is of a certain quality changes to a condition of
active existence is similar: thus the exercise of knowledge
follows at once upon the possession of it unless something
prevents it. So, too, what is of a certain quantity extends itself
over a certain space unless something prevents it. The thing in a
sense is and in a sense is not moved by one who moves what is
obstructing and preventing its motion (e.g. one who pulls away
a pillar from under a roof or one who removes a stone from a
wineskin in the water is the accidental cause of motion): and in
the same way the real cause of the motion of a ball rebounding
from a wall is not the wall but the thrower. So it is clear that in
all these cases the thing does not move itself, but it contains
within itself the source of motion - not of moving something or
of causing motion, but of suffering it.
If then the motion of all things that are in motion is either
natural or unnatural and violent, and all things whose motion is
violent and unnatural are moved by something, and something
other than themselves, and again all things whose motion is
814
natural are moved by something - both those that are moved by
themselves and those that are not moved by themselves (e.g.
light things and heavy things, which are moved either by that
which brought the thing into existence as such and made it
light and heavy, or by that which released what was hindering
and preventing it); then all things that are in motion must be
moved by something.
Now this may come about in either of two ways. Either the
movent is not itself responsible for the motion, which is to be
referred to something else which moves the movent, or the
movent is itself responsible for the motion. Further, in the latter
case, either the movent immediately precedes the last thing in
the series, or there may be one or more intermediate links: e.g.
the stick moves the stone and is moved by the hand, which
again is moved by the man: in the man, however, we have
reached a movent that is not so in virtue of being moved by
something else. Now we say that the thing is moved both by the
last and by the first movent in the series, but more strictly by
the first, since the first movent moves the last, whereas the last
does not move the first, and the first will move the thing
without the last, but the last will not move it without the first:
e.g. the stick will not move anything unless it is itself moved by
the man. If then everything that is in motion must be moved by
something, and the movent must either itself be moved by
something else or not, and in the former case there must be
some first movent that is not itself moved by anything else,
while in the case of the immediate movent being of this kind
there is no need of an intermediate movent that is also moved
(for it is impossible that there should be an infinite series of
815
movents, each of which is itself moved by something else, since
in an infinite series there is no first term) - if then everything
that is in motion is moved by something, and the first movent is
moved but not by anything else, it much be moved by itself.
This same argument may also be stated in another way as
follows. Every movent moves something and moves it with
something, either with itself or with something else: e.g. a man
moves a thing either himself or with a stick, and a thing is
knocked down either by the wind itself or by a stone propelled
by the wind. But it is impossible for that with which a thing is
moved to move it without being moved by that which imparts
motion by its own agency: on the other hand, if a thing imparts
motion by its own agency, it is not necessary that there should
be anything else with which it imparts motion, whereas if there
is a different thing with which it imparts motion, there must be
something that imparts motion not with something else but
with itself, or else there will be an infinite series. If, then,
anything is a movent while being itself moved, the series must
stop somewhere and not be infinite. Thus, if the stick moves
something in virtue of being moved by the hand, the hand
moves the stick: and if something else moves with the hand,
the hand also is moved by something different from itself. So
when motion by means of an instrument is at each stage
caused by something different from the instrument, this must
always be preceded by something else which imparts motion
with itself. Therefore, if this last movent is in motion and there
is nothing else that moves it, it must move itself. So this
reasoning also shows that when a thing is moved, if it is not
moved immediately by something that moves itself, the series
brings us at some time or other to a movent of this kind.
And if we consider the matter in yet a third wa Ly we shall get
this same result as follows. If everything that is in motion is
moved by something that is in motion, ether this being in
816
motion is an accidental attribute of the movents in question, so
that each of them moves something while being itself in
motion, but not always because it is itself in motion, or it is not
accidental but an essential attribute. Let us consider the former
alternative. If then it is an accidental attribute, it is not
necessary that that is in motion should be in motion: and if this
is so it is clear that there may be a time when nothing that
exists is in motion, since the accidental is not necessary but
contingent. Now if we assume the existence of a possibility, any
conclusion that we thereby reach will not be an impossibility
though it may be contrary to fact. But the nonexistence of
motion is an impossibility: for we have shown above that there
must always be motion.
Moreover, the conclusion to which we have been led is a
reasonable one. For there must be three things - the moved, the
movent, and the instrument of motion. Now the moved must be
in motion, but it need not move anything else: the instrument
of motion must both move something else and be itself in
motion (for it changes together with the moved, with which it is
in contact and continuous, as is clear in the case of things that
move other things locally, in which case the two things must up
to a certain point be in contact): and the movent - that is to say,
that which causes motion in such a manner that it is not
merely the instrument of motion - must be unmoved. Now we
have visual experience of the last term in this series, namely
that which has the capacity of being in motion, but does not
contain a motive principle, and also of that which is in motion
but is moved by itself and not by anything else: it is reasonable,
therefore, not to say necessary, to suppose the existence of the
third term also, that which causes motion but is itself unmoved.
So, too, Anaxagoras is right when he says that Mind is impassive
and unmixed, since he makes it the principle of motion: for it
could cause motion in this sense only by being itself unmoved,
and have supreme control only by being unmixed.
817
We will now take the second alternative. If the movement is not
accidentally but necessarily in motion - so that, if it were not in
motion, it would not move anything - then the movent, in so far
as it is in motion, must be in motion in one of two ways: it is
moved either as that is which is moved with the same kind of
motion, or with a different kind - either that which is heating, I
mean, is itself in process of becoming hot, that which is making
healthy in process of becoming healthy, and that which is
causing locomotion in process of locomotion, or else that which
is making healthy is, let us say, in process of locomotion, and
that which is causing locomotion in process of, say, increase.
But it is evident that this is impossible. For if we adopt the first
assumption we have to make it apply within each of the very
lowest species into which motion can be divided: e.g. we must
say that if some one is teaching some lesson in geometry, he is
also in process of being taught that same lesson in geometry,
and that if he is throwing he is in process of being thrown in
just the same manner. Or if we reject this assumption we must
say that one kind of motion is derived from another; e.g. that
that which is causing locomotion is in process of increase, that
which is causing this increase is in process of being altered by
something else, and that which is causing this alteration is in
process of suffering some different kind of motion. But the
series must stop somewhere, since the kinds of motion are
limited; and if we say that the process is reversible, and that
that which is causing alteration is in process of locomotion, we
do no more than if we had said at the outset that that which is
causing locomotion is in process of locomotion, and that one
who is teaching is in process of being taught: for it is clear that
everything that is moved is moved by the movent that is further
back in the series as well as by that which immediately moves
it: in fact the earlier movent is that which more strictly moves
it. But this is of course impossible: for it involves the
consequence that one who is teaching is in process of learning
818
what he is teaching, whereas teaching necessarily implies
possessing knowledge, and learning not possessing it. Still more
unreasonable is the consequence involved that, since
everything that is moved is moved by something that is itself
moved by something else, everything that has a capacity for
causing motion has as such a corresponding capacity for being
moved: i.e. it will have a capacity for being moved in the sense
in which one might say that everything that has a capacity for
making healthy, and exercises that capacity, has as such a
capacity for being made healthy, and that which has a capacity
for building has as such a capacity for being built. It will have
the capacity for being thus moved either immediately or
through one or more links (as it will if, while everything that
has a capacity for causing motion has as such a capacity for
being moved by something else, the motion that it has the
capacity for suffering is not that with which it affects what is
next to it, but a motion of a different kind; e.g. that which has a
capacity for making healthy might as such have a capacity for
learn, the series, however, could be traced back, as we said
before, until at some time or other we arrived at the same kind
of motion). Now the first alternative is impossible, and the
second is fantastic: it is absurd that that which has a capacity
for causing alteration should as such necessarily have a
capacity, let us say, for increase. It is not necessary, therefore,
that that which is moved should always be moved by something
else that is itself moved by something else: so there will be an
end to the series. Consequently the first thing that is in motion
will derive its motion either from something that is at rest or
from itself. But if there were any need to consider which of the
two, that which moves itself or that which is moved by
something else, is the cause and principle of motion, every one
would decide the former: for that which is itself independently
a cause is always prior as a cause to that which is so only in
819
virtue of being itself dependent upon something else that
makes it so.
We must therefore make a fresh start and consider the
question; if a thing moves itself, in what sense and in what
manner does it do so? Now everything that is in motion must be
infinitely divisible, for it has been shown already in our general
course on Physics, that everything that is essentially in motion
is continuous. Now it is impossible that that which moves itself
should in its entirety move itself: for then, while being
specifically one and indivisible, it would as a Whole both
undergo and cause the same locomotion or alteration: thus it
would at the same time be both teaching and being taught (the
same thing), or both restoring to and being restored to the same
health. Moreover, we have established the fact that it is the
movable that is moved; and this is potentially, not actually, in
motion, but the potential is in process to actuality, and motion
is an incomplete actuality of the movable. The movent on the
other hand is already in activity: e.g. it is that which is hot that
produces heat: in fact, that which produces the form is always
something that possesses it. Consequently (if a thing can move
itself as a whole), the same thing in respect of the same thing
may be at the same time both hot and not hot. So, too, in every
other case where the movent must be described by the same
name in the same sense as the moved. Therefore when a thing
moves itself it is one part of it that is the movent and another
part that is moved. But it is not self-moving in the sense that
each of the two parts is moved by the other part: the following
considerations make this evident. In the first place, if each of
the two parts is to move the other, there will be no first movent.
If a thing is moved by a series of movents, that which is earlier
in the series is more the cause of its being moved than that
which comes next, and will be more truly the movent: for we
found that there are two kinds of movent, that which is itself
moved by something else and that which derives its motion
820
from itself: and that which is further from the thing that is
moved is nearer to the principle of motion than that which is
intermediate. In the second place, there is no necessity for the
movent part to be moved by anything but itself: so it can only be
accidentally that the other part moves it in return. I take then
the possible case of its not moving it: then there will be a part
that is moved and a part that is an unmoved movent. In the
third place, there is no necessity for the movent to be moved in
return: on the contrary the necessity that there should always
be motion makes it necessary that there should be some
movent that is either unmoved or moved by itself. In the fourth
place we should then have a thing undergoing the same motion
that it is causing - that which is producing heat, therefore, being
heated. But as a matter of fact that which primarily moves itself
cannot contain either a single part that moves itself or a
number of parts each of which moves itself. For, if the whole is
moved by itself, it must be moved either by some part of itself
or as a whole by itself as a whole. If, then, it is moved in virtue
of some part of it being moved by that part itself, it is this part
that will be the primary self-movent, since, if this part is
separated from the whole, the part will still move itself, but the
whole will do so no longer. If on the other hand the whole is
moved by itself as a whole, it must be accidentally that the parts
move themselves: and therefore, their self-motion not being
necessary, we may take the case of their not being moved by
themselves. Therefore in the whole of the thing we may
distinguish that which imparts motion without itself being
moved and that which is moved: for only in this way is it
possible for a thing to be self-moved. Further, if the whole
moves itself we may distinguish in it that which imparts the
motion and that which is moved: so while we say that AB is
moved by itself, we may also say that it is moved by A. And
since that which imparts motion may be either a thing that is
moved by something else or a thing that is unmoved, and that
821
which is moved may be either a thing that imparts motion to
something else or a thing that does not, that which moves itself
must be composed of something that is unmoved but imparts
motion and also of something that is moved but does not
necessarily impart motion but may or may not do so. Thus let A
be something that imparts motion but is unmoved, B something
that is moved by A and moves G, G something that is moved by
B but moves nothing (granted that we eventually arrive at G we
may take it that there is only one intermediate term, though
there may be more). Then the whole ABG moves itself. But if I
take away G, AB will move itself, A imparting motion and B
being moved, whereas G will not move itself or in fact be moved
at all. Nor again will BG move itself apart from A: for B imparts
motion only through being moved by something else, not
through being moved by any part of itself. So only AB moves
itself. That which moves itself, therefore, must comprise
something that imparts motion but is unmoved and something
that is moved but does not necessarily move anything else: and
each of these two things, or at any rate one of them, must be in
contact with the other. If, then, that which imparts motion is a
continuous substance - that which is moved must of course be
so - it is clear that it is not through some part of the whole
being of such a nature as to be capable of moving itself that the
whole moves itself: it moves itself as a whole, both being moved
and imparting motion through containing a part that imparts
motion and a part that is moved. It does not impart motion as a
whole nor is it moved as a whole: it is A alone that imparts
motion and B alone that is moved. It is not true, further, that G
is moved by A, which is impossible.
Here a difficulty arises: if something is taken away from A
(supposing that that which imparts motion but is unmoved is a
continuous substance), or from B the part that is moved, will the
remainder of A continue to impart motion or the remainder of B
continue to be moved? If so, it will not be AB primarily that is
822
moved by itself, since, when something is taken away from AB,
the remainder of AB will still continue to move itself. Perhaps
we may state the case thus: there is nothing to prevent each of
the two parts, or at any rate one of them, that which is moved,
being divisible though actually undivided, so that if it is divided
it will not continue in the possession of the same capacity: and
so there is nothing to prevent self-motion residing primarily in
things that are potentially divisible.
From what has been said, then, it is evident that that which
primarily imparts motion is unmoved: for, whether the series is
closed at once by that which is in motion but moved by
something else deriving its motion directly from the first
unmoved, or whether the motion is derived from what is in
motion but moves itself and stops its own motion, on both
suppositions we have the result that in all cases of things being
in motion that which primarily imparts motion is unmoved.
Since there must always be motion without intermission, there
must necessarily be something, one thing or it may be a
plurality, that first imparts motion, and this first movent must
be unmoved. Now the question whether each of the things that
are unmoved but impart motion is eternal is irrelevant to our
present argument: but the following considerations will make it
clear that there must necessarily be some such thing, which,
while it has the capacity of moving something else, is itself
unmoved and exempt from all change, which can affect it
neither in an unqualified nor in an accidental sense. Let us
suppose, if any one likes, that in the case of certain things it is
possible for them at different times to be and not to be, without
823
any process of becoming and perishing (in fact it would seem to
be necessary, if a thing that has not parts at one time is and at
another time is not, that any such thing should without
undergoing any process of change at one time be and at another
time not be). And let us further suppose it possible that some
principles that are unmoved but capable of imparting motion at
one time are and at another time are not. Even so, this cannot
be true of all such principles, since there must clearly be
something that causes things that move themselves at one time
to be and at another not to be. For, since nothing that has not
parts can be in motion, that which moves itself must as a whole
have magnitude, though nothing that we have said makes this
necessarily true of every movent. So the fact that some things
become and others perish, and that this is so continuously,
cannot be caused by any one of those things that, though they
are unmoved, do not always exist: nor again can it be caused by
any of those which move certain particular things, while others
move other things. The eternity and continuity of the process
cannot be caused either by any one of them singly or by the
sum of them, because this causal relation must be eternal and
necessary, whereas the sum of these movents is infinite and
they do not all exist together. It is clear, then, that though there
may be countless instances of the perishing of some principles
that are unmoved but impart motion, and though many things
that move themselves perish and are succeeded by others that
come into being, and though one thing that is unmoved moves
one thing while another moves another, nevertheless there is
something that comprehends them all, and that as something
apart from each one of them, and this it is that is the cause of
the fact that some things are and others are not and of the
continuous process of change: and this causes the motion of
the other movents, while they are the causes of the motion of
other things. Motion, then, being eternal, the first movent, if
there is but one, will be eternal also: if there are more than one,
824
there will be a plurality of such eternal movents. We ought,
however, to suppose that there is one rather than many, and a
finite rather than an infinite number. When the consequences
of either assumption are the same, we should always assume
that things are finite rather than infinite in number, since in
things constituted by nature that which is finite and that which
is better ought, if possible, to be present rather than the reverse:
and here it is sufficient to assume only one movent, the first of
unmoved things, which being eternal will be the principle of
motion to everything else.
The following argument also makes it evident that the first
movent must be something that is one and eternal. We have
shown that there must always be motion. That being so, motion
must also be continuous, because what is always is continuous,
whereas what is merely in succession is not continuous. But
further, if motion is continuous, it is one: and it is one only if
the movent and the moved that constitute it are each of them
one, since in the event of a thing's being moved now by one
thing and now by another the whole motion will not be
continuous but successive.
Moreover a conviction that there is a first unmoved something
may be reached not only from the foregoing arguments, but also
by considering again the principles operative in movents. Now it
is evident that among existing things there are some that are
sometimes in motion and sometimes at rest. This fact has
served above to make it clear that it is not true either that all
things are in motion or that all things are at rest or that some
things are always at rest and the remainder always in motion:
on this matter proof is supplied by things that fluctuate
between the two and have the capacity of being sometimes in
motion and sometimes at rest. The existence of things of this
kind is clear to all: but we wish to explain also the nature of
each of the other two kinds and show that there are some
825
things that are always unmoved and some things that are
always in motion. In the course of our argument directed to this
end we established the fact that everything that is in motion is
moved by something, and that the movent is either unmoved or
in motion, and that, if it is in motion, it is moved either by itself
or by something else and so on throughout the series: and so we
proceeded to the position that the first principle that directly
causes things that are in motion to be moved is that which
moves itself, and the first principle of the whole series is the
unmoved. Further it is evident from actual observation that
there are things that have the characteristic of moving
themselves, e.g. the animal kingdom and the whole class of
living things. This being so, then, the view was suggested that
perhaps it may be possible for motion to come to be in a thing
without having been in existence at all before, because we see
this actually occurring in animals: they are unmoved at one
time and then again they are in motion, as it seems. We must
grasp the fact, therefore, that animals move themselves only
with one kind of motion, and that this is not strictly originated
by them. The cause of it is not derived from the animal itself: it
is connected with other natural motions in animals, which they
do not experience through their own instrumentality, e.g.
increase, decrease, and respiration: these are experienced by
every animal while it is at rest and not in motion in respect of
the motion set up by its own agency: here the motion is caused
by the atmosphere and by many things that enter into the
animal: thus in some cases the cause is nourishment: when it is
being digested animals sleep, and when it is being distributed
through the system they awake and move themselves, the first
principle of this motion being thus originally derived from
outside. Therefore animals are not always in continuous motion
by their own agency: it is something else that moves them, itself
being in motion and changing as it comes into relation with
each several thing that moves itself. (Moreover in all these self-
826
moving things the first movent and cause of their self-motion is
itself moved by itself, though in an accidental sense: that is to
say, the body changes its place, so that that which is in the body
changes its place also and is a self-movent through its exercise
of leverage.) Hence we may confidently conclude that if a thing
belongs to the class of unmoved movents that are also
themselves moved accidentally, it is impossible that it should
cause continuous motion. So the necessity that there should be
motion continuously requires that there should be a first
movent that is unmoved even accidentally, if, as we have said,
there is to be in the world of things an unceasing and undying
motion, and the world is to remain permanently self-contained
and within the same limits: for if the first principle is
permanent, the universe must also be permanent, since it is
continuous with the first principle. (We must distinguish,
however, between accidental motion of a thing by itself and
such motion by something else, the former being confined to
perishable things, whereas the latter belongs also to certain first
principles of heavenly bodies, of all those, that is to say, that
experience more than one locomotion.)
And further, if there is always something of this nature, a
movent that is itself unmoved and eternal, then that which is
first moved by it must be eternal. Indeed this is clear also from
the consideration that there would otherwise be no becoming
and perishing and no change of any kind in other things, which
require something that is in motion to move them: for the
motion imparted by the unmoved will always be imparted in
the same way and be one and the same, since the unmoved
does not itself change in relation to that which is moved by it.
But that which is moved by something that, though it is in
motion, is moved directly by the unmoved stands in varying
relations to the things that it moves, so that the motion that it
causes will not be always the same: by reason of the fact that it
occupies contrary positions or assumes contrary forms at
827
different times it will produce contrary motions in each several
thing that it moves and will cause it to be at one time at rest
and at another time in motion.
The foregoing argument, then, has served to clear up the point
about which we raised a difficulty at the outset - why is it that
instead of all things being either in motion or at rest, or some
things being always in motion and the remainder always at rest,
there are things that are sometimes in motion and sometimes
not? The cause of this is now plain: it is because, while some
things are moved by an eternal unmoved movent and are
therefore always in motion, other things are moved by a movent
that is in motion and changing, so that they too must change.
But the unmoved movent, as has been said, since it remains
permanently simple and unvarying and in the same state, will
cause motion that is one and simple.
This matter will be made clearer, however, if we start afresh
from another point. We must consider whether it is or is not
possible that there should be a continuous motion, and, if it is
possible, which this motion is, and which is the primary motion:
for it is plain that if there must always be motion, and a
particular motion is primary and continuous, then it is this
motion that is imparted by the first movent, and so it is
necessarily one and the same and continuous and primary.
Now of the three kinds of motion that there are - motion in
respect of magnitude, motion in respect of affection, and
motion in respect of place - it is this last, which we call
locomotion, that must be primary. This may be shown as
follows. It is impossible that there should be increase without
828
the previous occurrence of alteration: for that which is
increased, although in a sense it is increased by what is like
itself, is in a sense increased by what is unlike itself: thus it is
said that contrary is nourishment to contrary: but growth is
effected only by things becoming like to like. There must be
alteration, then, in that there is this change from contrary to
contrary. But the fact that a thing is altered requires that there
should be something that alters it, something e.g. that makes
the potentially hot into the actually hot: so it is plain that the
movent does not maintain a uniform relation to it but is at one
time nearer to and at another farther from that which is altered:
and we cannot have this without locomotion. If, therefore, there
must always be motion, there must also always be locomotion
as the primary motion, and, if there is a primary as
distinguished from a secondary form of locomotion, it must be
the primary form. Again, all affections have their origin in
condensation and rarefaction: thus heavy and light, soft and
hard, hot and cold, are considered to be forms of density and
rarity. But condensation and rarefaction are nothing more than
combination and separation, processes in accordance with
which substances are said to become and perish: and in being
combined and separated things must change in respect of place.
And further, when a thing is increased or decreased its
magnitude changes in respect of place.
Again, there is another point of view from which it will be
clearly seen that locomotion is primary. As in the case of other
things so too in the case of motion the word 'primary' may be
used in several senses. A thing is said to be prior to other things
when, if it does not exist, the others will not exist, whereas it
can exist without the others: and there is also priority in time
and priority in perfection of existence. Let us begin, then, with
the first sense. Now there must be motion continuously, and
there may be continuously either continuous motion or
successive motion, the former, however, in a higher degree than
829
the latter: moreover it is better that it should be continuous
rather than successive motion, and we always assume the
presence in nature of the better, if it be possible: since, then,
continuous motion is possible (this will be proved later: for the
present let us take it for granted), and no other motion can be
continuous except locomotion, locomotion must be primary. For
there is no necessity for the subject of locomotion to be the
subject either of increase or of alteration, nor need it become or
perish: on the other hand there cannot be any one of these
processes without the existence of the continuous motion
imparted by the first movent.
Secondly, locomotion must be primary in time: for this is the
only motion possible for things. It is true indeed that, in the
case of any individual thing that has a becoming, locomotion
must be the last of its motions: for after its becoming it first
experiences alteration and increase, and locomotion is a motion
that belongs to such things only when they are perfected. But
there must previously be something else that is in process of
locomotion to be the cause even of the becoming of things that
become, without itself being in process of becoming, as e.g. the
begotten is preceded by what begot it: otherwise becoming
might be thought to be the primary motion on the ground that
the thing must first become. But though this is so in the case of
any individual thing that becomes, nevertheless before anything
becomes, something else must be in motion, not itself
becoming but being, and before this there must again be
something else. And since becoming cannot be primary - for, if
it were, everything that is in motion would be perishable - it is
plain that no one of the motions next in order can be prior to
locomotion. By the motions next in order I mean increase and
then alteration, decrease, and perishing. All these are posterior
to becoming: consequently, if not even becoming is prior to
locomotion, then no one of the other processes of change is so
either.
830
Thirdly, that which is in process of becoming appears
universally as something imperfect and proceeding to a first
principle: and so what is posterior in the order of becoming is
prior in the order of nature. Now all things that go through the
process of becoming acquire locomotion last. It is this that
accounts for the fact that some living things, e.g. plants and
many kinds of animals, owing to lack of the requisite organ, are
entirely without motion, whereas others acquire it in the course
of their being perfected. Therefore, if the degree in which things
possess locomotion corresponds to the degree in which they
have realized their natural development, then this motion must
be prior to all others in respect of perfection of existence: and
not only for this reason but also because a thing that is in
motion loses its essential character less in the process of
locomotion than in any other kind of motion: it is the only
motion that does not involve a change of being in the sense in
which there is a change in quality when a thing is altered and a
change in quantity when a thing is increased or decreased.
Above all it is plain that this motion, motion in respect of place,
is what is in the strictest sense produced by that which moves
itself; but it is the self-movent that we declare to be the first
principle of things that are moved and impart motion and the
primary source to which things that are in motion are to be
referred.
It is clear, then, from the foregoing arguments that locomotion
is the primary motion. We have now to show which kind of
locomotion is primary. The same process of reasoning will also
make clear at the same time the truth of the assumption we
have made both now and at a previous stage that it is possible
that there should be a motion that is continuous and eternal.
Now it is clear from the following considerations that no other
than locomotion can be continuous. Every other motion and
change is from an opposite to an opposite: thus for the
processes of becoming and perishing the limits are the existent
831
and the non-existent, for alteration the various pairs of contrary
affections, and for increase and decrease either greatness and
smallness or perfection and imperfection of magnitude: and
changes to the respective contraries are contrary changes. Now
a thing that is undergoing any particular kind of motion, but
though previously existent has not always undergone it, must
previously have been at rest so far as that motion is concerned.
It is clear, then, that for the changing thing the contraries will
be states of rest. And we have a similar result in the case of
changes that are not motions: for becoming and perishing,
whether regarded simply as such without qualification or as
affecting something in particular, are opposites: therefore
provided it is impossible for a thing to undergo opposite
changes at the same time, the change will not be continuous,
but a period of time will intervene between the opposite
processes. The question whether these contradictory changes
are contraries or not makes no difference, provided only it is
impossible for them both to be present to the same thing at the
same time: the point is of no importance to the argument. Nor
does it matter if the thing need not rest in the contradictory
state, or if there is no state of rest as a contrary to the process of
change: it may be true that the non-existent is not at rest, and
that perishing is a process to the non-existent. All that matters
is the intervention of a time: it is this that prevents the change
from being continuous: so, too, in our previous instances the
important thing was not the relation of contrariety but the
impossibility of the two processes being present to a thing at
the same time. And there is no need to be disturbed by the fact
that on this showing there may be more than one contrary to
the same thing, that a particular motion will be contrary both to
rest and to motion in the contrary direction. We have only to
grasp the fact that a particular motion is in a sense the opposite
both of a state of rest and of the contrary motion, in the same
way as that which is of equal or standard measure is the
832
opposite both of that which surpasses it and of that which it
surpasses, and that it is impossible for the opposite motions or
changes to be present to a thing at the same time. Furthermore,
in the case of becoming and perishing it would seem to be an
utterly absurd thing if as soon as anything has become it must
necessarily perish and cannot continue to exist for any time:
and, if this is true of becoming and perishing, we have fair
grounds for inferring the same to be true of the other kinds of
change, since it would be in the natural order of things that they
should be uniform in this respect.
8
Let us now proceed to maintain that it is possible that there
should be an infinite motion that is single and continuous, and
that this motion is rotatory motion. The motion of everything
that is in process of locomotion is either rotatory or rectilinear
or a compound of the two: consequently, if one of the former
two is not continuous, that which is composed of them both
cannot be continuous either. Now it is plain that if the
locomotion of a thing is rectilinear and finite it is not
continuous locomotion: for the thing must turn back, and that
which turns back in a straight line undergoes two contrary
locomotions, since, so far as motion in respect of place is
concerned, upward motion is the contrary of downward motion,
forward motion of backward motion, and motion to the left of
motion to the right, these being the pairs of contraries in the
sphere of place. But we have already defined single and
continuous motion to be motion of a single thing in a single
period of time and operating within a sphere admitting of no
further specific differentiation (for we have three things to
consider, first that which is in motion, e.g. a man or a god,
833
secondly the 'when' of the motion, that is to say, the time, and
thirdly the sphere within which it operates, which may be
either place or affection or essential form or magnitude): and
contraries are specifically not one and the same but distinct:
and within the sphere of place we have the above-mentioned
distinctions. Moreover we have an indication that motion from
A to B is the contrary of motion from B to A in the fact that, if
they occur at the same time, they arrest and stop each other.
And the same is true in the case of a circle: the motion from A
towards B is the contrary of the motion from A towards G: for
even if they are continuous and there is no turning back they
arrest each other, because contraries annihilate or obstruct one
another. On the other hand lateral motion is not the contrary of
upward motion. But what shows most clearly that rectilinear
motion cannot be continuous is the fact that turning back
necessarily implies coming to a stand, not only when it is a
straight line that is traversed, but also in the case of locomotion
in a circle (which is not the same thing as rotatory locomotion:
for, when a thing merely traverses a circle, it may either proceed
on its course without a break or turn back again when it has
reached the same point from which it started). We may assure
ourselves of the necessity of this coming to a stand not only on
the strength of observation, but also on theoretical grounds. We
may start as follows: we have three points, starting-point,
middle-point, and finishing-point, of which the middle-point in
virtue of the relations in which it stands severally to the other
two is both a starting-point and a finishing-point, and though
numerically one is theoretically two. We have further the
distinction between the potential and the actual. So in the
straight line in question any one of the points lying between the
two extremes is potentially a middle-point: but it is not actually
so unless that which is in motion divides the line by coming to
a stand at that point and beginning its motion again: thus the
middle-point becomes both a starting-point and a goal, the
834
starting-point of the latter part and the finishing-point of the
first part of the motion. This is the case e.g. when A in the
course of its locomotion comes to a stand at B and starts again
towards G: but when its motion is continuous A cannot either
have come to be or have ceased to be at the point B: it can only
have been there at the moment of passing, its passage not being
contained within any period of time except the whole of which
the particular moment is a dividing-point. To maintain that it
has come to be and ceased to be there will involve the
consequence that A in the course of its locomotion will always
be coming to a stand: for it is impossible that A should
simultaneously have come to be at B and ceased to be there, so
that the two things must have happened at different points of
time, and therefore there will be the intervening period of time:
consequently A will be in a state of rest at B, and similarly at all
other points, since the same reasoning holds good in every case.
When to A, that which is in process of locomotion, B, the
middle-point, serves both as a finishing-point and as a starting-
point for its motion, A must come to a stand at B, because it
makes it two just as one might do in thought. However, the
point A is the real starting-point at which the moving body has
ceased to be, and it is at G that it has really come to be when its
course is finished and it comes to a stand. So this is how we
must meet the difficulty that then arises, which is as follows.
Suppose the line E is equal to the line Z, that A proceeds in
continuous locomotion from the extreme point of E to G, and
that, at the moment when A is at the point B, D is proceeding in
uniform locomotion and with the same velocity as A from the
extremity of Z to H: then, says the argument, D will have
reached H before A has reached G for that which makes an
earlier start and departure must make an earlier arrival: the
reason, then, for the late arrival of A is that it has not
simultaneously come to be and ceased to be at B: otherwise it
will not arrive later: for this to happen it will be necessary that
835
it should come to a stand there. Therefore we must not hold
that there was a moment when A came to be at B and that at
the same moment D was in motion from the extremity of Z: for
the fact of A's having come to be at B will involve the fact of its
also ceasing to be there, and the two events will not be
simultaneous, whereas the truth is that A is at B at a sectional
point of time and does not occupy time there. In this case,
therefore, where the motion of a thing is continuous, it is
impossible to use this form of expression. On the other hand in
the case of a thing that turns back in its course we must do so.
For suppose H in the course of its locomotion proceeds to D and
then turns back and proceeds downwards again: then the
extreme point D has served as finishing-point and as starting-
point for it, one point thus serving as two: therefore H must
have come to a stand there: it cannot have come to be at D and
departed from D simultaneously, for in that case it would
simultaneously be there and not be there at the same moment.
And here we cannot apply the argument used to solve the
difficulty stated above: we cannot argue that H is at D at a
sectional point of time and has not come to be or ceased to be
there. For here the goal that is reached is necessarily one that is
actually, not potentially, existent. Now the point in the middle is
potential: but this one is actual, and regarded from below it is a
finishing-point, while regarded from above it is a starting-point,
so that it stands in these same two respective relations to the
two motions. Therefore that which turns back in traversing a
rectilinear course must in so doing come to a stand.
Consequently there cannot be a continuous rectilinear motion
that is eternal.
The same method should also be adopted in replying to those
who ask, in the terms of Zeno's argument, whether we admit
that before any distance can be traversed half the distance must
be traversed, that these half-distances are infinite in number,
and that it is impossible to traverse distances infinite in number
836
- or some on the lines of this same argument put the questions
in another form, and would have us grant that in the time
during which a motion is in progress it should be possible to
reckon a half-motion before the whole for every half-distance
that we get, so that we have the result that when the whole
distance is traversed we have reckoned an infinite number,
which is admittedly impossible. Now when we first discussed
the question of motion we put forward a solution of this
difficulty turning on the fact that the period of time occupied in
traversing the distance contains within itself an infinite number
of units: there is no absurdity, we said, in supposing the
traversing of infinite distances in infinite time, and the element
of infinity is present in the time no less than in the distance.
But, although this solution is adequate as a reply to the
questioner (the question asked being whether it is possible in a
finite time to traverse or reckon an infinite number of units),
nevertheless as an account of the fact and explanation of its
true nature it is inadequate. For suppose the distance to be left
out of account and the question asked to be no longer whether
it is possible in a finite time to traverse an infinite number of
distances, and suppose that the inquiry is made to refer to the
time taken by itself (for the time contains an infinite number of
divisions): then this solution will no longer be adequate, and we
must apply the truth that we enunciated in our recent
discussion, stating it in the following way. In the act of dividing
the continuous distance into two halves one point is treated as
two, since we make it a starting-point and a finishing-point:
and this same result is also produced by the act of reckoning
halves as well as by the act of dividing into halves. But if
divisions are made in this way, neither the distance nor the
motion will be continuous: for motion if it is to be continuous
must relate to what is continuous: and though what is
continuous contains an infinite number of halves, they are not
actual but potential halves. If the halves are made actual, we
837
shall get not a continuous but an intermittent motion. In the
case of reckoning the halves, it is clear that this result follows:
for then one point must be reckoned as two: it will be the
finishing-point of the one half and the starting-point of the
other, if we reckon not the one continuous whole but the two
halves. Therefore to the question whether it is possible to pass
through an infinite number of units either of time or of distance
we must reply that in a sense it is and in a sense it is not. If the
units are actual, it is not possible: if they are potential, it is
possible. For in the course of a continuous motion the traveller
has traversed an infinite number of units in an accidental sense
but not in an unqualified sense: for though it is an accidental
characteristic of the distance to be an infinite number of half-
distances, this is not its real and essential character. It is also
plain that unless we hold that the point of time that divides
earlier from later always belongs only to the later so far as the
thing is concerned, we shall be involved in the consequence
that the same thing is at the same moment existent and not
existent, and that a thing is not existent at the moment when it
has become. It is true that the point is common to both times,
the earlier as well as the later, and that, while numerically one
and the same, it is theoretically not so, being the finishing-point
of the one and the starting-point of the other: but so far as the
thing is concerned it belongs to the later stage of what happens
to it. Let us suppose a time ABG and a thing D, D being white in
the time A and not-white in the time B. Then D is at the
moment G white and not-white: for if we were right in saying
that it is white during the whole time A, it is true to call it white
at any moment of A, and not-white in B, and G is in both A and
B. We must not allow, therefore, that it is white in the whole of
A, but must say that it is so in all of it except the last moment G.
G belongs already to the later period, and if in the whole of A
not-white was in process of becoming and white of perishing, at
G the process is complete. And so G is the first moment at
838
which it is true to call the thing white or not white respectively.
Otherwise a thing may be non-existent at the moment when it
has become and existent at the moment when it has perished:
or else it must be possible for a thing at the same time to be
white and not white and in fact to be existent and non-existent.
Further, if anything that exists after having been previously
non-existent must become existent and does not exist when it
is becoming, time cannot be divisible into time-atoms. For
suppose that D was becoming white in the time A and that at
another time B, a time-atom consecutive with the last atom of
A, D has already become white and so is white at that moment:
then, inasmuch as in the time A it was becoming white and so
was not white and at the moment B it is white, there must have
been a becoming between A and B and therefore also a time in
which the becoming took place. On the other hand, those who
deny atoms of time (as we do) are not affected by this
argument: according to them D has become and so is white at
the last point of the actual time in which it was becoming
white: and this point has no other point consecutive with or in
succession to it, whereas time-atoms are conceived as
successive. Moreover it is clear that if D was becoming white in
the whole time A, the time occupied by it in having become
white in addition to having been in process of becoming white
is no more than all that it occupied in the mere process of
becoming white.
These and such-like, then, are the arguments for our conclusion
that derive cogency from the fact that they have a special
bearing on the point at issue. If we look at the question from the
point of view of general theory, the same result would also
appear to be indicated by the following arguments. Everything
whose motion is continuous must, on arriving at any point in
the course of its locomotion, have been previously also in
process of locomotion to that point, if it is not forced out of its
path by anything: e.g. on arriving at B a thing must also have
839
been in process of locomotion to B, and that not merely when it
was near to B, but from the moment of its starting on its course,
since there can be, no reason for its being so at any particular
stage rather than at an earlier one. So, too, in the case of the
other kinds of motion. Now we are to suppose that a thing
proceeds in locomotion from A to G and that at the moment of
its arrival at G the continuity of its motion is unbroken and will
remain so until it has arrived back at A. Then when it is
undergoing locomotion from A to G it is at the same time
undergoing also its locomotion to A from G: consequently it is
simultaneously undergoing two contrary motions, since the two
motions that follow the same straight line are contrary to each
other. With this consequence there also follows another: we
have a thing that is in process of change from a position in
which it has not yet been: so, inasmuch as this is impossible,
the thing must come to a stand at G. Therefore the motion is
not a single motion, since motion that is interrupted by
stationariness is not single.
Further, the following argument will serve better to make this
point clear universally in respect of every kind of motion. If the
motion undergone by that which is in motion is always one of
those already enumerated, and the state of rest that it
undergoes is one of those that are the opposites of the motions
(for we found that there could be no other besides these), and
moreover that which is undergoing but does not always
undergo a particular motion (by this I mean one of the various
specifically distinct motions, not some particular part of the
whole motion) must have been previously undergoing the state
of rest that is the opposite of the motion, the state of rest being
privation of motion; then, inasmuch as the two motions that
follow the same straight line are contrary motions, and it is
impossible for a thing to undergo simultaneously two contrary
motions, that which is undergoing locomotion from A to G
cannot also simultaneously be undergoing locomotion from G
840
to A: and since the latter locomotion is not simultaneous with
the former but is still to be undergone, before it is undergone
there must occur a state of rest at G: for this, as we found, is the
state of rest that is the opposite of the motion from G. The
foregoing argument, then, makes it plain that the motion in
question is not continuous.
Our next argument has a more special bearing than the
foregoing on the point at issue. We will suppose that there has
occurred in something simultaneously a perishing of not-white
and a becoming of white. Then if the alteration to white and
from white is a continuous process and the white does not
remain any time, there must have occurred simultaneously a
perishing of not-white, a becoming of white, and a becoming of
not-white: for the time of the three will be the same.
Again, from the continuity of the time in which the motion
takes place we cannot infer continuity in the motion, but only
successiveness: in fact, how could contraries, e.g. whiteness and
blackness, meet in the same extreme point?
On the other hand, in motion on a circular line we shall find
singleness and continuity: for here we are met by no impossible
consequence: that which is in motion from A will in virtue of
the same direction of energy be simultaneously in motion to A
(since it is in motion to the point at which it will finally arrive),
and yet will not be undergoing two contrary or opposite
motions: for a motion to a point and a motion from that point
are not always contraries or opposites: they are contraries only
if they are on the same straight line (for then they are contrary
to one another in respect of place, as e.g. the two motions along
the diameter of the circle, since the ends of this are at the
greatest possible distance from one another), and they are
opposites only if they are along the same line. Therefore in the
case we are now considering there is nothing to prevent the
841
motion being continuous and free from all intermission: for
rotatory motion is motion of a thing from its place to its place,
whereas rectilinear motion is motion from its place to another
place.
Moreover the progress of rotatory motion is never localized
within certain fixed limits, whereas that of rectilinear motion
repeatedly is so. Now a motion that is always shifting its ground
from moment to moment can be continuous: but a motion that
is repeatedly localized within certain fixed limits cannot be so,
since then the same thing would have to undergo
simultaneously two opposite motions. So, too, there cannot be
continuous motion in a semicircle or in any other arc of a circle,
since here also the same ground must be traversed repeatedly
and two contrary processes of change must occur. The reason is
that in these motions the starting-point and the termination do
not coincide, whereas in motion over a circle they do coincide,
and so this is the only perfect motion.
This differentiation also provides another means of showing
that the other kinds of motion cannot be continuous either: for
in all of them we find that there is the same ground to be
traversed repeatedly; thus in alteration there are the
intermediate stages of the process, and in quantitative change
there are the intervening degrees of magnitude: and in
becoming and perishing the same thing is true. It makes no
difference whether we take the intermediate stages of the
process to be few or many, or whether we add or subtract one:
for in either case we find that there is still the same ground to
be traversed repeatedly. Moreover it is plain from what has been
said that those physicists who assert that all sensible things are
always in motion are wrong: for their motion must be one or
other of the motions just mentioned: in fact they mostly
conceive it as alteration (things are always in flux and decay,
they say), and they go so far as to speak even of becoming and
842
perishing as a process of alteration. On the other hand, our
argument has enabled us to assert the fact, applying universally
to all motions, that no motion admits of continuity except
rotatory motion: consequently neither alteration nor increase
admits of continuity. We need now say no more in support of
the position that there is no process of change that admits of
infinity or continuity except rotatory locomotion.
It can now be shown plainly that rotation is the primary
locomotion. Every locomotion, as we said before, is either
rotatory or rectilinear or a compound of the two: and the two
former must be prior to the last, since they are the elements of
which the latter consists. Moreover rotatory locomotion is prior
to rectilinear locomotion, because it is more simple and
complete, which may be shown as follows. The straight line
traversed in rectilinear motion cannot be infinite: for there is no
such thing as an infinite straight line; and even if there were, it
would not be traversed by anything in motion: for the
impossible does not happen and it is impossible to traverse an
infinite distance. On the other hand rectilinear motion on a
finite straight line is if it turns back a composite motion, in fact
two motions, while if it does not turn back it is incomplete and
perishable: and in the order of nature, of definition, and of time
alike the complete is prior to the incomplete and the
imperishable to the perishable. Again, a motion that admits of
being eternal is prior to one that does not. Now rotatory motion
can be eternal: but no other motion, whether locomotion or
motion of any other kind, can be so, since in all of them rest
must occur and with the occurrence of rest the motion has
perished. Moreover the result at which we have arrived, that
843
rotatory motion is single and continuous, and rectilinear motion
is not, is a reasonable one. In rectilinear motion we have a
definite starting-point, finishing-point, middle-point, which all
have their place in it in such a way that there is a point from
which that which is in motion can be said to start and a point at
which it can be said to finish its course (for when anything is at
the limits of its course, whether at the starting-point or at the
finishing-point, it must be in a state of rest). On the other hand
in circular motion there are no such definite points: for why
should any one point on the line be a limit rather than any
other? Any one point as much as any other is alike starting-
point, middle-point, and finishing-point, so that we can say of
certain things both that they are always and that they never are
at a starting-point and at a finishing-point (so that a revolving
sphere, while it is in motion, is also in a sense at rest, for it
continues to occupy the same place). The reason of this is that
in this case all these characteristics belong to the centre: that is
to say, the centre is alike starting-point, middle-point, and
finishing-point of the space traversed; consequently since this
point is not a point on the circular line, there is no point at
which that which is in process of locomotion can be in a state of
rest as having traversed its course, because in its locomotion it
is proceeding always about a central point and not to an
extreme point: therefore it remains still, and the whole is in a
sense always at rest as well as continuously in motion. Our next
point gives a convertible result: on the one hand, because
rotation is the measure of motions it must be the primary
motion (for all things are measured by what is primary): on the
other hand, because rotation is the primary motion it is the
measure of all other motions. Again, rotatory motion is also the
only motion that admits of being regular. In rectilinear
locomotion the motion of things in leaving the starting-point is
not uniform with their motion in approaching the finishing-
point, since the velocity of a thing always increases
844
proportionately as it removes itself farther from its position of
rest: on the other hand rotatory motion is the only motion
whose course is naturally such that it has no starting-point or
finishing-point in itself but is determined from elsewhere.
As to locomotion being the primary motion, this is a truth that
is attested by all who have ever made mention of motion in
their theories: they all assign their first principles of motion to
things that impart motion of this kind. Thus 'separation' and
'combination' are motions in respect of place, and the motion
imparted by 'Love' and 'Strife' takes these forms, the latter
'separating' and the former 'combining'. Anaxagoras, too, says
that 'Mind', his first movent, 'separates'. Similarly those who
assert no cause of this kind but say that 'void' accounts for
motion - they also hold that the motion of natural substance is
motion in respect of place: for their motion that is accounted
for by 'void' is locomotion, and its sphere of operation may be
said to be place. Moreover they are of opinion that the primary
substances are not subject to any of the other motions, though
the things that are compounds of these substances are so
subject: the processes of increase and decrease and alteration,
they say, are effects of the 'combination' and 'separation' of
atoms. It is the same, too, with those who make out that the
becoming or perishing of a thing is accounted for by 'density' or
'rarity': for it is by 'combination' and 'separation' that the place
of these things in their systems is determined. Moreover to
these we may add those who make Soul the cause of motion:
for they say that things that undergo motion have as their first
principle 'that which moves itself: and when animals and all
living things move themselves, the motion is motion in respect
of place. Finally it is to be noted that we say that a thing 'is in
motion' in the strict sense of the term only when its motion is
motion in respect of place: if a thing is in process of increase or
decrease or is undergoing some alteration while remaining at
rest in the same place, we say that it is in motion in some
845
particular respect: we do not say that it 'is in motion' without
qualification.
Our present position, then, is this: We have argued that there
always was motion and always will be motion throughout all
time, and we have explained what is the first principle of this
eternal motion: we have explained further which is the primary
motion and which is the only motion that can be eternal: and
we have pronounced the first movent to be unmoved.
10
We have now to assert that the first movent must be without
parts and without magnitude, beginning with the establishment
of the premisses on which this conclusion depends.
One of these premisses is that nothing finite can cause motion
during an infinite time. We have three things, the movent, the
moved, and thirdly that in which the motion takes place,
namely the time: and these are either all infinite or all finite or
partly - that is to say two of them or one of them - finite and
partly infinite. Let A be the movement, B the moved, and G the
infinite time. Now let us suppose that D moves E, a part of B.
Then the time occupied by this motion cannot be equal to G: for
the greater the amount moved, the longer the time occupied. It
follows that the time Z is not infinite. Now we see that by
continuing to add to D, I shall use up A and by continuing to add
to E, I shall use up B: but I shall not use up the time by
continually subtracting a corresponding amount from it,
because it is infinite. Consequently the duration of the part of G
which is occupied by all A in moving the whole of B, will be
finite. Therefore a finite thing cannot impart to anything an
846
infinite motion. It is clear, then, that it is impossible for the
finite to cause motion during an infinite time.
It has now to be shown that in no case is it possible for an
infinite force to reside in a finite magnitude. This can be shown
as follows: we take it for granted that the greater force is always
that which in less time than another does an equal amount of
work when engaged in any activity - in heating, for example, or
sweetening or throwing; in fact, in causing any kind of motion.
Then that on which the forces act must be affected to some
extent by our supposed finite magnitude possessing an infinite
force as well as by anything else, in fact to a greater extent than
by anything else, since the infinite force is greater than any
other. But then there cannot be any time in which its action
could take place. Suppose that A is the time occupied by the
infinite power in the performance of an act of heating or
pushing, and that AB is the time occupied by a finite power in
the performance of the same act: then by adding to the latter
another finite power and continually increasing the magnitude
of the power so added I shall at some time or other reach a
point at which the finite power has completed the motive act in
the time A: for by continual addition to a finite magnitude I
must arrive at a magnitude that exceeds any assigned limit, and
in the same way by continual subtraction I must arrive at one
that falls short of any assigned limit. So we get the result that
the finite force will occupy the same amount of time in
performing the motive act as the infinite force. But this is
impossible. Therefore nothing finite can possess an infinite
force. So it is also impossible for a finite force to reside in an
infinite magnitude. It is true that a greater force can reside in a
lesser magnitude: but the superiority of any such greater force
can be still greater if the magnitude in which it resides is
greater. Now let AB be an infinite magnitude. Then BG possesses
a certain force that occupies a certain time, let us say the time Z
in moving D. Now if I take a magnitude twice as great at BG, the
847
time occupied by this magnitude in moving D will be half of EZ
(assuming this to be the proportion): so we may call this time
ZH. That being so, by continually taking a greater magnitude in
this way I shall never arrive at the full AB, whereas I shall
always be getting a lesser fraction of the time given. Therefore
the force must be infinite, since it exceeds any finite force.
Moreover the time occupied by the action of any finite force
must also be finite: for if a given force moves something in a
certain time, a greater force will do so in a lesser time, but still a
definite time, in inverse proportion. But a force must always be
infinite - just as a number or a magnitude is - if it exceeds all
definite limits. This point may also be proved in another way -
by taking a finite magnitude in which there resides a force the
same in kind as that which resides in the infinite magnitude, so
that this force will be a measure of the finite force residing in
the infinite magnitude.
It is plain, then, from the foregoing arguments that it is
impossible for an infinite force to reside in a finite magnitude or
for a finite force to reside in an infinite magnitude. But before
proceeding to our conclusion it will be well to discuss a
difficulty that arises in connexion with locomotion. If
everything that is in motion with the exception of things that
move themselves is moved by something else, how is it that
some things, e.g. things thrown, continue to be in motion when
their movent is no longer in contact with them? If we say that
the movent in such cases moves something else at the same
time, that the thrower e.g. also moves the air, and that this in
being moved is also a movent, then it would be no more
possible for this second thing than for the original thing to be in
motion when the original movent is not in contact with it or
moving it: all the things moved would have to be in motion
simultaneously and also to have ceased simultaneously to be in
motion when the original movent ceases to move them, even if,
like the magnet, it makes that which it has moved capable of
848
being a movent. Therefore, while we must accept this
explanation to the extent of saying that the original movent
gives the power of being a movent either to air or to water or to
something else of the kind, naturally adapted for imparting and
undergoing motion, we must say further that this thing does
not cease simultaneously to impart motion and to undergo
motion: it ceases to be in motion at the moment when its
movent ceases to move it, but it still remains a movent, and so
it causes something else consecutive with it to be in motion,
and of this again the same may be said. The motion begins to
cease when the motive force produced in one member of the
consecutive series is at each stage less than that possessed by
the preceding member, and it finally ceases when one member
no longer causes the next member to be a movent but only
causes it to be in motion. The motion of these last two - of the
one as movent and of the other as moved - must cease
simultaneously, and with this the whole motion ceases. Now
the things in which this motion is produced are things that
admit of being sometimes in motion and sometimes at rest, and
the motion is not continuous but only appears so: for it is
motion of things that are either successive or in contact, there
being not one movent but a number of movents consecutive
with one another: and so motion of this kind takes place in air
and water. Some say that it is 'mutual replacement': but we
must recognize that the difficulty raised cannot be solved
otherwise than in the way we have described. So far as they are
affected by 'mutual replacement', all the members of the series
are moved and impart motion simultaneously, so that their
motions also cease simultaneously: but our present problem
concerns the appearance of continuous motion in a single
thing, and therefore, since it cannot be moved throughout its
motion by the same movent, the question is, what moves it?
Resuming our main argument, we proceed from the positions
that there must be continuous motion in the world of things,
849
that this is a single motion, that a single motion must be a
motion of a magnitude (for that which is without magnitude
cannot be in motion), and that the magnitude must be a single
magnitude moved by a single movent (for otherwise there will
not be continuous motion but a consecutive series of separate
motions), and that if the movement is a single thing, it is either
itself in motion or itself unmoved: if, then, it is in motion, it will
have to be subject to the same conditions as that which it
moves, that is to say it will itself be in process of change and in
being so will also have to be moved by something: so we have a
series that must come to an end, and a point will be reached at
which motion is imparted by something that is unmoved. Thus
we have a movent that has no need to change along with that
which it moves but will be able to cause motion always (for the
causing of motion under these conditions involves no effort):
and this motion alone is regular, or at least it is so in a higher
degree than any other, since the movent is never subject to any
change. So, too, in order that the motion may continue to be of
the same character, the moved must not be subject to change in
respect of its relation to the movent. Moreover the movent must
occupy either the centre or the circumference, since these are
the first principles from which a sphere is derived. But the
things nearest the movent are those whose motion is quickest,
and in this case it is the motion of the circumference that is the
quickest: therefore the movent occupies the circumference.
There is a further difficulty in supposing it to be possible for
anything that is in motion to cause motion continuously and
not merely in the way in which it is caused by something
repeatedly pushing (in which case the continuity amounts to no
more than successiveness). Such a movent must either itself
continue to push or pull or perform both these actions, or else
the action must be taken up by something else and be passed
on from one movent to another (the process that we described
before as occurring in the case of things thrown, since the air or
850
the water, being divisible, is a movent only in virtue of the fact
that different parts of the air are moved one after another): and
in either case the motion cannot be a single motion, but only a
consecutive series of motions. The only continuous motion,
then, is that which is caused by the unmoved movent: and this
motion is continuous because the movent remains always
invariable, so that its relation to that which it moves remains
also invariable and continuous.
Now that these points are settled, it is clear that the first
unmoved movent cannot have any magnitude. For if it has
magnitude, this must be either a finite or an infinite magnitude.
Now we have already'proved in our course on Physics that there
cannot be an infinite magnitude: and we have now proved that
it is impossible for a finite magnitude to have an infinite force,
and also that it is impossible for a thing to be moved by a finite
magnitude during an infinite time. But the first movent causes a
motion that is eternal and does cause it during an infinite time.
It is clear, therefore, that the first movent is indivisible and is
without parts and without magnitude.
851
Aristotle - On the Heavens
[Translated by J. L. Stocks]
Book I
The science which has to do with nature clearly concerns itself for
the most part with bodies and magnitudes and their properties and
movements, but also with the principles of this sort of substance, as
many as they may be. For of things constituted by nature some are
bodies and magnitudes, some possess body and magnitude, and
some are principles of things which possess these. Now a continuum
is that which is divisible into parts always capable of subdivision, and
a body is that which is every way divisible. A magnitude if divisible
one way is a line, if two ways a surface, and if three a body. Beyond
these there is no other magnitude, because the three dimensions are
all that there are, and that which is divisible in three directions is
divisible in all. For, as the Pythagoreans say, the world and all that is
in it is determined by the number three, since beginning and middle
and end give the number of an 'all', and the number they give is the
triad. And so, having taken these three from nature as (so to speak)
laws of it, we make further use of the number three in the worship of
the Gods. Further, we use the terms in practice in this way. Of two
things, or men, we say 'both', but not 'all': three is the first number to
which the term 'all' has been appropriated. And in this, as we have
said, we do but follow the lead which nature gives. Therefore, since
'every' and 'all' and 'complete' do not differ from one another in
respect of form, but only, if at all, in their matter and in that to which
they are applied, body alone among magnitudes can be complete. For
it alone is determined by the three dimensions, that is, is an 'all'. But
if it is divisible in three dimensions it is every way divisible, while the
other magnitudes are divisible in one dimension or in two alone: for
852
the divisibility and continuity of magnitudes depend upon the
number of the dimensions, one sort being continuous in one
direction, another in two, another in all. All magnitudes, then, which
are divisible are also continuous. Whether we can also say that
whatever is continuous is divisible does not yet, on our present
grounds, appear. One thing, however, is clear. We cannot pass beyond
body to a further kind, as we passed from length to surface, and from
surface to body. For if we could, it would cease to be true that body is
complete magnitude. We could pass beyond it only in virtue of a
defect in it; and that which is complete cannot be defective, since it
has being in every respect. Now bodies which are classed as parts of
the whole are each complete according to our formula, since each
possesses every dimension. But each is determined relatively to that
part which is next to it by contact, for which reason each of them is
in a sense many bodies. But the whole of which they are parts must
necessarily be complete, and thus, in accordance with the meaning of
the word, have being, not in some respect only, but in every respect.
The question as to the nature of the whole, whether it is infinite in
size or limited in its total mass, is a matter for subsequent inquiry.
We will now speak of those parts of the whole which are specifically
distinct. Let us take this as our starting-point. All natural bodies and
magnitudes we hold to be, as such, capable of locomotion; for nature,
we say, is their principle of movement. But all movement that is in
place, all locomotion, as we term it, is either straight or circular or a
combination of these two, which are the only simple movements.
And the reason of this is that these two, the straight and the circular
line, are the only simple magnitudes. Now revolution about the
centre is circular motion, while the upward and downward
movements are in a straight line, 'upward' meaning motion away
from the centre, and 'downward' motion towards it. All simple
motion, then, must be motion either away from or towards or about
the centre. This seems to be in exact accord with what we said above:
853
as body found its completion in three dimensions, so its movement
completes itself in three forms.
Bodies are either simple or compounded of such; and by simple
bodies I mean those which possess a principle of movement in their
own nature, such as fire and earth with their kinds, and whatever is
akin to them. Necessarily, then, movements also will be either simple
or in some sort compound - simple in the case of the simple bodies,
compound in that of the composite - and in the latter case the
motion will be that of the simple body which prevails in the
composition. Supposing, then, that there is such a thing as simple
movement, and that circular movement is an instance of it, and that
both movement of a simple body is simple and simple movement is
of a simple body (for if it is movement of a compound it will be in
virtue of a prevailing simple element), then there must necessarily be
some simple body which revolves naturally and in virtue of its own
nature with a circular movement. By constraint, of course, it may be
brought to move with the motion of something else different from
itself, but it cannot so move naturally, since there is one sort of
movement natural to each of the simple bodies. Again, if the
unnatural movement is the contrary of the natural and a thing can
have no more than one contrary, it will follow that circular
movement, being a simple motion, must be unnatural, if it is not
natural, to the body moved. If then (1) the body, whose movement is
circular, is fire or some other element, its natural motion must be the
contrary of the circular motion. But a single thing has a single
contrary; and upward and downward motion are the contraries of
one another. If, on the other hand, (2) the body moving with this
circular motion which is unnatural to it is something different from
the elements, there will be some other motion which is natural to it.
But this cannot be. For if the natural motion is upward, it will be fire
or air, and if downward, water or earth. Further, this circular motion
is necessarily primary. For the perfect is naturally prior to the
imperfect, and the circle is a perfect thing. This cannot be said of any
straight line: - not of an infinite line; for, if it were perfect, it would
have a limit and an end: nor of any finite line; for in every case there
is something beyond it, since any finite line can be extended. And so,
since the prior movement belongs to the body which naturally prior,
854
and circular movement is prior to straight, and movement in a
straight line belongs to simple bodies - fire moving straight upward
and earthy bodies straight downward towards the centre - since this
is so, it follows that circular movement also must be the movement
of some simple body. For the movement of composite bodies is, as we
said, determined by that simple body which preponderates in the
composition. These premises clearly give the conclusion that there is
in nature some bodily substance other than the formations we know,
prior to them all and more divine than they. But it may also be proved
as follows. We may take it that all movement is either natural or
unnatural, and that the movement which is unnatural to one body is
natural to another - as, for instance, is the case with the upward and
downward movements, which are natural and unnatural to fire and
earth respectively. It necessarily follows that circular movement,
being unnatural to these bodies, is the natural movement of some
other. Further, if, on the one hand, circular movement is natural to
something, it must surely be some simple and primary body which is
ordained to move with a natural circular motion, as fire is ordained to
fly up and earth down. If, on the other hand, the movement of the
rotating bodies about the centre is unnatural, it would be remarkable
and indeed quite inconceivable that this movement alone should be
continuous and eternal, being nevertheless contrary to nature. At any
rate the evidence of all other cases goes to show that it is the
unnatural which quickest passes away. And so, if, as some say, the
body so moved is fire, this movement is just as unnatural to it as
downward movement; for any one can see that fire moves in a
straight line away from the centre. On all these grounds, therefore,
we may infer with confidence that there is something beyond the
bodies that are about us on this earth, different and separate from
them; and that the superior glory of its nature is proportionate to its
distance from this world of ours.
855
In consequence of what has been said, in part by way of assumption
and in part by way of proof, it is clear that not every body either
possesses lightness or heaviness. As a preliminary we must explain
in what sense we are using the words 'heavy' and 'light', sufficiently,
at least, for our present purpose: we can examine the terms more
closely later, when we come to consider their essential nature. Let us
then apply the term 'heavy' to that which naturally moves towards
the centre, and 'light' to that which moves naturally away from the
centre. The heaviest thing will be that which sinks to the bottom of
all things that move downward, and the lightest that which rises to
the surface of everything that moves upward. Now, necessarily,
everything which moves either up or down possesses lightness or
heaviness or both - but not both relatively to the same thing: for
things are heavy and light relatively to one another; air, for instance,
is light relatively to water, and water light relatively to earth. The
body, then, which moves in a circle cannot possibly possess either
heaviness or lightness. For neither naturally nor unnaturally can it
move either towards or away from the centre. Movement in a straight
line certainly does not belong to it naturally, since one sort of
movement is, as we saw, appropriate to each simple body, and so we
should be compelled to identify it with one of the bodies which move
in this way. Suppose, then, that the movement is unnatural. In that
case, if it is the downward movement which is unnatural, the upward
movement will be natural; and if it is the upward which is unnatural,
the downward will be natural. For we decided that of contrary
movements, if the one is unnatural to anything, the other will be
natural to it. But since the natural movement of the whole and of its
part of earth, for instance, as a whole and of a small clod - have one
and the same direction, it results, in the first place, that this body can
possess no lightness or heaviness at all (for that would mean that it
could move by its own nature either from or towards the centre,
which, as we know, is impossible); and, secondly, that it cannot
possibly move in the way of locomotion by being forced violently
aside in an upward or downward direction. For neither naturally nor
unnaturally can it move with any other motion but its own, either
856
itself or any part of it, since the reasoning which applies to the whole
applies also to the part.
It is equally reasonable to assume that this body will be ungenerated
and indestructible and exempt from increase and alteration, since
everything that comes to be comes into being from its contrary and
in some substrate, and passes away likewise in a substrate by the
action of the contrary into the contrary, as we explained in our
opening discussions. Now the motions of contraries are contrary. If
then this body can have no contrary, because there can be no
contrary motion to the circular, nature seems justly to have
exempted from contraries the body which was to be ungenerated and
indestructible. For it is in contraries that generation and decay
subsist. Again, that which is subject to increase increases upon
contact with a kindred body, which is resolved into its matter. But
there is nothing out of which this body can have been generated. And
if it is exempt from increase and diminution, the same reasoning
leads us to suppose that it is also unalterable. For alteration is
movement in respect of quality; and qualitative states and
dispositions, such as health and disease, do not come into being
without changes of properties. But all natural bodies which change
their properties we see to be subject without exception to increase
and diminution. This is the case, for instance, with the bodies of
animals and their parts and with vegetable bodies, and similarly also
with those of the elements. And so, if the body which moves with a
circular motion cannot admit of increase or diminution, it is
reasonable to suppose that it is also unalterable.
The reasons why the primary body is eternal and not subject to
increase or diminution, but unaging and unalterable and unmodified,
will be clear from what has been said to any one who believes in our
assumptions. Our theory seems to confirm experience and to be
confirmed by it. For all men have some conception of the nature of
the gods, and all who believe in the existence of gods at all, whether
barbarian or Greek, agree in allotting the highest place to the deity,
surely because they suppose that immortal is linked with immortal
and regard any other supposition as inconceivable. If then there is, as
there certainly is, anything divine, what we have just said about the
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primary bodily substance was well said. The mere evidence of the
senses is enough to convince us of this, at least with human
certainty. For in the whole range of time past, so far as our inherited
records reach, no change appears to have taken place either in the
whole scheme of the outermost heaven or in any of its proper parts.
The common name, too, which has been handed down from our
distant ancestors even to our own day, seems to show that they
conceived of it in the fashion which we have been expressing. The
same ideas, one must believe, recur in men's minds not once or twice
but again and again. And so, implying that the primary body is
something else beyond earth, fire, air, and water, they gave the
highest place a name of its own, aither, derived from the fact that it
'runs always' for an eternity of time. Anaxagoras, however,
scandalously misuses this name, taking aither as equivalent to fire.
It is also clear from what has been said why the number of what we
call simple bodies cannot be greater than it is. The motion of a simple
body must itself be simple, and we assert that there are only these
two simple motions, the circular and the straight, the latter being
subdivided into motion away from and motion towards the centre.
That there is no other form of motion opposed as contrary to the
circular may be proved in various ways. In the first place, there is an
obvious tendency to oppose the straight line to the circular. For
concave and convex are a not only regarded as opposed to one
another, but they are also coupled together and treated as a unity in
opposition to the straight. And so, if there is a contrary to circular
motion, motion in a straight line must be recognized as having the
best claim to that name. But the two forms of rectilinear motion are
opposed to one another by reason of their places; for up and down is
a difference and a contrary opposition in place. Secondly, it may be
thought that the same reasoning which holds good of the rectilinear
path applies also the circular, movement from A to B being opposed
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as contrary to movement from B to A. But what is meant is still
rectilinear motion. For that is limited to a single path, while the
circular paths which pass through the same two points are infinite in
number. Even if we are confined to the single semicircle and the
opposition is between movement from C to D and from D to C along
that semicircle, the case is no better. For the motion is the same as
that along the diameter, since we invariably regard the distance
between two points as the length of the straight line which joins
them. It is no more satisfactory to construct a circle and treat motion
'along one semicircle as contrary to motion along the other. For
example, taking a complete circle, motion from E to F on the
semicircle G may be opposed to motion from F to E on the semicircle
H. But even supposing these are contraries, it in no way follows that
the reverse motions on the complete circumference contraries. Nor
again can motion along the circle from A to B be regarded as the
contrary of motion from A to C: for the motion goes from the same
point towards the same point, and contrary motion was
distinguished as motion from a contrary to its contrary. And even if
the motion round a circle is the contrary of the reverse motion, one
of the two would be ineffective: for both move to the same point,
because that which moves in a circle, at whatever point it begins,
must necessarily pass through all the contrary places alike. (By
contrarieties of place I mean up and down, back and front, and right
and left; and the contrary oppositions of movements are determined
by those of places.) One of the motions, then, would be ineffective, for
if the two motions were of equal strength, there would be no
movement either way, and if one of the two were preponderant, the
other would be inoperative. So that if both bodies were there, one of
them, inasmuch as it would not be moving with its own movement,
would be useless, in the sense in which a shoe is useless when it is
not worn. But God and nature create nothing that has not its use.
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This being clear, we must go on to consider the questions which
remain. First, is there an infinite body, as the majority of the ancient
philosophers thought, or is this an impossibility? The decision of this
question, either way, is not unimportant, but rather all-important, to
our search for the truth. It is this problem which has practically
always been the source of the differences of those who have written
about nature as a whole. So it has been and so it must be; since the
least initial deviation from the truth is multiplied later a
thousandfold. Admit, for instance, the existence of a minimum
magnitude, and you will find that the minimum which you have
introduced, small as it is, causes the greatest truths of mathematics
to totter. The reason is that a principle is great rather in power than
in extent; hence that which was small at the start turns out a giant at
the end. Now the conception of the infinite possesses this power of
principles, and indeed in the sphere of quantity possesses it in a
higher degree than any other conception; so that it is in no way
absurd or unreasonable that the assumption that an infinite body
exists should be of peculiar moment to our inquiry. The infinite, then,
we must now discuss, opening the whole matter from the beginning.
Every body is necessarily to be classed either as simple or as
composite; the infinite body, therefore, will be either simple or
composite.
But it is clear, further, that if the simple bodies are finite, the
composite must also be finite, since that which is composed of
bodies finite both in number and in magnitude is itself finite in
respect of number and magnitude: its quantity is in fact the same as
that of the bodies which compose it. What remains for us to consider,
then, is whether any of the simple bodies can be infinite in
magnitude, or whether this is impossible. Let us try the primary body
first, and then go on to consider the others.
The body which moves in a circle must necessarily be finite in every
respect, for the following reasons. (1) If the body so moving is infinite,
the radii drawn from the centre will be infinite. But the space
between infinite radii is infinite: and by the space between the radii I
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mean the area outside which no magnitude which is in contact with
the two lines can be conceived as falling. This, I say, will be infinite:
first, because in the case of finite radii it is always finite; and
secondly, because in it one can always go on to a width greater than
any given width; thus the reasoning which forces us to believe in
infinite number, because there is no maximum, applies also to the
space between the radii. Now the infinite cannot be traversed, and if
the body is infinite the interval between the radii is necessarily
infinite: circular motion therefore is an impossibility. Yet our eyes tell
us that the heavens revolve in a circle, and by argument also we have
determined that there is something to which circular movement
belongs.
(2) Again, if from a finite time a finite time be subtracted, what
remains must be finite and have a beginning. And if the time of a
journey has a beginning, there must be a beginning also of the
movement, and consequently also of the distance traversed. This
applies universally. Take a line, ACE, infinite in one direction, E, and
another line, BB, infinite in both directions. Let ACE describe a circle,
revolving upon C as centre. In its movement it will cut BB
continuously for a certain time. This will be a finite time, since the
total time is finite in which the heavens complete their circular orbit,
and consequently the time subtracted from it, during which the one
line in its motion cuts the other, is also finite. Therefore there will be
a point at which ACE began for the first time to cut BB. This, however,
is impossible. The infinite, then, cannot revolve in a circle; nor could
the world, if it were infinite.
(3) That the infinite cannot move may also be shown as follows. Let A
be a finite line moving past the finite line, B. Of necessity A will pass
clear of B and B of A at the same moment; for each overlaps the other
to precisely the same extent. Now if the two were both moving, and
moving in contrary directions, they would pass clear of one another
more rapidly; if one were still and the other moving past it, less
rapidly; provided that the speed of the latter were the same in both
cases. This, however, is clear: that it is impossible to traverse an
infinite line in a finite time. Infinite time, then, would be required.
(This we demonstrated above in the discussion of movement.) And it
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makes no difference whether a finite is passing by an infinite or an
infinite by a finite. For when A is passing B, then B overlaps A and it
makes no difference whether B is moved or unmoved, except that, if
both move, they pass clear of one another more quickly. It is,
however, quite possible that a moving line should in certain cases
pass one which is stationary quicker than it passes one moving in an
opposite direction. One has only to imagine the movement to be slow
where both move and much faster where one is stationary. To
suppose one line stationary, then, makes no difficulty for our
argument, since it is quite possible for A to pass B at a slower rate
when both are moving than when only one is. If, therefore, the time
which the finite moving line takes to pass the other is infinite, then
necessarily the time occupied by the motion of the infinite past the
finite is also infinite. For the infinite to move at all is thus absolutely
impossible; since the very smallest movement conceivable must take
an infinity of time. Moreover the heavens certainly revolve, and they
complete their circular orbit in a finite time; so that they pass round
the whole extent of any line within their orbit, such as the finite line
AB. The revolving body, therefore, cannot be infinite.
(4) Again, as a line which has a limit cannot be infinite, or, if it is
infinite, is so only in length, so a surface cannot be infinite in that
respect in which it has a limit; or, indeed, if it is completely
determinate, in any respect whatever. Whether it be a square or a
circle or a sphere, it cannot be infinite, any more than a foot-rule can.
There is then no such thing as an infinite sphere or square or circle,
and where there is no circle there can be no circular movement, and
similarly where there is no infinite at all there can be no infinite
movement; and from this it follows that, an infinite circle being itself
an impossibility, there can be no circular motion of an infinite body.
(5) Again, take a centre C, an infinite line, AB, another infinite line at
right angles to it, E, and a moving radius, CD. CD will never cease
contact with E, but the position will always be something like CE, CD
cutting E at F. The infinite line, therefore, refuses to complete the
circle.
862
(6) Again, if the heaven is infinite and moves in a circle, we shall have
to admit that in a finite time it has traversed the infinite. For suppose
the fixed heaven infinite, and that which moves within it equal to it.
It results that when the infinite body has completed its revolution, it
has traversed an infinite equal to itself in a finite time. But that we
know to be impossible.
(7) It can also be shown, conversely, that if the time of revolution is
finite, the area traversed must also be finite; but the area traversed
was equal to itself; therefore, it is itself finite.
We have now shown that the body which moves in a circle is not
endless or infinite, but has its limit.
Further, neither that which moves towards nor that which moves
away from the centre can be infinite. For the upward and downward
motions are contraries and are therefore motions towards contrary
places. But if one of a pair of contraries is determinate, the other
must be determinate also. Now the centre is determined; for, from
whatever point the body which sinks to the bottom starts its
downward motion, it cannot go farther than the centre. The centre,
therefore, being determinate, the upper place must also be
determinate. But if these two places are determined and finite, the
corresponding bodies must also be finite. Further, if up and down are
determinate, the intermediate place is also necessarily determinate.
For, if it is indeterminate, the movement within it will be infinite; and
that we have already shown to be an impossibility. The middle region
then is determinate, and consequently any body which either is in it,
or might be in it, is determinate. But the bodies which move up and
down may be in it, since the one moves naturally away from the
centre and the other towards it.
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From this alone it is clear that an infinite body is an impossibility; but
there is a further point. If there is no such thing as infinite weight,
then it follows that none of these bodies can be infinite. For the
supposed infinite body would have to be infinite in weight. (The same
argument applies to lightness: for as the one supposition involves
infinite weight, so the infinity of the body which rises to the surface
involves infinite lightness.) This is proved as follows. Assume the
weight to be finite, and take an infinite body, AB, of the weight C.
Subtract from the infinite body a finite mass, BD, the weight of which
shall be E. E then is less than C, since it is the weight of a lesser mass.
Suppose then that the smaller goes into the greater a certain number
of times, and take BF bearing the same proportion to BD which the
greater weight bears to the smaller. For you may subtract as much as
you please from an infinite. If now the masses are proportionate to
the weights, and the lesser weight is that of the lesser mass, the
greater must be that of the greater. The weights, therefore, of the
finite and of the infinite body are equal. Again, if the weight of a
greater body is greater than that of a less, the weight of GB will be
greater than that of FB; and thus the weight of the finite body is
greater than that of the infinite. And, further, the weight of unequal
masses will be the same, since the infinite and the finite cannot be
equal. It does not matter whether the weights are commensurable or
not. If (a) they are incommensurable the same reasoning holds. For
instance, suppose E multiplied by three is rather more than C: the
weight of three masses of the full size of BD will be greater than C.
We thus arrive at the same impossibility as before. Again (b) we may
assume weights which are commensurate; for it makes no difference
whether we begin with the weight or with the mass. For example,
assume the weight E to be commensurate with C, and take from the
infinite mass a part BD of weight E. Then let a mass BF be taken
having the same proportion to BD which the two weights have to one
another. (For the mass being infinite you may subtract from it as
much as you please.) These assumed bodies will be commensurate in
mass and in weight alike. Nor again does it make any difference to
our demonstration whether the total mass has its weight equally or
unequally distributed. For it must always be Possible to take from the
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infinite mass a body of equal weight to BD by diminishing or
increasing the size of the section to the necessary extent.
From what we have said, then, it is clear that the weight of the
infinite body cannot be finite. It must then be infinite. We have
therefore only to show this to be impossible in order to prove an
infinite body impossible. But the impossibility of infinite weight can
be shown in the following way. A given weight moves a given
distance in a given time; a weight which is as great and more moves
the same distance in a less time, the times being in inverse
proportion to the weights. For instance, if one weight is twice
another, it will take half as long over a given movement. Further, a
finite weight traverses any finite distance in a finite time. It
necessarily follows from this that infinite weight, if there is such a
thing, being, on the one hand, as great and more than as great as the
finite, will move accordingly, but being, on the other hand, compelled
to move in a time inversely proportionate to its greatness, cannot
move at all. The time should be less in proportion as the weight is
greater. But there is no proportion between the infinite and the finite:
proportion can only hold between a less and a greater finite time.
And though you may say that the time of the movement can be
continually diminished, yet there is no minimum. Nor, if there were,
would it help us. For some finite body could have been found greater
than the given finite in the same proportion which is supposed to
hold between the infinite and the given finite; so that an infinite and
a finite weight must have traversed an equal distance in equal time.
But that is impossible. Again, whatever the time, so long as it is finite,
in which the infinite performs the motion, a finite weight must
necessarily move a certain finite distance in that same time. Infinite
weight is therefore impossible, and the same reasoning applies also
to infinite lightness. Bodies then of infinite weight and of infinite
lightness are equally impossible.
That there is no infinite body may be shown, as we have shown it, by
a detailed consideration of the various cases. But it may also be
shown universally, not only by such reasoning as we advanced in our
discussion of principles (though in that passage we have already
determined universally the sense in which the existence of an
865
infinite is to be asserted or denied), but also suitably to our present
purpose in the following way. That will lead us to a further question.
Even if the total mass is not infinite, it may yet be great enough to
admit a plurality of universes. The question might possibly be raised
whether there is any obstacle to our believing that there are other
universes composed on the pattern of our own, more than one,
though stopping short of infinity. First, however, let us treat of the
infinite universally.
Every body must necessarily be either finite or infinite, and if infinite,
either of similar or of dissimilar parts. If its parts are dissimilar, they
must represent either a finite or an infinite number of kinds. That the
kinds cannot be infinite is evident, if our original presuppositions
remain unchallenged. For the primary movements being finite in
number, the kinds of simple body are necessarily also finite, since the
movement of a simple body is simple, and the simple movements are
finite, and every natural body must always have its proper motion.
Now if the infinite body is to be composed of a finite number of
kinds, then each of its parts must necessarily be infinite in quantity,
that is to say, the water, fire, &c, which compose it. But this is
impossible, because, as we have already shown, infinite weight and
lightness do not exist. Moreover it would be necessary also that their
places should be infinite in extent, so that the movements too of all
these bodies would be infinite. But this is not possible, if we are to
hold to the truth of our original presuppositions and to the view that
neither that which moves downward, nor, by the same reasoning,
that which moves upward, can prolong its movement to infinity. For
it is true in regard to quality, quantity, and place alike that any
process of change is impossible which can have no end. I mean that
if it is impossible for a thing to have come to be white, or a cubit long,
or in Egypt, it is also impossible for it to be in process of coming to be
any of these. It is thus impossible for a thing to be moving to a place
at which in its motion it can never by any possibility arrive. Again,
866
suppose the body to exist in dispersion, it may be maintained none
the less that the total of all these scattered particles, say, of fire, is
infinite. But body we saw to be that which has extension every way.
How can there be several dissimilar elements, each infinite? Each
would have to be infinitely extended every way.
It is no more conceivable, again, that the infinite should exist as a
whole of similar parts. For, in the first place, there is no other
(straight) movement beyond those mentioned: we must therefore
give it one of them. And if so, we shall have to admit either infinite
weight or infinite lightness. Nor, secondly, could the body whose
movement is circular be infinite, since it is impossible for the infinite
to move in a circle. This, indeed, would be as good as saying that the
heavens are infinite, which we have shown to be impossible.
Moreover, in general, it is impossible that the infinite should move at
all. If it did, it would move either naturally or by constraint: and if by
constraint, it possesses also a natural motion, that is to say, there is
another place, infinite like itself, to which it will move. But that is
impossible.
That in general it is impossible for the infinite to be acted upon by
the finite or to act upon it may be shown as follows.
(1. The infinite cannot be acted upon by the finite.) Let A be an
infinite, B a finite, C the time of a given movement produced by one
in the other. Suppose, then, that A was heated, or impelled, or
modified in any way, or caused to undergo any sort of movement
whatever, by in the time C. Let D be less than B; and, assuming that a
lesser agent moves a lesser patient in an equal time, call the quantity
thus modified by D, E. Then, as D is to B, so is E to some finite
quantum. We assume that the alteration of equal by equal takes
equal time, and the alteration of less by less or of greater by greater
takes the same time, if the quantity of the patient is such as to keep
the proportion which obtains between the agents, greater and less. If
so, no movement can be caused in the infinite by any finite agent in
any time whatever. For a less agent will produce that movement in a
less patient in an equal time, and the proportionate equivalent of
867
that patient will be a finite quantity, since no proportion holds
between finite and infinite.
(2. The infinite cannot act upon the finite.) Nor, again, can the infinite
produce a movement in the finite in any time whatever. Let A be an
infinite, B a finite, C the time of action. In the time C, D will produce
that motion in a patient less than B, say F. Then take E, bearing the
same proportion to D as the whole BF bears to F. E will produce the
motion in BF in the time C. Thus the finite and infinite effect the
same alteration in equal times. But this is impossible; for the
assumption is that the greater effects it in a shorter time. It will be
the same with any time that can be taken, so that there will no time
in which the infinite can effect this movement. And, as to infinite
time, in that nothing can move another or be moved by it. For such
time has no limit, while the action and reaction have.
(3. There is no interaction between infinites.) Nor can infinite be
acted upon in any way by infinite. Let A and B be infinites, CD being
the time of the action A of upon B. Now the whole B was modified in
a certain time, and the part of this infinite, E, cannot be so modified
in the same time, since we assume that a less quantity makes the
movement in a less time. Let E then, when acted upon by A, complete
the movement in the time D. Then, as D is to CD, so is E to some finite
part of B. This part will necessarily be moved by A in the time CD. For
we suppose that the same agent produces a given effect on a greater
and a smaller mass in longer and shorter times, the times and
masses varying proportionately. There is thus no finite time in which
infinites can move one another. Is their time then infinite? No, for
infinite time has no end, but the movement communicated has.
If therefore every perceptible body possesses the power of acting or of
being acted upon, or both of these, it is impossible that an infinite
body should be perceptible. All bodies, however, that occupy place are
perceptible. There is therefore no infinite body beyond the heaven.
Nor again is there anything of limited extent beyond it. And so
beyond the heaven there is no body at all. For if you suppose it an
object of intelligence, it will be in a place - since place is what
868
'within' and 'beyond' denote - and therefore an object of perception.
But nothing that is not in a place is perceptible.
The question may also be examined in the light of more general
considerations as follows. The infinite, considered as a whole of
similar parts, cannot, on the one hand, move in a circle. For there is
no centre of the infinite, and that which moves in a circle moves
about the centre. Nor again can the infinite move in a straight line.
For there would have to be another place infinite like itself to be the
goal of its natural movement and another, equally great, for the goal
of its unnatural movement. Moreover, whether its rectilinear
movement is natural or constrained, in either case the force which
causes its motion will have to be infinite. For infinite force is force of
an infinite body, and of an infinite body the force is infinite. So the
motive body also will be infinite. (The proof of this is given in our
discussion of movement, where it is shown that no finite thing
possesses infinite power, and no infinite thing finite power.) If then
that which moves naturally can also move unnaturally, there will be
two infinites, one which causes, and another which exhibits the
latter motion. Again, what is it that moves the infinite? If it moves
itself, it must be animate. But how can it possibly be conceived as an
infinite animal? And if there is something else that moves it, there
will be two infinites, that which moves and that which is moved,
differing in their form and power.
If the whole is not continuous, but exists, as Democritus and
Leucippus think, in the form of parts separated by void, there must
necessarily be one movement of all the multitude. They are
distinguished, we are told, from one another by their figures; but
their nature is one, like many pieces of gold separated from one
another. But each piece must, as we assert, have the same motion.
For a single clod moves to the same place as the whole mass of earth,
and a spark to the same place as the whole mass of fire. So that if it
be weight that all possess, no body is, strictly speaking, light: and if
lightness be universal, none is heavy. Moreover, whatever possesses
weight or lightness will have its place either at one of the extremes
or in the middle region. But this is impossible while the world is
conceived as infinite. And, generally, that which has no centre or
869
extreme limit, no up or down, gives the bodies no place for their
motion; and without that movement is impossible. A thing must
move either naturally or unnaturally, and the two movements are
determined by the proper and alien places. Again, a place in which a
thing rests or to which it moves unnaturally, must be the natural
place for some other body, as experience shows. Necessarily,
therefore, not everything possesses weight or lightness, but some
things do and some do not. From these arguments then it is clear
that the body of the universe is not infinite.
8
We must now proceed to explain why there cannot be more than one
heaven - the further question mentioned above. For it may be
thought that we have not proved universal of bodies that none
whatever can exist outside our universe, and that our argument
applied only to those of indeterminate extent.
Now all things rest and move naturally and by constraint. A thing
moves naturally to a place in which it rests without constraint, and
rests naturally in a place to which it moves without constraint. On
the other hand, a thing moves by constraint to a place in which it
rests by constraint, and rests by constraint in a place to which it
moves by constraint. Further, if a given movement is due to
constraint, its contrary is natural. If, then, it is by constraint that
earth moves from a certain place to the centre here, its movement
from here to there will be natural, and if earth from there rests here
without constraint, its movement hither will be natural. And the
natural movement in each case is one. Further, these worlds, being
similar in nature to ours, must all be composed of the same bodies as
it. Moreover each of the bodies, fire, I mean, and earth and their
intermediates, must have the same power as in our world. For if
these names are used equivocally, if the identity of name does not
rest upon an identity of form in these elements and ours, then the
whole to which they belong can only be called a world by
870
equivocation. Clearly, then, one of the bodies will move naturally
away from the centre and another towards the centre, since fire must
be identical with fire, earth with earth, and so on, as the fragments of
each are identical in this world. That this must be the case is evident
from the principles laid down in our discussion of the movements,
for these are limited in number, and the distinction of the elements
depends upon the distinction of the movements. Therefore, since the
movements are the same, the elements must also be the same
everywhere. The particles of earth, then, in another world move
naturally also to our centre and its fire to our circumference. This,
however, is impossible, since, if it were true, earth must, in its own
world, move upwards, and fire to the centre; in the same way the
earth of our world must move naturally away from the centre when it
moves towards the centre of another universe. This follows from the
supposed juxtaposition of the worlds. For either we must refuse to
admit the identical nature of the simple bodies in the various
universes, or, admitting this, we must make the centre and the
extremity one as suggested. This being so, it follows that there cannot
be more worlds than one.
To postulate a difference of nature in the simple bodies according as
they are more or less distant from their proper places is
unreasonable. For what difference can it make whether we say that a
thing is this distance away or that? One would have to suppose a
difference proportionate to the distance and increasing with it, but
the form is in fact the same. Moreover, the bodies must have some
movement, since the fact that they move is quite evident. Are we to
say then that all their movements, even those which are mutually
contrary, are due to constraint? No, for a body which has no natural
movement at all cannot be moved by constraint. If then the bodies
have a natural movement, the movement of the particular instances
of each form must necessarily have for goal a place numerically one,
i.e. a particular centre or a particular extremity. If it be suggested that
the goal in each case is one in form but numerically more than one,
on the analogy of particulars which are many though each
undifferentiated in form, we reply that the variety of goal cannot be
limited to this portion or that but must extend to all alike. For all are
equally undifferentiated in form, but any one is different numerically
871
from any other. What I mean is this: if the portions in this world
behave similarly both to one another and to those in another world,
then the portion which is taken hence will not behave differently
either from the portions in another world or from those in the same
world, but similarly to them, since in form no portion differs from
another. The result is that we must either abandon our present
assumption or assert that the centre and the extremity are each
numerically one. But this being so, the heaven, by the same evidence
and the same necessary inferences, must be one only and no more.
A consideration of the other kinds of movement also makes it plain
that there is some point to which earth and fire move naturally. For
in general that which is moved changes from something into
something, the starting-point and the goal being different in form,
and always it is a finite change. For instance, to recover health is to
change from disease to health, to increase is to change from
smallness to greatness. Locomotion must be similar: for it also has its
goal and starting-point - and therefore the starting-point and the
goal of the natural movement must differ in form - just as the
movement of coming to health does not take any direction which
chance or the wishes of the mover may select. Thus, too, fire and
earth move not to infinity but to opposite points; and since the
opposition in place is between above and below, these will be the
limits of their movement. (Even in circular movement there is a sort
of opposition between the ends of the diameter, though the
movement as a whole has no contrary: so that here too the
movement has in a sense an opposed and finite goal.) There must
therefore be some end to locomotion: it cannot continue to infinity.
This conclusion that local movement is not continued to infinity is
corroborated by the fact that earth moves more quickly the nearer it
is to the centre, and fire the nearer it is to the upper place. But if
movement were infinite speed would be infinite also; and if speed
then weight and lightness. For as superior speed in downward
movement implies superior weight, so infinite increase of weight
necessitates infinite increase of speed.
872
Further, it is not the action of another body that makes one of these
bodies move up and the other down; nor is it constraint, like the
'extrusion' of some writers. For in that case the larger the mass of fire
or earth the slower would be the upward or downward movement;
but the fact is the reverse: the greater the mass of fire or earth the
quicker always is its movement towards its own place. Again, the
speed of the movement would not increase towards the end if it were
due to constraint or extrusion; for a constrained movement always
diminishes in speed as the source of constraint becomes more
distant, and a body moves without constraint to the place whence it
was moved by constraint.
A consideration of these points, then, gives adequate assurance of
the truth of our contentions. The same could also be shown with the
aid of the discussions which fall under First Philosophy, as well as
from the nature of the circular movement, which must be eternal
both here and in the other worlds. It is plain, too, from the following
considerations that the universe must be one.
The bodily elements are three, and therefore the places of the
elements will be three also; the place, first, of the body which sinks to
the bottom, namely the region about the centre; the place, secondly,
of the revolving body, namely the outermost place, and thirdly, the
intermediate place, belonging to the intermediate body. Here in this
third place will be the body which rises to the surface; since, if not
here, it will be elsewhere, and it cannot be elsewhere: for we have
two bodies, one weightless, one endowed with weight, and below is
place of the body endowed with weight, since the region about the
centre has been given to the heavy body. And its position cannot be
unnatural to it, for it would have to be natural to something else, and
there is nothing else. It must then occupy the intermediate place.
What distinctions there are within the intermediate itself we will
explain later on.
We have now said enough to make plain the character and number of
the bodily elements, the place of each, and further, in general, how
many in number the various places are.
873
We must show not only that the heaven is one, but also that more
than one heaven is and, further, that, as exempt from decay and
generation, the heaven is eternal. We may begin by raising a
difficulty. From one point of view it might seem impossible that the
heaven should be one and unique, since in all formations and
products whether of nature or of art we can distinguish the shape in
itself and the shape in combination with matter. For instance the
form of the sphere is one thing and the gold or bronze sphere
another; the shape of the circle again is one thing, the bronze or
wooden circle another. For when we state the essential nature of the
sphere or circle we do not include in the formula gold or bronze,
because they do not belong to the essence, but if we are speaking of
the copper or gold sphere we do include them. We still make the
distinction even if we cannot conceive or apprehend any other
example beside the particular thing. This may, of course, sometimes
be the case: it might be, for instance, that only one circle could be
found; yet none the less the difference will remain between the being
of circle and of this particular circle, the one being form, the other
form in matter, i.e. a particular thing. Now since the universe is
perceptible it must be regarded as a particular; for everything that is
perceptible subsists, as we know, in matter. But if it is a particular,
there will be a distinction between the being of 'this universe' and of
'universe' unqualified. There is a difference, then, between 'this
universe' and simple 'universe'; the second is form and shape, the
first form in combination with matter; and any shape or form has, or
may have, more than one particular instance.
On the supposition of Forms such as some assert, this must be the
case, and equally on the view that no such entity has a separate
existence. For in every case in which the essence is in matter it is a
fact of observation that the particulars of like form are several or
infinite in number. Hence there either are, or may be, more heavens
than one. On these grounds, then, it might be inferred either that
there are or that there might be several heavens. We must, however,
874
return and ask how much of this argument is correct and how much
not.
Now it is quite right to say that the formula of the shape apart from
the matter must be different from that of the shape in the matter,
and we may allow this to be true. We are not, however, therefore
compelled to assert a plurality of worlds. Such a plurality is in fact
impossible if this world contains the entirety of matter, as in fact it
does. But perhaps our contention can be made clearer in this way.
Suppose 'aquilinity' to be curvature in the nose or flesh, and flesh to
be the matter of aquilinity. Suppose further, that all flesh came
together into a single whole of flesh endowed with this aquiline
quality. Then neither would there be, nor could there arise, any other
thing that was aquiline. Similarly, suppose flesh and bones to be the
matter of man, and suppose a man to be created of all flesh and all
bones in indissoluble union. The possibility of another man would be
removed. Whatever case you took it would be the same. The general
rule is this: a thing whose essence resides in a substratum of matter
can never come into being in the absence of all matter. Now the
universe is certainly a particular and a material thing: if however, it is
composed not of a part but of the whole of matter, then though the
being of 'universe' and of 'this universe' are still distinct, yet there is
no other universe, and no possibility of others being made, because
all the matter is already included in this. It remains, then, only to
prove that it is composed of all natural perceptible body.
First, however, we must explain what we mean by 'heaven' and in
how many senses we use the word, in order to make clearer the
object of our inquiry, (a) In one sense, then, we call 'heaven' the
substance of the extreme circumference of the whole, or that natural
body whose place is at the extreme circumference. We recognize
habitually a special right to the name 'heaven' in the extremity or
upper region, which we take to be the seat of all that is divine, (b) In
another sense, we use this name for the body continuous with the
extreme circumference which contains the moon, the sun, and some
of the stars; these we say are 'in the heaven', (c) In yet another sense
we give the name to all body included within extreme circumference,
875
since we habitually call the whole or totality 'the heaven'. The word,
then, is used in three senses.
Now the whole included within the extreme circumference must be
composed of all physical and sensible body, because there neither is,
nor can come into being, any body outside the heaven. For if there is
a natural body outside the extreme circumference it must be either a
simple or a composite body, and its position must be either natural or
unnatural. But it cannot be any of the simple bodies. For, first, it has
been shown that that which moves in a circle cannot change its
place. And, secondly, it cannot be that which moves from the centre
or that which lies lowest. Naturally they could not be there, since
their proper places are elsewhere; and if these are there unnaturally,
the exterior place will be natural to some other body, since a place
which is unnatural to one body must be natural to another: but we
saw that there is no other body besides these. Then it is not possible
that any simple body should be outside the heaven. But, if no simple
body, neither can any mixed body be there: for the presence of the
simple body is involved in the presence of the mixture. Further
neither can any body come into that place: for it will do so either
naturally or unnaturally, and will be either simple or composite; so
that the same argument will apply, since it makes no difference
whether the question is 'does A exist?' or 'could A come to exist?'
From our arguments then it is evident not only that there is not, but
also that there could never come to be, any bodily mass whatever
outside the circumference. The world as a whole, therefore, includes
all its appropriate matter, which is, as we saw, natural perceptible
body. So that neither are there now, nor have there ever been, nor can
there ever be formed more heavens than one, but this heaven of ours
is one and unique and complete.
It is therefore evident that there is also no place or void or time
outside the heaven. For in every place body can be present; and void
is said to be that in which the presence of body, though not actual, is
possible; and time is the number of movement. But in the absence of
natural body there is no movement, and outside the heaven, as we
have shown, body neither exists nor can come to exist. It is clear then
that there is neither place, nor void, nor time, outside the heaven.
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Hence whatever is there, is of such a nature as not to occupy any
place, nor does time age it; nor is there any change in any of the
things which lie beyond the outermost motion; they continue
through their entire duration unalterable and unmodified, living the
best and most selfsufficient of lives. As a matter of fact, this word
'duration' possessed a divine significance for the ancients, for the
fulfilment which includes the period of life of any creature, outside of
which no natural development can fall, has been called its duration.
On the same principle the fulfilment of the whole heaven, the
fulfilment which includes all time and infinity, is 'duration' - a name
based upon the fact that it is always - duration immortal and divine.
From it derive the being and life which other things, some more or
less articulately but others feebly, enjoy. So, too, in its discussions
concerning the divine, popular philosophy often propounds the view
that whatever is divine, whatever is primary and supreme, is
necessarily unchangeable. This fact confirms what we have said. For
there is nothing else stronger than it to move it - since that would
mean more divine - and it has no defect and lacks none of its proper
excellences. Its unceasing movement, then, is also reasonable, since
everything ceases to move when it comes to its proper place, but the
body whose path is the circle has one and the same place for
starting-point and goal.
10
Having established these distinctions, we may now proceed to the
question whether the heaven is ungenerated or generated,
indestructible or destructible. Let us start with a review of the
theories of other thinkers; for the proofs of a theory are difficulties
for the contrary theory. Besides, those who have first heard the pleas
of our adversaries will be more likely to credit the assertions which
we are going to make. We shall be less open to the charge of
procuring judgement by default. To give a satisfactory decision as to
the truth it is necessary to be rather an arbitrator than a party to the
dispute.
877
That the world was generated all are agreed, but, generation over,
some say that it is eternal, others say that it is destructible like any
other natural formation. Others again, with Empedliocles of Acragas
and Heraclitus of Ephesus, believe that there is alternation in the
destructive process, which takes now this direction, now that, and
continues without end.
Now to assert that it was generated and yet is eternal is to assert the
impossible; for we cannot reasonably attribute to anything any
characteristics but those which observation detects in many or all
instances. But in this case the facts point the other way: generated
things are seen always to be destroyed. Further, a thing whose
present state had no beginning and which could not have been other
than it was at any previous moment throughout its entire duration,
cannot possibly be changed. For there will have to be some cause of
change, and if this had been present earlier it would have made
possible another condition of that to which any other condition was
impossible. Suppose that the world was formed out of elements
which were formerly otherwise conditioned than as they are now.
Then (1) if their condition was always so and could not have been
otherwise, the world could never have come into being. And (2) if the
world did come into being, then, clearly, their condition must have
been capable of change and not eternal: after combination therefore
they will be dispersed, just as in the past after dispersion they came
into combination, and this process either has been, or could have
been, indefinitely repeated. But if this is so, the world cannot be
indestructible, and it does not matter whether the change of
condition has actually occurred or remains a possibility.
Some of those who hold that the world, though indestructible, was
yet generated, try to support their case by a parallel which is illusory
They say that in their statements about its generation they are doing
what geometricians do when they construct their figures, not
implying that the universe really had a beginning, but for didactic
reasons facilitating understanding by exhibiting the object, like the
figure, as in course of formation. The two cases, as we said, are not
parallel; for, in the construction of the figure, when the various steps
are completed the required figure forthwith results; but in these
878
other demonstrations what results is not that which was required.
Indeed it cannot be so; for antecedent and consequent, as assumed,
are in contradiction. The ordered, it is said, arose out of the
unordered; and the same thing cannot be at the same time both
ordered and unordered; there must be a process and a lapse of time
separating the two states. In the figure, on the other hand, there is no
temporal separation. It is clear then that the universe cannot be at
once eternal and generated.
To say that the universe alternately combines and dissolves is no
more paradoxical than to make it eternal but varying in shape. It is as
if one were to think that there was now destruction and now
existence when from a child a man is generated, and from a man a
child. For it is clear that when the elements come together the result
is not a chance system and combination, but the very same as before
- especially on the view of those who hold this theory, since they say
that the contrary is the cause of each state. So that if the totality of
body, which is a continuum, is now in this order or disposition and
now in that, and if the combination of the whole is a world or
heaven, then it will not be the world that comes into being and is
destroyed, but only its dispositions.
If the world is believed to be one, it is impossible to suppose that it
should be, as a whole, first generated and then destroyed, never to
reappear; since before it came into being there was always present
the combination prior to it, and that, we hold, could never change if it
was never generated. If, on the other hand, the worlds are infinite in
number the view is more plausible. But whether this is, or is not,
impossible will be clear from what follows. For there are some who
think it possible both for the ungenerated to be destroyed and for the
generated to persist undestroyed. (This is held in the Timaeus, where
Plato says that the heaven, though it was generated, will none the
less exist to eternity.) So far as the heaven is concerned we have
answered this view with arguments appropriate to the nature of the
heaven: on the general question we shall attain clearness when we
examine the matter universally.
879
11
We must first distinguish the senses in which we use the words
'ungenerated' and 'generated', 'destructible' and 'indestructible'.
These have many meanings, and though it may make no difference
to the argument, yet some confusion of mind must result from
treating as uniform in its use a word which has several distinct
applications. The character which is the ground of the predication
will always remain obscure.
The word 'ungenerated' then is used (a) in one sense whenever
something now is which formerly was not, no process of becoming or
change being involved. Such is the case, according to some, with
contact and motion, since there is no process of coming to be in
contact or in motion, (b) It is used in another sense, when something
which is capable of coming to be, with or without process, does not
exist; such a thing is ungenerated in the sense that its generation is
not a fact but a possibility, (c) It is also applied where there is general
impossibility of any generation such that the thing now is which
then was not. And 'impossibility' has two uses: first, where it is
untrue to say that the thing can ever come into being, and secondly,
where it cannot do so easily, quickly, or well. In the same way the
word 'generated' is used, (a) first, where what formerly was not
afterwards is, whether a process of becoming was or was not
involved, so long as that which then was not, now is; (b) secondly, of
anything capable of existing, 'capable' being defined with reference
either to truth or to facility; (c) thirdly, of anything to which the
passage from not being to being belongs, whether already actual, if
its existence is due to a past process of becoming, or not yet actual
but only possible. The uses of the words 'destructible' and
'indestructible' are similar. 'Destructible' is applied (a) to that which
formerly was and afterwards either is not or might not be, whether a
period of being destroyed and changed intervenes or not; and (b)
sometimes we apply the word to that which a process of destruction
may cause not to be; and also (c) in a third sense, to that which is
easily destructible, to the 'easily destroyed', so to speak. Of the
880
indestructible the same account holds good. It is either (a) that which
now is and now is not, without any process of destruction, like
contact, which without being destroyed afterwards is not, though
formerly it was; or (b) that which is but might not be, or which will at
some time not be, though it now is. For you exist now and so does the
contact; yet both are destructible, because a time will come when it
will not be true of you that you exist, nor of these things that they are
in contact. Thirdly (c) in its most proper use, it is that which is, but is
incapable of any destruction such that the thing which now is later
ceases to be or might cease to be; or again, that which has not yet
been destroyed, but in the future may cease to be. For indestructible
is also used of that which is destroyed with difficulty.
This being so, we must ask what we mean by 'possible' and
'impossible'. For in its most proper use the predicate 'indestructible'
is given because it is impossible that the thing should be destroyed,
i.e. exist at one time and not at another. And 'ungenerated' also
involves impossibility when used for that which cannot be generated,
in such fashion that, while formerly it was not, later it is. An instance
is a commensurable diagonal. Now when we speak of a power to
move or to lift weights, we refer always to the maximum. We speak,
for instance, of a power to lift a hundred talents or walk a hundred
stades - though a power to effect the maximum is also a power to
effect any part of the maximum - since we feel obliged in defining
the power to give the limit or maximum. A thing, then, which is
within it. If, for example, a man can lift a hundred talents, he can also
lift two, and if he can walk a hundred stades, he can also walk two.
But the power is of the maximum, and a thing said, with reference to
its maximum, to be incapable of so much is also incapable of any
greater amount. It is, for instance, clear that a person who cannot
walk a thousand stades will also be unable to walk a thousand and
one. This point need not trouble us, for we may take it as settled that
what is, in the strict sense, possible is determined by a limiting
maximum. Now perhaps the objection might be raised that there is
no necessity in this, since he who sees a stade need not see the
smaller measures contained in it, while, on the contrary, he who can
see a dot or hear a small sound will perceive what is greater. This,
however, does not touch our argument. The maximum may be
881
determined either in the power or in its object. The application of this
is plain. Superior sight is sight of the smaller body, but superior speed
is that of the greater body.
12
Having established these distinctions we car now proceed to the
sequel. If there are thing! capable both of being and of not being,
there must be some definite maximum time of their being and not
being; a time, I mean, during which continued existence is possible to
them and a time during which continued nonexistence is possible.
And this is true in every category, whether the thing is, for example,
'man', or 'white', or 'three cubits long', or whatever it may be. For if
the time is not definite in quantity, but longer than any that can be
suggested and shorter than none, then it will be possible for one and
the same thing to exist for infinite time and not to exist for another
infinity. This, however, is impossible.
Let us take our start from this point. The impossible and the false
have not the same significance. One use of 'impossible' and 'possible',
and 'false' and 'true', is hypothetical. It is impossible, for instance, on
a certain hypothesis that the triangle should have its angles equal to
two right angles, and on another the diagonal is commensurable. But
there are also things possible and impossible, false and true,
absolutely. Now it is one thing to be absolutely false, and another
thing to be absolutely impossible. To say that you are standing when
you are not standing is to assert a falsehood, but not an impossibility.
Similarly to say that a man who is playing the harp, but not singing,
is singing, is to say what is false but not impossible. To say, however,
that you are at once standing and sitting, or that the diagonal is
commensurable, is to say what is not only false but also impossible.
Thus it is not the same thing to make a false and to make an
impossible hypothesis, and from the impossible hypothesis
impossible results follow. A man has, it is true, the capacity at once of
sitting and of standing, because when he possesses the one he also
882
possesses the other; but it does not follow that he can at once sit and
stand, only that at another time he can do the other also. But if a
thing has for infinite time more than one capacity, another time is
impossible and the times must coincide. Thus if a thing which exists
for infinite time is destructible, it will have the capacity of not being.
Now if it exists for infinite time let this capacity be actualized; and it
will be in actuality at once existent and non-existent. Thus a false
conclusion would follow because a false assumption was made, but if
what was assumed had not been impossible its consequence would
not have been impossible.
Anything then which always exists is absolutely imperishable. It is
also ungenerated, since if it was generated it will have the power for
some time of not being. For as that which formerly was, but now is
not, or is capable at some future time of not being, is destructible, so
that which is capable of formerly not having been is generated. But in
the case of that which always is, there is no time for such a capacity
of not being, whether the supposed time is finite or infinite; for its
capacity of being must include the finite time since it covers infinite
time.
It is therefore impossible that one and the same thing should be
capable of always existing and of always not-existing. And 'not
always existing', the contradictory, is also excluded. Thus it is
impossible for a thing always to exist and yet to be destructible. Nor,
similarly, can it be generated. For of two attributes if B cannot be
present without A, the impossibility A of proves the impossibility of
B. What always is, then, since it is incapable of ever not being, cannot
possibly be generated. But since the contradictory of 'that which is
always capable of being' 'that which is not always capable of being';
while 'that which is always capable of not being' is the contrary,
whose contradictory in turn is 'that which is not always capable of
not being', it is necessary that the contradictories of both terms
should be predicable of one and the same thing, and thus that,
intermediate between what always is and what always is not, there
should be that to which being and not-being are both possible; for
the contradictory of each will at times be true of it unless it always
exists. Hence that which not always is not will sometimes be and
883
sometimes not be; and it is clear that this is true also of that which
cannot always be but sometimes is and therefore sometimes is not.
One thing, then, will have the power of being, and will thus be
intermediate between the other two.
Expresed universally our argument is as follows. Let there be two
attributes, A and B, not capable of being present in any one thing
together, while either A or C and either B or D are capable of being
present in everything. Then C and D must be predicated of everything
of which neither A nor B is predicated. Let E lie between A and B; for
that which is neither of two contraries is a mean between them. In E
both C and D must be present, for either A or C is present everywhere
and therefore in E. Since then A is impossible, C must be present, and
the same argument holds of D.
Neither that which always is, therefore, nor that which always is not
is either generated or destructible. And clearly whatever is generated
or destructible is not eternal. If it were, it would be at once capable of
always being and capable of not always being, but it has already been
shown that this is impossible. Surely then whatever is ungenerated
and in being must be eternal, and whatever is indestructible and in
being must equally be so. (I use the words 'ungenerated' and
'indestructible' in their proper sense, 'ungenerated' for that which
now is and could not at any previous time have been truly said not to
be; 'indestructible' for that which now is and cannot at any future
time be truly said not to be.) If, again, the two terms are coincident, if
the ungenerated is indestructible, and the indestructible
ungenearted, then each of them is coincident with 'eternal'; anything
ungenerated is eternal and anything indestructible is eternal. This is
clear too from the definition of the terms, Whatever is destructible
must be generated; for it is either ungenerated, or generated, but, if
ungenerated, it is by hypothesis indestructible. Whatever, further, is
generated must be destructible. For it is either destructible or
indestructible, but, if indestructible, it is by hypothesis ungenerated.
If, however, 'indestructible' and 'ungenerated' are not coincident,
there is no necessity that either the ungenerated or the
indestructible should be eternal. But they must be coincident, for the
884
following reasons. The terms 'generated' and 'destructible' are
coincident; this is obvious from our former remarks, since between
what always is and what always is not there is an intermediate
which is neither, and that intermediate is the generated and
destructible. For whatever is either of these is capable both of being
and of not being for a definite time: in either case, I mean, there is a
certain period of time during which the thing is and another during
which it is not. Anything therefore which is generated or destructible
must be intermediate. Now let A be that which always is and B that
which always is not, C the generated, and D the destructible. Then C
must be intermediate between A and B. For in their case there is no
time in the direction of either limit, in which either A is not or B is.
But for the generated there must be such a time either actually or
potentially, though not for A and B in either way. C then will be, and
also not be, for a limited length of time, and this is true also of D, the
destructible. Therefore each is both generated and destructible.
Therefore 'generated' and 'destructible' are coincident. Now let E
stand for the ungenerated, F for the generated, G for the
indestructible, and H for the destructible. As for F and H, it has been
shown that they are coincident. But when terms stand to one another
as these do, F and H coincident, E and F never predicated of the same
thing but one or other of everything, and G and H likewise, then E and
G must needs be coincident. For suppose that E is not coincident with
G, then F will be, since either E or F is predictable of everything. But of
that of which F is predicated H will be predicable also. H will then be
coincident with G, but this we saw to be impossible. And the same
argument shows that G is coincident with E.
Now the relation of the ungenerated (E) to the generated (F) is the
same as that of the indestructible (G) to the destructible (H). To say
then that there is no reason why anything should not be generated
and yet indestructible or ungenerated and yet destroyed, to imagine
that in the one case generation and in the other case destruction
occurs once for all, is to destroy part of the data. For (1) everything is
capable of acting or being acted upon, of being or not being, either for
an infinite, or for a definitely limited space of time; and the infinite
time is only a possible alternative because it is after a fashion
defined, as a length of time which cannot be exceeded. But infinity in
885
one direction is neither infinite or finite. (2) Further, why, after always
existing, was the thing destroyed, why, after an infinity of not being,
was it generated, at one moment rather than another? If every
moment is alike and the moments are infinite in number, it is clear
that a generated or destructible thing existed for an infinite time. It
has therefore for an infinite time the capacity of not being (since the
capacity of being and the capacity of not being will be present
together), if destructible, in the time before destruction, if generated,
in the time after generation. If then we assume the two capacities to
be actualized, opposites will be present together. (3) Further, this
second capacity will be present like the first at every moment, so that
the thing will have for an infinite time the capacity both of being and
of not being; but this has been shown to be impossible. (4) Again, if
the capacity is present prior to the activity, it will be present for all
time, even while the thing was as yet ungenerated and non-existent,
throughout the infinite time in which it was capable of being
generated. At that time, then, when it was not, at that same time it
had the capacity of being, both of being then and of being thereafter,
and therefore for an infinity of time.
It is clear also on other grounds that it is impossible that the
destructible should not at some time be destroyed. For otherwise it
will always be at once destructible and in actuality indestructible, so
that it will be at the same time capable of always existing and of not
always existing. Thus the destructible is at some time actually
destroyed. The generable, similarly, has been generated, for it is
capable of having been generated and thus also of not always
existing.
We may also see in the following way how impossible it is either for a
thing which is generated to be thenceforward indestructible, or for a
thing which is ungenerated and has always hitherto existed to be
destroyed. Nothing that is by chance can be indestructible or
ungenerated, since the products of chance and fortune are opposed
to what is, or comes to be, always or usually, while anything which
exists for a time infinite either absolutely or in one direction, is in
existence either always or usually. That which is by chance, then, is
by nature such as to exist at one time and not at another. But in
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things of that character the contradictory states proceed from one
and the same capacity, the matter of the thing being the cause
equally of its existence and of its non-existence. Hence
contradictories would be present together in actuality.
Further, it cannot truly be said of a thing now that it exists last year,
nor could it be said last year that it exists now. It is therefore
impossible for what once did not exist later to be eternal. For in its
later state it will possess the capacity of not existing, only not of not
existing at a time when it exists - since then it exists in actuality -
but of not existing last year or in the past. Now suppose it to be in
actuality what it is capable of being. It will then be true to say now
that it does not exist last year. But this is impossible. No capacity
relates to being in the past, but always to being in the present or
future. It is the same with the notion of an eternity of existence
followed later by non-existence. In the later state the capacity will be
present for that which is not there in actuality. Actualize, then, the
capacity. It will be true to say now that this exists last year or in the
past generally.
Considerations also not general like these but proper to the subject
show it to be impossible that what was formerly eternal should later
be destroyed or that what formerly was not should later be eternal.
Whatever is destructible or generated is always alterable. Now
alteration is due to contraries, and the things which compose the
natural body are the very same that destroy it.
Book II
887
That the heaven as a whole neither came into being nor admits of
destruction, as some assert, but is one and eternal, with no end or
beginning of its total duration, containing and embracing in itself the
infinity of time, we may convince ourselves not only by the
arguments already set forth but also by a consideration of the views
of those who differ from us in providing for its generation. If our view
is a possible one, and the manner of generation which they assert is
impossible, this fact will have great weight in convincing us of the
immortality and eternity of the world. Hence it is well to persuade
oneself of the truth of the ancient and truly traditional theories, that
there is some immortal and divine thing which possesses movement,
but movement such as has no limit and is rather itself the limit of all
other movement. A limit is a thing which contains; and this motion,
being perfect, contains those imperfect motions which have a limit
and a goal, having itself no beginning or end, but unceasing through
the infinity of time, and of other movements, to some the cause of
their beginning, to others offering the goal. The ancients gave to the
Gods the heaven or upper place, as being alone immortal; and our
present argument testifies that it is indestructible and ungenerated.
Further, it is unaffected by any mortal discomfort, and, in addition,
effortless; for it needs no constraining necessity to keep it to its path,
and prevent it from moving with some other movement more natural
to itself. Such a constrained movement would necessarily involve
effort the more so, the more eternal it were - and would be
inconsistent with perfection. Hence we must not believe the old tale
which says that the world needs some Atlas to keep it safe - a tale
composed, it would seem, by men who, like later thinkers, conceived
of all the upper bodies as earthy and endowed with weight, and
therefore supported it in their fabulous way upon animate necessity.
We must no more believe that than follow Empedocles when he says
that the world, by being whirled round, received a movement quick
enough to overpower its own downward tendency, and thus has been
kept from destruction all this time. Nor, again, is it conceivable that it
should persist eternally by the necessitation of a soul. For a soul
could not live in such conditions painlessly or happily, since the
movement involves constraint, being imposed on the first body,
888
whose natural motion is different, and imposed continuously. It must
therefore be uneasy and devoid of all rational satisfaction; for it could
not even, like the soul of mortal animals, take recreation in the bodily
relaxation of sleep. An Ixion's lot must needs possess it, without end
or respite. If then, as we said, the view already stated of the first
motion is a possible one, it is not only more appropriate so to
conceive of its eternity, but also on this hypothesis alone are we able
to advance a theory consistent with popular divinations of the divine
nature. But of this enough for the present.
Since there are some who say that there is a right and a left in the
heaven, with those who are known as Pythagoreans - to whom
indeed the view really belongs - we must consider whether, if we are
to apply these principles to the body of the universe, we should
follow their statement of the matter or find a better way. At the start
we may say that, if right and left are applicable, there are prior
principles which must first be applied. These principles have been
analysed in the discussion of the movements of animals, for the
reason that they are proper to animal nature. For in some animals we
find all such distinctions of parts as this of right and left clearly
present, and in others some; but in plants we find only above and
below. Now if we are to apply to the heaven such a distinction of
parts, we must exect, as we have said, to find in it also the distinction
which in animals is found first of them all. The distinctions are three,
namely, above and below, front and its opposite, right and left - all
these three oppositions we expect to find in the perfect body - and
each may be called a principle. Above is the principle of length, right
of breadth, front of depth. Or again we may connect them with the
various movements, taking principle to mean that part, in a thing
capable of movement, from which movement first begins. Growth
starts from above, locomotion from the right, sensemovement from
in front (for front is simply the part to which the senses are directed).
Hence we must not look for above and below, right and left, front and
889
back, in every kind of body, but only in those which, being animate,
have a principle of movement within themselves. For in no inanimate
thing do we observe a part from which movement originates. Some
do not move at all, some move, but not indifferently in any direction;
fire, for example, only upward, and earth only to the centre. It is true
that we speak of above and below, right and left, in these bodies
relatively to ourselves. The reference may be to our own right hands,
as with the diviner, or to some similarity to our own members, such
as the parts of a statue possess; or we may take the contrary spatial
order, calling right that which is to our left, and left that which is to
our right. We observe, however, in the things themselves none of
these distinctions; indeed if they are turned round we proceed to
speak of the opposite parts as right and left, a boy land below, front
and back. Hence it is remarkable that the Pythagoreans should have
spoken of these two principles, right and left, only, to the exclusion of
the other four, which have as good a title as they. There is no less
difference between above and below or front and back in animals
generally than between right and left. The difference is sometimes
only one of function, sometimes also one of shape; and while the
distinction of above and below is characteristic of all animate things,
whether plants or animals, that of right and left is not found in
plants. Further, inasmuch as length is prior to breadth, if above is the
principle of length, right of breadth, and if the principle of that which
is prior is itself prior, then above will be prior to right, or let us say,
since 'prior' is ambiguous, prior in order of generation. If, in addition,
above is the region from which movement originates, right the region
in which it starts, front the region to which it is directed, then on this
ground too above has a certain original character as compared with
the other forms of position. On these two grounds, then, they may
fairly be criticized, first, for omitting the more fundamental
principles, and secondly, for thinking that the two they mentioned
were attributable equally to everything.
Since we have already determined that functions of this kind belong
to things which possess, a principle of movement, and that the
heaven is animate and possesses a principle of movement, clearly
the heaven must also exhibit above and below, right and left. We need
not be troubled by the question, arising from the spherical shape of
890
the world, how there can be a distinction of right and left within it, all
parts being alike and all for ever in motion. We must think of the
world as of something in which right differs from left in shape as
well as in other respects, which subsequently is included in a sphere.
The difference of function will persist, but will appear not to by
reason of the regularity of shape. In the same fashion must we
conceive of the beginning of its movement. For even if it never began
to move, yet it must possess a principle from which it would have
begun to move if it had begun, and from which it would begin again if
it came to a stand. Now by its length I mean the interval between its
poles, one pole being above and the other below; for two
hemispheres are specially distinguished from all others by the
immobility of the poles. Further, by 'transverse' in the universe we
commonly mean, not above and below, but a direction crossing the
line of the poles, which, by implication, is length: for transverse
motion is motion crossing motion up and down. Of the poles, that
which we see above us is the lower region, and that which we do not
see is the upper. For right in anything is, as we say, the region in
which locomotion originates, and the rotation of the heaven
originates in the region from which the stars rise. So this will be the
right, and the region where they set the left. If then they begin from
the right and move round to the right, the upper must be the unseen
pole. For if it is the pole we see, the movement will be leftward, which
we deny to be the fact. Clearly then the invisible pole is above. And
those who live in the other hemisphere are above and to the right,
while we are below and to the left. This is just the opposite of the
view of the Pythagoreans, who make us above and on the right side
and those in the other hemisphere below and on the left side; the
fact being the exact opposite. Relatively, however, to the secondary
revolution, I mean that of the planets, we are above and on the right
and they are below and on the left. For the principle of their
movement has the reverse position, since the movement itself is the
contrary of the other: hence it follows that we are at its beginning
and they at its end. Here we may end our discussion of the
distinctions of parts created by the three dimensions and of the
consequent differences of position.
891
Since circular motion is not the contrary of the reverse circular
motion, we must consider why there is more than one motion,
though we have to pursue our inquiries at a distance - a distance
created not so much by our spatial position as by the fact that our
senses enable us to perceive very few of the attributes of the
heavenly bodies. But let not that deter us. The reason must be sought
in the following facts. Everything which has a function exists for its
function. The activity of God is immortality, i.e. eternal life. Therefore
the movement of that which is divine must be eternal. But such is the
heaven, viz. a divine body, and for that reason to it is given the
circular body whose nature it is to move always in a circle. Why, then,
is not the whole body of the heaven of the same character as that
part? Because there must be something at rest at the centre of the
revolving body; and of that body no part can be at rest, either
elsewhere or at the centre. It could do so only if the body's natural
movement were towards the centre. But the circular movement is
natural, since otherwise it could not be eternal: for nothing unnatural
is eternal. The unnatural is subsequent to the natural, being a
derangement of the natural which occurs in the course of its
generation. Earth then has to exist; for it is earth which is at rest at
the centre. (At present we may take this for granted: it shall be
explained later.) But if earth must exist, so must fire. For, if one of a
pair of contraries naturally exists, the other, if it is really contrary,
exists also naturally. In some form it must be present, since the
matter of contraries is the same. Also, the positive is prior to its
privation (warm, for instance, to cold), and rest and heaviness stand
for the privation of lightness and movement. But further, if fire and
earth exist, the intermediate bodies must exist also: each element
stands in a contrary relation to every other. (This, again, we will here
take for granted and try later to explain.) these four elements
generation clearly is involved, since none of them can be eternal: for
contraries interact with one another and destroy one another.
Further, it is inconceivable that a movable body should be eternal, if
its movement cannot be regarded as naturally eternal: and these
892
bodies we know to possess movement. Thus we see that generation
is necessarily involved. But if so, there must be at least one other
circular motion: for a single movement of the whole heaven would
necessitate an identical relation of the elements of bodies to one
another. This matter also shall be cleared up in what follows: but for
the present so much is clear, that the reason why there is more than
one circular body is the necessity of generation, which follows on the
presence of fire, which, with that of the other bodies, follows on that
of earth; and earth is required because eternal movement in one
body necessitates eternal rest in another.
The shape of the heaven is of necessity spherical; for that is the
shape most appropriate to its substance and also by nature primary
First, let us consider generally which shape is primary among planes
and solids alike. Every plane figure must be either rectilinear or
curvilinear. Now the rectilinear is bounded by more than one line, the
curvilinear by one only. But since in any kind the one is naturally
prior to the many and the simple to the complex, the circle will be
the first of plane figures. Again, if by complete, as previously defined,
we mean a thing outside which no part of itself can be found, and if
addition is always possible to the straight line but never to the
circular, clearly the line which embraces the circle is complete. If
then the complete is prior to the incomplete, it follows on this ground
also that the circle is primary among figures. And the sphere holds
the same position among solids. For it alone is embraced by a single
surface, while rectilinear solids have several. The sphere is among
solids what the circle is among plane figures. Further, those who
divide bodies into planes and generate them out of planes seem to
bear witness to the truth of this. Alone among solids they leave the
sphere undivided, as not possessing more than one surface: for the
division into surfaces is not just dividing a whole by cutting it into its
893
parts, but division of another fashion into parts different in form. It is
clear, then, that the sphere is first of solid figures.
If, again, one orders figures according to their numbers, it is most
natural to arrange them in this way. The circle corresponds to the
number one, the triangle, being the sum of two right angles, to the
number two. But if one is assigned to the triangle, the circle will not
be a figure at all.
Now the first figure belongs to the first body, and the first body is that
at the farthest circumference. It follows that the body which revolves
with a circular movement must be spherical. The same then will be
true of the body continuous with it: for that which is continuous with
the spherical is spherical. The same again holds of the bodies
between these and the centre. Bodies which are bounded by the
spherical and in contact with it must be, as wholes, spherical; and
the bodies below the sphere of the planets are contiguous with the
sphere above them. The sphere then will be spherical throughout; for
every body within it is contiguous and continuous with spheres.
Again, since the whole revolves, palpably and by assumption, in a
circle, and since it has been shown that outside the farthest
circumference there is neither void nor place, from these grounds
also it will follow necessarily that the heaven is spherical. For if it is
to be rectilinear in shape, it will follow that there is place and body
and void without it. For a rectilinear figure as it revolves never
continues in the same room, but where formerly was body, is now
none, and where now is none, body will be in a moment because of
the projection at the corners. Similarly, if the world had some other
figure with unequal radii, if, for instance, it were lentiform, or
oviform, in every case we should have to admit space and void
outside the moving body, because the whole body would not always
occupy the same room.
Again, if the motion of the heaven is the measure of all movements
whatever in virtue of being alone continuous and regular and eternal,
and if, in each kind, the measure is the minimum, and the minimum
movement is the swiftest, then, clearly, the movement of the heaven
must be the swiftest of all movements. Now of lines which return
894
upon themselves the line which bounds the circle is the shortest; and
that movement is the swiftest which follows the shortest line.
Therefore, if the heaven moves in a circle and moves more swiftly
than anything else, it must necessarily be spherical.
Corroborative evidence may be drawn from the bodies whose
position is about the centre. If earth is enclosed by water, water by air,
air by fire, and these similarly by the upper bodies - which while not
continuous are yet contiguous with them - and if the surface of
water is spherical, and that which is continuous with or embraces
the spherical must itself be spherical, then on these grounds also it is
clear that the heavens are spherical. But the surface of water is seen
to be spherical if we take as our starting-point the fact that water
naturally tends to collect in a hollow place - 'hollow' meaning 'nearer
the centre'. Draw from the centre the lines AB, AC, and let their
extremities be joined by the straight line BC. The line AD, drawn to
the base of the triangle, will be shorter than either of the radii.
Therefore the place in which it terminates will be a hollow place. The
water then will collect there until equality is established, that is until
the line AE is equal to the two radii. Thus water forces its way to the
ends of the radii, and there only will it rest: but the line which
connects the extremities of the radii is circular: therefore the surface
of the water BEC is spherical.
It is plain from the foregoing that the universe is spherical. It is plain,
further, that it is turned (so to speak) with a finish which no
manufactured thing nor anything else within the range of our
observation can even approach. For the matter of which these are
composed does not admit of anything like the same regularity and
finish as the substance of the enveloping body; since with each step
away from earth the matter manifestly becomes finer in the same
proportion as water is finer than earth.
895
Now there are two ways of moving along a circle, from A to B or from
A to C, and we have already explained that these movements are not
contrary to one another. But nothing which concerns the eternal can
be a matter of chance or spontaneity, and the heaven and its circular
motion are eternal. We must therefore ask why this motion takes one
direction and not the other. Either this is itself an ultimate fact or
there is an ultimate fact behind it. It may seem evidence of excessive
folly or excessive zeal to try to provide an explanation of some
things, or of everything, admitting no exception. The criticism,
however, is not always just: one should first consider what reason
there is for speaking, and also what kind of certainty is looked for,
whether human merely or of a more cogent kind. When any one shall
succeed in finding proofs of greater precision, gratitude will be due to
him for the discovery, but at present we must be content with a
probable solution. If nature always follows the best course possible,
and, just as upward movement is the superior form of rectilinear
movement, since the upper region is more divine than the lower, so
forward movement is superior to backward, then front and back
exhibits, like right and left, as we said before and as the difficulty just
stated itself suggests, the distinction of prior and posterior, which
provides a reason and so solves our difficulty. Supposing that nature
is ordered in the best way possible, this may stand as the reason of
the fact mentioned. For it is best to move with a movement simple
and unceasing, and, further, in the superior of two possible
directions.
We have next to show that the movement of the heaven is regular
and not irregular. This applies only to the first heaven and the first
movement; for the lower spheres exhibit a composition of several
movements into one. If the movement is uneven, clearly there will be
acceleration, maximum speed, and retardation, since these appear in
896
all irregular motions. The maximum may occur either at the starting-
point or at the goal or between the two; and we expect natural
motion to reach its maximum at the goal, unnatural motion at the
starting-point, and missiles midway between the two. But circular
movement, having no beginning or limit or middle in the direct sense
of the words, has neither whence nor whither nor middle: for in time
it is eternal, and in length it returns upon itself without a break. If
then its movement has no maximum, it can have no irregularity,
since irregularity is produced by retardation and acceleration.
Further, since everything that is moved is moved by something, the
cause of the irregularity of movement must lie either in the mover or
in the moved or both. For if the mover moved not always with the
same force, or if the moved were altered and did not remain the
same, or if both were to change, the result might well be an irregular
movement in the moved. But none of these possibilities can be
conceived as actual in the case of the heavens. As to that which is
moved, we have shown that it is primary and simple and
ungenerated and indestructible and generally unchanging; and the
mover has an even better right to these attributes. It is the primary
that moves the primary, the simple the simple, the indestructible and
ungenerated that which is indestructible and ungenerated. Since
then that which is moved, being a body, is nevertheless unchanging,
how should the mover, which is incorporeal, be changed?
It follows then, further, that the motion cannot be irregular. For if
irregularity occurs, there must be change either in the movement as
a whole, from fast to slow and slow to fast, or in its parts. That there
is no irregularity in the parts is obvious, since, if there were, some
divergence of the stars would have taken place before now in the
infinity of time, as one moved slower and another faster: but no
alteration of their intervals is ever observed. Nor again is a change in
the movement as a whole admissible. Retardation is always due to
incapacity, and incapacity is unnatural. The incapacities of animals,
age, decay, and the like, are all unnatural, due, it seems, to the fact
that the whole animal complex is made up of materials which differ
in respect of their proper places, and no single part occupies its own
place. If therefore that which is primary contains nothing unnatural,
being simple and unmixed and in its proper place and having no
897
contrary, then it has no place for incapacity, nor, consequently, for
retardation or (since acceleration involves retardation) for
acceleration. Again, it is inconceivable that the mover should first
show incapacity for an infinite time, and capacity afterwards for
another infinity. For clearly nothing which, like incapacity, unnatural
ever continues for an infinity of time; nor does the unnatural endure
as long as the natural, or any form of incapacity as long as the
capacity. But if the movement is retarded it must necessarily be
retarded for an infinite time. Equally impossible is perpetual
acceleration or perpetual retardation. For such movement would be
infinite and indefinite, but every movement, in our view, proceeds
from one point to another and is definite in character. Again, suppose
one assumes a minimum time in less than which the heaven could
not complete its movement. For, as a given walk or a given exercise
on the harp cannot take any and every time, but every performance
has its definite minimum time which is unsurpassable, so, one might
suppose, the movement of the heaven could not be completed in any
and every time. But in that case perpetual acceleration is impossible
(and, equally, perpetual retardation: for the argument holds of both
and each), if we may take acceleration to proceed by identical or
increasing additions of speed and for an infinite time. The remaining
alternative is to say that the movement exhibits an alternation of
slower and faster: but this is a mere fiction and quite inconceivable.
Further, irregularity of this kind would be particularly unlikely to pass
unobserved, since contrast makes observation easy.
That there is one heaven, then, only, and that it is ungenerated and
eternal, and further that its movement is regular, has now been
sufficiently explained.
We have next to speak of the stars, as they are called, of their
composition, shape, and movements. It would be most natural and
consequent upon what has been said that each of the stars should be
898
composed of that substance in which their path lies, since, as we
said, there is an element whose natural movement is circular. In so
saying we are only following the same line of thought as those who
say that the stars are fiery because they believe the upper body to be
fire, the presumption being that a thing is composed of the same
stuff as that in which it is situated. The warmth and light which
proceed from them are caused by the friction set up in the air by their
motion. Movement tends to create fire in wood, stone, and iron; and
with even more reason should it have that effect on air, a substance
which is closer to fire than these. An example is that of missiles,
which as they move are themselves fired so strongly that leaden balls
are melted; and if they are fired the surrounding air must be similarly
affected. Now while the missiles are heated by reason of their motion
in air, which is turned into fire by the agitation produced by their
movement, the upper bodies are carried on a moving sphere, so that,
though they are not themselves fired, yet the air underneath the
sphere of the revolving body is necessarily heated by its motion, and
particularly in that part where the sun is attached to it. Hence
warmth increases as the sun gets nearer or higher or overhead. Of
the fact, then, that the stars are neither fiery nor move in fire, enough
has been said.
8
Since changes evidently occur not only in the position of the stars
but also in that of the whole heaven, there are three possibilities.
Either (1) both are at rest, or (2) both are in motion, or (3) the one is at
rest and the other in motion.
(1) That both should be at rest is impossible; for, if the earth is at rest,
the hypothesis does not account for the observations; and we take it
as granted that the earth is at rest. It remains either that both are
moved, or that the one is moved and the other at rest.
899
(2) On the view, first, that both are in motion, we have the absurdity
that the stars and the circles move with the same speed, i.e. that the
ace of every star is that of the circle in it moves. For star and circle
are seen to come back to the same place at the same moment; from
which it follows that the star has traversed the circle and the circle
has completed its own movement, i.e. traversed its own
circumference, at one and the same moment. But it is difficult to
conceive that the pace of each star should be exactly proportioned to
the size of its circle. That the pace of each circle should be
proportionate to its size is not absurd but inevitable: but that the
same should be true of the movement of the stars contained in the
circles is quite incredible. For if, on the one and, we suppose that the
star which moves on the greater circle is necessarily swifter, clearly
we also admit that if stars shifted their position so as to exchange
circles, the slower would become swifter and the swifter slower. But
this would show that their movement was not their own, but due to
the circles. If, on the other hand, the arrangement was a chance
combination, the coincidence in every case of a greater circle with a
swifter movement of the star contained in it is too much to believe. In
one or two cases it might not inconceivably fall out so, but to imagine
it in every case alike is a mere fiction. Besides, chance has no place in
that which is natural, and what happens everywhere and in every
case is no matter of chance.
(3) The same absurdity is equally plain if it is supposed that the
circles stand still and that it is the stars themselves which move. For
it will follow that the outer stars are the swifter, and that the pace of
the stars corresponds to the size of their circles.
Since, then, we cannot reasonably suppose either that both are in
motion or that the star alone moves, the remaining alternative is that
the circles should move, while the stars are at rest and move with the
circles to which they are attached. Only on this supposition are we
involved in no absurd consequence. For, in the first place, the quicker
movement of the larger circle is natural when all the circles are
attached to the same centre. Whenever bodies are moving with their
proper motion, the larger moves quicker. It is the same here with the
revolving bodies: for the are intercepted by two radii will be larger in
900
the larger circle, and hence it is not surprising that the revolution of
the larger circle should take the same time as that of the smaller.
And secondly, the fact that the heavens do not break in pieces
follows not only from this but also from the proof already given of
the continuity of the whole.
Again, since the stars are spherical, as our opponents assert and we
may consistently admit, inasmuch as we construct them out of the
spherical body, and since the spherical body has two movements
proper to itself, namely rolling and spinning, it follows that if the
stars have a movement of their own, it will be one of these. But
neither is observed. (1) Suppose them to spin. They would then stay
where they were, and not change their place, as, by observation and
general consent, they do. Further, one would expect them all to
exhibit the same movement: but the only star which appears to
possess this movement is the sun, at sunrise or sunset, and this
appearance is due not to the sun itself but to the distance from
which we observe it. The visual ray being excessively prolonged
becomes weak and wavering. The same reason probably accounts for
the apparent twinkling of the fixed stars and the absence of
twinkling in the planets. The planets are near, so that the visual ray
reaches them in its full vigour, but when it comes to the fixed stars it
is quivering because of the distance and its excessive extension; and
its tremor produces an appearance of movement in the star: for it
makes no difference whether movement is set up in the ray or in the
object of vision.
(2) On the other hand, it is also clear that the stars do not roll. For
rolling involves rotation: but the 'face', as it is called, of the moon is
always seen. Therefore, since any movement of their own which the
stars possessed would presumably be one proper to themselves, and
no such movement is observed in them, clearly they have no
movement of their own.
There is, further, the absurdity that nature has bestowed upon them
no organ appropriate to such movement. For nature leaves nothing to
chance, and would not, while caring for animals, overlook things so
precious. Indeed, nature seems deliberately to have stripped them of
901
everything which makes selforiginated progression possible, and to
have removed them as far as possible from things which have organs
of movement. This is just why it seems proper that the whole heaven
and every star should be spherical. For while of all shapes the sphere
is the most convenient for movement in one place, making possible,
as it does, the swiftest and most selfcontained motion, for forward
movement it is the most unsuitable, least of all resembling shapes
which are self-moved, in that it has no dependent or projecting part,
as a rectilinear figure has, and is in fact as far as possible removed in
shape from ambulatory bodies. Since, therefore, the heavens have to
move in one lace, and the stars are not required to move themselves
forward, it is natural that both should be spherical - a shape which
best suits the movement of the one and the immobility of the other.
From all this it is clear that the theory that the movement of the stars
produces a harmony, i.e. that the sounds they make are concordant,
in spite of the grace and originality with which it has been stated, is
nevertheless untrue. Some thinkers suppose that the motion of
bodies of that size must produce a noise, since on our earth the
motion of bodies far inferior in size and in speed of movement has
that effect. Also, when the sun and the moon, they say, and all the
stars, so great in number and in size, are moving with so rapid a
motion, how should they not produce a sound immensely great?
Starting from this argument and from the observation that their
speeds, as measured by their distances, are in the same ratios as
musical concordances, they assert that the sound given forth by the
circular movement of the stars is a harmony. Since, however, it
appears unaccountable that we should not hear this music, they
explain this by saying that the sound is in our ears from the very
moment of birth and is thus indistinguishable from its contrary
silence, since sound and silence are discriminated by mutual
contrast. What happens to men, then, is just what happens to
coppersmiths, who are so accustomed to the noise of the smithy that
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it makes no difference to them. But, as we said before, melodious and
poetical as the theory is, it cannot be a true account of the facts.
There is not only the absurdity of our hearing nothing, the ground of
which they try to remove, but also the fact that no effect other than
sensitive is produced upon us. Excessive noises, we know, shatter the
solid bodies even of inanimate things: the noise of thunder, for
instance, splits rocks and the strongest of bodies. But if the moving
bodies are so great, and the sound which penetrates to us is
proportionate to their size, that sound must needs reach us in an
intensity many times that of thunder, and the force of its action must
be immense. Indeed the reason why we do not hear, and show in our
bodies none of the effects of violent force, is easily given: it is that
there is no noise. But not only is the explanation evident; it is also a
corroboration of the truth of the views we have advanced. For the
very difficulty which made the Pythagoreans say that the motion of
the stars produces a concord corroborates our view. Bodies which are
themselves in motion, produce noise and friction: but those which
are attached or fixed to a moving body, as the parts to a ship, can no
more create noise, than a ship on a river moving with the stream. Yet
by the same argument one might say it was absurd that on a large
vessel the motion of mast and poop should not make a great noise,
and the like might be said of the movement of the vessel itself. But
sound is caused when a moving body is enclosed in an unmoved
body, and cannot be caused by one enclosed in, and continuous with,
a moving body which creates no friction. We may say, then, in this
matter that if the heavenly bodies moved in a generally diffused
mass of air or fire, as every one supposes, their motion would
necessarily cause a noise of tremendous strength and such a noise
would necessarily reach and shatter us. Since, therefore, this effect is
evidently not produced, it follows that none of them can move with
the motion either of animate nature or of constraint. It is as though
nature had foreseen the result, that if their movement were other
than it is, nothing on this earth could maintain its character.
That the stars are spherical and are not selfmoved, has now been
explained.
903
10
With their order - I mean the position of each, as involving the
priority of some and the posteriority of others, and their respective
distances from the extremity - with this astronomy may be left to
deal, since the astronomical discussion is adequate. This discussion
shows that the movements of the several stars depend, as regards
the varieties of speed which they exhibit, on the distance of each
from the extremity. It is established that the outermost revolution of
the heavens is a simple movement and the swiftest of all, and that
the movement of all other bodies is composite and relatively slow, for
the reason that each is moving on its own circle with the reverse
motion to that of the heavens. This at once leads us to expect that
the body which is nearest to that first simple revolution should take
the longest time to complete its circle, and that which is farthest
from it the shortest, the others taking a longer time the nearer they
are and a shorter time the farther away they are. For it is the nearest
body which is most strongly influenced, and the most remote, by
reason of its distance, which is least affected, the influence on the
intermediate bodies varying, as the mathematicians show, with their
distance.
11
With regard to the shape of each star, the most reasonable view is
that they are spherical. It has been shown that it is not in their
nature to move themselves, and, since nature is no wanton or
random creator, clearly she will have given things which possess no
movement a shape particularly unadapted to movement. Such a
shape is the sphere, since it possesses no instrument of movement.
Clearly then their mass will have the form of a sphere. Again, what
holds of one holds of all, and the evidence of our eyes shows us that
the moon is spherical. For how else should the moon as it waxes and
904
wanes show for the most part a crescent-shaped or gibbous figure,
and only at one moment a half-moon? And astronomical arguments
give further confirmation; for no other hypothesis accounts for the
crescent shape of the sun's eclipses. One, then, of the heavenly
bodies being spherical, clearly the rest will be spherical also.
12
There are two difficulties, which may very reasonably here be raised,
of which we must now attempt to state the probable solution: for we
regard the zeal of one whose thirst after philosophy leads him to
accept even slight indications where it is very difficult to see one's
way, as a proof rather of modesty than of overconfidence.
Of many such problems one of the strangest is the problem why we
find the greatest number of movements in the intermediate bodies,
and not, rather, in each successive body a variety of movement
proportionate to its distance from the primary motion. For we should
expect, since the primary body shows one motion only, that the body
which is nearest to it should move with the fewest movements, say
two, and the one next after that with three, or some similar
arrangement. But the opposite is the case. The movements of the sun
and moon are fewer than those of some of the planets. Yet these
planets are farther from the centre and thus nearer to the primary
body than they, as observation has itself revealed. For we have seen
the moon, half-full, pass beneath the planet Mars, which vanished on
its shadow side and came forth by the bright and shining part.
Similar accounts of other stars are given by the Egyptians and
Babylonians, whose observations have been kept for very many years
past, and from whom much of our evidence about particular stars is
derived. A second difficulty which may with equal justice be raised is
this. Why is it that the primary motion includes such a multitude of
stars that their whole array seems to defy counting, while of the
other stars each one is separated off, and in no case do we find two
or more attached to the same motion?
905
On these questions, I say, it is well that we should seek to increase
our understanding, though we have but little to go upon, and are
placed at so great a distance from the facts in question. Nevertheless
there are certain principles on which if we base our consideration we
shall not find this difficulty by any means insoluble. We may object
that we have been thinking of the stars as mere bodies, and as units
with a serial order indeed but entirely inanimate; but should rather
conceive them as enjoying life and action. On this view the facts
cease to appear surprising. For it is natural that the best-conditioned
of all things should have its good without action, that which is
nearest to it should achieve it by little and simple action, and that
which is farther removed by a complexity of actions, just as with
men's bodies one is in good condition without exercise at all, another
after a short walk, while another requires running and wrestling and
hard training, and there are yet others who however hard they
worked themselves could never secure this good, but only some
substitute for it. To succeed often or in many things is difficult. For
instance, to throw ten thousand Coan throws with the dice would be
impossible, but to throw one or two is comparatively easy. In action,
again, when A has to be done to get B, B to get C, and C to get D, one
step or two present little difficulty, but as the series extends the
difficulty grows. We must, then, think of the action of the lower stars
as similar to that of animals and plants. For on our earth it is man
that has the greatest variety of actions - for there are many goods
that man can secure; hence his actions are various and directed to
ends beyond them - while the perfectly conditioned has no need of
action, since it is itself the end, and action always requires two terms,
end and means. The lower animals have less variety of action than
man; and plants perhaps have little action and of one kind only. For
either they have but one attainable good (as indeed man has), or, if
several, each contributes directly to their ultimate good. One thing
then has and enjoys the ultimate good, other things attain to it, one
immediately by few steps, another by many, while yet another does
not even attempt to secure it but is satisfied to reach a point not far
removed from that consummation. Thus, taking health as the end,
there will be one thing that always possesses health, others that
attain it, one by reducing flesh, another by running and thus reducing
906
flesh, another by taking steps to enable himself to run, thus further
increasing the number of movements, while another cannot attain
health itself, but only running or reduction of flesh, so that one or
other of these is for such a being the end. For while it is clearly best
for any being to attain the real end, yet, if that cannot be, the nearer
it is to the best the better will be its state. It is for this reason that the
earth moves not at all and the bodies near to it with few movements.
For they do not attain the final end, but only come as near to it as
their share in the divine principle permits. But the first heaven finds
it immediately with a single movement, and the bodies intermediate
between the first and last heavens attain it indeed, but at the cost of
a multiplicity of movement.
As to the difficulty that into the one primary motion is crowded a
vast multitude of stars, while of the other stars each has been
separately given special movements of its own, there is in the first
place this reason for regarding the arrangement as a natural one. In
thinking of the life and moving principle of the several heavens one
must regard the first as far superior to the others. Such a superiority
would be reasonable. For this single first motion has to move many of
the divine bodies, while the numerous other motions move only one
each, since each single planet moves with a variety of motions. Thus,
then, nature makes matters equal and establishes a certain order,
giving to the single motion many bodies and to the single body many
motions. And there is a second reason why the other motions have
each only one body, in that each of them except the last, i.e. that
which contains the one star, is really moving many bodies. For this
last sphere moves with many others, to which it is fixed, each sphere
being actually a body; so that its movement will be a joint product.
Each sphere, in fact, has its particular natural motion, to which the
general movement is, as it were, added. But the force of any limited
body is only adequate to moving a limited body.
The characteristics of the stars which move with a circular motion, in
respect of substance and shape, movement and order, have now been
sufficiently explained.
907
13
It remains to speak of the earth, of its position, of the question
whether it is at rest or in motion, and of its shape.
I. As to its position there is some difference of opinion. Most people -
all, in fact, who regard the whole heaven as finite - say it lies at the
centre. But the Italian philosophers known as Pythagoreans take the
contrary view. At the centre, they say, is fire, and the earth is one of
the stars, creating night and day by its circular motion about the
centre. They further construct another earth in opposition to ours to
which they give the name counterearth. In all this they are not
seeking for theories and causes to account for observed facts, but
rather forcing their observations and trying to accommodate them to
certain theories and opinions of their own. But there are many others
who would agree that it is wrong to give the earth the central
position, looking for confirmation rather to theory than to the facts of
observation. Their view is that the most precious place befits the
most precious thing: but fire, they say, is more precious than earth,
and the limit than the intermediate, and the circumference and the
centre are limits. Reasoning on this basis they take the view that it is
not earth that lies at the centre of the sphere, but rather fire. The
Pythagoreans have a further reason. They hold that the most
important part of the world, which is the centre, should be most
strictly guarded, and name it, or rather the fire which occupies that
place, the 'Guardhouse of Zeus', as if the word 'centre' were quite
unequivocal, and the centre of the mathematical figure were always
the same with that of the thing or the natural centre. But it is better
to conceive of the case of the whole heaven as analogous to that of
animals, in which the centre of the animal and that of the body are
different. For this reason they have no need to be so disturbed about
the world, or to call in a guard for its centre: rather let them look for
the centre in the other sense and tell us what it is like and where
nature has set it. That centre will be something primary and precious;
but to the mere position we should give the last place rather than the
first. For the middle is what is defined, and what defines it is the
908
limit, and that which contains or limits is more precious than that
which is limited, see ing that the latter is the matter and the former
the essence of the system.
II. As to the position of the earth, then, this is the view which some
advance, and the views advanced concerning its rest or motion are
similar. For here too there is no general agreement. All who deny that
the earth lies at the centre think that it revolves about the centre, and
not the earth only but, as we said before, the counter-earth as well.
Some of them even consider it possible that there are several bodies
so moving, which are invisible to us owing to the interposition of the
earth. This, they say, accounts for the fact that eclipses of the moon
are more frequent than eclipses of the sun: for in addition to the
earth each of these moving bodies can obstruct it. Indeed, as in any
case the surface of the earth is not actually a centre but distant from
it a full hemisphere, there is no more difficulty, they think, in
accounting for the observed facts on their view that we do not dwell
at the centre, than on the common view that the earth is in the
middle. Even as it is, there is nothing in the observations to suggest
that we are removed from the centre by half the diameter of the
earth. Others, again, say that the earth, which lies at the centre, is
'rolled', and thus in motion, about the axis of the whole heaven, So it
stands written in the Timaeus.
III. There are similar disputes about the shape of the earth. Some
think it is spherical, others that it is flat and drum-shaped. For
evidence they bring the fact that, as the sun rises and sets, the part
concealed by the earth shows a straight and not a curved edge,
whereas if the earth were spherical the line of section would have to
be circular. In this they leave out of account the great distance of the
sun from the earth and the great size of the circumference, which,
seen from a distance on these apparently small circles appears
straight. Such an appearance ought not to make them doubt the
circular shape of the earth. But they have another argument. They say
that because it is at rest, the earth must necessarily have this shape.
For there are many different ways in which the movement or rest of
the earth has been conceived.
909
The difficulty must have occurred to every one. It would indeed be a
complacent mind that felt no surprise that, while a little bit of earth,
let loose in mid-air moves and will not stay still, and more there is of
it the faster it moves, the whole earth, free in midair, should show no
movement at all. Yet here is this great weight of earth, and it is at
rest. And again, from beneath one of these moving fragments of
earth, before it falls, take away the earth, and it will continue its
downward movement with nothing to stop it. The difficulty then, has
naturally passed into a common place of philosophy; and one may
well wonder that the solutions offered are not seen to involve greater
absurdities than the problem itself.
By these considerations some have been led to assert that the earth
below us is infinite, saying, with Xenophanes of Colophon, that it has
'pushed its roots to infinity', - in order to save the trouble of seeking
for the cause. Hence the sharp rebuke of Empedocles, in the words 'if
the deeps of the earth are endless and endless the ample ether -
such is the vain tale told by many a tongue, poured from the mouths
of those who have seen but little of the whole. Others say the earth
rests upon water. This, indeed, is the oldest theory that has been
preserved, and is attributed to Thales of Miletus. It was supposed to
stay still because it floated like wood and other similar substances,
which are so constituted as to rest upon but not upon air. As if the
same account had not to be given of the water which carries the
earth as of the earth itself! It is not the nature of water, any more
than of earth, to stay in mid-air: it must have something to rest upon.
Again, as air is lighter than water, so is water than earth: how then
can they think that the naturally lighter substance lies below the
heavier? Again, if the earth as a whole is capable of floating upon
water, that must obviously be the case with any part of it. But
observation shows that this is not the case. Any piece of earth goes to
the bottom, the quicker the larger it is. These thinkers seem to push
their inquiries some way into the problem, but not so far as they
might. It is what we are all inclined to do, to direct our inquiry not by
the matter itself, but by the views of our opponents: and even when
interrogating oneself one pushes the inquiry only to the point at
which one can no longer offer any opposition. Hence a good inquirer
will be one who is ready in bringing forward the objections proper to
910
the genus, and that he will be when he has gained an understanding
of all the differences.
Anaximenes and Anaxagoras and Democritus give the flatness of the
earth as the cause of its staying still. Thus, they say, it does not cut,
but covers like a lid, the air beneath it. This seems to be the way of
flat-shaped bodies: for even the wind can scarcely move them
because of their power of resistance. The same immobility, they say,
is produced by the flatness of the surface which the earth presents to
the air which underlies it; while the air, not having room enough to
change its place because it is underneath the earth, stays there in a
mass, like the water in the case of the water-clock. And they adduce
an amount of evidence to prove that air, when cut off and at rest, can
bear a considerable weight.
Now, first, if the shape of the earth is not flat, its flatness cannot be
the cause of its immobility. But in their own account it is rather the
size of the earth than its flatness that causes it to remain at rest. For
the reason why the air is so closely confined that it cannot find a
passage, and therefore stays where it is, is its great amount: and this
amount great because the body which isolates it, the earth, is very
large. This result, then, will follow, even if the earth is spherical, so
long as it retains its size. So far as their arguments go, the earth will
still be at rest.
In general, our quarrel with those who speak of movement in this
way cannot be confined to the parts; it concerns the whole universe.
One must decide at the outset whether bodies have a natural
movement or not, whether there is no natural but only constrained
movement. Seeing, however, that we have already decided this
matter to the best of our ability, we are entitled to treat our results as
representing fact. Bodies, we say, which have no natural movement,
have no constrained movement; and where there is no natural and
no constrained movement there will be no movement at all. This is a
conclusion, the necessity of which we have already decided, and we
have seen further that rest also will be inconceivable, since rest, like
movement, is either natural or constrained. But if there is any natural
movement, constraint will not be the sole principle of motion or of
911
rest. If, then, it is by constraint that the earth now keeps its place, the
so-called 'whirling' movement by which its parts came together at
the centre was also constrained. (The form of causation supposed
they all borrow from observations of liquids and of air, in which the
larger and heavier bodies always move to the centre of the whirl. This
is thought by all those who try to generate the heavens to explain
why the earth came together at the centre. They then seek a reason
for its staying there; and some say, in the manner explained, that the
reason is its size and flatness, others, with Empedocles, that the
motion of the heavens, moving about it at a higher speed, prevents
movement of the earth, as the water in a cup, when the cup is given a
circular motion, though it is often underneath the bronze, is for this
same reason prevented from moving with the downward movement
which is natural to it.) But suppose both the 'whirl' and its flatness
(the air beneath being withdrawn) cease to prevent the earth's
motion, where will the earth move to then? Its movement to the
centre was constrained, and its rest at the centre is due to constraint;
but there must be some motion which is natural to it. Will this be
upward motion or downward or what? It must have some motion;
and if upward and downward motion are alike to it, and the air above
the earth does not prevent upward movement, then no more could
air below it prevent downward movement. For the same cause must
necessarily have the same effect on the same thing.
Further, against Empedocles there is another point which might be
made. When the elements were separated off by Hate, what caused
the earth to keep its place? Surely the 'whirl' cannot have been then
also the cause. It is absurd too not to perceive that, while the whirling
movement may have been responsible for the original coming
together of the art of earth at the centre, the question remains, why
now do all heavy bodies move to the earth. For the whirl surely does
not come near us. Why, again, does fire move upward? Not, surely,
because of the whirl. But if fire is naturally such as to move in a
certain direction, clearly the same may be supposed to hold of earth.
Again, it cannot be the whirl which determines the heavy and the
light. Rather that movement caused the pre-existent heavy and light
things to go to the middle and stay on the surface respectively. Thus,
before ever the whirl began, heavy and light existed; and what can
912
have been the ground of their distinction, or the manner and
direction of their natural movements? In the infinite chaos there can
have been neither above nor below, and it is by these that heavy and
light are determined.
It is to these causes that most writers pay attention: but there are
some, Anaximander, for instance, among the ancients, who say that
the earth keeps its place because of its indifference. Motion upward
and downward and sideways were all, they thought, equally
inappropriate to that which is set at the centre and indifferently
related to every extreme point; and to move in contrary directions at
the same time was impossible: so it must needs remain still. This
view is ingenious but not true. The argument would prove that
everything, whatever it be, which is put at the centre, must stay there.
Fire, then, will rest at the centre: for the proof turns on no peculiar
property of earth. But this does not follow. The observed facts about
earth are not only that it remains at the centre, but also that it moves
to the centre. The place to which any fragment of earth moves must
necessarily be the place to which the whole moves; and in the place
to which a thing naturally moves, it will naturally rest. The reason
then is not in the fact that the earth is indifferently related to every
extreme point: for this would apply to any body, whereas movement
to the centre is peculiar to earth. Again it is absurd to look for a
reason why the earth remains at the centre and not for a reason why
fire remains at the extremity. If the extremity is the natural place of
fire, clearly earth must also have a natural place. But suppose that
the centre is not its place, and that the reason of its remaining there
is this necessity of indifference - on the analogy of the hair which, it
is said, however great the tension, will not break under it, if it be
evenly distributed, or of the men who, though exceedingly hungry
and thirsty, and both equally, yet being equidistant from food and
drink, is therefore bound to stay where he is - even so, it still remains
to explain why fire stays at the extremities. It is strange, too, to ask
about things staying still but not about their motion, - why, I mean,
one thing, if nothing stops it, moves up, and another thing to the
centre. Again, their statements are not true. It happens, indeed, to be
the case that a thing to which movement this way and that is equally
inappropriate is obliged to remain at the centre. But so far as their
913
argument goes, instead of remaining there, it will move, only not as a
mass but in fragments. For the argument applies equally to fire. Fire,
if set at the centre, should stay there, like earth, since it will be
indifferently related to every point on the extremity. Nevertheless it
will move, as in fact it always does move when nothing stops it, away
from the centre to the extremity. It will not, however, move in a mass
to a single point on the circumference - the only possible result on
the lines of the indifference theory - but rather each corresponding
portion of fire to the corresponding part of the extremity, each fourth
part, for instance, to a fourth part of the circumference. For since no
body is a point, it will have parts. The expansion, when the body
increased the place occupied, would be on the same principle as the
contraction, in which the place was diminished. Thus, for all the
indifference theory shows to the contrary, earth also would have
moved in this manner away from the centre, unless the centre had
been its natural place.
We have now outlined the views held as to the shape, position, and
rest or movement of the earth.
14
Let us first decide the question whether the earth moves or is at rest.
For, as we said, there are some who make it one of the stars, and
others who, setting it at the centre, suppose it to be 'rolled' and in
motion about the pole as axis. That both views are untenable will be
clear if we take as our starting-point the fact that the earth's motion,
whether the earth be at the centre or away from it, must needs be a
constrained motion. It cannot be the movement of the earth itself. If
it were, any portion of it would have this movement; but in fact every
part moves in a straight line to the centre. Being, then, constrained
and unnatural, the movement could not be eternal. But the order of
the universe is eternal. Again, everything that moves with the
circular movement, except the first sphere, is observed to be passed,
and to move with more than one motion. The earth, then, also,
914
whether it move about the centre or as stationary at it, must
necessarily move with two motions. But if this were so, there would
have to be passings and turnings of the fixed stars. Yet no such thing
is observed. The same stars always rise and set in the same parts of
the earth.
Further, the natural movement of the earth, part and whole alike, is
the centre of the whole - whence the fact that it is now actually
situated at the centre - but it might be questioned since both centres
are the same, which centre it is that portions of earth and other
heavy things move to. Is this their goal because it is the centre of the
earth or because it is the centre of the whole? The goal, surely, must
be the centre of the whole. For fire and other light things move to the
extremity of the area which contains the centre. It happens, however,
that the centre of the earth and of the whole is the same. Thus they
do move to the centre of the earth, but accidentally, in virtue of the
fact that the earth's centre lies at the centre of the whole. That the
centre of the earth is the goal of their movement is indicated by the
fact that heavy bodies moving towards the earth do not parallel but
so as to make equal angles, and thus to a single centre, that of the
earth. It is clear, then, that the earth must be at the centre and
immovable, not only for the reasons already given, but also because
heavy bodies forcibly thrown quite straight upward return to the
point from which they started, even if they are thrown to an infinite
distance. From these considerations then it is clear that the earth
does not move and does not lie elsewhere than at the centre.
From what we have said the explanation of the earth's immobility is
also apparent. If it is the nature of earth, as observation shows, to
move from any point to the centre, as of fire contrariwise to move
from the centre to the extremity, it is impossible that any portion of
earth should move away from the centre except by constraint. For a
single thing has a single movement, and a simple thing a simple:
contrary movements cannot belong to the same thing, and
movement away from the centre is the contrary of movement to it. If
then no portion of earth can move away from the centre, obviously
still less can the earth as a whole so move. For it is the nature of the
whole to move to the point to which the part naturally moves. Since,
915
then, it would require a force greater than itself to move it, it must
needs stay at the centre. This view is further supported by the
contributions of mathematicians to astronomy, since the
observations made as the shapes change by which the order of the
stars is determined, are fully accounted for on the hypothesis that
the earth lies at the centre. Of the position of the earth and of the
manner of its rest or movement, our discussion may here end.
Its shape must necessarily be spherical. For every portion of earth has
weight until it reaches the centre, and the jostling of parts greater
and smaller would bring about not a waved surface, but rather
compression and convergence of part and part until the centre is
reached. The process should be conceived by supposing the earth to
come into being in the way that some of the natural philosophers
describe. Only they attribute the downward movement to constraint,
and it is better to keep to the truth and say that the reason of this
motion is that a thing which possesses weight is naturally endowed
with a centripetal movement. When the mixture, then, was merely
potential, the things that were separated off moved similarly from
every side towards the centre. Whether the parts which came
together at the centre were distributed at the extremities evenly, or in
some other way, makes no difference. If, on the one hand, there were
a similar movement from each quarter of the extremity to the single
centre, it is obvious that the resulting mass would be similar on every
side. For if an equal amount is added on every side the extremity of
the mass will be everywhere equidistant from its centre, i.e. the
figure will be spherical. But neither will it in any way affect the
argument if there is not a similar accession of concurrent fragments
from every side. For the greater quantity, finding a lesser in front of it,
must necessarily drive it on, both having an impulse whose goal is
the centre, and the greater weight driving the lesser forward till this
goal is reached. In this we have also the solution of a possible
difficulty. The earth, it might be argued, is at the centre and spherical
in shape: if, then, a weight many times that of the earth were added
to one hemisphere, the centre of the earth and of the whole will no
longer be coincident. So that either the earth will not stay still at the
centre, or if it does, it will be at rest without having its centre at the
place to which it is still its nature to move. Such is the difficulty. A
916
short consideration will give us an easy answer, if we first give
precision to our postulate that any body endowed with weight, of
whatever size, moves towards the centre. Clearly it will not stop
when its edge touches the centre. The greater quantity must prevail
until the body's centre occupies the centre. For that is the goal of its
impulse. Now it makes no difference whether we apply this to a clod
or common fragment of earth or to the earth as a whole. The fact
indicated does not depend upon degrees of size but applies
universally to everything that has the centripetal impulse. Therefore
earth in motion, whether in a mass or in fragments, necessarily
continues to move until it occupies the centre equally every way, the
less being forced to equalize itself by the greater owing to the forward
drive of the impulse.
If the earth was generated, then, it must have been formed in this
way, and so clearly its generation was spherical; and if it is
ungenerated and has remained so always, its character must be that
which the initial generation, if it had occurred, would have given it.
But the spherical shape, necessitated by this argument, follows also
from the fact that the motions of heavy bodies always make equal
angles, and are not parallel. This would be the natural form of
movement towards what is naturally spherical. Either then the earth
is spherical or it is at least naturally spherical. And it is right to call
anything that which nature intends it to be, and which belongs to it,
rather than that which it is by constraint and contrary to nature. The
evidence of the senses further corroborates this. How else would
eclipses of the moon show segments shaped as we see them? As it is,
the shapes which the moon itself each month shows are of every
kind straight, gibbous, and concave - but in eclipses the outline is
always curved: and, since it is the interposition of the earth that
makes the eclipse, the form of this line will be caused by the form of
the earth's surface, which is therefore spherical. Again, our
observations of the stars make it evident, not only that the earth is
circular, but also that it is a circle of no great size. For quite a small
change of position to south or north causes a manifest alteration of
the horizon. There is much change, I mean, in the stars which are
overhead, and the stars seen are different, as one moves northward
or southward. Indeed there are some stars seen in Egypt and in the
917
neighbourhood of Cyprus which are not seen in the northerly
regions; and stars, which in the north are never beyond the range of
observation, in those regions rise and set. All of which goes to show
not only that the earth is circular in shape, but also that it is a sphere
of no great size: for otherwise the effect of so slight a change of place
would not be quickly apparent. Hence one should not be too sure of
the incredibility of the view of those who conceive that there is
continuity between the parts about the pillars of Hercules and the
parts about India, and that in this way the ocean is one. As further
evidence in favour of this they quote the case of elephants, a species
occurring in each of these extreme regions, suggesting that the
common characteristic of these extremes is explained by their
continuity. Also, those mathematicians who try to calculate the size
of the earth's circumference arrive at the figure 400,000 stades. This
indicates not only that the earth's mass is spherical in shape, but also
that as compared with the stars it is not of great size.
Book III
We have already discussed the first heaven and its parts, the moving
stars within it, the matter of which these are composed and their
bodily constitution, and we have also shown that they are
ungenerated and indestructible. Now things that we call natural are
either substances or functions and attributes of substances. As
substances I class the simple bodies - fire, earth, and the other terms
of the series - and all things composed of them; for example, the
heaven as a whole and its parts, animals, again, and plants and their
parts. By attributes and functions I mean the movements of these
918
and of all other things in which they have power in themselves to
cause movement, and also their alterations and reciprocal
transformations. It is obvious, then, that the greater part of the
inquiry into nature concerns bodies: for a natural substance is either
a body or a thing which cannot come into existence without body
and magnitude. This appears plainly from an analysis of the
character of natural things, and equally from an inspection of the
instances of inquiry into nature. Since, then, we have spoken of the
primary element, of its bodily constitution, and of its freedom from
destruction and generation, it remains to speak of the other two. In
speaking of them we shall be obliged also to inquire into generation
and destruction. For if there is generation anywhere, it must be in
these elements and things composed of them.
This is indeed the first question we have to ask: is generation a fact
or not? Earlier speculation was at variance both with itself and with
the views here put forward as to the true answer to this question.
Some removed generation and destruction from the world altogether.
Nothing that is, they said, is generated or destroyed, and our
conviction to the contrary is an illusion. So maintained the school of
Melissus and Parmenides. But however excellent their theories may
otherwise be, anyhow they cannot be held to speak as students of
nature. There may be things not subject to generation or any kind of
movement, but if so they belong to another and a higher inquiry than
the study of nature. They, however, had no idea of any form of being
other than the substance of things perceived; and when they saw,
what no one previously had seen, that there could be no knowledge
or wisdom without some such unchanging entities, they naturally
transferred what was true of them to things perceived. Others,
perhaps intentionally, maintain precisely the contrary opinion to this.
It has been asserted that everything in the world was subject to
generation and nothing was ungenerated, but that after being
generated some things remained indestructible while the rest were
again destroyed. This had been asserted in the first instance by
Hesiod and his followers, but afterwards outside his circle by the
earliest natural philosophers. But what these thinkers maintained
was that all else has been generated and, as they said, 'is flowing
away, nothing having any solidity, except one single thing which
919
persists as the basis of all these transformations. So we may interpret
the statements of Heraclitus of Ephesus and many others. And some
subject all bodies whatever to generation, by means of the
composition and separation of planes.
Discussion of the other views may be postponed. But this last theory
which composes every body of planes is, as the most superficial
observation shows, in many respects in plain contradiction with
mathematics. It is, however, wrong to remove the foundations of a
science unless you can replace them with others more convincing.
And, secondly, the same theory which composes solids of planes
clearly composes planes of lines and lines of points, so that a part of
a line need not be a line. This matter has been already considered in
our discussion of movement, where we have shown that an
indivisible length is impossible. But with respect to natural bodies
there are impossibilities involved in the view which asserts
indivisible lines, which we may briefly consider at this point. For the
impossible consequences which result from this view in the
mathematical sphere will reproduce themselves when it is applied to
physical bodies, but there will be difficulties in physics which are not
present in mathematics; for mathematics deals with an abstract and
physics with a more concrete object. There are many attributes
necessarily present in physical bodies which are necessarily excluded
by indivisibility; all attributes, in fact, which are divisible. There can
be nothing divisible in an indivisible thing, but the attributes of
bodies are all divisible in one of two ways. They are divisible into
kinds, as colour is divided into white and black, and they are divisible
per accidens when that which has them is divisible. In this latter
sense attributes which are simple are nevertheless divisible.
Attributes of this kind will serve, therefore, to illustrate the
impossibility of the view. It is impossible, if two parts of a thing have
no weight, that the two together should have weight. But either all
perceptible bodies or some, such as earth and water, have weight, as
these thinkers would themselves admit. Now if the point has no
weight, clearly the lines have not either, and, if they have not, neither
have the planes. Therefore no body has weight. It is, further, manifest
that their point cannot have weight. For while a heavy thing may
always be heavier than something and a light thing lighter than
920
something, a thing which is heavier or lighter than something need
not be itself heavy or light, just as a large thing is larger than others,
but what is larger is not always large. A thing which, judged
absolutely, is small may none the less be larger than other things.
Whatever, then, is heavy and also heavier than something else, must
exceed this by something which is heavy. A heavy thing therefore is
always divisible. But it is common ground that a point is indivisible.
Again, suppose that what is heavy or weight is a dense body, and
what is light rare. Dense differs from rare in containing more matter
in the same cubic area. A point, then, if it may be heavy or light, may
be dense or rare. But the dense is divisible while a point is indivisible.
And if what is heavy must be either hard or soft, an impossible
consequence is easy to draw. For a thing is soft if its surface can be
pressed in, hard if it cannot; and if it can be pressed in it is divisible.
Moreover, no weight can consist of parts not possessing weight. For
how, except by the merest fiction, can they specify the number and
character of the parts which will produce weight? And, further, when
one weight is greater than another, the difference is a third weight;
from which it will follow that every indivisible part possesses weight.
For suppose that a body of four points possesses weight. A body
composed of more than four points will superior in weight to it, a
thing which has weight. But the difference between weight and
weight must be a weight, as the difference between white and whiter
is white. Here the difference which makes the superior weight
heavier is the single point which remains when the common number,
four, is subtracted. A single point, therefore, has weight.
Further, to assume, on the one hand, that the planes can only be put
in linear contact would be ridiculous. For just as there are two ways
of putting lines together, namely, end to and side by side, so there
must be two ways of putting planes together. Lines can be put
together so that contact is linear by laying one along the other,
though not by putting them end to end. But if, similarly, in putting
the lanes together, superficial contact is allowed as an alternative to
linear, that method will give them bodies which are not any element
nor composed of elements. Again, if it is the number of planes in a
body that makes one heavier than another, as the Timaeus explains,
921
clearly the line and the point will have weight. For the three cases
are, as we said before, analogous. But if the reason of differences of
weight is not this, but rather the heaviness of earth and the lightness
of fire, then some of the planes will be light and others heavy (which
involves a similar distinction in the lines and the points); the
earthplane, I mean, will be heavier than the fire-plane. In general, the
result is either that there is no magnitude at all, or that all magnitude
could be done away with. For a point is to a line as a line is to a plane
and as a plane is to a body. Now the various forms in passing into one
another will each be resolved into its ultimate constituents. It might
happen therefore that nothing existed except points, and that there
was no body at all. A further consideration is that if time is similarly
constituted, there would be, or might be, a time at which it was done
away with. For the indivisible now is like a point in a line. The same
consequences follow from composing the heaven of numbers, as
some of the Pythagoreans do who make all nature out of numbers.
For natural bodies are manifestly endowed with weight and
lightness, but an assemblage of units can neither be composed to
form a body nor possess weight.
The necessity that each of the simple bodies should have a natural
movement may be shown as follows. They manifestly move, and if
they have no proper movement they must move by constraint: and
the constrained is the same as the unnatural. Now an unnatural
movement presupposes a natural movement which it contravenes,
and which, however many the unnatural movements, is always one.
For naturally a thing moves in one way, while its unnatural
movements are manifold. The same may be shown, from the fact of
rest. Rest, also, must either be constrained or natural, constrained in
a place to which movement was constrained, natural in a place
movement to which was natural. Now manifestly there is a body
which is at rest at the centre. If then this rest is natural to it, clearly
motion to this place is natural to it. If, on the other hand, its rest is
922
constrained, what is hindering its motion? Something, which is at
rest: but if so, we shall simply repeat the same argument; and either
we shall come to an ultimate something to which rest where it is or
we shall have an infinite process, which is impossible. The hindrance
to its movement, then, we will suppose, is a moving thing - as
Empedocles says that it is the vortex which keeps the earth still - :
but in that case we ask, where would it have moved to but for the
vortex? It could not move infinitely; for to traverse an infinite is
impossible, and impossibilities do not happen. So the moving thing
must stop somewhere, and there rest not by constraint but naturally.
But a natural rest proves a natural movement to the place of rest.
Hence Leucippus and Democritus, who say that the primary bodies
are in perpetual movement in the void or infinite, may be asked to
explain the manner of their motion and the kind of movement which
is natural to them. For if the various elements are constrained by one
another to move as they do, each must still have a natural movement
which the constrained contravenes, and the prime mover must cause
motion not by constraint but naturally. If there is no ultimate natural
cause of movement and each preceding term in the series is always
moved by constraint, we shall have an infinite process. The same
difficulty is involved even if it is supposed, as we read in the Timaeus,
that before the ordered world was made the elements moved without
order. Their movement must have been due either to constraint or to
their nature. And if their movement was natural, a moment's
consideration shows that there was already an ordered world. For the
prime mover must cause motion in virtue of its own natural
movement, and the other bodies, moving without constraint, as they
came to rest in their proper places, would fall into the order in which
they now stand, the heavy bodies moving towards the centre and the
light bodies away from it. But that is the order of their distribution in
our world. There is a further question, too, which might be asked. Is it
possible or impossible that bodies in unordered movement should
combine in some cases into combinations like those of which bodies
of nature's composing are composed, such, I mean, as bones and
flesh? Yet this is what Empedocles asserts to have occurred under
Love. 'Many a head', says he, 'came to birth without a neck.' The
answer to the view that there are infinite bodies moving in an infinite
923
is that, if the cause of movement is single, they must move with a
single motion, and therefore not without order; and if, on the other
hand, the causes are of infinite variety, their motions too must be
infinitely varied. For a finite number of causes would produce a kind
of order, since absence of order is not proved by diversity of direction
in motions: indeed, in the world we know, not all bodies, but only
bodies of the same kind, have a common goal of movement. Again,
disorderly movement means in reality unnatural movement, since
the order proper to perceptible things is their nature. And there is
also absurdity and impossibility in the notion that the disorderly
movement is infinitely continued. For the nature of things is the
nature which most of them possess for most of the time. Thus their
view brings them into the contrary position that disorder is natural,
and order or system unnatural. But no natural fact can originate in
chance. This is a point which Anaxagoras seems to have thoroughly
grasped; for he starts his cosmogony from unmoved things. The
others, it is true, make things collect together somehow before they
try to produce motion and separation. But there is no sense in
starting generation from an original state in which bodies are
separated and in movement. Hence Empedocles begins after the
process ruled by Love: for he could not have constructed the heaven
by building it up out of bodies in separation, making them to
combine by the power of Love, since our world has its constituent
elements in separation, and therefore presupposes a previous state of
unity and combination.
These arguments make it plain that every body has its natural
movement, which is not constrained or contrary to its nature. We go
on to show that there are certain bodies whose necessary impetus is
that of weight and lightness. Of necessity, we assert, they must move,
and a moved thing which has no natural impetus cannot move either
towards or away from the centre. Suppose a body A without weight,
and a body B endowed with weight. Suppose the weightless body to
move the distance CD, while B in the same time moves the distance
CE, which will be greater since the heavy thing must move further.
Let the heavy body then be divided in the proportion CE: CD (for there
is no reason why a part of B should not stand in this relation to the
whole). Now if the whole moves the whole distance CE, the part must
924
in the same time move the distance CD. A weightless body, therefore,
and one which has weight will move the same distance, which is
impossible. And the same argument would fit the case of lightness.
Again, a body which is in motion but has neither weight nor
lightness, must be moved by constraint, and must continue its
constrained movement infinitely. For there will be a force which
moves it, and the smaller and lighter a body is the further will a given
force move it. Now let A, the weightless body, be moved the distance
CE, and B, which has weight, be moved in the same time the distance
CD. Dividing the heavy body in the proportion CE:CD, we subtract
from the heavy body a part which will in the same time move the
distance CE, since the whole moved CD: for the relative speeds of the
two bodies will be in inverse ratio to their respective sizes. Thus the
weightless body will move the same distance as the heavy in the
same time. But this is impossible. Hence, since the motion of the
weightless body will cover a greater distance than any that is
suggested, it will continue infinitely. It is therefore obvious that every
body must have a definite weight or lightness. But since 'nature'
means a source of movement within the thing itself, while a force is
a source of movement in something other than it or in itself qua
other, and since movement is always due either to nature or to
constraint, movement which is natural, as downward movement is to
a stone, will be merely accelerated by an external force, while an
unnatural movement will be due to the force alone. In either case the
air is as it were instrumental to the force. For air is both light and
heavy, and thus qua light produces upward motion, being propelled
and set in motion by the force, and qua heavy produces a downward
motion. In either case the force transmits the movement to the body
by first, as it were, impregnating the air. That is why a body moved by
constraint continues to move when that which gave the impulse
ceases to accompany it. Otherwise, i.e. if the air were not endowed
with this function, constrained movement would be impossible. And
the natural movement of a body may be helped on in the same way.
This discussion suffices to show (1) that all bodies are either light or
heavy, and (2) how unnatural movement takes place.
From what has been said earlier it is plain that there cannot be
generation either of everything or in an absolute sense of anything. It
925
is impossible that everything should be generated, unless an extra-
corporeal void is possible. For, assuming generation, the place which
is to be occupied by that which is coming to be, must have been
previously occupied by void in which no body was. Now it is quite
possible for one body to be generated out of another, air for instance
out of fire, but in the absence of any pre-existing mass generation is
impossible. That which is potentially a certain kind of body may, it is
true, become such in actuality, But if the potential body was not
already in actuality some other kind of body, the existence of an
extra-corporeal void must be admitted.
It remains to say what bodies are subject to generation, and why.
Since in every case knowledge depends on what is primary, and the
elements are the primary constituents of bodies, we must ask which
of such bodies are elements, and why; and after that what is their
number and character. The answer will be plain if we first explain
what kind of substance an element is. An element, we take it, is a
body into which other bodies may be analysed, present in them
potentially or in actuality (which of these, is still disputable), and not
itself divisible into bodies different in form. That, or something like it,
is what all men in every case mean by element. Now if what we have
described is an element, clearly there must be such bodies. For flesh
and wood and all other similar bodies contain potentially fire and
earth, since one sees these elements exuded from them; and, on the
other hand, neither in potentiality nor in actuality does fire contain
flesh or wood, or it would exude them. Similarly, even if there were
only one elementary body, it would not contain them. For though it
will be either flesh or bone or something else, that does not at once
show that it contained these in potentiality: the further question
remains, in what manner it becomes them. Now Anaxagoras opposes
Empedocles' view of the elements. Empedocles says that fire and
earth and the related bodies are elementary bodies of which all
things are composed; but this Anaxagoras denies. His elements are
926
the homoeomerous things, viz. flesh, bone, and the like. Earth and
fire are mixtures, composed of them and all the other seeds, each
consisting of a collection of all the homoeomerous bodies, separately
invisible; and that explains why from these two bodies all others are
generated. (To him fire and aither are the same thing.) But since
every natural body has it proper movement, and movements are
either simple or mixed, mixed in mixed bodies and simple in simple,
there must obviously be simple bodies; for there are simple
movements. It is plain, then, that there are elements, and why.
The next question to consider is whether the elements are finite or
infinite in number, and, if finite, what their number is. Let us first
show reason or denying that their number is infinite, as some
suppose. We begin with the view of Anaxagoras that all the
homoeomerous bodies are elements. Any one who adopts this view
misapprehends the meaning of element. Observation shows that
even mixed bodies are often divisible into homoeomerous parts;
examples are flesh, bone, wood, and stone. Since then the composite
cannot be an element, not every homoeomerous body can be an
element; only, as we said before, that which is not divisible into
bodies different in form. But even taking 'element' as they do, they
need not assert an infinity of elements, since the hypothesis of a
finite number will give identical results. Indeed even two or three
such bodies serve the purpose as well, as Empedocles' attempt
shows. Again, even on their view it turns out that all things are not
composed of homoeomerous bodies. They do not pretend that a face
is composed of faces, or that any other natural conformation is
composed of parts like itself. Obviously then it would be better to
assume a finite number of principles. They should, in fact, be as few
as possible, consistently with proving what has to be proved. This is
the common demand of mathematicians, who always assume as
principles things finite either in kind or in number. Again, if body is
distinguished from body by the appropriate qualitative difference,
927
and there is a limit to the number of differences (for the difference
lies in qualities apprehended by sense, which are in fact finite in
number, though this requires proof), then manifestly there is
necessarily a limit to the number of elements.
There is, further, another view - that of Leucippus and Democritus of
Abdera - the implications of which are also unacceptable. The
primary masses, according to them, are infinite in number and
indivisible in mass: one cannot turn into many nor many into one;
and all things are generated by their combination and involution.
Now this view in a sense makes things out to be numbers or
composed of numbers. The exposition is not clear, but this is its real
meaning. And further, they say that since the atomic bodies differ in
shape, and there is an infinity of shapes, there is an infinity of simple
bodies. But they have never explained in detail the shapes of the
various elements, except so far to allot the sphere to fire. Air, water,
and the rest they distinguished by the relative size of the atom,
assuming that the atomic substance was a sort of master-seed for
each and every element. Now, in the first place, they make the
mistake already noticed. The principles which they assume are not
limited in number, though such limitation would necessitate no
other alteration in their theory. Further, if the differences of bodies
are not infinite, plainly the elements will not be an infinity. Besides, a
view which asserts atomic bodies must needs come into conflict with
the mathematical sciences, in addition to invalidating many common
opinions and apparent data of sense perception. But of these things
we have already spoken in our discussion of time and movement.
They are also bound to contradict themselves. For if the elements are
atomic, air, earth, and water cannot be differentiated by the relative
sizes of their atoms, since then they could not be generated out of
one another. The extrusion of the largest atoms is a process that will
in time exhaust the supply; and it is by such a process that they
account for the generation of water, air, and earth from one another.
Again, even on their own presuppositions it does not seem as if the
elements would be infinite in number. The atoms differ in figure, and
all figures are composed of pyramids, rectilinear the case of
rectilinear figures, while the sphere has eight pyramidal parts. The
figures must have their principles, and, whether these are one or two
928
or more, the simple bodies must be the same in number as they.
Again, if every element has its proper movement, and a simple body
has a simple movement, and the number of simple movements is not
infinite, because the simple motions are only two and the number of
places is not infinite, on these grounds also we should have to deny
that the number of elements is infinite.
Since the number of the elements must be limited, it remains to
inquire whether there is more than one element. Some assume one
only, which is according to some water, to others air, to others fire, to
others again something finer than water and denser than air, an
infinite body - so they say - bracing all the heavens.
Now those who decide for a single element, which is either water or
air or a body finer than water and denser than air, and proceed to
generate other things out of it by use of the attributes density and
rarity, all alike fail to observe the fact that they are depriving the
element of its priority. Generation out of the elements is, as they say,
synthesis, and generation into the elements is analysis, so that the
body with the finer parts must have priority in the order of nature.
But they say that fire is of all bodies the finest. Hence fire will be first
in the natural order. And whether the finest body is fire or not makes
no difference; anyhow it must be one of the other bodies that is
primary and not that which is intermediate. Again, density and rarity,
as instruments of generation, are equivalent to fineness and
coarseness, since the fine is rare, and coarse in their use means
dense. But fineness and coarseness, again, are equivalent to
greatness and smallness, since a thing with small parts is fine and a
thing with large parts coarse. For that which spreads itself out widely
is fine, and a thing composed of small parts is so spread out. In the
end, then, they distinguish the various other substances from the
element by the greatness and smallness of their parts. This method
of distinction makes all judgement relative. There will be no absolute
929
distinction between fire, water, and air, but one and the same body
will be relatively to this fire, relatively to something else air. The same
difficulty is involved equally in the view elements and distinguishes
them by their greatness and smallness. The principle of distinction
between bodies being quantity, the various sizes will be in a definite
ratio, and whatever bodies are in this ratio to one another must be
air, fire, earth, and water respectively. For the ratios of smaller bodies
may be repeated among greater bodies.
Those who start from fire as the single element, while avoiding this
difficulty, involve themselves in many others. Some of them give fire
a particular shape, like those who make it a pyramid, and this on one
of two grounds. The reason given may be - more crudely - that the
pyramid is the most piercing of figures as fire is of bodies, or - more
ingeniously - the position may be supported by the following
argument. As all bodies are composed of that which has the finest
parts, so all solid figures are composed of pryamids: but the finest
body is fire, while among figures the pyramid is primary and has the
smallest parts; and the primary body must have the primary figure:
therefore fire will be a pyramid. Others, again, express no opinion on
the subject of its figure, but simply regard it as the of the finest parts,
which in combination will form other bodies, as the fusing of gold-
dust produces solid gold. Both of these views involve the same
difficulties. For (1) if, on the one hand, they make the primary body
an atom, the view will be open to the objections already advanced
against the atomic theory. And further the theory is inconsistent with
a regard for the facts of nature. For if all bodies are quantitatively
commensurable, and the relative size of the various homoeomerous
masses and of their several elements are in the same ratio, so that
the total mass of water, for instance, is related to the total mass of air
as the elements of each are to one another, and so on, and if there is
more air than water and, generally, more of the finer body than of the
coarser, obviously the element of water will be smaller than that of
air. But the lesser quantity is contained in the greater. Therefore the
air element is divisible. And the same could be shown of fire and of
all bodies whose parts are relatively fine. (2) If, on the other hand, the
primary body is divisible, then (a) those who give fire a special shape
will have to say that a part of fire is not fire, because a pyramid is not
930
composed of pyramids, and also that not every body is either an
element or composed of elements, since a part of fire will be neither
fire nor any other element. And (b) those whose ground of distinction
is size will have to recognize an element prior to the element, a
regress which continues infinitely, since every body is divisible and
that which has the smallest parts is the element. Further, they too
will have to say that the same body is relatively to this fire and
relatively to that air, to others again water and earth.
The common error of all views which assume a single element is that
they allow only one natural movement, which is the same for every
body. For it is a matter of observation that a natural body possesses a
principle of movement. If then all bodies are one, all will have one
movement. With this motion the greater their quantity the more they
will move, just as fire, in proportion as its quantity is greater, moves
faster with the upward motion which belongs to it. But the fact is
that increase of quantity makes many things move the faster
downward. For these reasons, then, as well as from the distinction
already established of a plurality of natural movements, it is
impossible that there should be only one element. But if the elements
are not an infinity and not reducible to one, they must be several and
finite in number.
First we must inquire whether the elements are eternal or subject to
generation and destruction; for when this question has been
answered their number and character will be manifest. In the first
place, they cannot be eternal. It is a matter of observation that fire,
water, and every simple body undergo a process of analysis, which
must either continue infinitely or stop somewhere. (1) Suppose it
infinite. Then the time occupied by the process will be infinite, and
also that occupied by the reverse process of synthesis. For the
processes of analysis and synthesis succeed one another in the
various parts. It will follow that there are two infinite times which are
931
mutually exclusive, the time occupied by the synthesis, which is
infinite, being preceded by the period of analysis. There are thus two
mutually exclusive infinites, which is impossible. (2) Suppose, on the
other hand, that the analysis stops somewhere. Then the body at
which it stops will be either atomic or, as Empedocles seems to have
intended, a divisible body which will yet never be divided. The
foregoing arguments show that it cannot be an atom; but neither can
it be a divisible body which analysis will never reach. For a smaller
body is more easily destroyed than a larger; and a destructive process
which succeeds in destroying, that is, in resolving into smaller
bodies, a body of some size, cannot reasonably be expected to fail
with the smaller body. Now in fire we observe a destruction of two
kinds: it is destroyed by its contrary when it is quenched, and by
itself when it dies out. But the effect is produced by a greater
quantity upon a lesser, and the more quickly the smaller it is. The
elements of bodies must therefore be subject to destruction and
generation.
Since they are generated, they must be generated either from
something incorporeal or from a body, and if from a body, either from
one another or from something else. The theory which generates
them from something incorporeal requires an extra-corporeal void.
For everything that comes to be comes to be in something, and that
in which the generation takes place must either be incorporeal or
possess body; and if it has body, there will be two bodies in the same
place at the same time, viz. that which is coming to be and that
which was previously there, while if it is incorporeal, there must be
an extra-corporeal void. But we have already shown that this is
impossible. But, on the other hand, it is equally impossible that the
elements should be generated from some kind of body. That would
involve a body distinct from the elements and prior to them. But if
this body possesses weight or lightness, it will be one of the
elements; and if it has no tendency to movement, it will be an
immovable or mathematical entity, and therefore not in a place at all.
A place in which a thing is at rest is a place in which it might move,
either by constraint, i.e. unnaturally, or in the absence of constraint,
i.e. naturally. If, then, it is in a place and somewhere, it will be one of
the elements; and if it is not in a place, nothing can come from it,
932
since that which comes into being and that out of which it comes
must needs be together. The elements therefore cannot be generated
from something incorporeal nor from a body which is not an
element, and the only remaining alternative is that they are
generated from one another.
We must, therefore, turn to the question, what is the manner of their
generation from one another? Is it as Empedocles and Democritus
say, or as those who resolve bodies into planes say, or is there yet
another possibility? (1) What the followers of Empedocles do, though
without observing it themselves, is to reduce the generation of
elements out of one another to an illusion. They make it a process of
excretion from a body of what was in it all the time - as though
generation required a vessel rather than a material - so that it
involves no change of anything. And even if this were accepted, there
are other implications equally unsatisfactory. We do not expect a
mass of matter to be made heavier by compression. But they will be
bound to maintain this, if they say that water is a body present in air
and excreted from air, since air becomes heavier when it turns into
water. Again, when the mixed body is divided, they can show no
reason why one of the constituents must by itself take up more room
than the body did: but when water turns into air, the room occupied
is increased. The fact is that the finer body takes up more room, as is
obvious in any case of transformation. As the liquid is converted into
vapour or air the vessel which contains it is often burst because it
does not contain room enough. Now, if there is no void at all, and if,
as those who take this view say, there is no expansion of bodies, the
impossibility of this is manifest: and if there is void and expansion,
there is no accounting for the fact that the body which results from
division cfpies of necessity a greater space. It is inevitable, too, that
generation of one out of another should come to a stop, since a finite
quantum cannot contain an infinity of finite quanta. When earth
produces water something is taken away from the earth, for the
933
process is one of excretion. The same thing happens again when the
residue produces water. But this can only go on for ever, if the finite
body contains an infinity, which is impossible. Therefore the
generation of elements out of one another will not always continue.
(2) We have now explained that the mutual transformations of the
elements cannot take place by means of excretion. The remaining
alternative is that they should be generated by changing into one
another. And this in one of two ways, either by change of shape, as
the same wax takes the shape both of a sphere and of a cube, or, as
some assert, by resolution into planes, (a) Generation by change of
shape would necessarily involve the assertion of atomic bodies. For if
the particles were divisible there would be a part of fire which was
not fire and a part of earth which was not earth, for the reason that
not every part of a pyramid is a pyramid nor of a cube a cube. But if
(b) the process is resolution into planes, the first difficulty is that the
elements cannot all be generated out of one another. This they are
obliged to assert, and do assert. It is absurd, because it is
unreasonable that one element alone should have no part in the
transformations, and also contrary to the observed data of sense,
according to which all alike change into one another. In fact their
explanation of the observations is not consistent with the
observations. And the reason is that their ultimate principles are
wrongly assumed: they had certain predetermined views, and were
resolved to bring everything into line with them. It seems that
perceptible things require perceptible principles, eternal things
eternal principles, corruptible things corruptible principles; and, in
general, every subject matter principles homogeneous with itself. But
they, owing to their love for their principles, fall into the attitude of
men who undertake the defence of a position in argument. In the
confidence that the principles are true they are ready to accept any
consequence of their application. As though some principles did not
require to be judged from their results, and particularly from their
final issue! And that issue, which in the case of productive knowledge
is the product, in the knowledge of nature is the unimpeachable
evidence of the senses as to each fact.
934
The result of their view is that earth has the best right to the name
element, and is alone indestructible; for that which is indissoluble is
indestructible and elementary, and earth alone cannot be dissolved
into any body but itself. Again, in the case of those elements which
do suffer dissolution, the 'suspension' of the triangles is
unsatisfactory. But this takes place whenever one is dissolved into
another, because of the numerical inequality of the triangles which
compose them. Further, those who hold these views must needs
suppose that generation does not start from a body. For what is
generated out of planes cannot be said to have been generated from a
body. And they must also assert that not all bodies are divisible,
coming thus into conflict with our most accurate sciences, namely
the mathematical, which assume that even the intelligible is
divisible, while they, in their anxiety to save their hypothesis, cannot
even admit this of every perceptible thing. For any one who gives
each element a shape of its own, and makes this the ground of
distinction between the substances, has to attribute to them
indivisibility; since division of a pyramid or a sphere must leave
somewhere at least a residue which is not sphere or a pyramid.
Either, then, a part of fire is not fire, so that there is a body prior to
the element - for every body is either an element or composed of
elements - or not every body is divisible.
8
In general, the attempt to give a shape to each of the simple bodies is
unsound, for the reason, first, that they will not succeed in filling the
whole. It is agreed that there are only three plane figures which can
fill a space, the triangle, the square, and the hexagon, and only two
solids, the pyramid and the cube. But the theory needs more than
these because the elements which it recognizes are more in number.
Secondly, it is manifest that the simple bodies are often given a
shape by the place in which they are included, particularly water and
air. In such a case the shape of the element cannot persist; for, if it
did, the contained mass would not be in continuous contact with the
935
containing body; while, if its shape is changed, it will cease to be
water, since the distinctive quality is shape. Clearly, then, their
shapes are not fixed. Indeed, nature itself seems to offer
corroboration of this theoretical conclusion. Just as in other cases the
substratum must be formless and unshapen - for thus the 'all-
receptive', as we read in the Timaeus, will be best for modelling - so
the elements should be conceived as a material for composite things;
and that is why they can put off their qualitative distinctions and
pass into one another. Further, how can they account for the
generation of flesh and bone or any other continuous body? The
elements alone cannot produce them because their collocation
cannot produce a continuum. Nor can the composition of planes; for
this produces the elements themselves, not bodies made up of them.
Any one then who insists upon an exact statement of this kind of
theory, instead of assenting after a passing glance at it, will see that it
removes generation from the world.
Further, the very properties, powers, and motions, to which they paid
particular attention in allotting shapes, show the shapes not to be in
accord with the bodies. Because fire is mobile and productive of heat
and combustion, some made it a sphere, others a pyramid. These
shapes, they thought, were the most mobile because they offer the
fewest points of contact and are the least stable of any; they were
also the most apt to produce warmth and combustion, because the
one is angular throughout while the other has the most acute angles,
and the angles, they say, produce warmth and combustion. Now, in
the first place, with regard to movement both are in error. These may
be the figures best adapted to movement; they are not, however, well
adapted to the movement of fire, which is an upward and rectilinear
movement, but rather to that form of circular movement which we
call rolling. Earth, again, they call a cube because it is stable and at
rest. But it rests only in its own place, not anywhere; from any other
it moves if nothing hinders, and fire and the other bodies do the
same. The obvious inference, therefore, is that fire and each several
element is in a foreign place a sphere or a pyramid, but in its own a
cube. Again, if the possession of angles makes a body produce heat
and combustion, every element produces heat, though one may do so
more than another. For they all possess angles, the octahedron and
936
dodecahedron as well as the pyramid; and Democritus makes even
the sphere a kind of angle, which cuts things because of its mobility.
The difference, then, will be one of degree: and this is plainly false.
They must also accept the inference that the mathematical produce
heat and combustion, since they too possess angles and contain
atomic spheres and pyramids, especially if there are, as they allege,
atomic figures. Anyhow if these functions belong to some of these
things and not to others, they should explain the difference, instead
of speaking in quite general terms as they do. Again, combustion of a
body produces fire, and fire is a sphere or a pyramid. The body, then,
is turned into spheres or pyramids. Let us grant that these figures
may reasonably be supposed to cut and break up bodies as fire does;
still it remains quite inexplicable that a pyramid must needs produce
pyramids or a sphere spheres. One might as well postulate that a
knife or a saw divides things into knives or saws. It is also ridiculous
to think only of division when allotting fire its shape. Fire is generally
thought of as combining and connecting rather than as separating.
For though it separates bodies different in kind, it combines those
which are the same; and the combining is essential to it, the
functions of connecting and uniting being a mark of fire, while the
separating is incidental. For the expulsion of the foreign body is an
incident in the compacting of the homogeneous. In choosing the
shape, then, they should have thought either of both functions or
preferably of the combining function. In addition, since hot and cold
are contrary powers, it is impossible to allot any shape to the cold.
For the shape given must be the contrary of that given to the hot, but
there is no contrariety between figures. That is why they have all left
the cold out, though properly either all or none should have their
distinguishing figures. Some of them, however, do attempt to explain
this power, and they contradict themselves. A body of large particles,
they say, is cold because instead of penetrating through the passages
it crushes. Clearly, then, that which is hot is that which penetrates
these passages, or in other words that which has fine particles. It
results that hot and cold are distinguished not by the figure but by
the size of the particles. Again, if the pyramids are unequal in size,
the large ones will not be fire, and that figure will produce not
combustion but its contrary.
937
From what has been said it is clear that the difference of the
elements does not depend upon their shape. Now their most
important differences are those of property, function, and power; for
every natural body has, we maintain, its own functions, properties,
and powers. Our first business, then, will be to speak of these, and
that inquiry will enable us to explain the differences of each from
each.
Book IV
We have now to consider the terms 'heavy' and 'light'. We must ask
what the bodies so called are, how they are constituted, and what is
the reason of their possessing these powers. The consideration of
these questions is a proper part of the theory of movement, since we
call things heavy and light because they have the power of being
moved naturally in a certain way. The activities corresponding to
these powers have not been given any name, unless it is thought that
'impetus' is such a name. But because the inquiry into nature is
concerned with movement, and these things have in themselves
some spark (as it were) of movement, all inquirers avail themselves
of these powers, though in all but a few cases without exact
discrimination. We must then first look at whatever others have said,
and formulate the questions which require settlement in the
interests of this inquiry, before we go on to state our own view of the
matter.
Language recognizes (a) an absolute, (b) a relative heavy and light. Of
two heavy things, such as wood and bronze, we say that the one is
938
relatively light, the other relatively heavy. Our predecessors have not
dealt at all with the absolute use, of the terms, but only with the
relative. I mean, they do not explain what the heavy is or what the
light is, but only the relative heaviness and lightness of things
possessing weight. This can be made clearer as follows. There are
things whose constant nature it is to move away from the centre,
while others move constantly towards the centre; and of these
movements that which is away from the centre I call upward
movement and that which is towards it I call downward movement.
(The view, urged by some, that there is no up and no down in the
heaven, is absurd. There can be, they say, no up and no down, since
the universe is similar every way, and from any point on the earth's
surface a man by advancing far enough will come to stand foot to
foot with himself. But the extremity of the whole, which we call
'above', is in position above and in nature primary. And since the
universe has an extremity and a centre, it must clearly have an up
and down. Common usage is thus correct, though inadequate. And
the reason of its inadequacy is that men think that the universe is
not similar every way. They recognize only the hemisphere which is
over us. But if they went on to think of the world as formed on this
pattern all round, with a centre identically related to each point on
the extremity, they would have to admit that the extremity was above
and the centre below.) By absolutely light, then, we mean that which
moves upward or to the extremity, and by absolutely heavy that
which moves downward or to the centre. By lighter or relatively light
we mean that one, of two bodies endowed with weight and equal in
bulk, which is exceeded by the other in the speed of its natural
downward movement.
Those of our predecessors who have entered upon this inquiry have
for the most part spoken of light and heavy things only in the sense
in which one of two things both endowed with weight is said to be
the lighter. And this treatment they consider a sufficient analysis also
939
of the notions of absolute heaviness, to which their account does not
apply. This, however, will become clearer as we advance. One use of
the terms 'lighter' and 'heavier' is that which is set forth in writing in
the Timaeus, that the body which is composed of the greater number
of identical parts is relatively heavy, while that which is composed of
a smaller number is relatively light. As a larger quantity of lead or of
bronze is heavier than a smaller - and this holds good of all
homogeneous masses, the superior weight always depending upon a
numerical superiority of equal parts - in precisely the same way, they
assert, lead is heavier than wood. For all bodies, in spite of the
general opinion to the contrary, are composed of identical parts and
of a single material. But this analysis says nothing of the absolutely
heavy and light. The facts are that fire is always light and moves
upward, while earth and all earthy things move downwards or
towards the centre. It cannot then be the fewness of the triangles (of
which, in their view, all these bodies are composed) which disposes
fire to move upward. If it were, the greater the quantity of fire the
slower it would move, owing to the increase of weight due to the
increased number of triangles. But the palpable fact, on the contrary,
is that the greater the quantity, the lighter the mass is and the
quicker its upward movement: and, similarly, in the reverse
movement from above downward, the small mass will move quicker
and the large slower. Further, since to be lighter is to have fewer of
these homogeneous parts and to be heavier is to have more, and air,
water, and fire are composed of the same triangles, the only
difference being in the number of such parts, which must therefore
explain any distinction of relatively light and heavy between these
bodies, it follows that there must be a certain quantum of air which
is heavier than water. But the facts are directly opposed to this. The
larger the quantity of air the more readily it moves upward, and any
portion of air without exception will rise up out of the water.
So much for one view of the distinction between light and heavy. To
others the analysis seems insufficient; and their views on the subject,
though they belong to an older generation than ours, have an air of
novelty. It is apparent that there are bodies which, when smaller in
bulk than others, yet exceed them in weight. It is therefore obviously
insufficient to say that bodies of equal weight are composed of an
940
equal number of primary parts: for that would give equality of bulk.
Those who maintain that the primary or atomic parts, of which
bodies endowed with weight are composed, are planes, cannot so
speak without absurdity; but those who regard them as solids are in a
better position to assert that of such bodies the larger is the heavier.
But since in composite bodies the weight obviously does not
correspond in this way to the bulk, the lesser bulk being often
superior in weight (as, for instance, if one be wool and the other
bronze), there are some who think and say that the cause is to be
found elsewhere. The void, they say, which is imprisoned in bodies,
lightens them and sometimes makes the larger body the lighter. The
reason is that there is more void. And this would also account for the
fact that a body composed of a number of solid parts equal to, or
even smaller than, that of another is sometimes larger in bulk than it.
In short, generally and in every case a body is relatively light when it
contains a relatively large amount of void. This is the way they put it
themselves, but their account requires an addition. Relative lightness
must depend not only on an excess of void, but also an a defect of
solid: for if the ratio of solid to void exceeds a certain proportion, the
relative lightness will disappear. Thus fire, they say, is the lightest of
things just for this reason that it has the most void. But it would
follow that a large mass of gold, as containing more void than a small
mass of fire, is lighter than it, unless it also contains many times as
much solid. The addition is therefore necessary.
Of those who deny the existence of a void some, like Anaxagoras and
Empedocles, have not tried to analyse the notions of light and heavy
at all; and those who, while still denying the existence of a void, have
attempted this, have failed to explain why there are bodies which are
absolutely heavy and light, or in other words why some move upward
and others downward. The fact, again, that the body of greater bulk is
sometimes lighter than smaller bodies is one which they have passed
over in silence, and what they have said gives no obvious suggestion
for reconciling their views with the observed facts.
But those who attribute the lightness of fire to its containing so much
void are necessarily involved in practically the same difficulties. For
though fire be supposed to contain less solid than any other body, as
941
well as more void, yet there will be a certain quantum of fire in which
the amount of solid or plenum is in excess of the solids contained in
some small quantity of earth. They may reply that there is an excess
of void also. But the question is, how will they discriminate the
absolutely heavy? Presumably, either by its excess of solid or by its
defect of void. On the former view there could be an amount of earth
so small as to contain less solid than a large mass of fire. And
similarly, if the distinction rests on the amount of void, there will be a
body, lighter than the absolutely light, which nevertheless moves
downward as constantly as the other moves upward. But that cannot
be so, since the absolutely light is always lighter than bodies which
have weight and move downward, while, on the other hand, that
which is lighter need not be light, because in common speech we
distinguish a lighter and a heavier (viz. water and earth) among
bodies endowed with weight. Again, the suggestion of a certain ratio
between the void and the solid in a body is no more equal to solving
the problem before us. The manner of speaking will issue in a similar
impossibility. For any two portions of fire, small or great, will exhibit
the same ratio of solid to void, but the upward movement of the
greater is quicker than that of the less, just as the downward
movement of a mass of gold or lead, or of any other body endowed
with weight, is quicker in proportion to its size. This, however, should
not be the case if the ratio is the ground of distinction between heavy
things and light. There is also an absurdity in attributing the upward
movement of bodies to a void which does not itself move. If, however,
it is the nature of a void to move upward and of a plenum to move
downward, and therefore each causes a like movement in other
things, there was no need to raise the question why composite bodies
are some light and some heavy; they had only to explain why these
two things are themselves light and heavy respectively, and to give,
further, the reason why the plenum and the void are not eternally
separated. It is also unreasonable to imagine a place for the void, as if
the void were not itself a kind of place. But if the void is to move, it
must have a place out of which and into which the change carries it.
Also what is the cause of its movement? Not, surely, its voidness: for
it is not the void only which is moved, but also the solid.
942
Similar difficulties are involved in all other methods of distinction,
whether they account for the relative lightness and heaviness of
bodies by distinctions of size, or proceed on any other principle, so
long as they attribute to each the same matter, or even if they
recognize more than one matter, so long as that means only a pair of
contraries. If there is a single matter, as with those who compose
things of triangles, nothing can be absolutely heavy or light: and if
there is one matter and its contrary - the void, for instance, and the
plenum - no reason can be given for the relative lightness and
heaviness of the bodies intermediate between the absolutely light
and heavy when compared either with one another or with these
themselves. The view which bases the distinction upon differences of
size is more like a mere fiction than those previously mentioned, but,
in that it is able to make distinctions between the four elements, it is
in a stronger position for meeting the foregoing difficulties. Since,
however, it imagines that these bodies which differ in size are all
made of one substance, it implies, equally with the view that there is
but one matter, that there is nothing absolutely light and nothing
which moves upward (except as being passed by other things or
forced up by them); and since a multitude of small atoms are heavier
than a few large ones, it will follow that much air or fire is heavier
than a little water or earth, which is impossible.
These, then, are the views which have been advanced by others and
the terms in which they state them. We may begin our own
statement by settling a question which to some has been the main
difficulty - the question why some bodies move always and naturally
upward and others downward, while others again move both upward
and downward. After that we will inquire into light and heavy and of
the various phenomena connected with them. The local movement
of each body into its own place must be regarded as similar to what
happens in connexion with other forms of generation and change.
There are, in fact, three kinds of movement, affecting respectively the
943
size, the form, and the place of a thing, and in each it is observable
that change proceeds from a contrary to a contrary or to something
intermediate: it is never the change of any chance subject in any
chance direction, nor, similarly, is the relation of the mover to its
object fortuitous: the thing altered is different from the thing
increased, and precisely the same difference holds between that
which produces alteration and that which produces increase. In the
same manner it must be thought that produces local motion and that
which is so moved are not fortuitously related. Now, that which
produces upward and downward movement is that which produces
weight and lightness, and that which is moved is that which is
potentially heavy or light, and the movement of each body to its own
place is motion towards its own form. (It is best to interpret in this
sense the common statement of the older writers that 'like moves to
like'. For the words are not in every sense true to fact. If one were to
remove the earth to where the moon now is, the various fragments of
earth would each move not towards it but to the place in which it
now is. In general, when a number of similar and undifferentiated
bodies are moved with the same motion this result is necessarily
produced, viz. that the place which is the natural goal of the
movement of each single part is also that of the whole. But since the
place of a thing is the boundary of that which contains it, and the
continent of all things that move upward or downward is the
extremity and the centre, and this boundary comes to be, in a sense,
the form of that which is contained, it is to its like that a body moves
when it moves to its own place. For the successive members of the
scries are like one another: water, I mean, is like air and air like fire,
and between intermediates the relation may be converted, though
not between them and the extremes; thus air is like water, but water
is like earth: for the relation of each outer body to that which is next
within it is that of form to matter.) Thus to ask why fire moves
upward and earth downward is the same as to ask why the healable,
when moved and changed qua healable, attains health and not
whiteness; and similar questions might be asked concerning any
other subject of aletion. Of course the subject of increase, when
changed qua increasable, attains not health but a superior size. The
same applies in the other cases. One thing changes in quality,
944
another in quantity: and so in place, a light thing goes upward, a
heavy thing downward. The only difference is that in the last case,
viz. that of the heavy and the light, the bodies are thought to have a
spring of change within themselves, while the subjects of healing
and increase are thought to be moved purely from without.
Sometimes, however, even they change of themselves, ie. in response
to a slight external movement reach health or increase, as the case
may be. And since the same thing which is healable is also receptive
of disease, it depends on whether it is moved qua healable or qua
liable to disease whether the motion is towards health or towards
disease. But the reason why the heavy and the light appear more
than these things to contain within themselves the source of their
movements is that their matter is nearest to being. This is indicated
by the fact that locomotion belongs to bodies only when isolated
from other bodies, and is generated last of the several kinds of
movement; in order of being then it will be first. Now whenever air
comes into being out of water, light out of heavy, it goes to the upper
place. It is forthwith light: becoming is at an end, and in that place it
has being. Obviously, then, it is a potentiality, which, in its passage to
actuality, comes into that place and quantity and quality which
belong to its actuality. And the same fact explains why what is
already actually fire or earth moves, when nothing obstructs it,
towards its own place. For motion is equally immediate in the case of
nutriment, when nothing hinders, and in the case of the thing
healed, when nothing stays the healing. But the movement is also
due to the original creative force and to that which removes the
hindrance or off which the moving thing rebounded, as was
explained in our opening discussions, where we tried to show how
none of these things moves itself. The reason of the various motions
of the various bodies, and the meaning of the motion of a body to its
own place, have now been explained.
945
We have now to speak of the distinctive properties of these bodies
and of the various phenomena connected with them. In accordance
with general conviction we may distinguish the absolutely heavy, as
that which sinks to the bottom of all things, from the absolutely light,
which is that which rises to the surface of all things. I use the term
'absolutely', in view of the generic character of 'light' and 'heavy', in
order to confine the application to bodies which do not combine
lightness and heaviness. It is apparent, I mean, that fire, in whatever
quantity, so long as there is no external obstacle moves upward, and
earth downward; and, if the quantity is increased, the movement is
the same, though swifter. But the heaviness and lightness of bodies
which combine these qualities is different from this, since while they
rise to the surface of some bodies they sink to the bottom of others.
Such are air and water. Neither of them is absolutely either light or
heavy. Both are lighter than earth - for any portion of either rises to
the surface of it - but heavier than fire, since a portion of either,
whatever its quantity, sinks to the bottom of fire; compared together,
however, the one has absolute weight, the other absolute lightness,
since air in any quantity rises to the surface of water, while water in
any quantity sinks to the bottom of air. Now other bodies are
severally light and heavy, and evidently in them the attributes are
due to the difference of their uncompounded parts: that is to say,
according as the one or the other happens to preponderate the bodies
will be heavy and light respectively. Therefore we need only speak of
these parts, since they are primary and all else consequential: and in
so doing we shall be following the advice which we gave to those
whose attribute heaviness to the presence of plenum and lightness to
that of void. It is due to the properties of the elementary bodies that a
body which is regarded as light in one place is regarded as heavy in
another, and vice versa. In air, for instance, a talent's weight of wood
is heavier than a mina of lead, but in water the wood is the lighter.
The reason is that all the elements except fire have weight and all
but earth lightness. Earth, then, and bodies in which earth
preponderates, must needs have weight everywhere, while water is
heavy anywhere but in earth, and air is heavy when not in water or
earth. In its own place each of these bodies has weight except fire,
946
even air. Of this we have evidence in the fact that a bladder when
inflated weighs more than when empty. A body, then, in which air
preponderates over earth and water, may well be lighter than
something in water and yet heavier than it in air, since such a body
does not rise in air but rises to the surface in water.
The following account will make it plain that there is an absolutely
light and an absolutely heavy body. And by absolutely light I mean
one which of its own nature always moves upward, by absolutely
heavy one which of its own nature always moves downward, if no
obstacle is in the way. There are, I say, these two kinds of body, and it
is not the case, as some maintain, that all bodies have weight.
Different views are in fact agreed that there is a heavy body, which
moves uniformly towards the centre. But is also similarly a light body.
For we see with our eyes, as we said before, that earthy things sink to
the bottom of all things and move towards the centre. But the centre
is a fixed point. If therefore there is some body which rises to the
surface of all things - and we observe fire to move upward even in air
itself, while the air remains at rest - clearly this body is moving
towards the extremity. It cannot then have any weight. If it had, there
would be another body in which it sank: and if that had weight, there
would be yet another which moved to the extremity and thus rose to
the surface of all moving things. In fact, however, we have no
evidence of such a body. Fire, then, has no weight. Neither has earth
any lightness, since it sinks to the bottom of all things, and that
which sinks moves to the centre. That there is a centre towards
which the motion of heavy things, and away from which that of light
things is directed, is manifest in many ways. First, because no
movement can continue to infinity. For what cannot be can no more
come-to-be than be, and movement is a coming-to-be in one place
from another. Secondly, like the upward movement of fire, the
downward movement of earth and all heavy things makes equal
angles on every side with the earth's surface: it must therefore be
directed towards the centre. Whether it is really the centre of the
earth and not rather that of the whole to which it moves, may be left
to another inquiry, since these are coincident. But since that which
sinks to the bottom of all things moves to the centre, necessarily that
which rises to the surface moves to the extremity of the region in
947
which the movement of these bodies takes place. For the centre is
opposed as contrary to the extremity, as that which sinks is opposed
to that which rises to the surface. This also gives a reasonable ground
for the duality of heavy and light in the spatial duality centre and
extremity. Now there is also the intermediate region to which each
name is given in opposition to the other extreme. For that which is
intermediate between the two is in a sense both extremity and
centre. For this reason there is another heavy and light; namely,
water and air. But in our view the continent pertains to form and the
contained to matter: and this distinction is present in every genus.
Alike in the sphere of quality and in that of quantity there is that
which corresponds rather to form and that which corresponds to
matter. In the same way, among spatial distinctions, the above
belongs to the determinate, the below to matter. The same holds,
consequently, also of the matter itself of that which is heavy and
light: as potentially possessing the one character, it is matter for the
heavy, and as potentially possessing the other, for the light. It is the
same matter, but its being is different, as that which is receptive of
disease is the same as that which is receptive of health, though in
being different from it, and therefore diseasedness is different from
healthiness.
A thing then which has the one kind of matter is light and always
moves upward, while a thing which has the opposite matter is heavy
and always moves downward. Bodies composed of kinds of matter
different from these but having relatively to each other the character
which these have absolutely, possess both the upward and the
downward motion. Hence air and water each have both lightness and
weight, and water sinks to the bottom of all things except earth,
while air rises to the surface of all things except fire. But since there
is one body only which rises to the surface of all things and one only
which sinks to the bottom of all things, there must needs be two
other bodies which sink in some bodies and rise to the surface of
948
others. The kinds of matter, then, must be as numerous as these
bodies, i.e. four, but though they are four there must be a common
matter of all - particularly if they pass into one another - which in
each is in being different. There is no reason why there should not be
one or more intermediates between the contraries, as in the case of
colour; for 'intermediate' and 'mean' are capable of more than one
application.
Now in its own place every body endowed with both weight and
lightness has weight - whereas earth has weight everywhere - but
they only have lightness among bodies to whose surface they rise.
Hence when a support is withdrawn such a body moves downward
until it reaches the body next below it, air to the place of water and
water to that of earth. But if the fire above air is removed, it will not
move upward to the place of fire, except by constraint; and in that
way water also may be drawn up, when the upward movement of air
which has had a common surface with it is swift enough to
overpower the downward impulse of the water. Nor does water move
upward to the place of air, except in the manner just described. Earth
is not so affected at all, because a common surface is not possible to
it. Hence water is drawn up into the vessel to which fire is applied,
but not earth. As earth fails to move upward, so fire fails to move
downward when air is withdrawn from beneath it: for fire has no
weight even in its own place, as earth has no lightness. The other two
move downward when the body beneath is withdrawn because, while
the absolutely heavy is that which sinks to the bottom of all things,
the relatively heavy sinks to its own place or to the surface of the
body in which it rises, since it is similar in matter to it.
It is plain that one must suppose as many distinct species of matter
as there are bodies. For if, first, there is a single matter of all things,
as, for instance, the void or the plenum or extension or the triangles,
either all things will move upward or all things will move downward,
and the second motion will be abolished. And so, either there will be
no absolutely light body, if superiority of weight is due to superior
size or number of the constituent bodies or to the fullness of the
body: but the contrary is a matter of observation, and it has been
shown that the downward and upward movements are equally
949
constant and universal: or, if the matter in question is the void or
something similar, which moves uniformly upward, there will be
nothing to move uniformly downward. Further, it will follow that the
intermediate bodies move downward in some cases quicker than
earth: for air in sufficiently large quantity will contain a larger
number of triangles or solids or particles. It is, however, manifest that
no portion of air whatever moves downward. And the same
reasoning applies to lightness, if that is supposed to depend on
superiority of quantity of matter. But if, secondly, the kinds of matter
are two, it will be difficult to make the intermediate bodies behave as
air and water behave. Suppose, for example, that the two asserted are
void and plenum. Fire, then, as moving upward, will be void, earth, as
moving downward, plenum; and in air, it will be said, fire
preponderates, in water, earth. There will then be a quantity of water
containing more fire than a little air, and a large amount of air will
contain more earth than a little water: consequently we shall have to
say that air in a certain quantity moves downward more quickly than
a little water. But such a thing has never been observed anywhere.
Necessarily, then, as fire goes up because it has something, e.g. void,
which other things do not have, and earth goes downward because it
has plenum, so air goes to its own place above water because it has
something else, and water goes downward because of some special
kind of body. But if the two bodies are one matter, or two matters
both present in each, there will be a certain quantity of each at which
water will excel a little air in the upward movement and air excel
water in the downward movement, as we have already often said.
The shape of bodies will not account for their moving upward or
downward in general, though it will account for their moving faster
or slower. The reasons for this are not difficult to see. For the problem
thus raised is why a flat piece of iron or lead floats upon water, while
smaller and less heavy things, so long as they are round or long - a
needle, for instance - sink down; and sometimes a thing floats
950
because it is small, as with gold dust and the various earthy and
dusty materials which throng the air. With regard to these questions,
it is wrong to accept the explanation offered by Democritus. He says
that the warm bodies moving up out of the water hold up heavy
bodies which are broad, while the narrow ones fall through, because
the bodies which offer this resistance are not numerous. But this
would be even more likely to happen in air - an objection which he
himself raises. His reply to the objection is feeble. In the air, he says,
the 'drive' (meaning by drive the movement of the upward moving
bodies) is not uniform in direction. But since some continua are
easily divided and others less easily, and things which produce
division differ similarly in the case with which they produce it, the
explanation must be found in this fact. It is the easily bounded, in
proportion as it is easily bounded, which is easily divided; and air is
more so than water, water than earth. Further, the smaller the
quantity in each kind, the more easily it is divided and disrupted.
Thus the reason why broad things keep their place is because they
cover so wide a surface and the greater quantity is less easily
disrupted. Bodies of the opposite shape sink down because they
occupy so little of the surface, which is therefore easily parted. And
these considerations apply with far greater force to air, since it is so
much more easily divided than water. But since there are two factors,
the force responsible for the downward motion of the heavy body
and the disruption-resisting force of the continuous surface, there
must be some ratio between the two. For in proportion as the force
applied by the heavy thing towards disruption and division exceeds
that which resides in the continuum, the quicker will it force its way
down; only if the force of the heavy thing is the weaker, will it ride
upon the surface.
We have now finished our examination of the heavy and the light
and of the phenomena connected with them.
951
Aristotle - On Generation and Corruption
[Translated by H. H.Joachim]
Book I
Our next task is to study coming-to-be and passing-away. We
are to distinguish the causes, and to state the definitions, of
these processes considered in general - as changes predicable
uniformly of all the things that come-to-be and pass-away by
nature. Further, we are to study growth and 'alteration'. We
must inquire what each of them is; and whether 'alteration' is
to be identified with coming-to-be, or whether to these different
names there correspond two separate processes with distinct
natures.
On this question, indeed, the early philosophers are divided.
Some of them assert that the so-called 'unqualified coming-to-
be' is 'alteration', while others maintain that 'alteration' and
coming-to-be are distinct. For those who say that the universe is
one something (i.e. those who generate all things out of one
thing) are bound to assert that coming-to-be is 'alteration', and
that whatever 'comes-to-be' in the proper sense of the term is
'being altered': but those who make the matter of things more
than one must distinguish coming-to-be from 'alteration'. To
this latter class belong Empedocles, Anaxagoras, and Leucippus.
And yet Anaxagoras himself failed to understand his own
utterance. He says, at all events, that coming-to-be and passing-
952
away are the same as 'being altered':' yet, in common with
other thinkers, he affirms that the elements are many. Thus
Empedocles holds that the corporeal elements are four, while all
the elements - including those which initiate movement - are
six in number; whereas Anaxagoras agrees with Leucippus and
Democritus that the elements are infinite.
(Anaxagoras posits as elements the 'homoeomeries', viz. bone,
flesh, marrow, and everything else which is such that part and
whole are the same in name and nature; while Democritus and
Leucippus say that there are indivisible bodies, infinite both in
number and in the varieties of their shapes, of which everything
else is composed - the compounds differing one from another
according to the shapes, 'positions', and 'groupings' of their
constituents.)
For the views of the school of Anaxagoras seem diametrically
opposed to those of the followers of Empedocles. Empedocles
says that Fire, Water, Air, and Earth are four elements, and are
thus 'simple' rather than flesh, bone, and bodies which, like
these, are 'homoeomeries'. But the followers of Anaxagoras
regard the 'homoeomeries' as 'simple' and elements, whilst
they affirm that Earth, Fire, Water, and Air are composite; for
each of these is (according to them) a 'common seminary' of all
the 'homoeomeries'.
Those, then, who construct all things out of a single element,
must maintain that coming-to-be and passing-away are
'alteration'. For they must affirm that the underlying something
always remains identical and one; and change of such a
substratum is what we call 'altering' Those, on the other hand,
who make the ultimate kinds of things more than one, must
maintain that 'alteration' is distinct from coming-to-be: for
coming-to-be and passing-away result from the consilience and
the dissolution of the many kinds. That is why Empedocles too
953
uses language to this effect, when he says 'There is no coming-
to-be of anything, but only a mingling and a divorce of what has
been mingled'. Thus it is clear (i) that to describe coming-to-be
and passing-away in these terms is in accordance with their
fundamental assumption, and (ii) that they do in fact so
describe them: nevertheless, they too must recognize
'alteration' as a fact distinct from coming-to-be, though it is
impossible for them to do so consistently with what they say.
That we are right in this criticism is easy to perceive. For
'alteration' is a fact of observation. While the substance of the
thing remains unchanged, we see it 'altering' just as we see in it
the changes of magnitude called 'growth' and 'diminution'.
Nevertheless, the statements of those who posit more 'original
reals' than one make 'alteration' impossible. For 'alteration, as
we assert, takes place in respect to certain qualities: and these
qualities (I mean, e.g. hot-cold, white-black, dry-moist, soft-
hard, and so forth) are, all of them, differences characterizing
the 'elements'. The actual words of Empedocles may be quoted
in illustration :
The sun everywhere bright to see, and hot,
The rain everywhere dark and cold;
and he distinctively characterizes his remaining elements in a
similar manner. Since, therefore, it is not possible for Fire to
become Water, or Water to become Earth, neither will it be
possible for anything white to become black, or anything soft to
become hard; and the same argument applies to all the other
qualities. Yet this is what 'alteration' essentially is.
It follows, as an obvious corollary, that a single matter must
always be assumed as underlying the contrary 'poles' of any
change whether change of place, or growth and diminution, or
'alteration'; further, that the being of this matter and the being
954
of 'alteration' stand and fall together. For if the change is
'alteration', then the substratum is a single element; i.e. all
things which admit of change into one another have a single
matter. And, conversely, if the substratum of the changing
things is one, there is 'alteration'.
Empedocles, indeed, seems to contradict his own statements as
well as the observed facts. For he denies that any one of his
elements comes-to-be out of any other, insisting on the
contrary that they are the things out of which everything else
comes-to-be; and yet (having brought the entirety of existing
things, except Strife, together into one) he maintains,
simultaneously with this denial, that each thing once more
comes-to-be out of the One. Hence it was clearly out of a One
that this came-to-be Water, and that Fire, various portions of it
being separated off by certain characteristic differences or
qualities - as indeed he calls the sun 'white and hot', and the
earth 'heavy and hard'. If, therefore, these characteristic
differences be taken away (for they can be taken away, since
they came-to-be), it will clearly be inevitable for Earth to come-
to-be out of Water and Water out of Earth, and for each of the
other elements to undergo a similar transformation - not only
then, but also now - if, and because, they change their qualities.
And, to judge by what he says, the qualities are such that they
can be 'attached' to things and can again be 'separated' from
them, especially since Strife and Love are still fighting with one
another for the mastery. It was owing to this same conflict that
the elements were generated from a One at the former period. I
say 'generated', for presumably Fire, Earth, and Water had no
distinctive existence at all while merged in one.
There is another obscurity in the theory Empedocles. Are we to
regard the One as his 'original real? Or is it the Many - i.e. Fire
and Earth, and the bodies co-ordinate with these? For the One is
an 'element' in so far as it underlies the process as matter - as
955
that out of which Earth and Fire come-to-be through a change
of qualities due to 'the motion'. On the other hand, in so far as
the One results from composition (by a consilience of the
Many), whereas they result from disintegration the Many are
more 'elementary' than the One, and prior to it in their nature.
We have therefore to discuss the whole subject of 'unqualified'
coming-to-be and passing-away; we have to inquire whether
these changes do or do not occur and, if they occur, to explain
the precise conditions of their occurrence. We must also discuss
the remaining forms of change, viz. growth and 'alteration'. For
though, no doubt, Plato investigated the conditions under which
things come-to-be and pass-away, he confined his inquiry to
these changes; and he discussed not all coming-to-be, but only
that of the elements. He asked no questions as to how flesh or
bones, or any of the other similar compound things, come-to-
be; nor again did he examine the conditions under which
'alteration' or growth are attributable to things.
A similar criticism applies to all our predecessors with the
single exception of Democritus. Not one of them penetrated
below the surface or made a thorough examination of a single
one of the problems. Democritus, however, does seem not only
to have thought carefully about all the problems, but also to be
distinguished from the outset by his method. For, as we are
saying, none of the other philosophers made any definite
statement about growth, except such as any amateur might
have made. They said that things grow 'by the accession of like
to like', but they did not proceed to explain the manner of this
accession. Nor did they give any account of 'combination': and
956
they neglected almost every single one of the remaining
problems, offering no explanation, e.g. of 'action' or 'passion'
how in physical actions one thing acts and the other undergoes
action. Democritus and Leucippus, however, postulate the
'figures', and make 'alteration' and coming-to-be result from
them. They explain coming-to-be and passing-away by their
'dissociation' and 'association', but 'alteration' by their
'grouping' and 'Position'. And since they thought that the 'truth
lay in the appearance, and the appearances are conflicting and
infinitely many, they made the 'figures' infinite in number.
Hence - owing to the changes of the compound - the same
thing seems different and conflicting to different people: it is
'transposed' by a small additional ingredient, and appears
utterly other by the 'transposition' of a single constituent. For
Tragedy and Comedy are both composed of the same letters.
Since almost all our predecessors think (i) that coming-to-be is
distinct from 'alteration', and (ii) that, whereas things 'alter' by
change of their qualities, it is by 'association' and 'dissociation'
that they come-to-be and pass-away, we must concentrate our
attention on these theses. For they lead to many perplexing and
well-grounded dilemmas. If, on the one hand, coming-to-be is
'association', many impossible consequences result: and yet
there are other arguments, not easy to unravel, which force the
conclusion upon us that coming-to-be cannot possibly be
anything else. If, on the other hand, coming-to-be is not
'association', either there is no such thing as coming-to-be at all
or it is 'alteration': or else we must endeavour to unravel this
dilemma too - and a stubborn one we shall find it. The
fundamental question, in dealing with all these difficulties, is
this: 'Do things come-to-be and «alter» and grow, and undergo
the contrary changes, because the primary «reals» are
indivisible magnitudes? Or is no magnitude indivisible?' For the
answer we give to this question makes the greatest difference.
And again, if the primary 'reals' are indivisible magnitudes, are
957
these bodies, as Democritus and Leucippus maintain? Or are
they planes, as is asserted in the Timaeus?
To resolve bodies into planes and no further - this, as we have
also remarked elsewhere, in itself a paradox. Hence there is
more to be said for the view that there are indivisible bodies. Yet
even these involve much of paradox. Still, as we have said, it is
possible to construct 'alteration' and coming-to-be with them, if
one 'transposes' the same by 'turning' and 'intercontact', and by
'the varieties of the figures', as Democritus does. (His denial of
the reality of colour is a corollary from this position: for,
according to him, things get coloured by 'turning' of the
'figures'.) But the possibility of such a construction no longer
exists for those who divide bodies into planes. For nothing
except solids results from putting planes together: they do not
even attempt to generate any quality from them.
Lack of experience diminishes our power of taking a
comprehensive view of the admitted facts. Hence those who
dwell in intimate association with nature and its phenomena
grow more and more able to formulate, as the foundations of
their theories, principles such as to admit of a wide and
coherent development: while those whom devotion to abstract
discussions has rendered unobservant of the facts are too ready
to dogmatize on the basis of a few observations. The rival
treatments of the subject now before us will serve to illustrate
how great is the difference between a 'scientific' and a
'dialectical' method of inquiry. For, whereas the Platonists argue
that there must be atomic magnitudes 'because otherwise «The
Triangle» will be more than one', Democritus would appear to
have been convinced by arguments appropriate to the subject,
i.e. drawn from the science of nature. Our meaning will become
clear as we proceed. For to suppose that a body (i.e. a
magnitude) is divisible through and through, and that this
958
division is possible, involves a difficulty. What will there be in
the body which escapes the division?
If it is divisible through and through, and if this division is
possible, then it might be, at one and the same moment, divided
through and through, even though the dividings had not been
effected simultaneously: and the actual occurrence of this
result would involve no impossibility. Hence the same principle
will apply whenever a body is by nature divisible through and
through, whether by bisection, or generally by any method
whatever: nothing impossible will have resulted if it has
actually been divided - not even if it has been divided into
innumerable parts, themselves divided innumerable times.
Nothing impossible will have resulted, though perhaps nobody
in fact could so divide it.
Since, therefore, the be dy is divisible through and through, let it
have been divided. What, then, will remain? A magnitude? No:
that is impossible, since then there will be something not
divided, whereas ex hypothesis the body was divisible through
and through. But if it be admitted that neither a body nor a
magnitude will remain, and yet division is to take place, the
constituents of the body will either be points (i.e. without
magnitude) or absolutely nothing. If its constituents are
nothings, then it might both come-to-be out of nothings and
exist as a composite of nothings: and thus presumably the
whole body will be nothing but an appearance. But if it consists
of points, a similar absurdity will result: it will not possess any
magnitude. For when the points were in contact and coincided
to form a single magnitude, they did not make the whole any
bigger (since, when the body was divided into two or more
parts, the whole was not a bit smaller or bigger than it was
before the division): hence, even if all the points be put together,
they will not make any magnitude.
959
But suppose that, as the body is being divided, a minute section
- a piece of sawdust, as it were - is extracted, and that in this
sense - a body 'comes away' from the magnitude, evading the
division. Even then the same argument applies. For in what
sense is that section divisible? But if what 'came away' was not
a body but a separable form or quality, and if the magnitude is
'points or contacts thus qualified': it is paradoxical that a
magnitude should consist of elements, which are not
magnitudes. Moreover, where will the points be? And are they
motionless or moving? And every contact is always a contact of
two somethings, i.e. there is always something besides the
contact or the division or the point.
These, then, are the difficulties resulting from the supposition
that any and every body, whatever its size, is divisible through
and through. There is, besides, this further consideration. If,
having divided a piece of wood or anything else, I put it
together, it is again equal to what it was, and is one. Clearly this
is so, whatever the point at which I cut the wood. The wood,
therefore, has been divided potentially through and through.
What, then, is there in the wood besides the division? For even
if we suppose there is some quality, yet how is the wood
dissolved into such constituents and how does it come-to-be
out of them? Or how are such constituents separated so as to
exist apart from one another? Since, therefore, it is impossible
for magnitudes to consist of contacts or points, there must be
indivisible bodies and magnitudes. Yet, if we do postulate the
latter, we are confronted with equally impossible consequences,
which we have examined in other works.' But we must try to
disentangle these perplexities, and must therefore formulate
the whole problem over again.
On the one hand, then, it is in no way paradoxical that every
perceptible body should be indivisible as well as divisible at any
and every point. For the second predicate will at. tach to it
960
potentially, but the first actually. On the other hand, it would
seem to be impossible for a body to be, even potentially,
divisible at all points simultaneously. For if it were possible,
then it might actually occur, with the result, not that the body
would simultaneously be actually both (indivisible and divided),
but that it would be simultaneously divided at any and every
point. Consequently, nothing will remain and the body will have
passed-away into what is incorporeal: and so it might come-to-
be again either out of points or absolutely out of nothing. And
how is that possible?
But now it is obvious that a body is in fact divided into separable
magnitudes which are smaller at each division - into
magnitudes which fall apart from one another and are actually
separated. Hence (it is urged) the process of dividing a body part
by part is not a 'breaking up' which could continue ad infinitum;
nor can a body be simultaneously divided at every point, for
that is not possible; but there is a limit, beyond which the
'breaking up' cannot proceed. The necessary consequence -
especially if coming-to-be and passing-away are to take place by
'association' and 'dissociation' respectively - is that a body must
contain atomic magnitudes which are invisible. Such is the
argument which is believed to establish the necessity of atomic
magnitudes: we must now show that it conceals a faulty
inference, and exactly where it conceals it.
For, since point is not 'immediately-next' to point, magnitudes
are 'divisible through and through' in one sense, and yet not in
another. When, however, it is admitted that a magnitude is
'divisible through and through', it is thought there is a point not
only anywhere, but also everywhere, in it: hence it is supposed
to follow, from the admission, that the magnitude must be
divided away into nothing. For it is supposed - there is a point
everywhere within it, so that it consists either of contacts or of
points. But it is only in one sense that the magnitude is
961
'divisible through and through', viz. in so far as there is one
point anywhere within it and all its points are everywhere
within it if you take them singly one by one. But there are not
more points than one anywhere within it, for the points are not
'consecutive': hence it is not simultaneously 'divisible through
and through'. For if it were, then, if it be divisible at its centre, it
will be divisible also at a point 'immediately-next' to its centre.
But it is not so divisible: for position is not 'immediately-next' to
position, nor point to point - in other words, division is not
'immediately-next' to division, nor composition to composition.
Hence there are both 'association' and 'dissociation', though
neither (a) into, and out of, atomic magnitudes (for that involves
many impossibilities), nor (b) so that division takes place
through and through - for this would have resulted only if point
had been 'immediately-next' to point: but 'dissociation' takes
place into small (i.e. relatively small) parts, and 'association'
takes place out of relatively small parts.
It is wrong, however, to suppose, as some assert, that coming-
to-be and passing-away in the unqualified and complete sense
are distinctively defined by 'association' and 'dissociation',
while the change that takes place in what is continuous is
'alteration'. On the contrary, this is where the whole error lies.
For unqualified coming-to-be and passing-away are not effected
by 'association' and 'dissociation'. They take place when a thing
changes, from this to that, as a whole. But the philosophers we
are criticizing suppose that all such change is 'alteration':
whereas in fact there is a difference. For in that which underlies
the change there is a factor corresponding to the definition and
there is a material factor. When, then, the change is in these
constitutive factors, there will be coming-to-be or passing-away:
but when it is in the thing's qualities, i.e. a change of the thing
per accidents, there will be 'alteration'.
962
'Dissociation' and 'association' affect the thing's susceptibility
to passing-away. For if water has first been 'dissociated' into
smallish drops, air comes-to-be out of it more quickly: while, if
drops of water have first been 'associated', air comes-to-be
more slowly. Our doctrine will become clearer in the sequel.'
Meantime, so much may be taken as established - viz. that
coming-to-be cannot be 'association', at least not the kind of
'association' some philosophers assert it to be.
Now that we have established the preceding distinctions, we
must first consider whether there is anything which comes-to-
be and passes-away in the unqualified sense: or whether
nothing comes-to-be in this strict sense, but everything always
comes-to-be something and out of something - I mean, e.g.
comes-to-be-healthy out of being-ill and ill out of being-healthy,
comes-to-be-small out of being-big and big out of being-small,
and so on in every other instance. For if there is to be coming-
to-be without qualification, 'something' must - without
qualification - 'come-to-be out of not-being', so that it would be
true to say that 'not-being is an attribute of some things'. For
qualified coming-to-be is a process out of qualified not-being
(e.g. out of not-white or not-beautiful), but unqualified coming-
to-be is a process out of unqualified not-being.
Now 'unqulified' means either (i) the primary predication within
each Category, or (ii) the universal, i.e. the all-comprehensive,
predication. Hence, if 'unqualified not-being' means the
negation of 'being' in the sense of the primary term of the
Category in question, we shall have, in 'unqualified coming-to-
be', a coming-to-be of a substance out of not-substance. But
963
that which is not a substance or a 'this' clearly cannot possess
predicates drawn from any of the other Categories either - e.g.
we cannot attribute to it any quality, quantity, or position.
Otherwise, properties would admit of existence in separation
from substances. If, on the other hand, 'unqualified not-being'
means 'what is not in any sense at all', it will be a universal
negation of all forms of being, so that what comes-to-be will
have to come-to-be out of nothing.
Although we have dealt with these problems at greater length
in another work.where we have set forth the difficulties and
established the distinguishing definitions, the following concise
restatement of our results must here be offered: In one sense
things come-to-be out of that which has no 'being' without
qualification: yet in another sense they come-to-be always out
of what is'. For coming-to-be necessarily implies the pre-
existence of something which potentially 'is', but actually 'is
not'; and this something is spoken of both as 'being' and as
'not-being'.
These distinctions may be taken as established: but even then it
is extraordinarily difficult to see how there can be 'unqualified
coming-to-be' (whether we suppose it to occur out of what
potentially 'is', or in some other way), and we must recall this
problem for further examination. For the question might be
raised whether substance (i.e. the 'this') comes-to-be at all. Is it
not rather the 'such', the 'so great', or the 'somewhere', which
comes-to-be? And the same question might be raised about
'passing-away' also. For if a substantial thing comes-to-be, it is
clear that there will 'be' (not actually, but potentially) a
substance, out of which its coming-to-be will proceed and into
which the thing that is passing-away will necessarily change.
Then will any predicate belonging to the remaining Categories
attach actually to this presupposed substance? In other words,
will that which is only potentially a 'this' (which only
964
potentially is), while without the qualification 'potentially' it is
not a 'this' (i.e. is not), possess, e.g. any determinate size or
quality or position? For (i) if it possesses none of these
determinations actually, but all of them only potentially, the
result is first that a being, which is not a determinate being, is
capable of separate existence; and in addition that coming-to-
be proceeds out of nothing pre-existing - a thesis which, more
than any other, preoccupied and alarmed the earliest
philosophers. On the other hand (ii) if, although it is not a 'this
somewhat' or a substance, it is to possess some of the
remaining determinations quoted above, then (as we said)'
properties will be separable from substances.
We must therefore concentrate all our powers on the discussion
of these difficulties and on the solution of a further question -
viz. What is the cause of the perpetuity of coming-to-be? Why is
there always unqualified, as well as partial, coming-to-be?
Cause' in this connexion has two senses. It means (i) the source
from which, as we say, the process 'originates', and (ii) the
matter. It is the material cause that we have here to state. For,
as to the other cause, we have already explained (in our treatise
on Motion that it involves (a) something immovable through all
time and (b) something always being moved. And the accurate
treatment of the first of these - of the immovable 'originative
source' - belongs to the province of the other, or 'prior',
philosophy: while as regards 'that which sets everything else in
motion by being itself continuously moved', we shall have to
explain later' which amongst the so-called 'specific' causes
exhibits this character. But at present we are to state the
material cause - the cause classed under the head of matter - to
which it is due that passing-away and coming-to-be never fail
to occur in Nature. For perhaps, if we succeed in clearing up this
question, it will simultaneously become clear what account we
ought to give of that which perplexed us just now, i.e. of
unqualified passing-away and coming-to-be.
965
Our new question too - viz. 'what is the cause of the unbroken
continuity of coming-to-be?' - is sufficiently perplexing, if in
fact what passes-away vanishes into 'what is not' and 'what is
not' is nothing (since 'what is not' is neither a thing, nor
possessed of a quality or quantity, nor in any place). If, then,
some one of the things 'which are' constantly disappearing, why
has not the whole of 'what is' been used up long ago and
vanished away assuming of course that the material of all the
several comings-to-be was finite? For, presumably, the unfailing
continuity of coming-to-be cannot be attributed to the infinity
of the material. That is impossible, for nothing is actually
infinite. A thing is infinite only potentially, i.e. the dividing of it
can continue indefinitely: so that we should have to suppose
there is only one kind of coming-to-be in the world - viz. one
which never fails, because it is such that what comes-to-be is
on each successive occasion smaller than before. But in fact this
is not what we see occurring.
Why, then, is this form of change necessarily ceaseless? Is it
because the passing-away of this is a coming-to-be of
something else, and the coming-to-be of this a passing-away of
something else?
The cause implied in this solution must no doubt be considered
adequate to account for coming-to-be and passing-away in their
general character as they occur in all existing things alike. Yet, if
the same process is a coming-to-be of this but a passing-away
of that, and a passing-away of this but a coming-to-be of that,
why are some things said to come-to-be and pass-away without
qualification, but others only with a qualification?
The distinction must be investigated once more, for it demands
some explanation. (It is applied in a twofold manner.) For (i) we
say 'it is now passing-away' without qualification, and not
merely 'this is passing-away': and we call this change 'coming-
966
to-be', and that 'passing-away', without qualification. And (ii)
so-and-so 'comes-to-be-something', but does not 'come-to-be'
without qualification; for we say that the student 'comes-to-be-
learned', not 'comes-to-be' without qualification.
(i) Now we often divide terms into those which signify a 'this
somewhat' and those which do not. And (the first form of) the
distinction, which we are investigating, results from a similar
division of terms: for it makes a difference into what the
changing thing changes. Perhaps, e.g. the passage into Fire is
'coming-to-be' unqualified, but 'passing-away-of-something'
(e.g. Earth): whilst the coming-to-be of Earth is qualified (not
unqualified) 'coming-to-be', though unqualified 'passing-away'
(e.g. of Fire). This would be the case on the theory set forth in
Parmenides: for he says that the things into which change takes
place are two, and he asserts that these two, viz. what is and
what is not, are Fire and Earth. Whether we postulate these, or
other things of a similar kind, makes no difference. For we are
trying to discover not what undergoes these changes, but what
is their characteristic manner. The passage, then, into what 'is'
not except with a qualification is unqualified passing-away,
while the passage into what 'is' without qualification is
unqualified coming-to-be. Hence whatever the contrasted
'poles' of the changes may be whether Fire and Earth, or some
other couple - the one of them will be 'a being' and the other 'a
not-being'.
We have thus stated one characteristic manner in which
unqualified will be distinguished from qualified coming-to-be
and passing-away: but they are also distinguished according to
the special nature of the material of the changing thing. For a
material, whose constitutive differences signify more a 'this
somewhat', is itself more 'substantial' or 'real': while a material,
whose constitutive differences signify privation, is 'not real'.
(Suppose, e.g. that 'the hot' is a positive predication, i.e. a 'form',
967
whereas 'cold' is a privation, and that Earth and Fire differ from
one another by these constitutive differences.)
The opinion, however, which most people are inclined to prefer,
is that the distinction depends upon the difference between 'the
perceptible' and 'the imperceptible'. Thus, when there is a
change into perceptible material, people say there is 'coming-to-
be'; but when there is a change into invisible material, they call
it 'passing-away'. For they distinguish 'what is' and 'what is not'
by their perceiving and not-perceiving, just as what is knowable
'is' and what is unknowable 'is not' - perception on their view
having the force of knowledge. Hence, just as they deem
themselves to live and to 'be' in virtue of their perceiving or
their capacity to perceive, so too they deem the things to 'be'
qua perceived or perceptible - and in this they are in a sense on
the track of the truth, though what they actually say is not true.
Thus unqualified coming-to-be and passing-away turn out to be
different according to common opinion from what they are in
truth. For Wind and Air are in truth more real more a 'this
somewhat' or a 'form' - than Earth. But they are less real to
perception which explains why things are commonly said to
'pass-away' without qualification when they change into Wind
and Air, and to 'come-to-be' when they change into what is
tangible, i.e. into Earth.
We have now explained why there is 'unqualified coming-to-be'
(though it is a passing-away-of-something) and 'unqualified
passing-away' (though it is a coming-to-be-of-something). For
this distinction of appellation depends upon a difference in the
material out of which, and into which, the changes are effected.
It depends either upon whether the material is or is not
'substantial', or upon whether it is more or less 'substantial', or
upon whether it is more or less perceptible.
968
(ii) But why are some things said to 'come-to-be' without
qualification, and others only to 'come-to-be-so-and-so', in
cases different from the one we have been considering where
two things come-to-be reciprocally out of one another? For at
present we have explained no more than this: - why, when two
things change reciprocally into one another, we do not attribute
coming-to-be and passing-away uniformly to them both,
although every coming-to-be is a passing-away of something
else and every passing-away some other thing's coming-to-be.
But the question subsequently formulated involves a different
problem - viz. why, although the learning thing is said to 'come-
to-be-learned' but not to 'come-to-be' without qualification, yet
the growing thing is said to 'come-to-be'.
The distinction here turns upon the difference of the Categories.
For some things signify a this somewhat, others a such, and
others a so-much. Those things, then, which do not signify
substance, are not said to 'come-to-be' without qualification,
but only to 'come-to-be-so-and-so'. Nevertheless, in all
changing things alike, we speak of 'coming-to-be' when the
thing comes-to-be something in one of the two Columns - e.g.
in Substance, if it comes-to-be Fire but not if it comes-to-be
Earth; and in Quality, if it comes-to-be learned but not when it
comes-to-be ignorant.
We have explained why some things come-to-be without
qualification, but not others both in general, and also when the
changing things are substances and nothing else; and we have
stated that the substratum is the material cause of the
continuous occurrence of coming-to-be, because it is such as to
change from contrary to contrary and because, in substances,
the coming-to-be of one thing is always a passing-away of
another, and the passing-away of one thing is always another's
coming-to-be. But there is no need even to discuss the other
question we raised - viz. why coming-to-be continues though
969
things are constantly being destroyed. For just as people speak
of 'a passing-away' without qualification when a thing has
passed into what is imperceptible and what in that sense 'is
not', so also they speak of 'a coming-to-be out of a not-being'
when a thing emerges from an imperceptible. Whether,
therefore, the substratum is or is not something, what comes-
to-be emerges out of a 'not-being': so that a thing comes-to-be
out of a not-being' just as much as it 'passes-away into what is
not'. Hence it is reasonable enough that coming-to-be should
never fail. For coming-to-be is a passing-away of 'what is not'
and passing-away is a coming-to-be of 'what is not'.
But what about that which 'is' not except with a qualification?
Is it one of the two contrary poles of the change - e.g. Earth (i.e.
the heavy) a 'not-being', but Fire (i.e. the light) a 'being? Or, on
the contrary, does what is 'include Earth as well as Fire, whereas
what is not' is matter - the matter of Earth and Fire alike? And
again, is the matter of each different? Or is it the same, since
otherwise they would not come-to-be reciprocally out of one
another, i.e. contraries out of contraries? For these things - Fire,
Earth, Water, Air - are characterized by 'the contraries'.
Perhaps the solution is that their matter is in one sense the
same, but in another sense different. For that which underlies
them, whatever its nature may be qua underlying them, is the
same: but its actual being is not the same. So much, then, on
these topics.
Next we must state what the difference is between coming-to-
be and 'alteration' - for we maintain that these changes are
distinct from one another.
970
Since, then, we must distinguish (a) the substratum, and (b) the
property whose nature it is to be predicated of the substratum;
and since change of each of these occurs; there is 'alteration'
when the substratum is perceptible and persists, but changes in
its own properties, the properties in question being opposed to
one another either as contraries or as intermediates. The body,
e.g. although persisting as the same body, is now healthy and
now ill; and the bronze is now spherical and at another time
angular, and yet remains the same bronze. But when nothing
perceptible persists in its identity as a substratum, and the
thing changes as a whole (when e.g. the seed as a whole is
converted into blood, or water into air, or air as a whole into
water), such an occurrence is no longer 'alteration'. It is a
coming-to-be of one substance and a passing-away of the other
- especially if the change proceeds from an imperceptible
something to something perceptible (either to touch or to all the
senses), as when water comes-to-be out of, or passes-away into,
air: for air is pretty well imperceptible. If, however, in such
cases, any property (being one of a pair of contraries) persists, in
the thing that has come-to-be, the same as it was in the thing
which has passed-away - if, e.g. when water comes-to-be out of
air, both are transparent or cold - the second thing, into which
the first changes, must not be a property of this persistent
identical something. Otherwise the change will be 'alteration.'
Suppose, e.g. that the musical man passed-away and an
unmusical man came-to-be, and that the man persists as
something identical. Now, if 'musicalness and unmusicalness'
had not been a property essentially inhering in man, these
changes would have been a coming-to-be of unmusicalness and
a passing-away of musicalness: but in fact 'musicalness and
unmusicalness' are a property of the persistent identity, viz.
man. (Hence, as regards man, these changes are 'modifications';
though, as regards musical man and unmusical man, they are a
passing-away and a coming-to-be.) Consequently such changes
971
are 'alteration.' When the change from contrary to contrary is in
quantity, it is 'growth and diminution'; when it is in place, it is
'motion'; when it is in property, i.e. in quality, it is 'alteration':
but, when nothing persists, of which the resultant is a property
(or an 'accident' in any sense of the term), it is 'coming-to-be',
and the converse change is 'passing-away'.
'Matter', in the most proper sense of the term, is to be identified
with the substratum which is receptive of coming-to-be and
passing-away: but the substratum of the remaining kinds of
change is also, in a certain sense, 'matter', because all these
substrata are receptive of 'contrarieties' of some kind. So much,
then, as an answer to the questions (i) whether coming-to-be 'is'
or 'is not' - i.e. what are the precise conditions of its occurrence
and (ii) what 'alteration' is: but we have still to treat of growth.
We must explain (i) wherein growth differs from coming-to-be
and from 'alteration', and ii) what is the process of growing and
the sprocess of diminishing in each and all of the things that
grow and diminish.
Hence our first question is this: Do these changes differ from
one another solely because of a difference in their respective
'spheres'? In other words, do they differ because, while a change
from this to that (viz. from potential to actual substance) is
coming-to-be, a change in the sphere of magnitude is growth
and one in the sphere of quality is 'alteration' - both growth and
'alteration' being changes from what is-potentially to what is-
actually magnitude and quality respectively? Or is there also a
difference in the manner of the change, since it is evident that,
whereas neither what is 'altering' nor what is coming-to-be
972
necessarily changes its place, what is growing or diminishing
changes its spatial position of necessity, though in a different
manner from that in which the moving thing does so? For that
which is being moved changes its place as a whole: but the
growing thing changes its place like a metal that is being
beaten, retaining its position as a whole while its parts change
their places. They change their places, but not in the same way
as the parts of a revolving globe. For the parts of the globe
change their places while the whole continues to occupy an
equal place: but the parts of the rowing thing expand over an
ever-increasing place and the parts of the diminishing thing
contract within an ever-diminishing area.
It is clear, then, that these changes - the changes of that which
is coming-to-be, of that which is 'altering', and of that which is
growing - differ in manner as well as in sphere. But how are we
to conceive the 'sphere' of the change which is growth and
diminution? The sphere' of growing and diminishing is believed
to be magnitude. Are we to suppose that body and magnitude
come-to-be out of something which, though potentially
magnitude and body, is actually incorporeal and devoid of
magnitude? And since this description may be understood in
two different ways, in which of these two ways are we to apply
it to the process of growth? Is the matter, out of which growth
takes place, (i) 'separate' and existing alone by itself, or (ii)
'separate' but contained in another body?
Perhaps it is impossible for growth to take place in either of
these ways. For since the matter is 'separate', either (a) it will
occupy no place (as if it were a point), or (b) it will be a 'void', i.e.
a non-perceptible body. But the first of these alternatives is
impossible. For since what comes-to-be out of this incorporeal
and sizeless something will always be 'somewhere', it too must
be 'somewhere' - either intrinsically or indirectly. And the
second alternative necessarily implies that the matter is
973
contained in some other body. But if it is to be 'in' another body
and yet remains 'separate' in such a way that it is in no sense a
part of that body (neither a part of its substantial being nor an
'accident' of it), many impossibilities will result. It is as if we
were to suppose that when, e.g. air comes-to-be out of water the
process were due not to a change of the but to the matter of the
air being 'contained in' the water as in a vessel. This is
impossible. For (i) there is nothing to prevent an indeterminate
number of matters being thus 'contained in' the water, so that
they might come-to-be actually an indeterminate quantity of
air; and (ii) we do not in fact see air coming-to-be out of water
in this fashion, viz. withdrawing out of it and leaving it
unchanged.
It is therefore better to suppose that in all instances of coming-
to-be the matter is inseparable, being numerically identical and
one with the 'containing' body, though isolable from it by
definition. But the same reasons also forbid us to regard the
matter, out of which the body comes-to-be, as points or lines.
The matter is that of which points and lines are limits, and it is
something that can never exist without quality and without
form.
Now it is no doubt true, as we have also established elsewhere,'
that one thing 'comes-to-be' (in the unqualified sense) out of
another thing: and further it is true that the efficient cause of
its coming-to-be is either (i) an actual thing (which is the same
as the effect either generically - or the efficient cause of the
coming-to-be of a hard thing is not a hard thing or specifically,
as e.g. fire is the efficient cause of the coming-to-be of fire or
one man of the birth of another), or (ii) an actuality.
Nevertheless, since there is also a matter out of which corporeal
substance itself comes-to-be (corporeal substance, however,
already characterized as such-and-such a determinate body, for
there is no such thing as body in general), this same matter is
974
also the matter of magnitude and quality - being separable from
these matters by definition, but not separable in place unless
Qualities are, in their turn, separable.
It is evident, from the preceding development and discussion of
difficulties, that growth is not a change out of something which,
though potentially a magnitude, actually possesses no
magnitude. For, if it were, the 'void' would exist in separation;
but we have explained in a former work' that this is impossible.
Moreover, a change of that kind is not peculiarly distinctive of
growth, but characterizes coming-to-be as such or in general.
For growth is an increase, and diminution is a lessening, of the
magnitude which is there already - that, indeed, is why the
growing thing must possess some magnitude. Hence growth
must not be regarded as a process from a matter without
magnitude to an actuality of magnitude: for this would be a
body's coming-to-be rather than its growth.
We must therefore come to closer quarters with the subject of
our inquiry. We must grapple' with it (as it were) from its
beginning, and determine the precise character of the growing
and diminishing whose causes we are investigating.
It is evident (i) that any and every part of the growing thing has
increased, and that similarly in diminution every part has
become smaller: also (ii) that a thing grows by the accession,
and diminishes by the departure, of something. Hence it must
grow by the accession either (a) of something incorporeal or (b)
of a body. Now, if (a) it grows by the accession of something
incorporeal, there will exist separate a void: but (as we have
stated before)' is impossible for a matter of magnitude to exist
'separate'. If, on the other hand (b) it grows by the accession of a
body, there will be two bodies - that which grows and that
which increases it - in the same place: and this too is
impossible.
975
But neither is it open to us to say that growth or diminution
occurs in the way in which e.g. air is generated from water. For,
although the volume has then become greater, the change will
not be growth, but a coming-to-be of the one - viz. of that into
which the change is taking place - and a passing-away of the
contrasted body. It is not a growth of either. Nothing grows in
the process; unless indeed there be something common to both
things (to that which is coming-to-be and to that which passed-
away), e.g. 'body', and this grows. The water has not grown, nor
has the air: but the former has passed-away and the latter has
come-to-be, and - if anything has grown - there has been a
growth of 'body.' Yet this too is impossible. For our account of
growth must preserve the characteristics of that which is
growing and diminishing. And these characteristics are three: (i)
any and every part of the growing magnitude is made bigger
(e.g. if flesh grows, every particle of the flesh gets bigger), (ii) by
the accession of something, and (iii) in such a way that the
growing thing is preserved and persists. For whereas a thing
does not persist in the processes of unqualified coming-to-be or
passing-away, that which grows or 'alters' persists in its identity
through the 'altering' and through the growing or diminishing,
though the quality (in 'alteration') and the size (in growth) do
not remain the same. Now if the generation of air from water is
to be regarded as growth, a thing might grow without the
accession (and without the persistence) of anything, and
diminish without the departure of anything - and that which
grows need not persist. But this characteristic must be
preserved: for the growth we are discussing has been assumed
to be thus characterized.
One might raise a further difficulty. What is 'that which grows?
Is it that to which something is added? If, e.g. a man grows in
his shin, is it the shin which is greater - but not that 'whereby'
he grows, viz. not the food? Then why have not both 'grown'?
For when A is added to B, both A and B are greater, as when you
976
mix wine with water; for each ingredient is alike increased in
volume. Perhaps the explanation is that the substance of the
one remains unchanged, but the substance of the other (viz. of
the food) does not. For indeed, even in the mixture of wine and
water, it is the prevailing ingredient which is said to have
increased in volume. We say, e.g. that the wine has increased,
because the whole mixture acts as wine but not as water. A
similar principle applies also to 'alteration'. Flesh is said to have
been 'altered' if, while its character and substance remain, some
one of its essential properties, which was not there before, now
qualifies it: on the other hand, that 'whereby' it has been
'altered' may have undergone no change, though sometimes it
too has been affected. The altering agent, however, and the
originative source of the process are in the growing thing and in
that which is being 'altered': for the efficient cause is in these.
No doubt the food, which has come in, may sometimes expand
as well as the body that has consumed it (that is so, e.g. if, after
having come in, a food is converted into wind), but when it has
undergone this change it has passedaway: and the efficient
cause is not in the food.
We have now developed the difficulties sufficiently and must
therefore try to find a solution of the problem. Our solution
must preserve intact the three characteristics of growth - that
the growing thing persists, that it grows by the accession (and
diminishes by the departure) of something, and further that
every perceptible particle of it has become either larger or
smaller. We must recognize also (a) that the growing body is not
'void' and that yet there are not two magnitudes in the same
place, and (b) that it does not grow by the accession of
something incorporeal.
Two preliminary distinctions will prepare us to grasp the cause
of growth. We must note (i) that the organic parts grow by the
growth of the tissues (for every organ is composed of these as
977
its constituents); and (ii) that flesh, bone, and every such part -
like every other thing which has its form immersed in matter -
has a twofold nature: for the form as well as the matter is called
'flesh' or 'bone'.
Now, that any and every part of the tissue qua form should grow
- and grow by the accession of something - is possible, but not
that any and every part of the tissue qua matter should do so.
For we must think of the tissue after the image of flowing water
that is measured by one and the same measure: particle after
particle comes-to-be, and each successive particle is different.
And it is in this sense that the matter of the flesh grows, some
flowing out and some flowing in fresh; not in the sense that
fresh matter accedes to every particle of it. There is, however, an
accession to every part of its figure or 'form'.
That growth has taken place proportionally, is more manifest in
the organic parts - e.g. in the hand. For there the fact that the
matter is distinct from the form is more manifest than in flesh,
i.e. than in the tissues. That is why there is a greater tendency
to suppose that a corpse still possesses flesh and bone than
that it still has a hand or an arm.
Hence in one sense it is true that any and every part of the flesh
has grown; but in another sense it is false. For there has been an
accession to every part of the flesh in respect to its form, but
not in respect to its matter. The whole, however, has become
larger. And this increase is due (a) on the one hand to the
accession of something, which is called 'food' and is said to be
'contrary' to flesh, but (b) on the other hand to the
transformation of this food into the same form as that of flesh
as if, e.g. 'moist' were to accede to 'dry' and, having acceded,
were to be transformed and to become 'dry'. For in one sense
'Like grows by Like', but in another sense 'Unlike grows by
Unlike'.
978
One might discuss what must be the character of that 'whereby'
a thing grows. Clearly it must be potentially that which is
growing - potentially flesh, e.g. if it is flesh that is growing.
Actually, therefore, it must be 'other' than the growing thing.
This 'actual other', then, has passed-away and come-to-be flesh.
But it has not been transformed into flesh alone by itself (for
that would have been a coming-to-be, not a growth): on the
contrary, it is the growing thing which has come-to-be flesh
(and grown) by the food. In what way, then, has the food been
modified by the growing thing? Perhaps we should say that it
has been 'mixed' with it, as if one were to pour water into wine
and the wine were able to convert the new ingredient into wine.
And as fire lays hold of the inflammable, so the active principle
of growth, dwelling in the growing thing that which is actually
flesh), lays hold of an acceding food which is potentially flesh
and converts it into actual flesh. The acceding food, therefore,
must be together with the growing thing: for if it were apart
from it, the change would be a coming-to-be. For it is possible to
produce fire by piling logs on to the already burning fire. That is
'growth'. But when the logs themselves are set on fire, that is
'coming-to-be'.
'Quantum-in-general' does not come-to-be any more than
'animal' which is neither man nor any other of the specific
forms of animal: what 'animal-in-general' is in coming-to-be,
that 'quantum-in-general' is in growth. But what does come-to-
be in growth is flesh or bone - or a hand or arm (i.e. the tissues
of these organic parts). Such things come-to-be, then, by the
accession not of quantified-flesh but of a quantified-something.
In so far as this acceding food is potentially the double result
e.g. is potentially so-much-flesh it produces growth: for it is
bound to become actually both so-much and flesh. But in so far
as it is potentially flesh only, it nourishes: for it is thus that
'nutrition' and 'growth' differ by their definition. That is why a
body's 'nutrition' continues so long as it is kept alive (even when
979
it is diminishing), though not its 'growth'; and why nutrition,
though 'the same' as growth, is yet different from it in its actual
being. For in so far as that which accedes is potentially 'so
much-flesh' it tends to increase flesh: whereas, in so far as it is
potentially 'flesh' only, it is nourishment.
The form of which we have spoken is a kind of power immersed
in matter - a duct, as it were. If, then, a matter accedes - a
matter, which is potentially a duct and also potentially
possesses determinate quantity the ducts to which it accedes
will become bigger. But if it is no longer able to act - if it has
been weakened by the continued influx of matter, just as water,
continually mixed in greater and greater quantity with wine, in
the end makes the wine watery and converts it into water -
then it will cause a diminution of the quantum; though still the
form persists.
(In discussing the causes of coming-to-be) we must first
investigate the matter, i.e. the so-called 'elements'. We must ask
whether they really are elements or not, i.e. whether each of
them is eternal or whether there is a sense in which they come-
to-be: and, if they do come-to-be, whether all of them come-to-
be in the same manner reciprocally out of one another, or
whether one amongst them is something primary. Hence we
must begin by explaining certain preliminary matters, about
which the statements now current are vague.
For all (the pluralist philosophers) - those who generate the
'elements' as well as those who generate the bodies that are
compounded of the elements - make use of 'dissociation' and
'association', and of 'action' and 'passion'. Now 'association' is
980
'combination'; but the precise meaning of the process we call
'combining' has not been explained. Again, (all the monists
make use of 'alteration': but) without an agent and a patient
there cannot be 'altering' any more than there can be
'dissociating' and 'associating'. For not only those who postulate
a plurality of elements employ their reciprocal action and
passion to generate the compounds: those who derive things
from a single element are equally compelled to introduce
'acting'. And in this respect Diogenes is right when he argues
that 'unless all things were derived from one, reciprocal action
and passion could not have occurred'. The hot thing, e.g. would
not be cooled and the cold thing in turn be warmed: for heat
and cold do not change reciprocally into one another, but what
changes (it is clear) is the substratum. Hence, whenever there is
action and passion between two things, that which underlies
them must be a single something. No doubt, it is not true to say
that all things are of this character: but it is true of all things
between which there is reciprocal action and passion.
But if we must investigate 'action-passion' and 'combination',
we must also investigate 'contact'. For action and passion (in
the proper sense of the terms) can only occur between things
which are such as to touch one another; nor can things enter
into combination at all unless they have come into a certain
kind of contact. Hence we must give a definite account of these
three things - of 'contact', 'combination', and 'acting'.
Let us start as follows. All things which admit of 'combination'
must be capable of reciprocal contact: and the same is true of
any two things, of which one 'acts' and the other 'suffers action'
in the proper sense of the terms. For this reason we must treat
of 'contact' first, every term which possesses a variety of
meaning includes those various meanings either owing to a
mere coincidence of language, or owing to a real order of
derivation in the different things to which it is applied: but,
981
though this may be taken to hold of 'contact' as of all such
terms, it is nevertheless true that contact' in the proper sense
applies only to things which have 'position'. And 'position'
belongs only to those things which also have a Place': for in so
far as we attribute 'contact' to the mathematical things, we
must also attribute 'place' to them, whether they exist in
separation or in some other fashion. Assuming, therefore, that
'to touch' is - as we have defined it in a previous work - 'to have
the extremes together', only those things will touch one another
which, being separate magnitudes and possessing position,
have their extremes 'together'. And since position belongs only
to those things which also have a 'place', while the primary
differentiation of 'place' is the above' and 'the below' (and the
similar pairs of opposites), all things which touch one another
will have 'weight' or 'lightness' either both these qualities or
one or the other of them. But bodies which are heavy or light
are such as to 'act' and 'suffer action'. Hence it is clear that
those things are by nature such as to touch one another, which
(being separate magnitudes) have their extremes 'together' and
are able to move, and be moved by, one another.
The manner in which the 'mover' moves the moved' not always
the same: on the contrary, whereas one kind of 'mover' can only
impart motion by being itself moved, another kind can do so
though remaining itself unmoved. Clearly therefore we must
recognize a corresponding variety in speaking of the 'acting'
thing too: for the 'mover' is said to 'act' (in a sense) and the
'acting' thing to 'impart motion'. Nevertheless there is a
difference and we must draw a distinction. For not every 'mover'
can 'act', if (a) the term 'agent' is to be used in contrast to
'patient' and (b) 'patient' is to be applied only to those things
whose motion is a 'qualitative affection' - i.e. a quality, like
white' or 'hot', in respect to which they are moved' only in the
sense that they are 'altered': on the contrary, to 'impart motion'
is a wider term than to 'act'. Still, so much, at any rate, is clear:
982
the things which are 'such as to impart motion', if that
description be interpreted in one sense, will touch the things
which are 'such as to be moved by them' - while they will not
touch them, if the description be interpreted in a different
sense. But the disjunctive definition of 'touching' must include
and distinguish (a) 'contact in general' as the relation between
two things which, having position, are such that one is able to
impart motion and the other to be moved, and (b) 'reciprocal
contact' as the relation between two things, one able to impart
motion and the other able to be moved in such a way that
'action and passion' are predicable of them.
As a rule, no doubt, if A touches B, B touches A. For indeed
practically all the 'movers' within our ordinary experience
impart motion by being moved: in their case, what touches
inevitably must, and also evidently does, touch something
which reciprocally touches it. Yet, if A moves B, it is possible - as
we sometimes express it - for A 'merely to touch' B, and that
which touches need not touch a something which touches it.
Nevertheless it is commonly supposed that 'touching' must be
reciprocal. The reason of this belief is that 'movers' which
belong to the same kind as the 'moved' impart motion by being
moved. Hence if anything imparts motion without itself being
moved, it may touch the 'moved' and yet itself be touched by
nothing - for we say sometimes that the man who grieves us
'touches' us, but not that we 'touch' him.
The account just given may serve to distinguish and define the
'contact' which occurs in the things of Nature.
983
Next in order we must discuss 'action' and 'passion'. The
traditional theories on the subject are conflicting. For (i) most
thinkers are unanimous in maintaining (a) that 'like' is always
unaffected by 'like', because (as they argue) neither of two 'likes'
is more apt than the other either to act or to suffer action, since
all the properties which belong to the one belong identically
and in the same degree to the other; and (b) that 'unlikes', i.e.
'differents', are by nature such as to act and suffer action
reciprocally. For even when the smaller fire is destroyed by the
greater, it suffers this effect (they say) owing to its 'contrariety'
since the great is contrary to the small. But (ii) Democritus
dissented from all the other thinkers and maintained a theory
peculiar to himself. He asserts that agent and patient are
identical, i.e. 'like'. It is not possible (he says) that 'others', i.e.
'differents', should suffer action from one another: on the
contrary, even if two things, being 'others', do act in some way
on one another, this happens to them not qua 'others' but qua
possessing an identical property.
Such, then, are the traditional theories, and it looks as if the
statements of their advocates were in manifest conflict. But the
reason of this conflict is that each group is in fact stating a part,
whereas they ought to have taken a comprehensive view of the
subject as a whole. For (i) if A and B are 'like' - absolutely and in
all respects without difference from one another - it is
reasonable to infer that neither is in any way affected by the
other. Why, indeed, should either of them tend to act any more
than the other? Moreover, if 'like' can be affected by 'like', a
thing can also be affected by itself: and yet if that were so - if
'like' tended in fact to act qua 'like' - there would be nothing
indestructible or immovable, for everything would move itself.
And (ii) the same consequence follows if A and B are absolutely
'other', i.e. in no respect identical. Whiteness could not be
984
affected in any way by line nor line by whiseness - except
perhaps 'coincidentally', viz. if the line happened to be white or
black: for unless two things either are, or are composed of,
'contraries', neither drives the other out of its natural condition.
But (iii) since only those things which either involve a
'contrariety' or are 'contraries' - and not any things selected at
random - are such as to suffer action and to act, agent and
patient must be 'like' (i.e. identical) in kind and yet 'unlike' (i.e.
contrary) in species. (For it is a law of nature that body is
affected by body, flavour by flavour, colour by colour, and so in
general what belongs to any kind by a member of the same kind
- the reason being that 'contraries' are in every case within a
single identical kind, and it is 'contraries' which reciprocally act
and suffer action.) Hence agent and patient must be in one
sense identical, but in another sense other than (i.e. 'unlike')
one another. And since (a) patient and agent are generically
identical (i.e. 'like') but specifically 'unlike', while (b) it is
'contraries' that exhibit this character: it is clear that 'contraries'
and their 'intermediates' are such as to suffer action and to act
reciprocally - for indeed it is these that constitute the entire
sphere of passing-away and coming-to-be.
We can now understand why fire heats and the cold thing cools,
and in general why the active thing assimilates to itself the
patient. For agent and patient are contrary to one another, and
coming-to-be is a process into the contrary: hence the patient
must change into the agent, since it is only thus that coming-to-
be will be a process into the contrary. And, again, it is intelligible
that the advocates of both views, although their theories are not
the same, are yet in contact with the nature of the facts. For
sometimes we speak of the substratum as suffering action (e.g.
of 'the man' as being healed, being warmed and chilled, and
similarly in all the other cases), but at other times we say 'what
is cold is 'being warmed', 'what is sick is being healed': and in
both these ways of speaking we express the truth, since in one
985
sense it is the 'matter', while in another sense it is the
'contrary', which suffers action. (We make the same distinction
in speaking of the agent: for sometimes we say that 'the man',
but at other times that 'what is hot', produces heat.) Now the
one group of thinkers supposed that agent and patient must
possess something identical, because they fastened their
attention on the substratum: while the other group maintained
the opposite because their attention was concentrated on the
'contraries'. We must conceive the same account to hold of
action and passion as that which is true of 'being moved' and
'imparting motion'. For the 'mover', like the 'agent', has two
meanings. Both (a) that which contains the originative source of
the motion is thought to 'impart motion' (for the originative
source is first amongst the causes), and also (b) that which is
last, i.e. immediately next to the moved thing and to the
coming-to-be. A similar distinction holds also of the agent: for
we speak not only (a) of the doctor, but also (b) of the wine, as
healing. Now, in motion, there is nothing to prevent the firs;
mover being unmoved (indeed, as regards some 'first' movers'
this is actually necessary) although the last mover always
imparts motion by being itself moved: and, in action, there is
nothing to prevent the first agent being unaffected, while the
last agent only acts by suffering action itself. For agent and
patient have not the same matter, agent acts without being
affected: thus the art of healing produces health without itself
being acted upon in any way by that which is being healed. But
(b) the food, in acting, is itself in some way acted upon: for, in
acting, it is simultaneously heated or cooled or otherwise
affected. Now the art of healing corresponds to an 'originative
source', while the food corresponds to 'the last' (i.e.
'continuous') mover.
Those active powers, then, whose forms are not embodied in
matter, are unaffected: but those whose forms are in matter are
such as to be affected in acting. For we maintain that one and
986
the same 'matter' is equally, so to say, the basis of either of the
two opposed things - being as it were a 'kind'; and that that
which can he hot must be made hot, provided the heating agent
is there, i.e. comes near. Hence (as we have said) some of the
active powers are unaffected while others are such as to be
affected; and what holds of motion is true also of the active
powers. For as in motion 'the first mover' is unmoved, so among
the active powers 'the first agent' is unaffected.
The active power is a 'cause' in the sense of that from which the
process originates: but the end, for the sake of which it takes
place, is not 'active'. (That is why health is not 'active', except
metaphorically.) For when the agent is there, the patient
becomes something: but when 'states' are there, the patient no
longer becomes but already is - and 'forms' (i.e. 'lends') are a
kind of 'state'. As to the 'matter', it (qua matter) is passive. Now
fire contains 'the hot' embodied in matter: but a 'hot' separate
from matter (if such a thing existed) could not suffer any action.
Perhaps, indeed, it is impossible that 'the hot' should exist in
separation from matter: but if there are any entities thus
separable, what we are saying would be true of them.
We have thus explained what action and passion are, what
things exhibit them, why they do so, and in what manner. We
must go on to discuss how it is possible for action and passion
to take place.
8
Some philosophers think that the 'last' agent - the 'agent' in the
strictest sense - enters in through certain pores, and so the
patient suffers action. It is in this way, they assert, that we see
and hear and exercise all our other senses. Moreover, according
987
to them, things are seen through air and water and other
transparent bodies, because such bodies possess pores, invisible
indeed owing to their minuteness, but close-set and arranged in
rows: and the more transparent the body, the more frequent
and serial they suppose its pores to be. Such was the theory
which some philosophers (induding Empedocles) advanced in
regard to the structure of certain bodies. They do not restrict it
to the bodies which act and suffer action: but 'combination' too,
they say, takes place 'only between bodies whose pores are in
reciprocal symmetry'. The most systematic and consistent
theory, however, and one that applied to all bodies, was
advanced by Leucippus and Democritus: and, in maintaining it,
they took as their starting-point what naturally comes first.
For some of the older philosophers thought that 'what is' must
of necessity be 'one' and immovable. The void, they argue, 'is
not': but unless there is a void with a separate being of its own,
'what is' cannot be moved - nor again can it be 'many', since
there is nothing to keep things apart. And in this respect, they
insist, the view that the universe is not 'continuous' but
'discretes-in-contact' is no better than the view that there are
'many' (and not 'one') and a void. For (suppose that the universe
is discretes-in-contact. Then), if it is divisible through and
through, there is no 'one', and therefore no 'many' either, but
the Whole is void; while to maintain that it is divisible at some
points, but not at others, looks like an arbitrary fiction. For up to
what limit is it divisible? And for what reason is part of the
Whole indivisible, i.e. a plenum, and part divided? Further, they
maintain, it is equally necessary to deny the existence of
motion.
Reasoning in this way, therefore, they were led to transcend
sense-perception, and to disregard it on the ground that 'one
ought to follow the argument': and so they assert that the
universe is 'one' and immovable. Some of them add that it is
988
'infinite', since the limit (if it had one) would be a limit against
the void.
There were, then, certain thinkers who, for the reasons we have
stated, enunciated views of this kind as their theory of 'The
Truth'.... Moreover, although these opinions appear to follow
logically in a dialectical discussion, yet to believe them seems
next door to madness when one considers the facts. For indeed
no lunatic seems to be so far out of his senses as to suppose
that fire and ice are 'one': it is only between what is right and
what seems right from habit, that some people are mad enough
to see no difference.
Leucippus, however, thought he had a theory which harmonized
with sense-perception and would not abolish either coming-to-
be and passing-away or motion and the multiplicity of things.
He made these concessions to the facts of perception: on the
other hand, he conceded to the Monists that there could be no
motion without a void. The result is a theory which he states as
follows: 'The void is a «not being», and no part of «what is» is a
«not-being»; for what «is» in the strict sense of the term is an
absolute plenum. This plenum, however, is not «one»: on the
contrary, it is a many» infinite in number and invisible owing to
the minuteness of their bulk. The «many» move in the void (for
there is a void): and by coming together they produce «coming-
to-be», while by separating they produce «passing-away».
Moreover, they act and suffer action wherever they chance to be
in contact (for there they are not «one»), and they generate by
being put together and becoming intertwined. From the
genuinely-one, on the other hand, there never could have come-
to-be a multiplicity, nor from the genuinely-many a «one»: that
is impossible. But (just as Empedocles and some of the other
philosophers say that things suffer action through their pores,
so) 'all «alteration» and all «passion» take place in the way that
has been explained: breaking-up (i.e. passing-away) is effected
989
by means of the void, and so too is growth-solids creeping in to
fill the void places.' Empedocles too is practically bound to
adopt the same theory as Leucippus. For he must say that there
are certain solids which, however, are indivisible - unless there
are continuous pores all through the body. But this last
alternative is impossible: for then there will be nothing solid in
the body (nothing beside the pores) but all of it will be void. It is
necessary, therefore, for his 'contiguous discretes' to be
indivisible, while the intervals between them - which he calls
'pores' - must be void. But this is precisely Leucippus' theory of
action and passion.
Such, approximately, are the current explanations of the
manner in which some things 'act' while others 'suffer action'.
And as regards the Atomists, it is not only clear what their
explanation is: it is also obvious that it follows with tolerable
consistency from the assumptions they employ. But there is less
obvious consistency in the explanation offered by the other
thinkers. It is not clear, for instance, how, on the theory of
Empedocles, there is to be 'passing-away' as well as 'alteration'.
For the primary bodies of the Atomists - the primary
constituents of which bodies are composed, and the ultimate
elements into which they are dissolved - are indivisible,
differing from one another only in figure. In the philosophy of
Empedocles, on the other hand, it is evident that all the other
bodies down to the 'elements' have their coming-to-be and
their passing-away: but it is not clear how the 'elements'
themselves, severally in their aggregated masses, come-to-be
and pass-away. Nor is it possible for Empedocles to explain how
they do so, since he does not assert that Fire too (and similarly
every one of his other 'elements') possesses 'elementary
constituents' of itself.
Such an assertion would commit him to doctrines like those
which Plato has set forth in the Timaeus. For although both
990
Plato and Leucippus postulate elementary constituents that are
indivisible and distinctively characterized by figures, there is
this great difference between the two theories: the 'indivisibles'
of Leucippus (i) are solids, while those of Plato are planes, and
(ii) are characterized by an infinite variety of figures, while the
characterizing figures employed by Plato are limited in number.
Thus the 'comings-to-be' and the 'dissociations' result from the
'indivisibles' (a) according to Leucippus through the void and
through contact (for it is at the point of contact that each of the
composite bodies is divisible), but (b) according to Plato in virtue
of contact alone, since he denies there is a void.
Now we have discussed 'indivisible planes' in the preceding
treatise.' But with regard to the assumption of 'indivisible
solids', although we must not now enter upon a detailed study
of its consequences, the following criticisms fall within the
compass of a short digression: i. The Atomists are committed to
the view that every 'indivisible' is incapable alike of receiving a
sensible property (for nothing can 'suffer action' except through
the void) and of producing one - no 'indivisible' can be, e.g.
either hard or cold. Yet it is surely a paradox that an exception
is made of 'the hot' - 'the hot' being assigned as peculiar to the
spherical figure: for, that being so, its 'contrary' also ('the cold')
is bound to belong to another of the figures. If, however, these
properties (heat and cold) do belong to the 'indivisibles', it is a
further paradox that they should not possess heaviness and
lightness, and hardness and softness. And yet Democritus says
'the more any indivisible exceeds, the heavier it is' - to which
we must clearly add 'and the hotter it is'. But if that is their
character, it is impossible they should not be affected by one
another: the 'slightly-hot indivisible', e.g. will inevitably suffer
action from one which far exceeds it in heat. Again, if any
'indivisible' is 'hard', there must also be one which is 'soft': but
'the soft' derives its very name from the fact that it suffers a
certain action - for 'soft' is that which yields to pressure.
991
II. But further, not only is it paradoxical (i) that no property
except figure should belong to the 'indivisibles': it is also
paradoxical (ii) that, if other properties do belong to them, one
only of these additional properties should attach to each - e.g.
that this 'indivisible' should be cold and that 'indivisible' hot.
For, on that supposition, their substance would not even be
uniform. And it is equally impossible (iii) that more than one of
these additional properties should belong to the single
'indivisible'. For, being indivisible, it will possess these
properties in the same point - so that, if it 'suffers action' by
being chilled, it will also, qua chilled, 'act' or 'suffer action' in
some other way. And the same line of argument applies to all
the other properties too: for the difficulty we have just raised
confronts, as a necessary consequence, all who advocate
'indivisibles' (whether solids or planes), since their 'indivisibles'
cannot become either 'rarer' or 'derser' inasmuch as there is no
void in them.
III. It is a further paradox that there should be small
'indivisibles', but not large ones. For it is natural enough, from
the ordinary point of view, that the larger bodies should be more
liable to fracture than the small ones, since they (viz. the large
bodies) are easily broken up because they collide with many
other bodies. But why should indivisibility as such be the
property of small, rather than of large, bodies?
IV. Again, is the substance of all those solids uniform, or do they
fall into sets which differ from one another - as if, e.g. some of
them, in their aggregated bulk, were 'fiery', others earthy? For
(i) if all of them are uniform in substance, what is it that
separated one from another? Or why, when they come into
contact, do they not coalesce into one, as drops of water run
together when drop touches drop (for the two cases are
precisely parallel)? On the other hand (ii) if they fall into
differing sets, how are these characterized? It is clear, too, that
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these, rather than the 'figures', ought to be postulated as
'original reals', i.e. causes from which the phenomena result.
Moreover, if they differed in substance, they would both act and
suffer action on coming into reciprocal contact.
V. Again, what is it which sets them moving? For if their 'mover'
is other than themselves, they are such as to 'suffer action'. If,
on the other hand, each of them sets itself in motion, either (a)
it will be divisible ('imparting motion' qua this, 'being moved'
qua that), or (b) contrary properties will attach to it in the same
respect - i.e. 'matter' will be identical in-potentiality as well as
numerically-identical.
As to the thinkers who explain modification of property
through the movement facilitated by the pores, if this is
supposed to occur notwithstanding the fact that the pores are
filled, their postulate of pores is superfluous. For if the whole
body suffers action under these conditions, it would suffer
action in the same way even if it had no pores but were just its
own continuous self. Moreover, how can their account of 'vision
through a medium' be correct? It is impossible for (the visual
ray) to penetrate the transparent bodies at their 'contacts'; and
impossible for it to pass through their pores if every pore be full.
For how will that differ from having no pores at all? The body
will be uniformly 'full' throughout. But, further, even if these
passages, though they must contain bodies, are 'void', the same
consequence will follow once more. And if they are 'too minute
to admit any body', it is absurd to suppose there is a 'minute'
void and yet to deny the existence of a 'big' one (no matter how
small the 'big' may be), or to imagine 'the void' means anything
else than a body's place - whence it clearly follows that to every
body there will correspond a void of equal cubic capacity.
As a general criticism we must urge that to postulate pores is
superfluous. For if the agent produces no effect by touching the
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patient, neither will it produce any by passing through its pores.
On the other hand, if it acts by contact, then - even without
pores - some things will 'suffer action' and others will 'act',
provided they are by nature adapted for reciprocal action and
passion. Our arguments have shown that it is either false or
futile to advocate pores in the sense in which some thinkers
conceive them. But since bodies are divisible through and
through, the postulate of pores is ridiculous: for, qua divisible, a
body can fall into separate parts.
Let explain the way in which things in fact possess the power of
generating, and of acting and suffering action: and let us start
from the principle we have often enunciated. For, assuming the
distinction between (a) that which is potentially and (b) that
which is actually such-and-such, it is the nature of the first,
precisely in so far as it is what it is, to suffer action through and
through, not merely to be susceptible in some parts while
insusceptible in others. But its susceptibility varies in degree,
according as it is more or less; such-and-such, and one would
be more justified in speaking of 'pores' in this connexion: for
instance, in the metals there are veins of 'the susceptible'
stretching continuously through the substance.
So long, indeed, as any body is naturally coherent and one, it is
insusceptible. So, too, bodies are insusceptible so long as they
are not in contact either with one another or with other bodies
which are by nature such as to act and suffer action. (To
illustrate my meaning: Fire heats not only when in contact, but
also from a distance. For the fire heats the air, and the air -
being by nature such as both to act and suffer action - heats the
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body.) But the supposition that a body is 'susceptible in some
parts, but insusceptible in others' (is only possible for those who
hold an erroneous view concerning the divisibility of
magnitudes. For us) the following account results from the
distinctions we established at the beginning. For (i) if
magnitudes are not divisible through and through - if, on the
contrary, there are indivisible solids or planes - then indeed no
body would be susceptible through and through :but neither
would any be continuous. Since, however, (ii) this is false, i.e.
since every body is divisible, there is no difference between
'having been divided into parts which remain in contact' and
'being divisible'. For if a body 'can be separated at the contacts'
(as some thinkers express it), then, even though it has not yet
been divided, it will be in a state of dividedness - since, as it can
be divided, nothing inconceivable results. And (iii) the
suposition is open to this general objection - it is a paradox that
'passion' should occur in this manner only, viz. by the bodies
being split. For this theory abolishes 'alteration': but we see the
same body liquid at one time and solid at another, without
losing its continuity. It has suffered this change not by 'division'
and composition', nor yet by 'turning' and 'intercontact' as
Democritus asserts; for it has passed from the liquid to the solid
state without any change of 'grouping' or 'position' in the
constituents of its substance. Nor are there contained within it
those 'hard' (i.e. congealed) particles 'indivisible in their bulk':
on the contrary, it is liquid - and again, solid and congealed -
uniformly all through. This theory, it must be added, makes
growth and diminution impossible also. For if there is to be
opposition (instead of the growing thing having changed as a
whole, either by the admixture of something or by its own
transformation), increase of size will not have resulted in any
and every part.
So much, then, to establish that things generate and are
generated, act and suffer action, reciprocally; and to distinguish
995
the way in which these processes can occur from the
(impossible) way in which some thinkers say they occur.
10
But we have still to explain 'combination', for that was the third
of the subjects we originally proposed to discuss. Our
explanation will proceed on the same method as before. We
must inquire: What is 'combination', and what is that which can
'combine? Of what things, and under what conditions, is
'combination' a property? And, further, does 'combination' exist
in fact, or is it false to assert its existence?
For, according to some thinkers, it is impossible for one thing to
be combined with another. They argue that (i) if both the
'combined' constituents persist unaltered, they are no more
'combined' now than they were before, but are in the same
condition: while (ii) if one has been destroyed, the constituents
have not been 'combined' - on the contrary, one constituent is
and the other is not, whereas 'combination' demands
uniformity of condition in them both: and on the same principle
(iii) even if both the combining constituents have been
destroyed as the result of their coalescence, they cannot 'have
been combined' since they have no being at all.
What we have in this argument is, it would seem, a demand for
the precise distinction of 'combination' from coming-to-be and
passing-away (for it is obvious that 'combination', if it exists,
must differ from these processes) and for the precise distinction
of the 'combinable' from that which is such as to come-to-be
and pass-away. As soon, therefore, as these distinctions are
clear, the difficulties raised by the argument would be solved.
996
Now (i) we do not speak of the wood as 'combined' with the fire,
nor of its burning as a 'combining' either of its particles with
one another or of itself with the fire: what we say is that 'the
fire is coming-to-be, but the wood is 'passing-away'. Similarly,
we speak neither (ii) of the food as 'combining' with the body,
nor (iii) of the shape as 'combining' with the wax and thus
fashioning the lump. Nor can body 'combine' with white, nor (to
generalize) 'properties' and 'states' with 'things': for we see
them persisting unaltered. But again (iv) white and knowledge
cannot be 'combined' either, nor any other of the 'adjectivals'.
(Indeed, this is a blemish in the theory of those who assert that
'once upon a time all things were together and combined'. For
not everything can 'combine' with everything. On the contrary,
both of the constituents that are combined in the compound
must originally have existed in separation: but no property can
have separate existence.)
Since, however, some things are-potentially while others are-
actually, the constituents combined in a compound can 'be' in a
sense and yet 'not-be'. The compound may be-actually other
than the constituents from which it has resulted; nevertheless
each of them may still be-potentially what it was before they
were combined, and both of them may survive undestroyed.
(For this was the difficulty that emerged in the previous
argument: and it is evident that the combining constituents not
only coalesce, having formerly existed in separation, but also
can again be separated out from the compound.) The
constituents, therefore, neither (a) persist actually, as 'body' and
'white' persist: nor (b) are they destroyed (either one of them or
both), for their 'power of action' is preserved. Hence these
difficulties may be dismissed: but the problem immediately
connected with them - whether combination is something
relative to perception' must be set out and discussed.
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When the combining constituents have been divided into parts
so small, and have been juxtaposed in such a manner, that
perception fails to discriminate them one from another, have
they then 'been combined Or ought we to say 'No, not until any
and every part of one constituent is juxtaposed to a part of the
other? The term, no doubt, is applied in the former sense: we
speak, e.g. of wheat having been 'combined' with barley when
each grain of the one is juxtaposed to a grain of the other. But
every body is divisible and therefore, since body 'combined' with
body is uniform in texture throughout, any and every part of
each constituent ought to be juxtaposed to a part of the other.
No body, however, can be divided into its 'least' parts: and
'composition' is not identical with 'combination', but other than
it. From these premises it clearly follows (i) that so long as the
constituents are preserved in small particles, we must not
speak of them as 'combined'. (For this will be a 'composition'
instead of a 'blending' or 'combination': nor will every portion of
the resultant exhibit the same ratio between its constituents as
the whole. But we maintain that, if 'combination' has taken
place, the compound must be uniform in texture throughout -
any part of such a compound being the same as the whole, just
as any part of water is water: whereas, if 'combination' is
'composition of the small particles', nothing of the kind will
happen. On the contrary, the constituents will only be
'combined' relatively to perception: and the same thing will be
'combined' to one percipient, if his sight is not sharp, (but not to
another,) while to the eye of Lynceus nothing will be
'combined'.) It clearly follows (ii) that we must not speak of the
constituents as 'combined in virtue of a division such that any
and every part of each is juxtaposed to a part of the other: for it
is impossible for them to be thus divided. Either, then, there is
no 'combination', or we have still to explain the manner in
which it can take place.
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Now, as we maintain, some things are such as to act and others
such as to suffer action from them. Moreover, some things - viz.
those which have the same matter - 'reciprocate', i.e. are such
as to act upon one another and to suffer action from one
another; while other things, viz. agents which have not the
same matter as their patients, act without themselves suffering
action. Such agents cannot 'combine' - that is why neither the
art of healing nor health produces health by 'combining' with
the bodies of the patients. Amongst those things, however,
which are reciprocally active and passive, some are easily-
divisible. Now (i) if a great quantity (or a large bulk) of one of
these easily-divisible 'reciprocating' materials be brought
together with a little (or with a small piece) of another, the
effect produced is not 'combination', but increase of the
dominant: for the other material is transformed into the
dominant. (That is why a drop of wine does not 'combine' with
ten thousand gallons of water: for its form is dissolved, and it is
changed so as to merge in the total volume of water.) On the
other hand (ii) when there is a certain equilibrium between
their 'powers of action', then each of them changes out of its
own nature towards the dominant: yet neither becomes the
other, but both become an intermediate with properties
common to both.
Thus it is clear that only those agents are 'combinable' which
involve a contrariety - for these are such as to suffer action
reciprocally. And, further, they combine more freely if small
pieces of each of them are juxtaposed. For in that condition
they change one another more easily and more quickly;
whereas this effect takes a long time when agent and patient
are present in bulk.
Hence, amongst the divisible susceptible materials, those whose
shape is readily adaptable have a tendency to combine: for they
are easily divided into small particles, since that is precisely
999
what 'being readily adaptable in shape' implies. For instance,
liquids are the most 'combinable' of all bodies - because, of all
divisible materials, the liquid is most readily adaptable in shape,
unless it be viscous. Viscous liquids, it is true, produce no effect
except to increase the volume and bulk. But when one of the
constituents is alone susceptible - or superlatively susceptible,
the other being susceptible in a very slight degree - the
compound resulting from their combination is either no greater
in volume or only a little greater. This is what happens when tin
is combined with bronze. For some things display a hesitating
and ambiguous attitude towards one another - showing a slight
tendency to combine and also an inclination to behave as
'receptive matter' and 'form' respectively. The behaviour of
these metals is a case in point. For the tin almost vanishes,
behaving as if it were an immaterial property of the bronze:
having been combined, it disappears, leaving no trace except
the colour it has imparted to the bronze. The same
phenomenon occurs in other instances too.
It is clear, then, from the foregoing account, that 'combination'
occurs, what it is, to what it is due, and what kind of thing is
'combinable'. The phenomenon depends upon the fact that
some things are such as to be (a) reciprocally susceptible and (b)
readily adaptable in shape, i.e. easily divisible. For such things
can be 'combined' without its being necessary either that they
should have been destroyed or that they should survive
absolutely unaltered: and their 'combination' need not be a
'composition', nor merely 'relative to perception'. On the
contrary: anything is 'combinable' which, being readily
adaptable in shape, is such as to suffer action and to act; and it
is 'combinable with' another thing similarly characterized (for
the 'combinable' is relative to the 'combinable'); and
'combination' is unification of the 'combinables', resulting from
their 'alteration'.
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Book II
We have explained under what conditions 'combination',
'contact', and 'action-passion' are attributable to the things
which undergo natural change. Further, we have discussed
'unqualified' coming-to-be and passing-away, and explained
under what conditions they are predicable, of what subject, and
owing to what cause. Similarly, we have also discussed
'alteration', and explained what 'altering' is and how it differs
from coming-to-be and passing-away. But we have still to
investigate the so-called 'elements' of bodies.
For the complex substances whose formation and maintenance
are due to natural processes all presuppose the perceptible
bodies as the condition of their coming-to-be and passing-away:
but philosophers disagree in regard to the matter which
underlies these perceptible bodies. Some maintain it is single,
supposing it to be, e.g. Air or Fire, or an 'intermediate' between
these two (but still a body with a separate existence). Others, on
the contrary, postulate two or more materials - ascribing to
their 'association' and 'dissociation', or to their 'alteration', the
coming-to-be and passing-away of things. (Some, for instance,
postulate Fire and Earth: some add Air, making three: and some,
like Empedocles, reckon Water as well, thus postulating four.)
1001
Now we may agree that the primary materials, whose change
(whether it be 'association and dissociation' or a process of
another kind) results in coming-to-be and passing-away, are
rightly described as 'originative sources, i.e. elements'. But (i)
those thinkers are in error who postulate, beside the bodies we
have mentioned, a single matter - and that corporeal and
separable matter. For this 'body' of theirs cannot possibly exist
without a 'perceptible contrariety': this 'Boundless', which some
thinkers identify with the 'original real', must be either light or
heavy, either cold or hot. And (ii) what Plato has written in the
Timaeus is not based on any precisely-articulated conception.
For he has not stated clearly whether his 'Omnirecipient' exists
in separation from the 'elements'; nor does he make any use of
it. He says, indeed, that it is a substratum prior to the so-called
'elements' - underlying them, as gold underlies the things that
are fashioned of gold. (And yet this comparison, if thus
expressed, is itself open to criticism. Things which come-to-be
and pass-away cannot be called by the name of the material out
of which they have come-to-be: it is only the results of
'alteration' which retain the name of the substratum whose
'alterations' they are. However, he actually says 'that the truest
account is to affirm that each of them is «gold»'.) Nevertheless
he carries his analysis of the 'elements' - solids though they are
- back to 'planes', and it is impossible for 'the Nurse' (i.e. the
primary matter) to be identical with 'the planes'.
Our own doctrine is that although there is a matter of the
perceptible bodies (a matter out of which the so-called
'elements' come-to-be), it has no separate existence, but is
always bound up with a contrariety. A more precise account of
these presuppositions has been given in another work': we
must, however, give a detailed explanation of the primary
bodies as well, since they too are similarly derived from the
matter. We must reckon as an 'originative source' and as
'primary' the matter which underlies, though it is inseparable
1002
from, the contrary qualities: for the hot' is not matter for 'the
cold' nor 'the cold' for 'the hot', but the substratum is matter for
them both. We therefore have to recognize three 'originative
sources': firstly that which potentially perceptible body,
secondly the contrarieties (I mean, e.g. heat and cold), and
thirdly Fire, Water, and the like. Only 'thirdly', however: for these
bodies change into one another (they are not immutable as
Empedocles and other thinkers assert, since 'alteration' would
then have been impossible), whereas the contrarieties do not
change.
Nevertheless, even so the question remains: What sorts of
contrarieties, and how many of them, are to be accounted
'originative sources' of body? For all the other thinkers assume
and use them without explaining why they are these or why
they are just so many.
Since, then, we are looking for 'originative sources' of
perceptible body; and since 'perceptible' is equivalent to
'tangible', and 'tangible' is that of which the perception is touch;
it is clear that not all the contrarieties constitute 'forms' and
'originative sources' of body, but only those which correspond to
touch. For it is in accordance with a contrariety - a contrariety,
moreover, of tangible qualities - that the primary bodies are
differentiated. That is why neither whiteness (and blackness),
nor sweetness (and bitterness), nor (similarly) any quality
belonging to the other perceptible contrarieties either,
constitutes an 'element'. And yet vision is prior to touch, so that
its object also is prior to the object of touch. The object of vision,
however, is a quality of tangible body not qua tangible, but qua
1003
something else - qua something which may well be naturally
prior to the object of touch.
Accordingly, we must segregate the tangible differences and
contrarieties, and distinguish which amongst them are primary.
Contrarieties correlative to touch are the following: hot-cold,
dry-moist, heavy-light, hard-soft, viscous-brittle, rough-smooth,
coarse-fine. Of these (i) heavy and light are neither active nor
susceptible. Things are not called 'heavy' and 'light' because
they act upon, or suffer action from, other things. But the
'elements' must be reciprocally active and susceptible, since
they 'combine' and are transformed into one another. On the
other hand (ii) hot and cold, and dry and moist, are terms, of
which the first pair implies power to act and the second pair
susceptibility. 'Hot' is that which 'associates' things of the same
kind (for 'dissociating', which people attribute to Fire as its
function, is 'associating' things of the same class, since its effect
is to eliminate what is foreign), while 'cold' is that which brings
together, i.e. 'associates', homogeneous and heterogeneous
things alike. And moise is that which, being readily adaptable in
shape, is not determinable by any limit of its own: while 'dry' is
that which is readily determinable by its own limit, but not
readily adaptable in shape.
From moist and dry are derived (iii) the fine and coarse, viscous
and brittle, hard and soft, and the remaining tangible
differences. For (a) since the moist has no determinate shape,
but is readily adaptable and follows the outline of that which is
in contact with it, it is characteristic of it to be 'such as to fill
up'. Now 'the fine' is 'such as to fill up'. For the fine' consists of
subtle particles; but that which consists of small particles is
'such as to fill up', inasmuch as it is in contact whole with
whole - and 'the fine' exhibits this character in a superlative
degree. Hence it is evident that the fine derives from the moist,
while the coarse derives from the dry. Again (b) the viscous'
1004
derives from the moist: for 'the viscous' (e.g. oil) is a 'moist'
modified in a certain way. 'The brittle', on the other hand,
derives from the dry: for 'brittle' is that which is completely dry
- so completely, that its solidification has actually been due to
failure of moisture. Further (c) 'the soft' derives from the moist.
For 'soft' is that which yields to pressure by retiring into itself,
though it does not yield by total displacement as the moist does
- which explains why the moist is not 'soft', although 'the soft'
derives from the moist. 'The hard', on the other hand, derives
from the dry: for 'hard' is that which is solidified, and the
solidified is dry.
The terms 'dry' and 'moist' have more senses than one. For 'the
damp', as well as the moist, is opposed to the dry: and again
'the solidified', as well as the dry, is opposed to the moist. But
all these qualities derive from the dry and moist we mentioned
first.' For (i) the dry is opposed to the damp: i.e. 'damp' is that
which has foreign moisture on its surface ('sodden' being that
which is penetrated to its core), while 'dry' is that which has
lost foreign moisture. Hence it is evident that the damp will
derive from the moist, and 'the dry' which is opposed to it will
derive from the primary dry. Again (ii) the 'moist' and the
solidified derive in the same way from the primary pair. For
'moist' is that which contains moisture of its own deep within it
('sodden' being that which is deeply penetrated by foreign
mosture), whereas 'solidigied' is that which has lost this inner
moisture. Hence these too derive from the primary pair, the
'solidified' from the dry and the 'solidified' from the dry the
'liquefiable' from the moist.
It is clear, then, that all the other differences reduce to the first
four, but that these admit of no further reduction. For the hot is
not essentially moist or dry, nor the moist essentially hot or
cold: nor are the cold and the dry derivative forms, either of one
another or of the hot and the moist. Hence these must be four.
1005
The elementary qualities are four, and any four terms can be
combined in six couples. Contraries, however, refuse to be
coupled: for it is impossible for the same thing to be hot and
cold, or moist and dry Hence it is evident that the 'couplings' of
the elementary qualities will be four: hot with dry and moist
with hot, and again cold with dry and cold with moist. And
these four couples have attached themselves to the apparently
'simple' bodies (Fire, Air, Water, and Earth) in a manner
consonant with theory. For Fire is hot and dry, whereas Air is
hot and moist (Air being a sort of aqueous vapour); and Water is
cold and moist, while Earth is cold and dry. Thus the differences
are reasonably distributed among the primary bodies, and the
number of the latter is consonant with theory. For all who make
the simple bodies 'elements' postulate either one, or two, or
three, or four. Now (i) those who assert there is one only, and
then generate everything else by condensation and rarefaction,
are in effect making their 'originative sources' two, viz. the rare
and the dense, or rather the hot and the cold: for it is these
which are the moulding forces, while the 'one' underlies them
as a 'matter'. But (ii) those who postulate two from the start - as
Parmenides postulated Fire and Earth - make the intermediates
(e.g. Air and Water) blends of these. The same course is followed
(iii) by those who advocate three. (We may compare what Plato
does in Me Divisions': for he makes 'the middle' a blend.)
Indeed, there is practically no difference between those who
postulate two and those who postulate three, except that the
former split the middle 'element' into two, while the latter treat
it as only one. But (iv) some advocate four from the start, e.g.
1006
Empedocles: yet he too draws them together so as to reduce
them to the two, for he opposes all the others to Fire.
In fact, however, fire and air, and each of the bodies we have
mentioned, are not simple, but blended. The 'simple' bodies are
indeed similar in nature to them, but not identical with them.
Thus the 'simple' body corresponding to fire is 'such -as -fire, not
fire: that which corresponds to air is 'such-as-air': and so on
with the rest of them. But fire is an excess of heat, just as ice is
an excess of cold. For freezing and boiling are excesses of heat
and cold respectively. Assuming, therefore, that ice is a freezing
of moist and cold, fire analogously will be a boiling of dry and
hot: a fact, by the way, which explains why nothing comes-to-be
either out of ice or out of fire.
The 'simple' bodies, since they are four, fall into two pairs which
belong to the two regions, each to each: for Fire and Air are
forms of the body moving towards the 'limit', while Earth and
Water are forms of the body which moves towards the 'centre'.
Fire and Earth, moreover, are extremes and purest: Water and
Air, on the contrary are intermediates and more like blends.
And, further, the members of either pair are contrary to those of
the other, Water being contrary to Fire and Earth to Air; for the
qualities constituting Water and Earth are contrary to those that
constitute Fire and Air. Nevertheless, since they are four, each of
them is characterized par excellence a single quality: Earth by
dry rather than by cold, Water by cold rather than by moist, Air
by moist rather than by hot, and Fire by hot rather than by dry.
It has been established before' that the coming-to-be of the
'simple' bodies is reciprocal. At the same time, it is manifest,
1007
even on the evidence of perception, that they do come-to-be: for
otherwise there would not have been 'alteration, since
'alteration' is change in respect to the qualities of the objects of
touch. Consequently, we must explain (i) what is the manner of
their reciprocal transformation, and (ii) whether every one of
them can come-to-be out of every one - or whether some can
do so, but not others.
Now it is evident that all of them are by nature such as to
change into one another: for coming-to-be is a change into
contraries and out of contraries, and the 'elements' all involve a
contrariety in their mutual relations because their distinctive
qualities are contrary. For in some of them both qualities are
contrary - e.g. in Fire and Water, the first of these being dry and
hot, and the second moist and cold: while in others one of the
qualities (though only one) is contrary - e.g. in Air and Water,
the first being moist and hot, and the second moist and cold. It
is evident, therefore, if we consider them in general, that every
one is by nature such as to come-to-be out of every one: and
when we come to consider them severally, it is not difficult to
see the manner in which their transformation is effected. For,
though all will result from all, both the speed and the facility of
their conversion will differ in degree.
Thus (i) the process of conversion will be quick between those
which have interchangeable 'complementary factors', but slow
between those which have none. The reason is that it is easier
for a single thing to change than for many. Air, e.g. will result
from Fire if a single quality changes: for Fire, as we saw, is hot
and dry while Air is hot and moist, so that there will be Air if
the dry be overcome by the moist. Again, Water will result from
Air if the hot be overcome by the cold: for Air, as we saw, is hot
and moist while Water is cold and moist, so that, if the hot
changes, there will be Water. So too, in the same manner, Earth
will result from Water and Fire from Earth, since the two
1008
'elements' in both these couples have interchangeable
'complementary factors'. For Water is moist and cold while
Earth is cold and dry - so that, if the moist be overcome, there
will be Earth: and again, since Fire is dry and hot while Earth is
cold and dry, Fire will result from Earth if the cold pass-away.
It is evident, therefore, that the coming-to-be of the 'simple'
bodies will be cyclical; and that this cyclical method of
transformation is the easiest, because the consecutive
'elements' contain interchangeable 'complementary factors'. On
the other hand (ii) the transformation of Fire into Water and of
Air into Earth, and again of Water and Earth into Fire and Air
respectively, though possible, is more difficult because it
involves the change of more qualities. For if Fire is to result
from Water, both the cold and the moist must pass-away: and
again, both the cold and the dry must pass-away if Air is to
result from Earth. So' too, if Water and Earth are to result from
Fire and Air respectively - both qualities must change.
This second method of coming-to-be, then, takes a longer time.
But (iii) if one quality in each of two 'elements' pass-away, the
transformation, though easier, is not reciprocal. Still, from Fire
plus Water there will result Earth and Air, and from Air plus
Earth Fire and Water. For there will be Air, when the cold of the
Water and the dry of the Fire have passed-away (since the hot of
the latter and the moist of the former are left): whereas, when
the hot of the Fire and the moist of the Water have passed-away,
there will be Earth, owing to the survival of the dry of the Fire
and the cold of the Water. So, too, in the same Way, Fire and
Water will result from Air plus Earth. For there will be Water,
when the hot of the Air and the dry of the Earth have passed-
away (since the moist of the former and the cold of the latter
are left): whereas, when the moist of the Air and the cold of the
Earth have passed-away, there will be Fire, owing to the survival
of the hot of the Air and the dry of the Earth - qualities
1009
essentially constitutive of Fire. Moreover, this mode of Fire's
coming-to-be is confirmed by perception. For flame is par
excellence Fire: but flame is burning smoke, and smoke consists
of Air and Earth.
No transformation, however, into any of the 'simple' bodies can
result from the passing-away of one elementary quality in each
of two 'elements' when they are taken in their consecutive
order, because either identical or contrary qualities are left in
the pair: but no 'simple' body can be formed either out of
identical, or out of contrary, qualities. Thus no 'simple' body
would result, if the dry of Fire and the moist of Air were to pass-
away: for the hot is left in both. On the other hand, if the hot
pass-away out both, the contraries - dry and moist - are left. A
similar result will occur in all the others too: for all the
consecutive 'elements' contain one identical, and one contrary,
quality. Hence, too, it clearly follows that, when one of the
consecutive 'elements' is transformed into one, the coming-to-
be is effected by the passing-away of a single quality: whereas,
when two of them are transformed into a third, more than one
quality must have passedaway.
We have stated that all the 'elements' come-to-be out of any
one of them; and we have explained the manner in which their
mutual conversion takes place. Let us nevertheless supplement
our theory by the following speculations concerning them.
If Water, Air, and the like are a 'matter' of which the natural
bodies consist, as some thinkers in fact believe, these 'elements'
must be either one, or two, or more. Now they cannot all of
them be one - they cannot, e.g. all be Air or Water or Fire or
1010
Earth - because 'Change is into contraries'. For if they all were
Air, then (assuming Air to persist) there will be 'alteration'
instead of coming-to-be. Besides, nobody supposes a single
'element' to persist, as the basis of all, in such a way that it is
Water as well as Air (or any other 'element') at the same time.
So there will be a certain contrariety, i.e. a differentiating
quality: and the other member of this contrariety, e.g. heat, will
belong to some other 'element', e.g. to Fire. But Fire will
certainly not be 'hot Air'. For a change of that kind (a) is
'alteration', and (b) is not what is observed. Moreover (c) if Air is
again to result out of the Fire, it will do so by the conversion of
the hot into its contrary: this contrary, therefore, will belong to
Air, and Air will be a cold something: hence it is impossible for
Fire to be 'hot Air', since in that case the same thing will be
simultaneously hot and cold. Both Fire and Air, therefore, will be
something else which is the same; i.e. there will be some
'matter', other than either, common to both.
The same argument applies to all the 'elements', proving that
there is no single one of them out of which they all originate.
But neither is there, beside these four, some other body from
which they originate - a something intermediate, e.g. between
Air and Water (coarser than Air, but finer than Water), or
between Air and Fire (coarser than Fire, but finer than Air). For
the supposed 'intermediate' will be Air and Fire when a pair of
contrasted qualities is added to it: but, since one of every two
contrary qualities is a 'privation', the 'intermediate' never can
exist - as some thinkers assert the 'Boundless' or the
'Environing' exists - in isolation. It is, therefore, equally and
indifferently any one of the 'elements', or else it is nothing.
Since, then, there is nothing - at least, nothing perceptible -
prior to these, they must be all. That being so, either they must
always persist and not be transformable into one another: or
they must undergo transformation - either all of them, or some
1011
only (as Plato wrote in the Timaeus). Now it has been proved
before that they must undergo reciprocal transformation. It has
also been proved that the speed with which they come-to-be,
one out of another, is not uniform - since the process of
reciprocal transformation is relatively quick between the
'elements' with a 'complementary factor', but relatively slow
between those which possess no such factor. Assuming, then,
that the contrariety, in respect to which they are transformed, is
one, the elements' will inevitably be two: for it is 'matter' that is
the 'mean' between the two contraries, and matter is
imperceptible and inseparable from them. Since, however, the
'elements' are seen to be more than two, the contrarieties must
at the least be two. But the contrarieties being two, the
'elements' must be four (as they evidently are) and cannot be
three: for the couplings' are four, since, though six are possible,
the two in which the qualities are contrary to one another
cannot occur.
These subjects have been discussed before:' but the following
arguments will make it clear that, since the 'elements' are
transformed into one another, it is impossible for any one of
them - whether it be at the end or in the middle - to be an
'originative source' of the rest. There can be no such 'originative
element' at the ends: for all of them would then be Fire or Earth,
and this theory amounts to the assertion that all things are
made of Fire or Earth. Nor can a 'middle-element' be such an
originative source - as some thinkers suppose that Air is
transformed both into Fire and into Water, and Water both into
Air and into Earth, while the 'end-elements' are not further
transformed into one another. For the process must come to a
stop, and cannot continue ad infinitum in a straight line in
either direction, since otherwise an infinite number of
contrarieties would attach to the single 'element'. Let E stand
for Earth, W for Water, A for Air, and F for Fire. Then (i) since A is
transformed into F and W, there will be a contrariety belonging
1012
to A F. Let these contraries be whiteness and blackness. Again
(ii) since A is transformed into W, there will be another
contrariety: for W is not the same as F. Let this second
contrariety be dryness and moistness, D being dryness and M
moistness. Now if, when A is transformed into W, the 'white'
persists, Water will be moist and white: but if it does not persist,
Water will be black since change is into contraries. Water,
therefore, must be either white or black. Let it then be the first.
On similar grounds, therefore, D (dryness) will also belong to F.
Consequently F (Fire) as well as Air will be able to be
transformed into Water: for it has qualities contrary to those of
Water, since Fire was first taken to be black and then to be dry,
while Water was moist and then showed itself white. Thus it is
evident that all the 'elements' will be able to be transformed out
of one another; and that, in the instances we have taken, E
(Earth) also will contain the remaining two 'complementary
factors', viz. the black and the moist (for these have not yet
been coupled).
We have dealt with this last topic before the thesis we set out to
prove. That thesis - viz. that the process cannot continue ad
infinitum - will be clear from the following considerations. If
Fire (which is represented by F) is not to revert, but is to be
transformed in turn into some other 'element' (e.g. into Q), a
new contrariety, other than those mentioned, will belong to Fire
and Q: for it has been assumed that Q is not the same as any of
the four, E W A and F. Let K, then, belong to F and Y to Q. Then K
will belong to all four, E W A and F: for they are transformed into
one another. This last point, however, we may admit, has not yet
been proved: but at any rate it is clear that if Q is to be
transformed in turn into yet another 'element', yet another
contrariety will belong not only to Q but also to F (Fire). And,
similarly, every addition of a new 'element' will carry with it the
attachment of a new contrariety to the preceding elements'.
Consequently, if the 'elements' are infinitely many, there will
1013
also belong to the single 'element' an infinite number of
contrarieties. But if that be so, it will be impossible to define any
'element': impossible also for any to come-to-be. For if one is to
result from another, it will have to pass through such a vast
number of contrarieties - and indeed even more than any
determinate number. Consequently (i) into some 'elements'
transformation will never be effected - viz. if the intermediates
are infinite in number, as they must be if the 'elements' are
infinitely many: further (ii) there will not even be a
transformation of Air into Fire, if the contrarieties are infinitely
many: moreover (iii) all the 'elements' become one. For all the
contrarieties of the 'elements' above F must belong to those
below F, and vice versa: hence they will all be one.
As for those who agree with Empedocles that the 'elements' of
body are more than one, so that they are not transformed into
one another - one may well wonder in what sense it is open to
them to maintain that the 'elements' are comparable. Yet
Empedocles says 'For these are all not only equal...'
If it is meant that they are comparable in their amount, all the
'comparables' must possess an identical something whereby
they are measured. If, e.g. one pint of Water yields ten of Air,
both are measured by the same unit; and therefore both were
from the first an identical something. On the other hand,
suppose (ii) they are not 'comparable in their amount' in the
sense that so-much of the one yields so much of the other, but
comparable in 'power of action (a pint of Water, e.g. having a
power of cooling equal to that of ten pints of Air); even so, they
are 'comparable in their amount', though not qua 'amount' but
1014
qua 'so-much power'. There is also (iii) a third possibility.
Instead of comparing their powers by the measure of their
amount, they might be compared as terms in a
'correspondence': e.g. 'as x is hot, so correspondingly y is white'.
But 'correspondence', though it means equality in the quantum,
means similarity in a quale. Thus it is manifestly absurd that
the 'simple' bodies, though they are not transformable, are
comparable not merely as 'corresponding', but by a measure of
their powers; i.e. that so-much Fire is comparable with many
times that amount of Air, as being 'equally' or 'similarly' hot. For
the same thing, if it be greater in amount, will, since it belongs
to the same kind, have its ratio correspondingly increased.
A further objection to the theory of Empedocles is that it makes
even growth impossible, unless it be increase by addition. For
his Fire increases by Fire: 'And Earth increases its own frame
and Ether increases Ether.» These, however, are cases of
addition: but it is not by addition that growing things are
believed to increase. And it is far more difficult for him to
account for the coming-to-be which occurs in nature. For the
things which come-to-be by natural process all exhibit, in their
coming-to-be, a uniformity either absolute or highly regular:
while any exceptions any results which are in accordance
neither with the invariable nor with the general rule are
products of chance and luck. Then what is the cause
determining that man comes-to-be from man, that wheat
(instead of an olive) comes-to-be from wheat, either invariably
or generally? Are we to say 'Bone comes-to-be if the «elements»
be put together in such-and-such a manner? For, according to
his own estatements, nothing comes-to-be from their
'fortuitous consilience', but only from their 'consilience' in a
certain proportion. What, then, is the cause of this proportional
consilience? Presumably not Fire or Earth. But neither is it Love
and Strife: for the former is a cause of 'association' only, and the
latter only of 'dissociation'. No: the cause in question is the
1015
essential nature of each thing (not merely to quote his words) 'a
mingling and a divorce of what has been mingled'. And chance,
not proportion, 'is the name given to these occurrences': for
things can be 'mingled' fortuitously.
The cause, therefore, of the coming-to-be of the things which
owe their existence to nature is that they are in such-and-such
a determinate condition: and it is this which constitutes, the
'nature' of each thing - a 'nature' about which he says nothing.
What he says, therefore, is no explanation of 'nature'. Moreover,
it is this which is both 'the excellence' of each thing and its
'good': whereas he assigns the whole credit to the 'mingling'.
(And yet the 'elements' at all events are 'dissociated' not by
Strife, but by Love: since the 'elements' are by nature prior to
the Deity, and they too are Deities.)
Again, his account of motion is vague. For it is not an adequate
explanation to say that 'Love and Strife set things moving,
unless the very nature of Love is a movement of this kind and
the very nature of Strife a movement of that kind. He ought,
then, either to have defined or to have postulated these
characteristic movements, or to have demonstrated them -
whether strictly or laxly or in some other fashion. Moreover,
since (a) the 'simple' bodies appear to move 'naturally' as well
as by compulsion, i.e. in a manner contrary to nature (fire, e.g.
appears to move upwards without compulsion, though it
appears to move by compulsion downwards); and since (b) what
is 'natural' is contrary to that which is due to compulsion, and
movement by compulsion actually occurs; it follows that
'natural movement' can also occur in fact. Is this, then, the
movement that Love sets going? No: for, on the contrary, the
'natural movement' moves Earth downwards and resembles
'dissociation', and Strife rather than Love is its cause - so that in
general, too, Love rather than Strife would seem to be contrary
to nature. And unless Love or Strife is actually setting them in
1016
motion, the 'simple' bodies themselves have absolutely no
movement or rest. But this is paradoxical: and what is more,
they do in fact obviously move. For though Strife 'dissociated', it
was not by Strife that the 'Ether' was borne upwards. On the
contrary, sometimes he attributes its movement to something
like chance ('For thus, as it ran, it happened to meet them then,
though often otherwise»), while at other times he says it is the
nature of Fire to be borne upwards, but 'the Ether' (to quote his
words) 'sank down upon the Earth with long roots'. With such
statements, too, he combines the assertion that the Order of the
World is the same now, in the reign of Strife, as it was formerly
in the reign of Love. What, then, is the 'first mover' of the
'elements'? What causes their motion? Presumably not Love
and Strife: on the contrary, these are causes of a particular
motion, if at least we assume that 'first mover' to be an
originative source'.
An additional paradox is that the soul should consist of the
'elements', or that it should be one of them. How are the soul's
'alterations' to take Place? How, e.g. is the change from being
musical to being unmusical, or how is memory or forgetting, to
occur? For clearly, if the soul be Fire, only such modifications
will happen to it as characterize Fire qua Fire: while if it be
compounded out of the elements', only the corporeal
modifications will occur in it. But the changes we have
mentioned are none of them corporeal.
The discussion of these difficulties, however, is a task
appropriate to a different investigation:' let us return to the
'elements' of which bodies are composed. The theories that
1017
'there is something common to all the «elements», and that
they are reciprocally transformed', are so related that those who
accept either are bound to accept the other as well. Those, on
the other hand, who do not make their coming-to-be reciprocal
- who refuse to suppose that any one of the 'elements' comes-
to-be out of any other taken singly, except in the sense in which
bricks come-to-be out of a wall - are faced with a paradox. How,
on their theory, are flesh and bones or any of the other
compounds to result from the 'elements' taken together?
Indeed, the point we have raised constitutes a problem even for
those who generate the 'elements' out of one another. In what
manner does anything other than, and beside, the 'elements'
come-to-be out of them? Let me illustrate my meaning. Water
can come-to-be out of Fire and Fire out of Water; for their
substralum is something common to them both. But flesh too,
presumably, and marrow come-to-be out of them. How, then, do
such things come-to-be? For (a) how is the manner of their
coming-to-be to be conceived by those who maintain a theory
like that of Empedocles? They must conceive it as composition -
just as a wall comes-to-be out of bricks and stones: and the
'Mixture', of which they speak, will be composed of the
'elements', these being preserved in it unaltered but with their
small particles juxtaposed each to each. That will be the
manner, presumably, in which flesh and every other compound
results from the 'elements'. Consequently, it follows that Fire
and Water do not come-to-be 'out of any and every part of
flesh'. For instance, although a sphere might come-to-be out of
this part of a lump of wax and a pyramid out of some other
part, it was nevertheless possible for either figure to have come-
to-be out of either part indifferently: that is the manner of
coming-to-be when 'both Fire and Water come-to-be out of any
and every part of flesh'. Those, however, who maintain the
theory in question, are not at liberty to conceive that 'both
come-to-be out of flesh' in that manner, but only as a stone and
1018
a brick 'both come-to-be out of a wall' - viz. each out of a
different place or part. Similarly (b) even for those who
postulate a single matter of their 'elements' there is a certain
difficulty in explaining how anything is to result from two of
them taken together - e.g. from 'cold' and hot', or from Fire and
Earth. For if flesh consists of both and is neither of them, nor
again is a 'composition' of them in which they are preserved
unaltered, what alternative is left except to identify the
resultant of the two 'elements' with their matter? For the
passing-away of either 'element' produces either the other or
the matter.
Perhaps we may suggest the following solution, (i) There are
differences of degree in hot and cold. Although, therefore, when
either is fully real without qualification, the other will exist
potentially; yet, when neither exists in the full completeness of
its being, but both by combining destroy one another's excesses
so that there exist instead a hot which (for a 'hot') is cold and a
cold which (for a 'cold') is hot; then what results from these two
contraries will be neither their matter, nor either of them
existing in its full reality without qualification. There will result
instead an 'intermediate': and this 'intermediate', according as
it is potentially more hot than cold or vice versa, will possess a
power-of-heating that is double or triple its power-of-cooling, or
otherwise related thereto in some similar ratio. Thus all the
other bodies will result from the contraries, or rather from the
'elements', in so far as these have been 'combined': while the
elements' will result from the contraries, in so far as these 'exist
potentially' in a special sense - not as matter 'exists potentially',
but in the sense explained above. And when a thing comes-to-
be in this manner, the process is cobination'; whereas what
comes-to-be in the other manner is matter. Moreover (ii)
contraries also 'suffer action', in accordance with the
disjunctively-articulated definition established in the early part
of this work.' For the actually-hot is potentially-cold and the
1019
actually cold potentially-hot; so that hot and cold, unless they
are equally balanced, are transformed into one another (and all
the other contraries behave in a similar way). It is thus, then,
that in the first place the 'elements' are transformed; and that
(in the second place) out of the 'elements' there come-to-be
flesh and bones and the like - the hot becoming cold and the
cold becoming hot when they have been brought to the 'mean'.
For at the 'mean' is neither hot nor cold. The 'mean', however, is
of considerable extent and not indivisible. Similarly, it is qua
reduced to a 'mean' condition that the dry and the moist, as
well as the contraries we have used as examples, produce flesh
and bone and the remaining compounds.
8
All the compound bodies - all of which exist in the region
belonging to the central body - are composed of all the 'simple'
bodies. For they all contain Earth because every 'simple' body is
to be found specially and most abundantly in its own place. And
they all contain Water because (a) the compound must possess
a definite outline and Water, alone of the 'simple' bodies, is
readily adaptable in shape: moreover (b) Earth has no power of
cohesion without the moist. On the contrary, the moist is what
holds it together; for it would fall to pieces if the moist were
eliminated from it completely.
They contain Earth and Water, then, for the reasons we have
given: and they contain Air and Fire, because these are contrary
to Earth and Water (Earth being contrary to Air and Water to
Fire, in so far as one Substance can be 'contrary' to another).
Now all compounds presuppose in their coming-to-be
constituents which are contrary to one another: and in all
1020
compounds there is contained one set of the contrasted
extremes. Hence the other set must be contained in them also,
so that every compound will include all the 'simple' bodies.
Additional evidence seems to be furnished by the food each
compound takes. For all of them are fed by substances which
are the same as their constituents, and all of them are fed by
more substances than one. Indeed, even the plants, though it
might be thought they are fed by one substance only, viz. by
Water, are fed by more than one: for Earth has been mixed with
the Water. That is why farmers too endeavour to mix before
watering. Although food is akin to the matter, that which is fed
is the 'figure' - i.e. the 'form' taken along with the matter. This
fact enables us to understand why, whereas all the 'simple'
bodies come-to-be out of one another, Fire is the only one of
them which (as our predecessors also assert) 'is fed'. For Fire
alone - or more than all the rest - is akin to the 'form' because it
tends by nature to be borne towards the limit. Now each of
them naturally tends to be borne towards its own place; but the
'figure' - i.e. the 'form' - of them all is at the limits.
Thus we have explained that all the compound bodies are
composed of all the 'simple' bodies.
Since some things are such as to come-to-be and pass-away,
and since coming-to-be in fact occurs in the region about the
centre, we must explain the number and the nature of the
'originative sources' of all coming-to-be alike: for a grasp of the
true theory of any universal facilitates the understanding of its
specific forms.
1021
The 'originative sources', then, of the things which come-to-be
are equal in number to, and identical in kind with, those in the
sphere of the eternal and primary things. For there is one in the
sense of 'matter', and a second in the sense of 'form': and, in
addition, the third 'originative source' must be present as well.
For the two first are not sufficient to bring things into being, any
more than they are adequate to account for the primary things.
Now cause, in the sense of material origin, for the things which
are such as to come-to-be is 'that which can be-and-not-be':
and this is identical with 'that which can come-to-be-and-pass-
away', since the latter, while it is at one time, at another time is
not. (For whereas some things are of necessity, viz. the eternal
things, others of necessity are not. And of these two sets of
things, since they cannot diverge from the necessity of their
nature, it is impossible for the first not to he and impossible for
the second to he. Other things, however, can both be and not
he.) Hence coming-to-be and passing-away must occur within
the field of 'that which can be-and-not-be'. This, therefore, is
cause in the sense of material origin for the things which are
such as to come-to-be; while cause, in the sense of their 'end', is
their 'figure' or 'form' - and that is the formula expressing the
essential nature of each of them.
But the third 'originative source' must be present as well - the
cause vaguely dreamed of by all our predecessors, definitely
stated by none of them. On the contrary (a) some amongst them
thought the nature of 'the Forms' was adequate to account for
coming-to-be. Thus Socrates in the Phaedo first blames
everybody else for having given no explanation; and then lays it
down; that 'some things are Forms, others Participants in the
Forms', and that 'while a thing is said to «be» in virtue of the
Form, it is said to «come-to-be» qua sharing in,» to «pass-away»
qua «losing,» the 'Form'. Hence he thinks that 'assuming the
truth of these theses, the Forms must be causes both of coming-
1022
to-be and of passing-away'. On the other hand (b) there were
others who thought 'the matter' was adequate by itself to
account for coming-to-be, since 'the movement originates from
the matter'.
Neither of these theories, however, is sound. For (a) if the Forms
are causes, why is their generating activity intermittent instead
of perpetual and continuous - since there always are
Participants as well as Forms? Besides, in some instances we
see that the cause is other than the Form. For it is the doctor
who implants health and the man of science who implants
science, although 'Health itself and 'Science itself are as well
as the Participants: and the same principle applies to everything
else that is produced in accordance with an art. On the other
hand (b) to say that 'matter generates owing to its movement'
would be, no doubt, more scientific than to make such
statements as are made by the thinkers we have been
criticizing. For what 'alters' and transfigures plays a greater part
in bringing, things into being; and we are everywhere
accustomed, in the products of nature and of art alike, to look
upon that which can initiate movement as the producing cause.
Nevertheless this second theory is not right either.
For, to begin with, it is characteristic of matter to suffer action,
i.e. to be moved: but to move, i.e. to act, belongs to a different
'power'. This is obvious both in the things that come-to-be by
art and in those that come-to-be by nature. Water does not of
itself produce out of itself an animal: and it is the art, not the
wood, that makes a bed. Nor is this their only error. They make
a second mistake in omitting the more controlling cause: for
they eliminate the essential nature, i.e. the 'form'. And what is
more, since they remove the formal cause, they invest the forces
they assign to the 'simple' bodies - the forces which enable
these bodies to bring things into being - with too instrumental a
character. For 'since' (as they say) 'it is the nature of the hot to
1023
dissociate, of the cold to bring together, and of each remaining
contrary either to act or to suffer action', it is out of such
materials and by their agency (so they maintain) that everything
else comes-to-be and passes-away. Yet (a) it is evident that even
Fire is itself moved, i.e. suffers action. Moreover (b) their
procedure is virtually the same as if one were to treat the saw
(and the various instruments of carpentry) as 'the cause' of the
things that come-to-be: for the wood must be divided if a man
saws, must become smooth if he planes, and so on with the
remaining tools. Hence, however true it may be that Fire is
active, i.e. sets things moving, there is a further point they fail to
observe - viz. that Fire is inferior to the tools or instruments in
the manner in which it sets things moving.
10
As to our own theory - we have given a general account of the
causes in an earlier work - we have now explained and
distinguished the 'matter' and the 'form'. Further, since the
change which is motion has been proved' to be eternal, the
continuity of the occurrence of coming-to-be follows necessarily
from what we have established: for the eternal motion, by
causing 'the generator' to approach and retire, will produce
coming-to-be uninterruptedly. At the same time it is clear that
we were right when, in an earlier work,' we called motion (not
coming-to-be) 'the primary form of change'. For it is far more
reasonable that what is should cause the coming-to-be of what
is not, than that what is not should cause the being of what is.
Now that which is being moved is, but that which is coming-to-
be is not: hence, also, motion is prior to coming-to-be.
1024
We have assumed, and have proved, that coming-to-be and
passing-away happen to things continuously; and we assert
that motion causes coming-to-be. That being so, it is evident
that, if the motion be single, both processes cannot occur since
they are contrary to one another: for it is a law of nature that
the same cause, provided it remain in the same condition,
always produces the same effect, so that, from a single motion,
either coming-to-be or passing-away will always result. The
movements must, on the contrary, be more than one, and they
must be contrasted with one another either by the sense of
their motion or by its irregularity: for contrary effects demand
contraries as their causes.
This explains why it is not the primary motion that causes
coming-to-be and passing-away, but the motion along the
inclined circle: for this motion not only possesses the necessary
continuity, but includes a duality of movements as well. For if
coming-to-be and passing-away are always to be continuous,
there must be some body always being moved (in order that
these changes may not fail) and moved with a duality of
movements (in order that both changes, not one only, may
result). Now the continuity of this movement is caused by the
motion of the whole: but the approaching and retreating of the
moving body are caused by the inclination. For the consequence
of the inclination is that the body becomes alternately remote
and near; and since its distance is thus unequal, its movement
will be irregular. Therefore, if it generates by approaching and by
its proximity, it - this very same body - destroys by retreating
and becoming remote: and if it generates by many successive
approaches, it also destroys by many successive retirements. For
contrary effects demand contraries as their causes; and the
natural processes of passing-away and coming-to-be occupy
equal periods of time. Hence, too, the times - i.e. the lives - of
the several kinds of living things have a number by which they
are distinguished: for there is an Order controlling all things,
1025
and every time (i.e. every life) is measured by a period. Not all of
them, however, are measured by the same period, but some by a
smaller and others by a greater one: for to some of them the
period, which is their measure, is a year, while to some it is
longer and to others shorter.
And there are facts of observation in manifest agreement with
our theories. Thus we see that coming-to-be occurs as the sun
approaches and decay as it retreats; and we see that the two
processes occupy equal times. For the durations of the natural
processes of passing-away and coming-to-be are equal.
Nevertheless it Often happens that things pass-away in too
short a time. This is due to the 'intermingling' by which the
things that come-to-be and pass-away are implicated with one
another. For their matter is 'irregular', i.e. is not everywhere the
same: hence the processes by which they come-to-be must be
'irregular' too, i.e. some too quick and others too slow.
Consequently the phenomenon in question occurs, because the
'irregular' coming-to-be of these things is the passing-away of
other things.
Coming-to-be and passing-away will, as we have said, always be
continuous, and will never fail owing to the cause we stated.
And this continuity has a sufficient reason on our theory. For in
all things, as we affirm, Nature always strives after 'the better'.
Now 'being' (we have explained elsewhere the exact variety of
meanings we recognize in this term) is better than 'not-being':
but not all things can possess 'being', since they are too far
removed from the 'originative source. 'God therefore adopted
the remaining alternative, and fulfilled the perfection of the
universe by making coming-to-be uninterrupted: for the
greatest possible coherence would thus be secured to existence,
because that 'coming-to-be should itself come-to-be
perpetually' is the closest approximation to eternal being.
1026
The cause of this perpetuity of coming-to-be, as we have often
said, is circular motion: for that is the only motion which is
continuous. That, too, is why all the other things - the things, I
mean, which are reciprocally transformed in virtue of their
'passions' and their 'powers of action' e.g. the 'simple'
bodiesimitate circular motion. For when Water is transformed
into Air, Air into Fire, and the Fire back into Water, we say the
coming-to-be 'has completed the circle', because it reverts again
to the beginning. Hence it is by imitating circular motion that
rectilinear motion too is continuous.
These considerations serve at the same time to explain what is
to some people a baffling problem - viz. why the 'simple' bodies,
since each them is travelling towards its own place, have not
become dissevered from one another in the infinite lapse of
time. The reason is their reciprocal transformation. For, had
each of them persisted in its own place instead of being
transformed by its neighbour, they would have got dissevered
long ago. They are transformed, however, owing to the motion
with its dual character: and because they are transformed, none
of them is able to persist in any place allotted to it by the Order.
It is clear from what has been said (i) that coming-to-be and
passing-away actually occur, (ii) what causes them, and (iii)
what subject undergoes them. But (a) if there is to be movement
(as we have explained elsewhere, in an earlier work') there must
be something which initiates it; if there is to be movement
always, there must always be something which initiates it; if the
movement is to be continuous, what initiates it must be single,
unmoved, ungenerated, and incapable of 'alteration'; and if the
circular movements are more than one, their initiating causes
must all of them, in spite of their plurality, be in some way
subordinated to a single 'originative source'. Further (b) since
time is continuous, movement must be continuous, inasmuch
as there can be no time without movement. Time, therefore, is a
1027
'number' of some continuous movement - a 'number', therefore,
of the circular movement, as was established in the discussions
at the beginning. But (c) is movement continuous because of the
continuity of that which is moved, or because that in which the
movement occurs (I mean, e.g. the place or the quality) is
continuous? The answer must clearly be 'because that which is
moved is continuous'. (For how can the quality be continuous
except in virtue of the continuity of the thing to which it
belongs? But if the continuity of 'that in which' contributes to
make the movement continuous, this is true only of 'the place
in which'; for that has 'magnitude' in a sense.) But (d) amongst
continuous bodies which are moved, only that which is moved
in a circle is 'continuous' in such a way that it preserves its
continuity with itself throughout the movement. The conclusion
therefore is that this is what produces continuous movement,
viz. the body which is being moved in a circle; and its
movement makes time continuous.
11
Wherever there is continuity in any process (coming-to-be or
'alteration' or any kind of change whatever) we observe
consecutiveness', i.e. this coming-to-be after that without any
interval. Hence we must investigate whether, amongst the
consecutive members, there is any whose future being is
necessary; or whether, on the contrary, every one of them may
fail to come-to-be. For that some of them may fail to occur, is
clear, (a) We need only appeal to the distinction between the
statements 'x will be' and 'x is about to which depends upon
this fact. For if it be true to say of x that it 'will be', it must at
some time be true to say of it that 'it is': whereas, though it be
true to say of x now that 'it is about to occur', it is quite possible
1028
for it not to come-to-be - thus a man might not walk, though he
is now 'about to' walk. And (b) since (to appeal to a general
principle) amongst the things which 'are' some are capable also
of not-being', it is clear that the same ambiguous character will
attach to them no less when they are coming-to-be: in other
words, their coming-to-be will not be necessary.
Then are all the things that come-to-be of this contingent
character? Or, on the contrary, is it absolutely necessary for
some of them to come-to-be? Is there, in fact, a distinction in
the field of 'coming-to-be' corresponding to the distinction,
within the field of 'being', between things that cannot possibly
'not-be' and things that can 'not-be'? For instance, is it
necessary that solstices shall come-to-be, i.e. impossible that
they should fail to be able to occur?
Assuming that the antecedent must have come-to-be if the
consequent is to be (e.g. that foundations must have come-to-be
if there is to be a house: clay, if there are to be foundations), is
the converse also true? If foundations have come-to-be, must a
house come-to-be? The answer seems to be that the necessary
nexus no longer holds, unless it is 'necessary' for the
consequent (as well as for the antecedent) to come-to-be -
'necessary' absolutely. If that be the case, however, 'a house
must come-to-be if foundations have come-to-be', as well as
vice versa. For the antecedent was assumed to be so related to
the consequent that, if the latter is to be, the antecedent must
have come-to-be before it. If, therefore, it is necessary that the
consequent should come-to-be, the antecedent also must have
come-to-be: and if the antecedent has come-to-be, then the
consequent also must come-to-be - not, however, because of
the antecedent, but because the future being of the consequent
was assumed as necessary. Hence, in any sequence, when the
being of the consequent is necessary, the nexus is reciprocal -
1029
in other words, when the antecedent has come-to-be the
consequent must always come-to-be too.
Now (i) if the sequence of occurrences is to proceed ad
infinitum 'downwards', the coming-to-be of any determinate
'this' amongst the later members of the sequence will not be
absolutely, but only conditionally, necessary. For it will always
be necessary that some other member shall have come-to-be
before 'this' as the presupposed condition of the necessity that
'this' should come-to-be: consequently, since what is 'infinite'
has no 'originative source', neither will there be in the infinite
sequence any 'primary' member which will make it 'necessary'
for the remaining members to come-to-be.
Nor again (ii) will it be possible to say with truth, even in regard
to the members of a limited sequence, that it is 'absolutely
necessary' for any one of them to come-to-be. We cannot truly
say, e.g. that 'it is absolutely necessary for a house to come-to-
be when foundations have been laid': for (unless it is always
necessary for a house to be coming-to-be) we should be faced
with the consequence that, when foundations have been laid, a
thing, which need not always be, must always be. No: if its
coming-to-be is to be 'necessary', it must be 'always' in its
coming-to-be. For what is 'of necessity' coincides with what is
'always', since that which 'must be' cannot possibly 'not-be'.
Hence a thing is eternal if its 'being' is necessary: and if it is
eternal, its 'being' is necessary. And if, therefore, the 'coming-to-
be' of a thing is necessary, its 'coming-to-be' is eternal; and if
eternal, necessary.
It follows that the coming-to-be of anything, if it is absolutely
necessary, must be cyclical - i.e. must return upon itself. For
coming-to-be must either be limited or not limited: and if not
limited, it must be either rectilinear or cyclical. But the first of
these last two alternatives is impossible if coming-to-be is to be
1030
eternal, because there could not be any 'originative source'
whatever in an infinite rectilinear sequence, whether its
members be taken 'downwards' (as future events) or 'upwards'
(as past events). Yet coming-to-be must have an 'originative
source' (if it is to be necessary and therefore eternal), nor can it
be eternal if it is limited. Consequently it must be cyclical.
Hence the nexus must be reciprocal. By this I mean that the
necessary occurrence of 'this' involves the necessary occurrence
of its antecedent: and conversely that, given the antecedent, it
is also necessary for the consequent to come-to-be. And this
reciprocal nexus will hold continuously throughout the
sequence: for it makes no difference whether the reciprocal
nexus, of which we are speaking, is mediated by two, or by
many, members.
It is in circular movement, therefore, and in cyclical coming-to-
be that the 'absolutely necessary' is to be found. In other words,
if the coming-to-be of any things is cyclical, it is 'necessary' that
each of them is coming-to-be and has come-to-be: and if the
coming-to-be of any things is 'necessary', their coming-to-be is
cyclical.
The result we have reached is logically concordant with the
eternity of circular motion, i.e. the eternity of the revolution of
the heavens (a fact which approved itself on other and
independent evidence),' since precisely those movements which
belong to, and depend upon, this eternal revolution 'come-to-be'
of necessity, and of necessity 'will be'. For since the revolving
body is always setting something else in motion, the movement
of the things it moves must also be circular. Thus, from the
being of the 'upper revolution' it follows that the sun revolves in
this determinate manner; and since the sun revolves thus, the
seasons in consequence come-to-be in a cycle, i.e. return upon
themselves; and since they come-to-be cyclically, so in their
turn do the things whose coming-to-be the seasons initiate.
1031
Then why do some things manifestly come-to-be in this cyclical
fashion (as, e.g. showers and air, so that it must rain if there is
to be a cloud and, conversely, there must be a cloud if it is to
rain), while men and animals do not 'return upon themselves'
so that the same individual comes-to-be a second time (for
though your coming-to-be presupposes your father's, his
coming-to-be does not presuppose yours)? Why, on the contrary,
does this coming-to-be seem to constitute a rectilinear
sequence?
In discussing this new problem, we must begin by inquiring
whether all things 'return upon themselves' in a uniform
manner; or whether, on the contrary, though in some sequences
what recurs is numerically the same, in other sequences it is
the same only in species. In consequence of this distinction, it is
evident that those things, whose 'substance' - that which is
undergoing the process - is imperishable, will be numerically, as
well as specifically, the same in their recurrence: for the
character of the process is determined by the character of that
which undergoes it. Those things, on the other hand, whose
'substance' is perish, able (not imperishable) must 'return upon
themselves' in the sense that what recurs, though specifically
the same, is not the same numerically. That why, when Water
comes-to-be from Air and Air from Water, the Air is the same
'specifically', not 'numerically': and if these too recur
numerically the same, at any rate this does not happen with
things whose 'substance' comes-to-be - whose 'substance' is
such that it is essentially capable of not-being.
1032
Aristotle - Meteorology
[Translated by E. W. Webster]
Book I
We have already discussed the first causes of nature, and all
natural motion, also the stars ordered in the motion of the
heavens, and the physical element - enumerating and
specifying them and showing how they change into one
another - and becoming and perishing in general. There
remains for consideration a part of this inquiry which all our
predecessors called meteorology. It is concerned with events
that are natural, though their order is less perfect than that of
the first of the elements of bodies. They take place in the region
nearest to the motion of the stars. Such are the milky way, and
comets, and the movements of meteors. It studies also all the
affections we may call common to air and water, and the kinds
and parts of the earth and the affections of its parts. These
throw light on the causes of winds and earthquakes and all the
consequences the motions of these kinds and parts involve. Of
these things some puzzle us, while others admit of explanation
in some degree. Further, the inquiry is concerned with the
falling of thunderbolts and with whirlwinds and fire-winds, and
further, the recurrent affections produced in these same bodies
by concretion. When the inquiry into these matters is concluded
let us consider what account we can give, in accordance with
the method we have followed, of animals and plants, both
generally and in detail. When that has been done we may say
1033
that the whole of our original undertaking will have been
carried out.
After this introduction let us begin by discussing our immediate
subject.
We have already laid down that there is one physical element
which makes up the system of the bodies that move in a circle,
and besides this four bodies owing their existence to the four
principles, the motion of these latter bodies being of two kinds:
either from the centre or to the centre. These four bodies are
fire, air, water, earth. Fire occupies the highest place among
them all, earth the lowest, and two elements correspond to
these in their relation to one another, air being nearest to fire,
water to earth. The whole world surrounding the earth, then,
the affections of which are our subject, is made up of these
bodies. This world necessarily has a certain continuity with the
upper motions: consequently all its power and order is derived
from them. (For the originating principle of all motion is the
first cause. Besides, that clement is eternal and its motion has
no limit in space, but is always complete; whereas all these
other bodies have separate regions which limit one another.) So
we must treat fire and earth and the elements like them as the
material causes of the events in this world (meaning by material
what is subject and is affected), but must assign causality in the
sense of the originating principle of motion to the influence of
the eternally moving bodies.
1034
Let us first recall our original principles and the distinctions
already drawn and then explain the 'milky way' and comets and
the other phenomena akin to these.
Fire, air, water, earth, we assert, originate from one another, and
each of them exists potentially in each, as all things do that can
be resolved into a common and ultimate substrate.
The first difficulty is raised by what is called the air. What are
we to take its nature to be in the world surrounding the earth?
And what is its position relatively to the other physical
elements. (For there is no question as to the relation of the bulk
of the earth to the size of the bodies which exist around it, since
astronomical demonstrations have by this time proved to us
that it is actually far smaller than some individual stars. As for
the water, it is not observed to exist collectively and separately,
nor can it do so apart from that volume of it which has its seat
about the earth: the sea, that is, and rivers, which we can see,
and any subterranean water that may be hidden from our
observation.) The question is really about that which lies
between the earth and the nearest stars. Are we to consider it to
be one kind of body or more than one? And if more than one,
how many are there and what are the bounds of their regions?
We have already described and characterized the first element,
and explained that the whole world of the upper motions is full
of that body.
This is an opinion we are not alone in holding: it appears to be
an old assumption and one which men have held in the past,
for the word ether has long been used to denote that element.
Anaxagoras, it is true, seems to me to think that the word
means the same as fire. For he thought that the upper regions
were full of fire, and that men referred to those regions when
1035
they spoke of ether. In the latter point he was right, for men
seem to have assumed that a body that was eternally in motion
was also divine in nature; and, as such a body was different
from any of the terrestrial elements, they determined to call it
'ether'.
For the um opinions appear in cycles among men not once nor
twice, but infinitely often.
Now there are some who maintain that not only the bodies in
motion but that which contains them is pure fire, and the
interval between the earth and the stars air: but if they had
considered what is now satisfactorily established by
mathematics, they might have given up this puerile opinion. For
it is altogether childish to suppose that the moving bodies are
all of them of a small size, because they so to us, looking at
them from the earth.
This a matter which we have already discussed in our
treatment of the upper region, but we may return to the point
now.
If the intervals were full of fire and the bodies consisted of fire
every one of the other elements would long ago have vanished.
However, they cannot simply be said to be full of air either; for
even if there were two elements to fill the space between the
earth and the heavens, the air would far exceed the quantitu
required to maintain its proper proportion to the other
elements. For the bulk of the earth (which includes the whole
volume of water) is infinitesimal in comparison with the whole
world that surrounds it. Now we find that the excess in volume
is not proportionately great where water dissolves into air or air
into fire. Whereas the proportion between any given small
quantity of water and the air that is generated from it ought to
hold good between the total amount of air and the total amount
1036
of water. Nor does it make any difference if any one denies that
the elements originate from one another, but asserts that they
are equal in power. For on this view it is certain amounts of
each that are equal in power, just as would be the case if they
actually originated from one another.
So it is clear that neither air nor fire alone fills the intermediate
space.
It remains to explain, after a preliminary discussion of
difficulties, the relation of the two elements air and fire to the
position of the first element, and the reason why the stars in
the upper region impart heat to the earth and its
neighbourhood. Let us first treat of the air, as we proposed, and
then go on to these questions.
Since water is generated from air, and air from water, why are
clouds not formed in the upper air? They ought to form there
the more, the further from the earth and the colder that region
is. For it is neither appreciably near to the heat of the stars, nor
to the rays relected from the earth. It is these that dissolve any
formation by their heat and so prevent clouds from forming
near the earth. For clouds gather at the point where the
reflected rays disperse in the infinity of space and are lost. To
explain this we must suppose either that it is not all air which
water is generated, or, if it is produced from all air alike, that
what immediately surrounds the earth is not mere air, but a
sort of vapour, and that its vaporous nature is the reason why it
condenses back to water again. But if the whole of that vast
region is vapour, the amount of air and of water will be
disproportionately great. For the spaces left by the heavenly
bodies must be filled by some element. This cannot be fire, for
then all the rest would have been dried up. Consequently, what
fills it must be air and the water that surrounds the whole
earth-vapour being water dissolved.
1037
After this exposition of the difficulties involved, let us go on to
lay down the truth, with a view at once to what follows and to
what has already been said. The upper region as far as the
moon we affirm to consist of a body distinct both from fire and
from air, but varying degree of purity and in kind, especially
towards its limit on the side of the air, and of the world
surrounding the earth. Now the circular motion of the first
element and of the bodies it contains dissolves, and inflames by
its motion, whatever part of the lower world is nearest to it, and
so generates heat. From another point of view we may look at
the motion as follows. The body that lies below the circular
motion of the heavens is, in a sort, matter, and is potentially
hot, cold, dry, moist, and possessed of whatever other qualities
are derived from these. But it actually acquires or retains one of
these in virtue of motion or rest, the cause and principle of
which has already been explained. So at the centre and round it
we get earth and water, the heaviest and coldest elements, by
themselves; round them and contiguous with them, air and
what we commonly call fire. It is not really fire, for fire is an
excess of heat and a sort of ebullition; but in reality, of what we
call air, the part surrounding the earth is moist and warm,
because it contains both vapour and a dry exhalation from the
earth. But the next part, above that, is warm and dry. For vapour
is naturally moist and cold, but the exhalation warm and dry;
and vapour is potentially like water, the exhalation potentially
like fire. So we must take the reason why clouds are not formed
in the upper region to be this: that it is filled not with mere air
but rather with a sort of fire.
However, it may well be that the formation of clouds in that
upper region is also prevented by the circular motion. For the air
round the earth is necessarily all of it in motion, except that
which is cut off inside the circumference which makes the
earth a complete sphere. In the case of winds it is actually
observable that they originate in marshy districts of the earth;
1038
and they do not seem to blow above the level of the highest
mountains. It is the revolution of the heaven which carries the
air with it and causes its circular motion, fire being continuous
with the upper element and air with fire. Thus its motion is a
second reason why that air is not condensed into water.
But whenever a particle of air grows heavy, the warmth in it is
squeezed out into the upper region and it sinks, and other
particles in turn are carried up together with the fiery
exhalation. Thus the one region is always full of air and the
other of fire, and each of them is perpetually in a state of
change.
So much to explain why clouds are not formed and why the air
is not condensed into water, and what account must be given of
the space between the stars and the earth, and what is the body
that fills it.
As for the heat derived from the sun, the right place for a
special and scientific account of it is in the treatise about sense,
since heat is an affection of sense, but we may now explain how
it can be produced by the heavenly bodies which are not
themselves hot.
We see that motion is able to dissolve and inflame the air;
indeed, moving bodies are often actually found to melt. Now the
sun's motion alone is sufficient to account for the origin of
terrestrial warmth and heat. For a motion that is to have this
effect must be rapid and near, and that of the stars is rapid but
distant, while that of the moon is near but slow, whereas the
sun's motion combines both conditions in a sufficient degree.
That most heat should be generated where the sun is present is
easy to understand if we consider the analogy of terrestrial
phenomena, for here, too, it is the air that is nearest to a thing
in rapid motion which is heated most. This is just what we
1039
should expect, as it is the nearest air that is most dissolved by
the motion of a solid body.
This then is one reason why heat reaches our world. Another is
that the fire surrounding the air is often scattered by the motion
of the heavens and driven downwards in spite of itself.
Shooting-stars further suffix to prove that the celestial sphere is
not hot or fiery: for they do not occur in that upper region but
below: yet the more and the faster a thing moves, the more apt
it is to take fire. Besides, the sun, which most of all the stars is
considered to be hot, is really white and not fiery in colour.
Having determined these principles let us explain the cause of
the appearance in the sky of burning flames and of shooting-
stars, and of 'torches', and 'goats', as some people call them. All
these phenomena are one and the same thing, and are due to
the same cause, the difference between them being one of
degree.
The explanation of these and many other phenomena is this.
When the sun warms the earth the evaporation which takes
place is necessarily of two kinds, not of one only as some think.
One kind is rather of the nature of vapour, the other of the
nature of a windy exhalation. That which rises from the
moisture contained in the earth and on its surface is vapour,
while that rising from the earth itself, which is dry, is like
smoke. Of these the windy exhalation, being warm, rises above
the moister vapour, which is heavy and sinks below the other.
Hence the world surrounding the earth is ordered as follows.
First below the circular motion comes the warm and dry
1040
element, which we call fire, for there is no word fully adequate
to every state of the fumid evaporation: but we must use this
terminology since this element is the most inflammable of all
bodies. Below this comes air. We must think of what we just
called fire as being spread round the terrestrial sphere on the
outside like a kind of fuel, so that a little motion often makes it
burst into flame just as smoke does: for flame is the ebullition
of a dry exhalation. So whenever the circular motion stirs this
stuff up in any way, it catches fire at the point at which it is
most inflammable. The result differs according to the
disposition and quantity of the combustible material. If this is
broad and long, we often see a flame burning as in a field of
stubble: if it burns lengthwise only, we see what are called
'torches' and 'goats' and shooting-stars. Now when the
inflammable material is longer than it is broad sometimes it
seems to throw off sparks as it burns. (This happens because
matter catches fire at the sides in small portions but
continuously with the main body.) Then it is called a 'goat'.
When this does not happen it is a 'torch'. But if the whole
length of the exhalation is scattered in small parts and in many
directions and in breadth and depth alike, we get what are
called shooting-stars.
The cause of these shooting-stars is sometimes the motion
which ignites the exhalation. At other times the air is
condensed by cold and squeezes out and ejects the hot element;
making their motion look more like that of a thing thrown than
like a running fire. For the question might be raised whether the
'shooting' of a 'star' is the same thing as when you put an
exhalation below a lamp and it lights the lower lamp from the
flame above. For here too the flame passes wonderfully quickly
and looks like a thing thrown, and not as if one thing after
another caught fire. Or is a 'star' when it 'shoots' a single body
that is thrown? Apparently both cases occur: sometimes it is
like the flame from the lamp and sometimes bodies are
1041
projected by being squeezed out (like fruit stones from one's
fingers) and so are seen to fall into the sea and on the dry land,
both by night and by day when the sky is clear. They are thrown
downwards because the condensation which propels them
inclines downwards. Thunderbolts fall downwards for the same
reason: their origin is never combustion but ejection under
pressure, since naturally all heat tends upwards.
When the phenomenon is formed in the upper region it is due
to the combustion of the exhalation. When it takes place at a
lower level it is due to the ejection of the exhalation by the
condensing and cooling of the moister evaporation: for this
latter as it condenses and inclines downward contracts, and
thrusts out the hot element and causes it to be thrown
downwards. The motion is upwards or downwards or sideways
according to the way in which the evaporation lies, and its
disposition in respect of breadth and depth. In most cases the
direction is sideways because two motions are involved, a
compulsory motion downwards and a natural motion upwards,
and under these circumstances an object always moves
obliquely. Hence the motion of 'shooting-stars' is generally
oblique.
So the material cause of all these phenomena is the exhalation,
the efficient cause sometimes the upper motion, sometimes the
contraction and condensation of the air. Further, all these
things happen below the moon. This is shown by their apparent
speed, which is equal to that of things thrown by us; for it is
because they are close to us, that these latter seem far to exceed
in speed the stars, the sun, and the moon.
1042
Sometimes on a fine night we see a variety of appearances that
form in the sky: 'chasms' for instance and 'trenches' and blood-
red colours. These, too, have the same cause. For we have seen
that the upper air condenses into an inflammable condition and
that the combustion sometimes takes on the appearance of a
burning flame, sometimes that of moving torches and stars. So
it is not surprising that this same air when condensing should
assume a variety of colours. For a weak light shining through a
dense air, and the air when it acts as a mirror, will cause all
kinds of colours to appear, but especially crimson and purple.
For these colours generally appear when fire-colour and white
are combined by superposition. Thus on a hot day, or through a
smoky, medium, the stars when they rise and set look crimson.
The light will also create colours by reflection when the mirror
is such as to reflect colour only and not shape.
These appearances do not persist long, because the
condensation of the air is transient.
'Chasms' get their appearance of depth from light breaking out
of a dark blue or black mass of air. When the process of
condensation goes further in such a case we often find 'torches'
ejected. When the 'chasm' contracts it presents the appearance
of a 'trench'.
In general, white in contrast with black creates a variety of
colours; like flame, for instance, through a medium of smoke.
But by day the sun obscures them, and, with the exception of
crimson, the colours are not seen at night because they are
dark.
These then must be taken to be the causes of 'shooting-stars'
and the phenomena of combustion and also of the other
transient appearances of this kind.
1043
Let us go on to explain the nature of comets and the 'milky
way', after a preliminary discussion of the views of others.
Anaxagoras and Democritus declare that comets are a
conjunction of the planets approaching one another and so
appearing to touch one another.
Some of the Italians called Pythagoreans say that the comet is
one of the planets, but that it appears at great intervals of time
and only rises a little above the horizon. This is the case with
Mercury too; because it only rises a little above the horizon it
often fails to be seen and consequently appears at great
intervals of time.
A view like theirs was also expressed by Hippocrates of Chios
and his pupil Aeschylus. Only they say that the tail does not
belong to the comet iself, but is occasionally assumed by it on
its course in certain situations, when our sight is reflected to
the sun from the moisture attracted by the comet. It appears at
greater intervals than the other stars because it is slowest to get
clear of the sun and has been left behind by the sun to the
extent of the whole of its circle before it reappears at the same
point. It gets clear of the sun both towards the north and
towards the south. In the space between the tropics it does not
draw water to itself because that region is dried up by the sun
on its course. When it moves towards the south it has no lack of
the necessary moisture, but because the segment of its circle
which is above the horizon is small, and that below it many
times as large, it is impossible for the sun to be reflected to our
sight, either when it approaches the southern tropic, or at the
summer solstice. Hence in these regions it does not develop a
1044
tail at all. But when it is visible in the north it assumes a tail
because the arc above the horizon is large and that below it
small. For under these circumstances there is nothing to
prevent our vision from being reflected to the sun.
These views involve impossibilities, some of which are common
to all of them, while others are peculiar to some only.
This is the case, first, with those who say that the comet is one
of the planets. For all the planets appear in the circle of the
zodiac, whereas many comets have been seen outside that
circle. Again more comets than one have often appeared
simultaneously. Besides, if their tail is due to reflection, as
Aeschylus and Hippocrates say, this planet ought sometimes to
be visible without a tail since, as they it does not possess a tail
in every place in which it appears. But, as a matter of fact, no
planet has been observed besides the five. And all of them are
often visible above the horizon together at the same time.
Further, comets are often found to appear, as well when all the
planets are visible as when some are not, but are obscured by
the neighbourhood of the sun. Moreover the statement that a
comet only appears in the north, with the sun at the summer
solstice, is not true either. The great comet which appeared at
the time of the earthquake in Achaea and the tidal wave rose
due west; and many have been known to appear in the south.
Again in the archonship of Euclees, son of Molon, at Athens
there appeared a comet in the north in the month Gamelion,
the sun being about the winter solstice. Yet they themselves
admit that reflection over so great a space is an impossibility.
An objection that tells equally against those who hold this
theory and those who say that comets are a coalescence of the
planets is, first, the fact that some of the fixed stars too get a
tail. For this we must not only accept the authority of the
Egyptians who assert it, but we have ourselves observed the
1045
fact. For a star in the thigh of the Dog had a tail, though a faint
one. If you fixed your sight on it its light was dim, but if you just
glanced at it, it appeared brighter. Besides, all the comets that
have been seen in our day have vanished without setting,
gradually fading away above the horizon; and they have not left
behind them either one or more stars. For instance the great
comet we mentioned before appeared to the west in winter in
frosty weather when the sky was clear, in the archonship of
Asteius. On the first day it set before the sun and was then not
seen. On the next day it was seen, being ever so little behind the
sun and immediately setting. But its light extended over a third
part of the sky like a leap, so that people called it a 'path'. This
comet receded as far as Orion's belt and there dissolved.
Democritus however, insists upon the truth of his view and
affirms that certain stars have been seen when comets dissolve.
But on his theory this ought not to occur occasionally but
always. Besides, the Egyptians affirm that conjunctions of the
planets with one another, and with the fixed stars, take place,
and we have ourselves observed Jupiter coinciding with one of
the stars in the Twins and hiding it, and yet no comet was
formed. Further, we can also give a rational proof of our point. It
is true that some stars seem to be bigger than others, yet each
one by itself looks indivisible. Consequently, just as, if they
really had been indivisible, their conjunction could not have
created any greater magnitude, so now that they are not in fact
indivisible but look as if they were, their conjunction will not
make them look any bigger.
Enough has been said, without further argument, to show that
the causes brought forward to explain comets are false.
1046
We consider a satisfactory explanation of phenomena
inaccessible to observation to have been given when our
account of them is free from impossibilities. The observations
before us suggest the following account of the phenomena we
are now considering. We know that the dry and warm
exhalation is the outermost part of the terrestrial world which
falls below the circular motion. It, and a great part of the air that
is continuous with it below, is carried round the earth by the
motion of the circular revolution. In the course of this motion it
often ignites wherever it may happen to be of the right
consistency, and this we maintain to be the cause of the
'shooting' of scattered 'stars'. We may say, then, that a comet is
formed when the upper motion introduces into a gathering of
this kind a fiery principle not of such excessive strength as to
burn up much of the material quickly, nor so weak as soon to be
extinguished, but stronger and capable of burning up much
material, and when exhalation of the right consistency rises
from below and meets it. The kind of comet varies according to
the shape which the exhalation happens to take. If it is diffused
equally on every side the star is said to be fringed, if it stretches
out in one direction it is called bearded. We have seen that
when a fiery principle of this kind moves we seem to have a
shooting-star: similarly when it stands still we seem to have a
star standing still. We may compare these phenomena to a heap
or mass of chaff into which a torch is thrust, or a spark thrown.
That is what a shooting-star is like. The fuel is so inflammable
that the fire runs through it quickly in a line. Now if this fire
were to persist instead of running through the fuel and
perishing away, its course through the fuel would stop at the
point where the latter was densest, and then the whole might
begin to move. Such is a comet - like a shooting-star that
contains its beginning and end in itself.
1047
When the matter begins to gather in the lower region
independently the comet appears by itself. But when the
exhalation is constituted by one of the fixed stars or the
planets, owing to their motion, one of them becomes a comet.
The fringe is not close to the stars themselves. Just as haloes
appear to follow the sun and the moon as they move, and
encircle them, when the air is dense enough for them to form
along under the sun's course, so too the fringe. It stands in the
relation of a halo to the stars, except that the colour of the halo
is due to reflection, whereas in the case of comets the colour is
something that appears actually on them.
Now when this matter gathers in relation to a star the comet
necessarily appears to follow the same course as the star. But
when the comet is formed independently it falls behind the
motion of the universe, like the rest of the terrestrial world. It is
this fact, that a comet often forms independently, indeed
oftener than round one of the regular stars, that makes it
impossible to maintain that a comet is a sort of reflection, not
indeed, as Hippocrates and his school say, to the sun, but to the
very star it is alleged to accompany - in fact, a kind of halo in
the pure fuel of fire.
As for the halo we shall explain its cause later.
The fact that comets when frequent foreshadow wind and
drought must be taken as an indication of their fiery
constitution. For their origin is plainly due to the plentiful
supply of that secretion. Hence the air is necessarily drier and
the moist evaporation is so dissolved and dissipated by the
quantity of the hot exhalation as not readily to condense into
water. - But this phenomenon too shall be explained more
clearly later when the time comes to speak of the winds. - So
when there are many comets and they are dense, it is as we say,
and the years are clearly dry and windy. When they are fewer
1048
and fainter this effect does not appear in the same degree,
though as a rule the is found to be excessive either in duration
or strength. For instance when the stone at Aegospotami fell out
of the air - it had been carried up by a wind and fell down in the
daytime - then too a comet happened to have appeared in the
west. And at the time of the great comet the winter was dry and
north winds prevailed, and the wave was due to an opposition
of winds. For in the gulf a north wind blew and outside it a
violent south wind. Again in the archonship of Nicomachus a
comet appeared for a few days about the equinoctial circle (this
one had not risen in the west), and simultaneously with it there
happened the storm at Corinth.
That there are few comets and that they appear rarely and
outside the tropic circles more than within them is due to the
motion of the sun and the stars. For this motion does not only
cause the hot principle to be secreted but also dissolves it when
it is gathering. But the chief reason is that most of this stuff
collects in the region of the milky way.
8
Let us now explain the origin, cause, and nature of the milky
way. And here too let us begin by discussing the statements of
others on the subject.
(1) Of the so-called Pythagoreans some say that this is the path
of one of the stars that fell from heaven at the time of
Phaethon's downfall. Others say that the sun used once to move
in this circle and that this region was scorched or met with
some other affection of this kind, because of the sun and its
motion.
1049
But it is absurd not to see that if this were the reason the circle
of the Zodiac ought to be affected in the same way, and indeed
more so than that of the milky way, since not the sun only but
all the planets move in it. We can see the whole of this circle
(half of it being visible at any time of the night), but it shows no
signs of any such affection except where a part of it touches the
circle of the milky way.
(2) Anaxagoras, Democritus, and their schools say that the milky
way is the light of certain stars. For, they say, when the sun
passes below the earth some of the stars are hidden from it.
Now the light of those on which the sun shines is invisible,
being obscured by the of the sun. But the milky way is the
peculiar light of those stars which are shaded by the earth from
the sun's rays.
This, too, is obviously impossible. The milky way is always
unchanged and among the same constellations (for it is clearly
a greatest circle), whereas, since the sun does not remain in the
same place, what is hidden from it differs at different times.
Consequently with the change of the sun's position the milky
way ought to change its position too: but we find that this does
not happen. Besides, if astronomical demonstrations are correct
and the size of the sun is greater than that of the earth and the
distance of the stars from the earth many times greater than
that of the sun (just as the sun is further from the earth than
the moon), then the cone made by the rays of the sun would
terminate at no great distance from the earth, and the shadow
of the earth (what we call night) would not reach the stars. On
the contrary, the sun shines on all the stars and the earth
screens none of them.
(3) There is a third theory about the milky way. Some say that it
is a reflection of our sight to the sun, just as they say that the
comet is.
1050
But this too is impossible. For if the eye and the mirror and the
whole of the object were severally at rest, then the same part of
the image would appear at the same point in the mirror. But if
the mirror and the object move, keeping the same distance from
the eye which is at rest, but at different rates of speed and so
not always at the same interval from one another, then it is
impossible for the same image always to appear in the same
part of the mirror. Now the constellations included in the circle
of the milky way move; and so does the sun, the object to which
our sight is reflected; but we stand still. And the distance of
those two from us is constant and uniform, but their distance
from one another varies. For the Dolphin sometimes rises at
midnight, sometimes in the morning. But in each case the same
parts of the milky way are found near it. But if it were a
reflection and not a genuine affection of these this ought not to
be the case.
Again, we can see the milky way reflected at night in water and
similar mirrors. But under these circumstances it is impossible
for our sight to be reflected to the sun.
These considerations show that the milky way is not the path of
one of the planets, nor the light of imperceptible stars, nor a
reflection. And those are the chief theories handed down by
others hitherto.
Let us recall our fundamental principle and then explain our
views. We have already laid down that the outermost part of
what is called the air is potentially fire and that therefore when
the air is dissolved by motion, there is separated off a kind of
matter - and of this matter we assert that comets consist. We
must suppose that what happens is the same as in the case of
the comets when the matter does not form independently but is
formed by one of the fixed stars or the planets. Then these stars
appear to be fringed, because matter of this kind follows their
1051
course. In the same way, a certain kind of matter follows the
sun, and we explain the halo as a reflection from it when the air
is of the right constitution. Now we must assume that what
happens in the case of the stars severally happens in the case of
the whole of the heavens and all the upper motion. For it is
natural to suppose that, if the motion of a single star excites a
flame, that of all the stars should have a similar result, and
especially in that region in which the stars are biggest and most
numerous and nearest to one another. Now the circle of the
zodiac dissolves this kind of matter because of the motion of
the sun and the planets, and for this reason most comets are
found outside the tropic circles. Again, no fringe appears round
the sun or moon: for they dissolve such matter too quickly to
admit of its formation. But this circle in which the milky way
appears to our sight is the greatest circle, and its position is
such that it extends far outside the tropic circles. Besides the
region is full of the biggest and brightest constellations and also
of what called 'scattered' stars (you have only to look to see this
clearly). So for these reasons all this matter is continually and
ceaselessly collecting there. A proof of the theory is this: In the
circle itself the light is stronger in that half where the milky way
is divided, and in it the constellations are more numerous and
closer to one another than in the other half; which shows that
the cause of the light is the motion of the constellations and
nothing else. For if it is found in the circle in which there are
most constellations and at that point in the circle at which they
are densest and contain the biggest and the most stars, it is
natural to suppose that they are the true cause of the affection
in question. The circle and the constellations in it may be seen
in the diagram. The so-called 'scattered' stars it is not possible
to set down in the same way on the sphere because none of
them have an evident permanent position; but if you look up to
the sky the point is clear. For in this circle alone are the
intervals full of these stars: in the other circles there are
1052
obvious gaps. Hence if we accept the cause assigned for the
appearance of comets as plausible we must assume that the
same kind of thing holds good of the milky way. For the fringe
which in the former case is an affection of a single star here
forms in the same way in relation to a whole circle. So if we are
to define the milky way we may call it 'a fringe attaching to the
greatest circle, and due to the matter secreted'. This, as we said
before, explains why there are few comets and why they appear
rarely; it is because at each revolution of the heavens this
matter has always been and is always being separated off and
gathered into this region.
We have now explained the phenomena that occur in that part
of the terrestrial world which is continuous with the motions of
the heavens, namely, shooting-stars and the burning flame,
comets and the milky way, these being the chief affections that
appear in that region.
Let us go on to treat of the region which follows next in order
after this and which immediately surrounds the earth. It is the
region common to water and air, and the processes attending
the formation of water above take place in it. We must consider
the principles and causes of all these phenomena too as before.
The efficient and chief and first cause is the circle in which the
sun moves. For the sun as it approaches or recedes, obviously
causes dissipation and condensation and so gives rise to
generation and destruction. Now the earth remains but the
moisture surrounding it is made to evaporate by the sun's rays
and the other heat from above, and rises. But when the heat
which was raising it leaves it, in part dispersing to the higher
1053
region, in part quenched through rising so far into the upper air,
then the vapour cools because its heat is gone and because the
place is cold, and condenses again and turns from air into
water. And after the water has formed it falls down again to the
earth.
The exhalation of water is vapour: air condensing into water is
cloud. Mist is what is left over when a cloud condenses into
water, and is therefore rather a sign of fine weather than of rain;
for mist might be called a barren cloud. So we get a circular
process that follows the course of the sun. For according as the
sun moves to this side or that, the moisture in this process rises
or falls. We must think of it as a river flowing up and down in a
circle and made up partly of air, partly of water. When the sun is
near, the stream of vapour flows upwards; when it recedes, the
stream of water flows down: and the order of sequence, at all
events, in this process always remains the same. So if 'Oceanus'
had some secret meaning in early writers, perhaps they may
have meant this river that flows in a circle about the earth.
So the moisture is always raised by the heat and descends to
the earth again when it gets cold. These processes and, in some
cases, their varieties are distinguished by special names. When
the water falls in small drops it is called a drizzle; when the
drops are larger it is rain.
10
Some of the vapour that is formed by day does not rise high
because the ratio of the fire that is raising it to the water that is
being raised is small. When this cools and descends at night it is
called dew and hoar-frost. When the vapour is frozen before it
has condensed to water again it is hoar-frost; and this appears
1054
in winter and is commoner in cold places. It is dew when the
vapour has condensed into water and the heat is not so great as
to dry up the moisture that has been raised nor the cold
sufficient (owing to the warmth of the climate or season) for the
vapour itself to freeze. For dew is more commonly found when
the season or the place is warm, whereas the opposite, as has
been said, is the case with hoar-frost. For obviously vapour is
warmer than water, having still the fire that raised it:
consequently more cold is needed to freeze it.
Both dew and hoar-frost are found when the sky is clear and
there is no wind. For the vapour could not be raised unless the
sky were clear, and if a wind were blowing it could not
condense.
The fact that hoar-frost is not found on mountains contributes
to prove that these phenomena occur because the vapour does
not rise high. One reason for this is that it rises from hollow and
watery places, so that the heat that is raising it, bearing as it
were too heavy a burden cannot lift it to a great height but soon
lets it fall again. A second reason is that the motion of the air is
more pronounced at a height, and this dissolves a gathering of
this kind.
Everywhere, except in Pontus, dew is found with south winds
and not with north winds. There the opposite is the case and it
is found with north winds and not with south. The reason is the
same as that which explains why dew is found in warm
weather and not in cold. For the south wind brings warm, and
the north, wintry weather. For the north wind is cold and so
quenches the heat of the evaporation. But in Pontus the south
wind does not bring warmth enough to cause evaporation,
whereas the coldness of the north wind concentrates the heat
by a sort of recoil, so that there is more evaporation and not
less. This is a thing which we can often observe in other places
1055
too. Wells, for instance, give off more vapour in a north than in a
south wind. Only the north winds quench the heat before any
considerable quantity of vapour has gathered, while in a south
wind the evaporation is allowed to accumulate.
Water, once formed, does not freeze on the surface of the earth,
in the way that it does in the region of the clouds.
11
From the latter there fall three bodies condensed by cold,
namely rain, snow, hail. Two of these correspond to the
phenomena on the lower level and are due to the same causes,
differing from them only in degree and quantity.
Snow and hoar-frost are one and the same thing, and so are rain
and dew: only there is a great deal of the former and little of the
latter. For rain is due to the cooling of a great amount of vapour,
for the region from which and the time during which the
vapour is collected are considerable. But of dew there is little:
for the vapour collects for it in a single day and from a small
area, as its quick formation and scanty quantity show.
The relation of hoar-frost and snow is the same: when cloud
freezes there is snow, when vapour freezes there is hoar-frost.
Hence snow is a sign of a cold season or country. For a great
deal of heat is still present and unless the cold were
overpowering it the cloud would not freeze. For there still
survives in it a great deal of the heat which caused the moisture
to rise as vapour from the earth.
Hail on the other hand is found in the upper region, but the
corresponding phenomenon in the vaporous region near the
1056
earth is lacking. For, as we said, to snow in the upper region
corresponds hoar-frost in the lower, and to rain in the upper
region, dew in the lower. But there is nothing here to correspond
to hail in the upper region. Why this is so will be clear when we
have explained the nature of hail.
12
But we must go on to collect the facts bearing on the origin of it,
both those which raise no difficulties and those which seem
paradoxical.
Hail is ice, and water freezes in winter; yet hailstorms occur
chiefly in spring and autumn and less often in the late summer,
but rarely in winter and then only when the cold is less intense.
And in general hailstorms occur in warmer, and snow in colder
places. Again, there is a difficulty about water freezing in the
upper region. It cannot have frozen before becoming water: and
water cannot remain suspended in the air for any space of time.
Nor can we say that the case is like that of particles of moisture
which are carried up owing to their small size and rest on the
iar (the water swimming on the air just as small particles of
earth and gold often swim on water). In that case large drops
are formed by the union of many small, and so fall down. This
cannot take place in the case of hail, since solid bodies cannot
coalesce like liquid ones. Clearly then drops of that size were
suspended in the air or else they could not have been so large
when frozen.
Some think that the cause and origin of hail is this. The cloud is
thrust up into the upper atmosphere, which is colder because
the reflection of the sun's rays from the earth ceases there, and
upon its arrival there the water freezes. They think that this
1057
explains why hailstorms are commoner in summer and in
warm countries; the heat is greater and it thrusts the clouds
further up from the earth. But the fact is that hail does not
occur at all at a great height: yet it ought to do so, on their
theory, just as we see that snow falls most on high mountains.
Again clouds have often been observed moving with a great
noise close to the earth, terrifying those who heard and saw
them as portents of some catastrophe. Sometimes, too, when
such clouds have been seen, without any noise, there follows a
violent hailstorm, and the stones are of incredible size, and
angular in shape. This shows that they have not been falling for
long and that they were frozen near to the earth, and not as
that theory would have it. Moreover, where the hailstones are
large, the cause of their freezing must be present in the highest
degree: for hail is ice as every one can see. Now those hailstones
are large which are angular in shape. And this shows that they
froze close to the earth, for those that fall far are worn away by
the length of their fall and become round and smaller in size.
It clearly follows that the congelation does not take place
because the cloud is thrust up into the cold upper region.
Now we see that warm and cold react upon one another by
recoil. Hence in warm weather the lower parts of the earth are
cold and in a frost they are warm. The same thing, we must
suppose, happens in the air, so that in the warmer seasons the
cold is concentrated by the surrounding heat and causes the
cloud to go over into water suddenly. (For this reason rain-drops
are much larger on warm days than in winter, and showers
more violent. A shower is said to be more violent in proportion
as the water comes down in a body, and this happens when the
condensation takes place quickly, - though this is just the
opposite of what Anaxagoras says. He says that this happens
when the cloud has risen into the cold air; whereas we say that
it happens when the cloud has descended into the warm air,
1058
and that the more the further the cloud has descended). But
when the cold has been concentrated within still more by the
outer heat, it freezes the water it has formed and there is hail.
We get hail when the process of freezing is quicker than the
descent of the water. For if the water falls in a certain time and
the cold is sufficient to freeze it in less, there is no difficulty
about its having frozen in the air, provided that the freezing
takes place in a shorter time than its fall. The nearer to the
earth, and the more suddenly, this process takes place, the more
violent is the rain that results and the larger the raindrops and
the hailstones because of the shortness of their fall. For the
same reason large raindrops do not fall thickly. Hail is rarer in
summer than in spring and autumn, though commoner than in
winter, because the air is drier in summer, whereas in spring it
is still moist, and in autumn it is beginning to grow moist. It is
for the same reason that hailstorms sometimes occur in the late
summer as we have said.
The fact that the water has previously been warmed contributes
to its freezing quickly: for so it cools sooner. Hence many
people, when they want to cool hot water quickly, begin by
putting it in the sun. So the inhabitants of Pontus when they
encamp on the ice to fish (they cut a hole in the ice and then
fish) pour warm water round their reeds that it may freeze the
quicker, for they use the ice like lead to fix the reeds. Now it is
in hot countries and seasons that the water which forms soon
grows warm.
It is for the same reason that rain falls in summer and not in
winter in Arabia and Ethiopia too, and that in torrents and
repeatedly on the same day. For the concentration or recoil due
to the extreme heat of the country cools the clouds quickly.
So much for an account of the nature and causes of rain, dew,
snow, hoar-frost, and hail.
1059
13
Let us explain the nature of winds, and all windy vapours, also
of rivers and of the sea. But here, too, we must first discuss the
difficulties involved: for, as in other matters, so in this no theory
has been handed down to us that the most ordinary man could
not have thought of.
Some say that what is called air, when it is in motion and flows,
is wind, and that this same air when it condenses again
becomes cloud and water, implying that the nature of wind and
water is the same. So they define wind as a motion of the air.
Hence some, wishing to say a clever thing, assert that all the
winds are one wind, because the air that moves is in fact all of it
one and the same; they maintain that the winds appear to
differ owing to the region from which the air may happen to
flow on each occasion, but really do not differ at all. This is just
like thinking that all rivers are one and the same river, and the
ordinary unscientific view is better than a scientific theory like
this. If all rivers flow from one source, and the same is true in
the case of the winds, there might be some truth in this theory;
but if it is no more true in the one case than in the other, this
ingenious idea is plainly false. What requires investigation is
this: the nature of wind and how it originates, its efficient cause
and whence they derive their source; whether one ought to
think of the wind as issuing from a sort of vessel and flowing
until the vessel is empty, as if let out of a wineskin, or, as
painters represent the winds, as drawing their source from
themselves.
We find analogous views about the origin of rivers. It is thought
that the water is raised by the sun and descends in rain and
1060
gathers below the earth and so flows from a great reservoir, all
the rivers from one, or each from a different one. No water at all
is generated, but the volume of the rivers consists of the water
that is gathered into such reservoirs in winter. Hence rivers are
always fuller in winter than in summer, and some are perennial,
others not. Rivers are perennial where the reservoir is large and
so enough water has collected in it to last out and not be used
up before the winter rain returns. Where the reservoirs are
smaller there is less water in the rivers, and they are dried up
and their vessel empty before the fresh rain comes on.
But if any one will picture to himself a reservoir adequate to the
water that is continuously flowing day by day, and consider the
amount of the water, it is obvious that a receptacle that is to
contain all the water that flows in the year would be larger than
the earth, or, at any rate, not much smaller.
Though it is evident that many reservoirs of this kind do exist in
many parts of the earth, yet it is unreasonable for any one to
refuse to admit that air becomes water in the earth for the same
reason as it does above it. If the cold causes the vaporous air to
condense into water above the earth we must suppose the cold
in the earth to produce this same effect, and recognize that
there not only exists in it and flows out of it actually formed
water, but that water is continually forming in it too.
Again, even in the case of the water that is not being formed
from day to day but exists as such, we must not suppose as
some do that rivers have their source in definite subterranean
lakes. On the contrary, just as above the earth small drops form
and these join others, till finally the water descends in a body as
rain, so too we must suppose that in the earth the water at first
trickles together little by little, and that the sources of the rivers
drip, as it were, out of the earth and then unite. This is proved
by facts. When men construct an aqueduct they collect the
1061
water in pipes and trenches, as if the earth in the higher ground
were sweating the water out. Hence, too, the head-waters of
rivers are found to flow from mountains, and from the greatest
mountains there flow the most numerous and greatest rivers.
Again, most springs are in the neighbourhood of mountains and
of high ground, whereas if we except rivers, water rarely
appears in the plains. For mountains and high ground,
suspended over the country like a saturated sponge, make the
water ooze out and trickle together in minute quantities but in
many places. They receive a great deal of water falling as rain
(for it makes no difference whether a spongy receptacle is
concave and turned up or convex and turned down: in either
case it will contain the same volume of matter) and, they also
cool the vapour that rises and condense it back into water.
Hence, as we said, we find that the greatest rivers flow from the
greatest mountains. This can be seen by looking at itineraries:
what is recorded in them consists either of things which the
writer has seen himself or of such as he has compiled after
inquiry from those who have seen them.
In Asia we find that the most numerous and greatest rivers flow
from the mountain called Parnassus, admittedly the greatest of
all mountains towards the south-east. When you have crossed it
you see the outer ocean, the further limit of which is unknown
to the dwellers in our world. Besides other rivers there flow
from it the Bactrus, the Choaspes, the Araxes: from the last a
branch separates off and flows into lake Maeotis as the Tanais.
From it, too, flows the Indus, the volume of whose stream is
greatest of all rivers. From the Caucasus flows the Phasis, and
very many other great rivers besides. Now the Caucasus is the
greatest of the mountains that lie to the northeast, both as
regards its extent and its height. A proof of its height is the fact
that it can be seen from the so-called 'deeps' and from the
entrance to the lake. Again, the sun shines on its peaks for a
1062
third part of the night before sunrise and again after sunset. Its
extent is proved by the fact that thought contains many
inhabitable regions which are occupied by many nations and in
which there are said to be great lakes, yet they say that all these
regions are visible up to the last peak. From Pyrene (this is a
mountain towards the west in Celtice) there flow the Istrus and
the Tartessus. The latter flows outside the pillars, while the
Istrus flows through all Europe into the Euxine. Most of the
remaining rivers flow northwards from the Hercynian
mountains, which are the greatest in height and extent about
that region. In the extreme north, beyond furthest Scythia, are
the mountains called Rhipae. The stories about their size are
altogether too fabulous: however, they say that the most and
(after the Istrus) the greatest rivers flow from them. So, too, in
Libya there flow from the Aethiopian mountains the Aegon and
the Nyses; and from the so-called Silver Mountain the two
greatest of named rivers, the river called Chremetes that flows
into the outer ocean, and the main source of the Nile. Of the
rivers in the Greek world, the Achelous flows from Pindus, the
Inachus from the same mountain; the Strymon, the Nestus, and
the Hebrus all three from Scombrus; many rivers, too, flow from
Rhodope.
All other rivers would be found to flow in the same way, but we
have mentioned these as examples. Even where rivers flow
from marshes, the marshes in almost every case are found to lie
below mountains or gradually rising ground.
It is clear then that we must not suppose rivers to originate
from definite reservoirs: for the whole earth, we might almost
say, would not be sufficient (any more than the region of the
clouds would be) if we were to suppose that they were fed by
actually existing water only and it were not the case that as
some water passed out of existence some more came into
existence, but rivers always drew their stream from an existing
1063
store. Secondly, the fact that rivers rise at the foot of mountains
proves that a place transmits the water it contains by gradual
percolation of many drops, little by little, and that this is how
the sources of rivers originate. However, there is nothing
impossible about the existence of such places containing a
quantity of water like lakes: only they cannot be big enough to
produce the supposed effect. To think that they are is just as
absurd as if one were to suppose that rivers drew all their water
from the sources we see (for most rivers do flow from springs).
So it is no more reasonable to suppose those lakes to contain
the whole volume of water than these springs.
That there exist such chasms and cavities in the earth we are
taught by the rivers that are swallowed up. They are found in
many parts of the earth: in the Peloponnesus, for instance, there
are many such rivers in Arcadia. The reason is that Arcadia is
mountainous and there are no channels from its valleys to the
sea. So these places get full of water, and this, having no outlet,
under the pressure of the water that is added above, finds a way
out for itself underground. In Greece this kind of thing happens
on quite a small scale, but the lake at the foot of the Caucasus,
which the inhabitants of these parts call a sea, is considerable.
Many great rivers fall into it and it has no visible outlet but
issues below the earth off the land of the Coraxi about the so-
called 'deeps of Pontus'. This is a place of unfathomable depth
in the sea: at any rate no one has yet been able to find bottom
there by sounding. At this spot, about three hundred stadia
from land, there comes up sweet water over a large area, not all
of it together but in three places. And in Liguria a river equal in
size to the Rhodanus is swallowed up and appears again
elsewhere: the Rhodanus being a navigable river.
1064
14
The same parts of the earth are not always moist or dry, but
they change according as rivers come into existence and dry up.
And so the relation of land to sea changes too and a place does
not always remain land or sea throughout all time, but where
there was dry land there comes to be sea, and where there is
now sea, there one day comes to be dry land. But we must
suppose these changes to follow some order and cycle. The
principle and cause of these changes is that the interior of the
earth grows and decays, like the bodies of plants and animals.
Only in the case of these latter the process does not go on by
parts, but each of them necessarily grows or decays as a whole,
whereas it does go on by parts in the case of the earth. Here the
causes are cold and heat, which increase and diminish on
account of the sun and its course. It is owing to them that the
parts of the earth come to have a different character, that some
parts remain moist for a certain time, and then dry up and grow
old, while other parts in their turn are filled with life and
moisture. Now when places become drier the springs
necessarily give out, and when this happens the rivers first
decrease in size and then finally become dry; and when rivers
change and disappear in one part and come into existence
correspondingly in another, the sea must needs be affected.
If the sea was once pushed out by rivers and encroached upon
the land anywhere, it necessarily leaves that place dry when it
recedes; again, if the dry land has encroached on the sea at all
by a process of silting set up by the rivers when at their full, the
time must come when this place will be flooded again.
But the whole vital process of the earth takes place so gradually
and in periods of time which are so immense compared with
the length of our life, that these changes are not observed, and
before their course can be recorded from beginning to end
1065
whole nations perish and are destroyed. Of such destructions
the most utter and sudden are due to wars; but pestilence or
famine cause them too. Famines, again, are either sudden and
severe or else gradual. In the latter case the disappearance of a
nation is not noticed because some leave the country while
others remain; and this goes on until the land is unable to
maintain any inhabitants at all. So a long period of time is likely
to elapse from the first departure to the last, and no one
remembers and the lapse of time destroys all record even before
the last inhabitants have disappeared. In the same way a nation
must be supposed to lose account of the time when it first
settled in a land that was changing from a marshy and watery
state and becoming dry. Here, too, the change is gradual and
lasts a long time and men do not remember who came first, or
when, or what the land was like when they came. This has been
the case with Egypt. Here it is obvious that the land is
continually getting drier and that the whole country is a deposit
of the river Nile. But because the neighbouring peoples settled
in the land gradually as the marshes dried, the lapse of time has
hidden the beginning of the process. However, all the mouths of
the Nile, with the single exception of that at Canopus, are
obviously artificial and not natural. And Egypt was nothing
more than what is called Thebes, as Homer, too, shows, modern
though he is in relation to such changes. For Thebes is the place
that he mentions; which implies that Memphis did not yet exist,
or at any rate was not as important as it is now. That this should
be so is natural, since the lower land came to be inhabited later
than that which lay higher. For the parts that lie nearer to the
place where the river is depositing the silt are necessarily
marshy for a longer time since the water always lies most in the
newly formed land. But in time this land changes its character,
and in its turn enjoys a period of prosperity. For these places dry
up and come to be in good condition while the places that were
formerly well-tempered some day grow excessively dry and
1066
deteriorate. This happened to the land of Argos and Mycenae in
Greece. In the time of the Trojan wars the Argive land was
marshy and could only support a small population, whereas the
land of Mycenae was in good condition (and for this reason
Mycenae was the superior). But now the opposite is the case, for
the reason we have mentioned: the land of Mycenae has
become completely dry and barren, while the Argive land that
was formerly barren owing to the water has now become
fruitful. Now the same process that has taken place in this
small district must be supposed to be going on over whole
countries and on a large scale.
Men whose outlook is narrow suppose the cause of such events
to be change in the universe, in the sense of a coming to be of
the world as a whole. Hence they say that the sea being dried up
and is growing less, because this is observed to have happened
in more places now than formerly. But this is only partially true.
It is true that many places are now dry, that formerly were
covered with water. But the opposite is true too: for if they look
they will find that there are many places where the sea has
invaded the land. But we must not suppose that the cause of
this is that the world is in process of becoming. For it is absurd
to make the universe to be in process because of small and
trifling changes, when the bulk and size of the earth are surely
as nothing in comparison with the whole world. Rather we
must take the cause of all these changes to be that, just as
winter occurs in the seasons of the year, so in determined
periods there comes a great winter of a great year and with it
excess of rain. But this excess does not always occur in the
same place. The deluge in the time of Deucalion, for instance,
took place chiefly in the Greek world and in it especially about
ancient Hellas, the country about Dodona and the Achelous, a
river which has often changed its course. Here the Selli dwelt
and those who were formerly called Graeci and now Hellenes.
When, therefore, such an excess of rain occurs we must
1067
suppose that it suffices for a long time. We have seen that some
say that the size of the subterranean cavities is what makes
some rivers perennial and others not, whereas we maintain that
the size of the mountains is the cause, and their density and
coldness; for great, dense, and cold mountains catch and keep
and create most water: whereas if the mountains that overhang
the sources of rivers are small or porous and stony and clayey,
these rivers run dry earlier. We must recognize the same kind of
thing in this case too. Where such abundance of rain falls in the
great winter it tends to make the moisture of those places
almost everlasting. But as time goes on places of the latter type
dry up more, while those of the former, moist type, do so less:
until at last the beginning of the same cycle returns.
Since there is necessarily some change in the whole world, but
not in the way of coming into existence or perishing (for the
universe is permanent), it must be, as we say, that the same
places are not for ever moist through the presence of sea and
rivers, nor for ever dry. And the facts prove this. The whole land
of the Egyptians, whom we take to be the most ancient of men,
has evidently gradually come into existence and been produced
by the river. This is clear from an observation of the country,
and the facts about the Red Sea suffice to prove it too. One of
their kings tried to make a canal to it (for it would have been of
no little advantage to them for the whole region to have become
navigable; Sesostris is said to have been the first of the ancient
kings to try), but he found that the sea was higher than the
land. So he first, and Darius afterwards, stopped making the
canal, lest the sea should mix with the river water and spoil it.
So it is clear that all this part was once unbroken sea. For the
same reason Libya - the country of Ammon - is, strangely
enough, lower and hollower than the land to the seaward of it.
For it is clear that a barrier of silt was formed and after it lakes
and dry land, but in course of time the water that was left
behind in the lakes dried up and is now all gone. Again the
1068
silting up of the lake Maeotis by the rivers has advanced so
much that the limit to the size of the ships which can now sail
into it to trade is much lower than it was sixty years ago. Hence
it is easy to infer that it, too, like most lakes, was originally
produced by the rivers and that it must end by drying up
entirely.
Again, this process of silting up causes a continuous current
through the Bosporus; and in this case we can directly observe
the nature of the process. Whenever the current from the
Asiatic shore threw up a sandbank, there first formed a small
lake behind it. Later it dried up and a second sandbank formed
in front of the first and a second lake. This process went on
uniformly and without interruption. Now when this has been
repeated often enough, in the course of time the strait must
become like a river, and in the end the river itself must dry up.
So it is clear, since there will be no end to time and the world is
eternal, that neither the Tanais nor the Nile has always been
flowing, but that the region whence they flow was once dry: for
their effect may be fulfilled, but time cannot. And this will be
equally true of all other rivers. But if rivers come into existence
and perish and the same parts of the earth were not always
moist, the sea must needs change correspondingly. And if the
sea is always advancing in one place and receding in another it
is clear that the same parts of the whole earth are not always
either sea or land, but that all this changes in course of time.
So we have explained that the same parts of the earth are not
always land or sea and why that is so: and also why some rivers
are perennial and others not.
1069
Book II
Let us explain the nature of the sea and the reason why such a
large mass of water is salt and the way in which it originally
came to be.
The old writers who invented theogonies say that the sea has
springs, for they want earth and sea to have foundations and
roots of their own. Presumably they thought that this view was
grander and more impressive as implying that our earth was an
important part of the universe. For they believed that the whole
world had been built up round our earth and for its sake, and
that the earth was the most important and primary part of it.
Others, wiser in human knowledge, give an account of its origin.
At first, they say, the earth was surrounded by moisture. Then
the sun began to dry it up, part of it evaporated and is the cause
of winds and the turnings back of the sun and the moon, while
the remainder forms the sea. So the sea is being dried up and is
growing less, and will end by being some day entirely dried up.
Others say that the sea is a kind of sweat exuded by the earth
when the sun heats it, and that this explains its saltness: for all
sweat is salt. Others say that the saltness is due to the earth.
Just as water strained through ashes becomes salt, so the sea
owes its saltness to the admixture of earth with similar
properties.
We must now consider the facts which prove that the sea
cannot possibly have springs. The waters we find on the earth
either flow or are stationary. All flowing water has springs. (By a
spring, as we have explained above, we must not understand a
source from which waters are ladled as it were from a vessel,
1070
but a first point at which the water which is continually forming
and percolating gathers.) Stationary water is either that which
has collected and has been left standing, marshy pools, for
instance, and lakes, which differ merely in size, or else it comes
from springs. In this case it is always artificial, I mean as in the
case of wells, otherwise the spring would have to be above the
outlet. Hence the water from fountains and rivers flows of itself,
whereas wells need to be worked artificially. All the waters that
exist belong to one or other of these classes.
On the basis of this division we can sec that the sea cannot
have springs. For it falls under neither of the two classes; it does
not flow and it is not artificial; whereas all water from springs
must belong to one or other of them. Natural standing water
from springs is never found on such a large scale.
Again, there are several seas that have no communication with
one another at all. The Red Sea, for instance, communicates but
slightly with the ocean outside the straits, and the Hyrcanian
and Caspian seas are distinct from this ocean and people dwell
all round them. Hence, if these seas had had any springs
anywhere they must have been discovered.
It is true that in straits, where the land on either side contracts
an open sea into a small space, the sea appears to flow. But this
is because it is swinging to and fro. In the open sea this motion
is not observed, but where the land narrows and contracts the
sea the motion that was imperceptible in the open necessarily
strikes the attention.
The whole of the Mediterranean does actually flow. The
direction of this flow is determined by the depth of the basins
and by the number of rivers. Maeotis flows into Pontus and
Pontus into the Aegean. After that the flow of the remaining
seas is not so easy to observe. The current of Maeotis and
Pontus is due to the number of rivers (more rivers flow into the
1071
Euxine and Maeotis than into the whole Mediterranean with its
much larger basin), and to their own shallowness. For we find
the sea getting deeper and deeper. Pontus is deeper than
Maeotis, the Aegean than Pontus, the Sicilian sea than the
Aegean; the Sardinian and Tyrrhenic being the deepest of all.
(Outside the pillars of Heracles the sea is shallow owing to the
mud, but calm, for it lies in a hollow.) We see, then, that just as
single rivers flow from mountains, so it is with the earth as a
whole: the greatest volume of water flows from the higher
regions in the north. Their alluvium makes the northern seas
shallow, while the outer seas are deeper. Some further evidence
of the height of the northern regions of the earth is afforded by
the view of many of the ancient meteorologists. They believed
that the sun did not pass below the earth, but round its
northern part, and that it was the height of this which obscured
the sun and caused night.
So much to prove that there cannot be sources of the sea and to
explain its observed flow.
We must now discuss the origin of the sea, if it has an origin,
and the cause of its salt and bitter taste.
What made earlier writers consider the sea to be the original
and main body of water is this. It seems reasonable to suppose
that to be the case on the analogy of the other elements. Each of
them has a main bulk which by reason of its mass is the origin
of that element, and any parts which change and mix with the
other elements come from it. Thus the main body of fire is in
the upper region; that of air occupies the place next inside the
region of fire; while the mass of the earth is that round which
1072
the rest of the elements are seen to lie. So we must clearly look
for something analogous in the case of water. But here we can
find no such single mass, as in the case of the other elements,
except the sea. River water is not a unity, nor is it stable, but is
seen to be in a continuous process of becoming from day to day.
It was this difficulty which made people regard the sea as the
origin and source of moisture and of all water. And so we find it
maintained that rivers not only flow into the sea but originate
from it, the salt water becoming sweet by filtration.
But this view involves another difficulty. If this body of water is
the origin and source of all water, why is it salt and not sweet?
The reason for this, besides answering this question, will ensure
our having a right first conception of the nature of the sea.
The earth is surrounded by water, just as that is by the sphere of
air, and that again by the sphere called that of fire (which is the
outermost both on the common view and on ours). Now the
sun, moving as it does, sets up processes of change and
becoming and decay, and by its agency the finest and sweetest
water is every day carried up and is dissolved into vapour and
rises to the upper region, where it is condensed again by the
cold and so returns to the earth. This, as we have said before, is
the regular course of nature.
Hence all my predecessors who supposed that the sun was
nourished by moisture are absurdly mistaken. Some go on to
say that the solstices are due to this, the reason being that the
same places cannot always supply the sun with nourishment
and that without it he must perish. For the fire we are familiar
with lives as long as it is fed, and the only food for fire is
moisture. As if the moisture that is raised could reach the sun!
or this ascent were really like that performed by flame as it
comes into being, and to which they supposed the case of the
sun to be analogous! Really there is no similarity. A flame is a
1073
process of becoming, involving a constant interchange of moist
and dry. It cannot be said to be nourished since it scarcely
persists as one and the same for a moment. This cannot be true
of the sun; for if it were nourished like that, as they say it is, we
should obviously not only have a new sun every day, as
Heraclitus says, but a new sun every moment. Again, when the
sun causes the moisture to rise, this is like fire heating water.
So, as the fire is not fed by the water above it, it is absurd to
suppose that the sun feeds on that moisture, even if its heat
made all the water in the world evaporate. Again, it is absurd,
considering the number and size of the stars, that these
thinkers should consider the sun only and overlook the
question how the rest of the heavenly bodies subsist. Again,
they are met by the same difficulty as those who say that at
first the earth itself was moist and the world round the earth
was warmed by the sun, and so air was generated and the
whole firmament grew, and the air caused winds and solstices.
The objection is that we always plainly see the water that has
been carried up coming down again. Even if the same amount
does not come back in a year or in a given country, yet in a
certain period all that has been carried up is returned. This
implies that the celestial bodies do not feed on it, and that we
cannot distinguish between some air which preserves its
character once it is generated and some other which is
generated but becomes water again and so perishes; on the
contrary, all the moisture alike is dissolved and all of it
condensed back into water.
The drinkable, sweet water, then, is light and is all of it drawn
up: the salt water is heavy and remains behind, but not in its
natural place. For this is a question which has been sufficiently
discussed (I mean about the natural place that water, like the
other elements, must in reason have), and the answer is this.
The place which we see the sea filling is not its natural place
but that of water. It seems to belong to the sea because the
1074
weight of the salt water makes it remain there, while the sweet,
drinkable water which is light is carried up. The same thing
happens in animal bodies. Here, too, the food when it enters the
body is sweet, yet the residuum and dregs of liquid food are
found to be bitter and salt. This is because the sweet and
drinkable part of it has been drawn away by the natural animal
heat and has passed into the flesh and the other parts of the
body according to their several natures. Now just as here it
would be wrong for any one to refuse to call the belly the place
of liquid food because that disappears from it soon, and to call
it the place of the residuum because this is seen to remain, so in
the case of our present subject. This place, we say, is the place of
water. Hence all rivers and all the water that is generated flow
into it: for water flows into the deepest place, and the deepest
part of the earth is filled by the sea. Only all the light and sweet
part of it is quickly carried off by the sun, while herest remains
for the reason we have explained. It is quite natural that some
people should have been puzzled by the old question why such
a mass of water leaves no trace anywhere (for the sea does not
increase though innumerable and vast rivers are flowing into it
every day.) But if one considers the matter the solution is easy.
The same amount of water does not take as long to dry up
when it is spread out as when it is gathered in a body, and
indeed the difference is so great that in the one case it might
persist the whole day long while in the other it might all
disappear in a moment - as for instance if one were to spread
out a cup of water over a large table. This is the case with the
rivers: all the time they are flowing their water forms a compact
mass, but when it arrives at a vast wide place it quickly and
imperceptibly evaporates.
But the theory of the Phaedo about rivers and the sea is
impossible. There it is said that the earth is pierced by
intercommunicating channels and that the original head and
source of all waters is what is called Tartarus - a mass of water
1075
about the centre, from which all waters, flowing and standing,
are derived. This primary and original water is always surging to
and fro, and so it causes the rivers to flow on this side of the
earth's centre and on that; for it has no fixed seat but is always
oscillating about the centre. Its motion up and down is what
fills rivers. Many of these form lakes in various places (our sea is
an instance of one of these), but all of them come round again
in a circle to the original source of their flow, many at the same
point, but some at a point opposite to that from which they
issued; for instance, if they started from the other side of the
earth's centre, they might return from this side of it. They
descend only as far as the centre, for after that all motion is
upwards. Water gets its tastes and colours from the kind of
earth the rivers happened to flow through.
But on this theory rivers do not always flow in the same sense.
For since they flow to the centre from which they issue forth
they will not be flowing down any more than up, but in
whatever direction the surging of Tartarus inclines to. But at this
rate we shall get the proverbial rivers flowing upwards, which is
impossible. Again, where is the water that is generated and
what goes up again as vapour to come from? For this must all of
it simply be ignored, since the quantity of water is always the
same and all the water that flows out from the original source
flows back to it again. This itself is not true, since all rivers are
seen to end in the sea except where one flows into another. Not
one of them ends in the earth, but even when one is swallowed
up it comes to the surface again. And those rivers are large
which flow for a long distance through a lowying country, for by
their situation and length they cut off the course of many
others and swallow them up. This is why the Istrus and the Nile
are the greatest of the rivers which flow into our sea. Indeed, so
many rivers fall into them that there is disagreement as to the
sources of them both. All of which is plainly impossible on the
theory, and the more so as it derives the sea from Tartarus.
1076
Enough has been said to prove that this is the natural place of
water and not of the sea, and to explain why sweet water is only
found in rivers, while salt water is stationary, and to show that
the sea is the end rather than the source of water, analogous to
the residual matter of all food, and especially liquid food, in
animal bodies.
We must now explain why the sea is salt, and ask whether it
eternally exists as identically the same body, or whether it did
not exist at all once and some day will exist no longer, but will
dry up as some people think.
Every one admits this, that if the whole world originated the sea
did too; for they make them come into being at the same time.
It follows that if the universe is eternal the same must be true
of the sea. Any one who thinks like Democritus that the sea is
diminishing and will disappear in the end reminds us of Aesop's
tales. His story was that Charybdis had twice sucked in the sea:
the first time she made the mountains visible; the second time
the islands; and when she sucks it in for the last time she will
dry it up entirely. Such a tale is appropriate enough to Aesop in
a rage with the ferryman, but not to serious inquirers. Whatever
made the sea remain at first, whether it was its weight, as some
even of those who hold these views say (for it is easy to see the
cause here), or some other reason - clearly the same thing must
make it persist for ever. They must either deny that the water
raised by the sun will return at all, or, if it does, they must admit
that the sea persists for ever or as long as this process goes on,
and again, that for the same period of time that sweet water
must have been carried up beforehand. So the sea will never dry
1077
up: for before that can happen the water that has gone up
beforehand will return to it: for if you say that this happens
once you must admit its recurrence. If you stop the sun's course
there is no drying agency. If you let it go on it will draw up the
sweet water as we have said whenever it approaches, and let it
descend again when it recedes. This notion about the sea is
derived from the fact that many places are found to be drier
now than they once were. Why this is so we have explained. The
phenomenon is due to temporary excess of rain and not to any
process of becoming in which the universe or its parts are
involved. Some day the opposite will take place and after that
the earth will grow dry once again. We must recognize that this
process always goes on thus in a cycle, for that is more
satisfactory than to suppose a change in the whole world in
order to explain these facts. But we have dwelt longer on this
point than it deserves.
To return to the saltness of the sea: those who create the sea
once for all, or indeed generate it at all, cannot account for its
saltness. It makes no difference whether the sea is the residue
of all the moisture that is about the earth and has been drawn
up by the sun, or whether all the flavour existing in the whole
mass of sweet water is due to the admixture of a certain kind of
earth. Since the total volume of the sea is the same once the
water that evaporated has returned, it follows that it must
either have been salt at first too, or, if not at first, then not now
either. If it was salt from the very beginning, then we want to
know why that was so; and why, if salt water was drawn up
then, that is not the case now.
Again, if it is maintained that an admixture of earth makes the
sea salt (for they say that earth has many flavours and is
washed down by the rivers and so makes the sea salt by its
admixture), it is strange that rivers should not be salt too. How
can the admixture of this earth have such a striking effect in a
1078
great quantity of water and not in each river singly? For the sea,
differing in nothing from rivers but in being salt, is evidently
simply the totality of river water, and the rivers are the vehicle
in which that earth is carried to their common destination.
It is equally absurd to suppose that anything has been
explained by calling the sea 'the sweat of the earth', like
Empedicles. Metaphors are poetical and so that expression of
his may satisfy the requirements of a poem, but as a scientific
theory it is unsatisfactory. Even in the case of the body it is a
question how the sweet liquid drunk becomes salt sweat
whether it is merely by the departure of some element in it
which is sweetest, or by the admixture of something, as when
water is strained through ashes. Actually the saltness seems to
be due to the same cause as in the case of the residual liquid
that gathers in the bladder. That, too, becomes bitter and salt
though the liquid we drink and that contained in our food is
sweet. If then the bitterness is due in these cases (as with the
water strained through lye) to the presence of a certain sort of
stuff that is carried along by the urine (as indeed we actually
find a salt deposit settling in chamber-pots) and is secreted
from the flesh in sweat (as if the departing moisture were
washing the stuff out of the body), then no doubt the admixture
of something earthy with the water is what makes the sea salt.
Now in the body stuff of this kind, viz. the sediment of food, is
due to failure to digest: but how there came to be any such
thing in the earth requires explanation. Besides, how can the
drying and warming of the earth cause the secretion such a
great quantity of water; especially as that must be a mere
fragment of what is left in the earth? Again, waiving the
question of quantity, why does not the earth sweat now when it
happens to be in process of drying? If it did so then, it ought to
do so now. But it does not: on the contrary, when it is dry it
graws moist, but when it is moist it does not secrete anything at
1079
all. How then was it possible for the earth at the beginning
when it was moist to sweat as it grew dry? Indeed, the theory
that maintains that most of the moisture departed and was
drawn up by the sun and that what was left over is the sea is
more reasonable; but for the earth to sweat when it is moist is
impossible.
Since all the attempts to account for the saltness of the sea
seem unsuccessful let us explain it by the help of the principle
we have used already.
Since we recognize two kinds of evaporation, one moist, the
other dry, it is clear that the latter must be recognized as the
source of phenomena like those we are concerned with.
But there is a question which we must discuss first. Does the
sea always remain numerically one and consisting of the same
parts, or is it, too, one in form and volume while its parts are in
continual change, like air and sweet water and fire? All of these
are in a constant state of change, but the form and the quantity
of each of them are fixed, just as they are in the case of a
flowing river or a burning flame. The answer is clear, and there
is no doubt that the same account holds good of all these things
alike. They differ in that some of them change more rapidly or
more slowly than others; and they all are involved in a process
of perishing and becoming which yet affects them all in a
regular course.
This being so we must go on to try to explain why the sea is
salt. There are many facts which make it clear that this taste is
due to the admixture of something. First, in animal bodies what
is least digested, the residue of liquid food, is salt and bitter, as
we said before. All animal excreta are undigested, but especially
that which gathers in the bladder (its extreme lightness proves
this; for everything that is digested is condensed), and also
sweat; in these then is excreted (along with other matter) an
1080
identical substance to which this flavour is due. The case of
things burnt is analogous. What heat fails to assimilate
becomes the excrementary residue in animal bodies, and, in
things burnt, ashes. That is why some people say that it was
burnt earth that made the sea salt. To say that it was burnt
earth is absurd; but to say that it was something like burnt
earth is true. We must suppose that just as in the cases we have
described, so in the world as a whole, everything that grows and
is naturally generated always leaves an undigested residue, like
that of things burnt, consisting of this sort of earth. All the
earthy stuff in the dry exhalation is of this nature, and it is the
dry exhalation which accounts for its great quantity. Now since,
as we have said, the moist and the dry evaporations are mixed,
some quantity of this stuff must always be included in the
clouds and the water that are formed by condensation, and
must redescend to the earth in rain. This process must always
go on with such regularity as the sublunary world admits of.
and it is the answer to the question how the sea comes to be
salt.
It also explains why rain that comes from the south, and the
first rains of autumn, are brackish. The south is the warmest of
winds and it blows from dry and hot regions. Hence it carries
little moist vapour and that is why it is hot. (It makes no
difference even if this is not its true character and it is originally
a cold wind, for it becomes warm on its way by incorporating
with itself a great quantity of dry evaporation from the places it
passes over.) The north wind, on the other hand, comb ing from
moist regions, is full of vapour and therefore cold. It is dry in
our part of the world because it drives the clouds away before it,
but in the south it is rainy; just as the south is a dry wind in
Libya. So the south wind charges the rain that falls with a great
quantity of this stuff. Autumn rain is brackish because the
heaviest water must fall first; so that that which contains the
greatest quantity of this kind of earth descends quickest.
1081
This, too, is why the sea is warm. Everything that has been
exposed to fire contains heat potentially, as we see in the case
of lye and ashes and the dry and liquid excreta of animals.
Indeed those animals which are hottest in the belly have the
hottest excreta.
The action of this cause is continually making the sea more salt,
but some part of its saltness is always being drawn up with the
sweet water. This is less than the sweet water in the same ratio
in which the salt and brackish element in rain is less than the
sweet, and so the saltness of the sea remains constant on the
whole. Salt water when it turns into vapour becomes sweet, and
the vapour does not form salt water when it condenses again.
This I know by experiment. The same thing is true in every case
of the kind: wine and all fluids that evaporate and condense
back into a liquid state become water. They all are water
modified by a certain admixture, the nature of which
determines their flavour. But this subject must be considered on
another more suitable occasion.
For the present let us say this. The sea is there and some of it is
continually being drawn up and becoming sweet; this returns
from above with the rain. But it is now different from what it
was when it was drawn up, and its weight makes it sink below
the sweet water. This process prevents the sea, as it does rivers,
from drying up except from local causes (this must happen to
sea and rivers alike). On the other hand the parts neither of the
earth nor of the sea remain constant but only their whole bulk.
For the same thing is true of the earth as of the sea: some of it is
carried up and some comes down with the rain, and both that
which remains on the surface and that which comes down
again change their situations.
There is more evidence to prove that saltness is due to the
admixture of some substance, besides that which we have
1082
adduced. Make a vessel of wax and put it in the sea, fastening
its mouth in such a way as to prevent any water getting in. Then
the water that percolates through the wax sides of the vessel is
sweet, the earthy stuff, the admixture of which makes the water
salt, being separated off as it were by a filter. It is this stuff
which make salt water heavy (it weighs more than fresh water)
and thick. The difference in consistency is such that ships with
the same cargo very nearly sink in a river when they are quite
fit to navigate in the sea. This circumstance has before now
caused loss to shippers freighting their ships in a river. That the
thicker consistency is due to an admixture of something is
proved by the fact that if you make strong brine by the
admixture of salt, eggs, even when they are full, float in it. It
almost becomes like mud; such a quantity of earthy matter is
there in the sea. The same thing is done in salting fish.
Again if, as is fabled, there is a lake in Palestine, such that if you
bind a man or beast and throw it in it floats and does not sink,
this would bear out what we have said. They say that this lake is
so bitter and salt that no fish live in it and that if you soak
clothes in it and shake them it cleans them. The following facts
all of them support our theory that it is some earthy stuff in the
water which makes it salt. In Chaonia there is a spring of
brackish water that flows into a neighbouring river which is
sweet but contains no fish. The local story is that when Heracles
came from Erytheia driving the oxen and gave the inhabitants
the choice, they chose salt in preference to fish. They get the
salt from the spring. They boil off some of the water and let the
rest stand; when it has cooled and the heat and moisture have
evaporated together it gives them salt, not in lumps but loose
and light like snow. It is weaker than ordinary salt and added
freely gives a sweet taste, and it is not as white as salt generally
is. Another instance of this is found in Umbria. There is a place
there where reeds and rushes grow. They burn some of these,
1083
put the ashes into water and boil it off. When a little water is
left and has cooled it gives a quantity of salt.
Most salt rivers and springs must once have been hot. Then the
original fire in them was extinguished but the earth through
which they percolate preserves the character of lye or ashes.
Springs and rivers with all kinds of flavours are found in many
places. These flavours must in every case be due to the fire that
is or was in them, for if you expose earth to different degrees of
heat it assumes various kinds and shades of flavour. It becomes
full of alum and lye and other things of the kind, and the fresh
water percolates through these and changes its character.
Sometimes it becomes acid as in Sicania, a part of Sicily. There
they get a salt and acid water which they use as vinegar to
season some of their dishes. In the neighbourhood of Lyncus,
too, there is a spring of acid water, and in Scythia a bitter spring.
The water from this makes the whole of the river into which it
flows bitter. These differences are explained by a knowledge of
the particular mixtures that determine different savours. But
these have been explained in another treatise.
We have now given an account of waters and the sea, why they
persist, how they change, what their nature is, and have
explained most of their natural operations and affections.
Let us proceed to the theory of winds. Its basis is a distinction
we have already made. We recognize two kinds of evaporation,
one moist, the other dry. The former is called vapour: for the
other there is no general name but we must call it a sort of
smoke, applying to the whole of it a word that is proper to one
of its forms. The moist cannot exist without the dry nor the dry
1084
without the moist: whenever we speak of either we mean that it
predominates. Now when the sun in its circular course
approaches, it draws up by its heat the moist evaporation: when
it recedes the cold makes the vapour that had been raised
condense back into water which falls and is distributed through
the earth. (This explains why there is more rain in winter and
more by night than by day: though the fact is not recognized
because rain by night is more apt to escape observation than by
day.) But there is a great quantity of fire and heat in the earth,
and the sun not only draws up the moisture that lies on the
surface of it, but warms and dries the earth itself. Consequently,
since there are two kinds of evaporation, as we have said, one
like vapour, the other like smoke, both of them are necessarily
generated. That in which moisture predominates is the source
of rain, as we explained before, while the dry evaporation is the
source and substance of all winds. That things must necessarily
take this course is clear from the resulting phenomena
themselves, for the evaporation that is to produce them must
necessarily differ; and the sun and the warmth in the earth not
only can but must produce these evaporations.
Since the two evaporations are specifically distinct, wind and
rain obviously differ and their substance is not the same, as
those say who maintain that one and the same air when in
motion is wind, but when it condenses again is water. Air, as we
have explained in an earlier book, is made up of these as
constituents. Vapour is moist and cold (for its fluidity is due to
its moistness, and because it derives from water it is naturally
cold, like water that has not been warmed): whereas the smoky
evaporation is hot and dry. Hence each contributes a part, and
air is moist and hot. It is absurd that this air that surrounds us
should become wind when in motion, whatever be the source of
its motion on the contrary the case of winds is like that of
rivers. We do not call water that flows anyhow a river, even if
there is a great quantity of it, but only if the flow comes from a
1085
spring. So too with the winds; a great quantity of air might be
moved by the fall of some large object without flowing from any
source or spring.
The facts bear out our theory. It is because the evaporation
takes place uninterruptedly but differs in degree and quantity
that clouds and winds appear in their natural proportion
according to the season; and it is because there is now a great
excess of the vaporous, now of the dry and smoky exhalation,
that some years are rainy and wet, others windy and dry.
Sometimes there is much drought or rain, and it prevails over a
great and continuous stretch of country. At other times it is
local; the surrounding country often getting seasonable or even
excessive rains while there is drought in a certain part; or,
contrariwise, all the surrounding country gets little or even no
rain while a certain part gets rain in abundance. The reason for
all this is that while the same affection is generally apt to
prevail over a considerable district because adjacent places
(unless there is something special to differentiate them) stand
in the same relation to the sun, yet on occasion the dry
evaporation will prevail in one part and the moist in another, or
conversely. Again the reason for this latter is that each
evaporation goes over to that of the neighbouring district: for
instance, the dry evaporation circulates in its own place while
the moist migrates to the next district or is even driven by
winds to some distant place: or else the moist evaporation
remains and the dry moves away. Just as in the case of the body
when the stomach is dry the lower belly is often in the contrary
state, and when it is dry the stomach is moist and cold, so it
often happens that the evaporations reciprocally take one
another's place and interchange.
Further, after rain wind generally rises in those places where
the rain fell, and when rain has come on the wind ceases. These
are necessary effects of the principles we have explained. After
1086
rain the earth is being dried by its own heat and that from
above and gives off the evaporation which we saw to be the
material cause of. wind. Again, suppose this secretion is present
and wind prevails; the heat is continually being thrown off,
rising to the upper region, and so the wind ceases; then the fall
in temperature makes vapour form and condense into water.
Water also forms and cools the dry evaporation when the
clouds are driven together and the cold concentrated in them.
These are the causes that make wind cease on the advent of
rain, and rain fall on the cessation of wind.
The cause of the predominance of winds from the north and
from the south is the same. (Most winds, as a matter of fact, are
north winds or south winds.) These are the only regions which
the sun does not visit: it approaches them and recedes from
them, but its course is always over the west and the east. Hence
clouds collect on either side, and when the sun approaches it
provokes the moist evaporation, and when it recedes to the
opposite side there are storms and rain. So summer and winter
are due to the sun's motion to and from the solstices, and water
ascends and falls again for the same reason. Now since most
rain falls in those regions towards which and from which the
sun turns and these are the north and the south, and since
most evaporation must take place where there is the greatest
rainfall, just as green wood gives most smoke, and since this
evaporation is wind, it is natural that the most and most
important winds should come from these quarters. (The winds
from the north are called Boreae, those from the south Noti.)
The course of winds is oblique: for though the evaporation rises
straight up from the earth, they blow round it because all the
surrounding air follows the motion of the heavens. Hence the
question might be asked whether winds originate from above or
from below. The motion comes from above: before we feel the
wind blowing the air betrays its presence if there are clouds or a
1087
mist, for their motion shows that the wind has begun to blow
before it has actually reached us; and this implies that the
source of winds is above. But since wind is defined as 'a
quantity of dry evaporation from the earth moving round the
earth', it is clear that while the origin of the motion is from
above, the matter and the generation of wind come from below.
The oblique movement of the rising evaporation is caused from
above: for the motion of the heavens determines the processes
that are at a distance from the earth, and the motion from
below is vertical and every cause is more active where it is
nearest to the effect; but in its generation and origin wind
plainly derives from the earth.
The facts bear out the view that winds are formed by the
gradual union of many evaporations just as rivers derive their
sources from the water that oozes from the earth. Every wind is
weakest in the spot from which it blows; as they proceed and
leave their source at a distance they gather strength. Thus the
winter in the north is windless and calm: that is, in the north
itself; but, the breeze that blows from there so gently as to
escape observation becomes a great wind as it passes on.
We have explained the nature and origin of wind, the
occurrence of drought and rains, the reason why rain stops
wind and wind rises after rain, the prevalence of north and
south winds and also why wind moves in the way it does.
The sun both checks the formation of winds and stimulates it.
When the evaporation is small in amount and faint the sun
wastes it and dissipates by its greater heat the lesser heat
contained in the evaporation. It also dries up the earth, the
1088
source of the evaporation, before the latter has appeared in
bulk: just as, when you throw a little fuel into a great fire, it is
often burnt up before giving off any smoke. In these ways the
sun checks winds and prevents them from rising at all: it checks
them by wasting the evaporation, and prevents their rising by
drying up the earth quickly. Hence calm is very apt to prevail
about the rising of Orion and lasts until the coming of the
Etesiae and their 'forerunners'.
Calm is due to two causes. Either cold quenches the
evaporation, for instance a sharp frost: or excessive heat wastes
it. In the intermediate periods, too, the causes are generally
either that the evaporation has not had time to develop or that
it has passed away and there is none as yet to replace it.
Both the setting and the rising of Orion are considered to be
treacherous and stormy, because they place at a change of
season (namely of summer or winter; and because the size of
the constellation makes its rise last over many days) and a state
of change is always indefinite and therefore liable to
disturbance.
The Etesiae blow after the summer solstice and the rising of the
dog-star: not at the time when the sun is closest nor when it is
distant; and they blow by day and cease at night. The reason is
that when the sun is near it dries up the earth before
evaporation has taken place, but when it has receded a little its
heat and the evaporation are present in the right proportion; so
the ice melts and the earth, dried by its own heat and that of
the sun, smokes and vapours. They abate at night because the
cold pf the nights checks the melting of the ice. What is frozen
gives off no evaporation, nor does that which contains no
dryness at all: it is only where something dry contains moisture
that it gives off evaporation under the influence of heat.
1089
The question is sometimes asked: why do the north winds
which we call the Etesiae blow continuously after the summer
solstice, when there are no corresponding south winds after the
winter solstice? The facts are reasonable enough: for the so-
called 'white south winds' do blow at the corresponding season,
though they are not equally continuous and so escape
observation and give rise to this inquiry. The reason for this is
that the north wind I from the arctic regions which are full of
water and snow. The sun thaws them and so the Etesiae blow:
after rather than at the summer solstice. (For the greatest heat
is developed not when the sun is nearest to the north, but when
its heat has been felt for a considerable period and it has not yet
receded far. The 'bird winds' blow in the same way after the
winter solstice. They, too, are weak Etesiae, but they blow less
and later than the Etesiae. They begin to blow only on the
seventieth day because the sun is distant and therefore weaker.
They do not blow so continuously because only things on the
surface of the earth and offering little resistance evaporate
then, the thoroughly frozen parts requiring greater heat to melt
them. So they blow intermittently till the true Etesiae come on
again at the summer solstice: for from that time onwards the
wind tends to blow continuously.) But the south wind blows
from the tropic of Cancer and not from the antarctic region.
There are two inhabitable sections of the earth: one near our
upper, or nothern pole, the other near the other or southern
pole; and their shape is like that of a tambourine. If you draw
lines from the centre of the earth they cut out a drum-shaped
figure. The lines form two cones; the base of the one is the
tropic, of the other the ever visible circle, their vertex is at the
centre of the earth. Two other cones towards the south pole give
corresponding segments of the earth. These sections alone are
habitable. Beyond the tropics no one can live: for there the
shade would not fall to the north, whereas the earth is known
to be uninhabitable before the sun is in the zenith or the shade
1090
is thrown to the south: and the regions below the Bear are
uninhabitable because of the cold.
(The Crown, too, moves over this region: for it is in the zenith
when it is on our meridian.)
So we see that the way in which they now describe the
geography of the earth is ridiculous. They depict the inhabited
earth as round, but both ascertained facts and general
considerations show this to be impossible. If we reflect we see
that the inhabited region is limited in breadth, while the
climate admits of its extending all round the earth. For we meet
with no excessive heat or cold in the direction of its length but
only in that of its breadth; so that there is nothing to prevent
our travelling round the earth unless the extent of the sea
presents an obstacle anywhere. The records of journeys by sea
and land bear this out. They make the length far greater than
the breadth. If we compute these voyages and journeys the
distance from the Pillars of Heracles to India exceeds that from
Aethiopia to Maeotis and the northernmost Scythians by a ratio
of more than 5 to 3, as far as such matters admit of accurate
statement. Yet we know the whole breadth of the region we
dwell in up to the uninhabited parts: in one direction no one
lives because of the cold, in the other because of the heat.
But it is the sea which divides as it seems the parts beyond
India from those beyond the Pillars of Heracles and prevents the
earth from being inhabited all round.
Now since there must be a region bearing the same relation to
the southern pole as the place we live in bears to our pole, it
will clearly correspond in the ordering of its winds as well as in
other things. So just as we have a north wind here, they must
have a corresponding wind from the antarctic. This wind cannot
reach us since our own north wind is like a land breeze and
does not even reach the limits of the region we live in. The
1091
prevalence of north winds here is due to our lying near the
north. Yet even here they give out and fail to penetrate far: in
the southern sea beyond Libya east and west winds are always
blowing alternately, like north and south winds with us. So it is
clear that the south wind is not the wind that blows from the
south pole. It is neither that nor the wind from the winter
tropic. For symmetry would require another wind blowing from
the summer tropic, which there is not, since we know that only
one wind blows from that quarter. So the south wind clearly
blows from the torrid region. Now the sun is so near to that
region that it has no water, or snow which might melt and
cause Etesiae. But because that place is far more extensive and
open the south wind is greater and stronger and warmer than
the north and penetrates farther to the north than the north
wind does to the south.
The origin of these winds and their relation to one another has
now been explained.
Let us now explain the position of the winds, their oppositions,
which can blow simultaneously with which, and which cannot,
their names and number, and any other of their affections that
have not been treated in the 'particular questions'. What we say
about their position must be followed with the help of the
figure. For clearness' sake we have drawn the circle of the
horizon, which is round, but it represents the zone in which we
live; for that can be divided in the same way. Let us also begin
by laying down that those things are locally contrary which are
locally most distant from one another, just as things specifically
most remote from one another are specific contraries. Now
1092
things that face one another from opposite ends of a diameter
are locally most distant from one another. (See diagram.)
Let A be the point where the sun sets at the equinox and B, the
point opposite, the place where it rises at the equinox. Let there
be another diameter cutting this at right angles, and let the
point H on it be the north and its diametrical opposite the
south. Let Z be the rising of the sun at the summer solstice and
E its setting at the summer solstice; D its rising at the winter
solstice, and G its setting at the winter solstice. Draw a diameter
from Z to G from D to E. Then since those things are locally
contrary which are most distant from one another in space, and
points diametrically opposite are most distant from one
another, those winds must necessarily be contrary to one
another that blow from opposite ends of a diameter.
The names of the winds according to their position are these.
Zephyrus is the wind that blows from A, this being the point
where the sun sets at the equinox. Its contrary is Apeliotes
blowing from B the point where the sun rises at the equinox.
The wind blowing from H, the north, is the true north wind,
called Aparctias: while Notus blowing from is its contrary; for
this point is the south and is contrary to H, being
diametrically opposite to it. Caecias blows from Z, where the
sun rises at the summer solstice. Its contrary is not the wind
blowing from E but Lips blowing from G. For Lips blows from the
point where the sun sets at the winter solstice and is
diametrically opposite to Caecias: so it is its contrary. Eurus
blows from D, coming from the point where the sun rises at the
winter solstice. It borders on Notus, and so we often find that
people speak of 'Euro-Noti'. Its contrary is not Lips blowing from
G but the wind that blows from E which some call Argestes,
some Olympias, and some Sciron. This blows from the point
where the sun sets at the summer solstice, and is the only wind
1093
that is diametrically opposite to Eurus. These are the winds that
are diametrically opposite to one another and their contraries.
There are other winds which have no contraries. The wind they
call Thrascias, which lies between Argestes and Aparctias, blows
from I; and the wind called Meses, which lies between Caecias
and Aparctias, from K. (The line IK nearly coincides with the
ever visible circle, but not quite.) These winds have no
contraries. Meses has not, or else there would be a wind blowing
from the point M which is diametrically opposite. Thrascias
corresponding to the point I has not, for then there would be a
wind blowing from N, the point which is diametrically opposite.
(But perhaps a local wind which the inhabitants of those parts
call Phoenicias blows from that point.)
These are the most important and definite winds and these
their places.
There are more winds from the north than from the south. The
reason for this is that the region in which we live lies nearer to
the north. Also, much more water and snow is pushed aside
into this quarter because the other lies under the sun and its
course. When this thaws and soaks into the earth and is
exposed to the heat of the sun and the earth it necessarily
causes evaporation to rise in greater quantities and over a
greater space.
Of the winds we have described Aparctias is the north wind in
the strict sense. Thrascias and Meses are north winds too.
(Caecias is half north and half east.) South are that which blows
from due south and Lips. East, the wind from the rising of the
sun at the equinox and Eurus. Phoenicias is half south and half
east. West, the wind from the true west and that called Argestes.
More generally these winds are classified as northerly or
southerly. The west winds are counted as northerly, for they
blow from the place of sunset and are therefore colder; the east
1094
winds as southerly, for they are warmer because they blow from
the place of sunrise. So the distinction of cold and hot or warm
is the basis for the division of the winds into northerly and
southerly. East winds are warmer than west winds because the
sun shines on the east longer, whereas it leaves the west sooner
and reaches it later.
Since this is the distribution of the winds it is clear that
contrary winds cannot blow simultaneously. They are
diametrically opposite to one another and one of the two must
be overpowered and cease. Winds that are not diametrically
opposite to one another may blow simultaneously: for instance
the winds from Z and from D. Hence it sometimes happens that
both of them, though different winds and blowing from
different quarters, are favourable to sailors making for the same
point.
Contrary winds commonly blow at opposite seasons. Thus
Caecias and in general the winds north of the summer solstice
blow about the time of the spring equinox, but about the
autumn equinox Lips; and Zephyrus about the summer solstice,
but about the winter solstice Eurus.
Aparctias, Thrascias, and Argestes are the winds that fall on
others most and stop them. Their source is so close to us that
they are greater and stronger than other winds. They bring fair
weather most of all winds for the same reason, for, blowing as
they do, from close at hand, they overpower the other winds
and stop them; they also blow away the clouds that are forming
and leave a clear sky - unless they happen to be very cold. Then
they do not bring fair weather, but being colder than they are
strong they condense the clouds before driving them away.
Caecias does not bring fair weather because it returns upon
itself. Hence the saying: 'Bringing it on himself as Caecias does
clouds.'
1095
When they cease, winds are succeeded by their neighbours in
the direction of the movement of the sun. For an effect is most
apt to be produced in the neighbourhood of its cause, and the
cause of winds moves with the sun.
Contrary winds have either the same or contrary effects. Thus
Lips and Caecias, sometimes called Hellespontias, are both
rainy gestes and Eurus are dry: the latter being dry at first and
rainy afterwards. Meses and Aparctias are coldest and bring
most snow. Aparctias, Thrascias, and Argestes bring hail. Notus,
Zephyrus, and Eurus are hot. Caecias covers the sky with heavy
clouds, Lips with lighter ones. Caecias does this because it
returns upon itself and combines the qualities of Boreas and
Eurus. By being cold it condenses and gathers the vaporous air,
and because it is easterly it carries with it and drives before it a
great quantity of such matter. Aparctias, Thrascias, and Argestes
bring fair weather for the reason we have explained before.
These winds and Meses are most commonly accompanied by
lightning. They are cold because they blow from the north, and
lightning is due to cold, being ejected when the clouds contract.
Some of these same bring hail with them for the same reason;
namely, that they cause a sudden condensation.
Hurricanes are commonest in autumn, and next in spring:
Aparctias, Thrascias, and Argestes give rise to them most. This is
because hurricanes are generally formed when some winds are
blowing and others fall on them; and these are the winds which
are most apt to fall on others that are blowing; the reason for
which, too, we have explained before.
The Etesiae veer round: they begin from the north, and become
for dwellers in the west Thrasciae, Argestae, and Zephyrus (for
Zephyrus belongs to the north). For dwellers in the east they
veer round as far as Apeliotes.
1096
So much for the winds, their origin and nature and the
properties common to them all or peculiar to each.
We must go on to discuss earthquakes next, for their cause is
akin to our last subject.
The theories that have been put forward up to the present date
are three, and their authors three men, Anaxagoras of
Clazomenae, and before him Anaximenes of Miletus, and later
Democritus of Abdera.
Anaxagoras says that the ether, which naturally moves
upwards, is caught in hollows below the earth and so shakes it,
for though the earth is really all of it equally porous, its surface
is clogged up by rain. This implies that part of the whole sphere
is 'above' and part 'below': 'above' being the part on which we
live, 'below' the other.
This theory is perhaps too primitive to require refutation. It is
absurd to think of up and down otherwise than as meaning that
heavy bodies move to the earth from every quarter, and light
ones, such as fire, away from it; especially as we see that, as far
as our knowledge of the earth goes, the horizon always changes
with a change in our position, which proves that the earth is
convex and spherical. It is absurd, too, to maintain that the
earth rests on the air because of its size, and then to say that
impact upwards from below shakes it right through. Besides he
gives no account of the circumstances attendant on
earthquakes: for not every country or every season is subject to
them.
1097
Democritus says that the earth is full of water and that when a
quantity of rain-water is added to this an earthquake is the
result. The hollows in the earth being unable to admit the
excess of water it forces its way in and so causes an earthquake.
Or again, the earth as it dries draws the water from the fuller to
the emptier parts, and the inrush of the water as it changes its
place causes the earthquake.
Anaximenes says that the earth breaks up when it grows wet or
dry, and earthquakes are due to the fall of these masses as they
break away. Hence earthquakes take place in times of drought
and again of heavy rain, since, as we have explained, the earth
grows dry in time of drought and breaks up, whereas the rain
makes it sodden and destroys its cohesion.
But if this were the case the earth ought to be found to be
sinking in many places. Again, why do earthquakes frequently
occur in places which are not excessively subject to drought or
rain, as they ought to be on the theory? Besides, on this view,
earthquakes ought always to be getting fewer, and should come
to an end entirely some day: the notion of contraction by
packing together implies this. So this is impossible the theory
must be impossible too.
8
We have already shown that wet and dry must both give rise to
an evaporation: earthquakes are a necessary consequence of
this fact. The earth is essentially dry, but rain fills it with
moisture. Then the sun and its own fire warm it and give rise to
a quantity of wind both outside and inside it. This wind
sometimes flows outwards in a single body, sometimes inwards,
and sometimes it is divided. All these are necessary laws. Next
1098
we must find out what body has the greatest motive force. This
will certainly be the body that naturally moves farthest and is
most violent. Now that which has the most rapid motion is
necessarily the most violent; for its swiftness gives its impact
the greatest force. Again, the rarest body, that which can most
readily pass through every other body, is that which naturally
moves farthest. Wind satisfies these conditions in the highest
degree (fire only becomes flame and moves rapidly when wind
accompanies it): so that not water nor earth is the cause of
earthquakes but wind - that is, the inrush of the external
evaporation into the earth.
Hence, since the evaporation generally follows in a continuous
body in the direction in which it first started, and either all of it
flows inwards or all outwards, most earthquakes and the
greatest are accompanied by calm. It is true that some take
place when a wind is blowing, but this presents no difficulty. We
sometimes find several winds blowing simultaneously. If one of
these enters the earth we get an earthquake attended by wind.
Only these earthquakes are less severe because their source and
cause is divided.
Again, most earthquakes and the severest occur at night or, if by
day, about noon, that being generally the calmest part of the
day. For when the sun exerts its full power (as it does about
noon) it shuts the evaporation into the earth. Night, too, is
calmer than day. The absence of the sun makes the evaporation
return into the earth like a sort of ebb tide, corresponding to the
outward flow; especially towards dawn, for the winds, as a rule,
begin to blow then, and if their source changes about like the
Euripus and flows inwards the quantity of wind in the earth is
greater and a more violent earthquake results.
The severest earthquakes take place where the sea is full of
currents or the earth spongy and cavernous: so they occur near
1099
the Hellespont and in Achaea and Sicily, and those parts of
Euboea which correspond to our description - where the sea is
supposed to flow in channels below the earth. The hot springs,
too, near Aedepsus are due to a cause of this kind. It is the
confined character of these places that makes them so liable to
earthquakes. A great and therefore violent wind is developed,
which would naturally blow away from the earth: but the
onrush of the sea in a great mass thrusts it back into the earth.
The countries that are spongy below the surface are exposed to
earthquakes because they have room for so much wind.
For the same reason earthquakes usually take place in spring
and autumn and in times of wet and of drought - because these
are the windiest seasons. Summer with its heat and winter with
its frost cause calm: winter is too cold, summer too dry for
winds to form. In time of drought the air is full of wind; drought
is just the predominance of the dry over the moist evaporation.
Again, excessive rain causes more of the evaporation to form in
the earth. Then this secretion is shut up in a narrow compass
and forced into a smaller space by the water that fills the
cavities. Thus a great wind is compressed into a smaller space
and so gets the upper hand, and then breaks out and beats
against the earth and shakes it violently.
We must suppose the action of the wind in the earth to be
analogous to the tremors and throbbings caused in us by the
force of the wind contained in our bodies. Thus some
earthquakes are a sort of tremor, others a sort of throbbing.
Again, we must think of an earthquake as something like the
tremor that often runs through the body after passing water as
the wind returns inwards from without in one volume.
The force wind can have may be gathered not only from what
happens in the air (where one might suppose that it owed its
power to produce such effects to its volume), but also from what
1100
is observed in animal bodies. Tetanus and spasms are motions
of wind, and their force is such that the united efforts of many
men do not succeed in overcoming the movements of the
patients. We must suppose, then (to compare great things with
small), that what happens in the earth is just like that. Our
theory has been verified by actual observation in many places. It
has been known to happen that an earthquake has continued
until the wind that caused it burst through the earth into the air
and appeared visibly like a hurricane. This happened lately near
Heracleia in Pontus and some time past at the island Hiera, one
of the group called the Aeolian islands. Here a portion of the
earth swelled up and a lump like a mound rose with a noise:
finally it burst, and a great wind came out of it and threw up
live cinders and ashes which buried the neighbouring town of
Lipara and reached some of the towns in Italy. The spot where
this eruption occurred is still to be seen.
Indeed, this must be recognized as the cause of the fire that is
generated in the earth: the air is first broken up in small
particles and then the wind is beaten about and so catches fire.
A phenomenon in these islands affords further evidence of the
fact that winds move below the surface of the earth. When a
south wind is going to blow there is a premonitory indication: a
sound is heard in the places from which the eruptions issue.
This is because the sea is being pushed on from a distance and
its advance thrusts back into the earth the wind that was
issuing from it. The reason why there is a noise and no
earthquake is that the underground spaces are so extensive in
proportion to the quantity of the air that is being driven on that
the wind slips away into the void beyond.
Again, our theory is supported by the facts that the sun appears
hazy and is darkened in the absence of clouds, and that there is
sometimes calm and sharp frost before earthquakes at sunrise.
1101
The sun is necessarily obscured and darkened when the
evaporation which dissolves and rarefies the air begins to
withdraw into the earth. The calm, too, and the cold towards
sunrise and dawn follow from the theory. The calm we have
already explained. There must as a rule be calm because the
wind flows back into the earth: again, it must be most marked
before the more violent earthquakes, for when the wind is not
part outside earth, part inside, but moves in a single body, its
strength must be greater. The cold comes because the
evaporation which is naturally and essentially hot enters the
earth. (Wind is not recognized to be hot, because it sets the air
in motion, and that is full of a quantity of cold vapour. It is the
same with the breath we blow from our mouth: close by it is
warm, as it is when we breathe out through the mouth, but
there is so little of it that it is scarcely noticed, whereas at a
distance it is cold for the same reason as wind.) Well, when this
evaporation disappears into the earth the vaporous exhalation
concentrates and causes cold in any place in which this
disappearance occurs.
A sign which sometimes precedes earthquakes can be
explained in the same way. Either by day or a little after sunset,
in fine weather, a little, light, long-drawn cloud is seen, like a
long very straight line. This is because the wind is leaving the
air and dying down. Something analogous to this happens on
the sea-shore. When the sea breaks in great waves the marks
left on the sand are very thick and crooked, but when the sea is
calm they are slight and straight (because the secretion is
small). As the sea is to the shore so the wind is to the cloudy air;
so, when the wind drops, this very straight and thin cloud is
left, a sort of wave-mark in the air.
An earthquake sometimes coincides with an eclipse of the
moon for the same reason. When the earth is on the point of
being interposed, but the light and heat of the sun has not quite
1102
vanished from the air but is dying away, the wind which causes
the earthquake before the eclipse, turns off into the earth, and
calm ensues. For there often are winds before eclipses: at
nightfall if the eclipse is at midnight, and at midnight if the
eclipse is at dawn. They are caused by the lessening of the
warmth from the moon when its sphere approaches the point
at which the eclipse is going to take place. So the influence
which restrained and quieted the air weakens and the air
moves again and a wind rises, and does so later, the later the
eclipse.
A severe earthquake does not stop at once or after a single
shock, but first the shocks go on, often for about forty days;
after that, for one or even two years it gives premonitory
indications in the same place. The severity of the earthquake is
determined by the quantity of wind and the shape of the
passages through which it flows. Where it is beaten back and
cannot easily find its way out the shocks are most violent, and
there it must remain in a cramped space like water that cannot
escape. Any throbbing in the body does not cease suddenly or
quickly, but by degrees according as the affection passes off. So
here the agency which created the evaporation and gave it an
impulse to motion clearly does not at once exhaust the whole of
the material from which it forms the wind which we call an
earthquake. So until the rest of this is exhausted the shocks
must continue, though more gently, and they must go on until
there is too little of the evaporation left to have any perceptible
effect on the earth at all.
Subterranean noises, too, are due to the wind; sometimes they
portend earthquakes but sometimes they have been heard
without any earthquake following. Just as the air gives off
various sounds when it is struck, so it does when it strikes other
things; for striking involves being struck and so the two cases
are the same. The sound precedes the shock because sound is
1103
thinner and passes through things more readily than wind. But
when the wind is too weak by reason of thinness to cause an
earthquake the absence of a shock is due to its filtering through
readily, though by striking hard and hollow masses of different
shapes it makes various noises, so that the earth sometimes
seems to 'bellow' as the portentmongers say.
Water has been known to burst out during an earthquake. But
that does not make water the cause of the earthquake. The
wind is the efficient cause whether it drives the water along the
surface or up from below: just as winds are the causes of waves
and not waves of winds. Else we might as well say that earth
was the cause; for it is upset in an earthquake, just like water
(for effusion is a form of upsetting). No, earth and water are
material causes (being patients, not agents): the true cause is
the wind.
The combination of a tidal wave with an earthquake is due to
the presence of contrary winds. It occurs when the wind which
is shaking the earth does not entirely succeed in driving off the
sea which another wind is bringing on, but pushes it back and
heaps it up in a great mass in one place. Given this situation it
follows that when this wind gives way the whole body of the
sea, driven on by the other wind, will burst out and overwhelm
the land. This is what happened in Achaea. There a south wind
was blowing, but outside a north wind; then there was a calm
and the wind entered the earth, and then the tidal wave came
on and simultaneously there was an earthquake. This was the
more violent as the sea allowed no exit to the wind that had
entered the earth, but shut it in. So in their struggle with one
another the wind caused the earthquake, and the wave by its
settling down the inundation.
Earthquakes are local and often affect a small district only;
whereas winds are not local. Such phenomena are local when
1104
the evaporations at a given place are joined by those from the
next and unite; this, as we explained, is what happens when
there is drought or excessive rain locally. Now earthquakes do
come about in this way but winds do not. For earthquakes,
rains, and droughts have their source and origin inside the
earth, so that the sun is not equally able to direct all the
evaporations in one direction. But on the evaporations in the air
the sun has more influence so that, when once they have been
given an impulse by its motion, which is determined by its
various positions, they flow in one direction.
When the wind is present in sufficient quantity there is an
earthquake. The shocks are horizontal like a tremor; except
occasionally, in a few places, where they act vertically, upwards
from below, like a throbbing. It is the vertical direction which
makes this kind of earthquake so rare. The motive force does
not easily accumulate in great quantity in the position required,
since the surface of the earth secretes far more of the
evaporation than its depths. Wherever an earthquake of this
kind does occur a quantity of stones comes to the surface of the
earth (as when you throw up things in a winnowing fan), as we
see from Sipylus and the Phlegraean plain and the district in
Liguria, which were devastated by this kind of earthquake.
Islands in the middle of the sea are less exposed to earthquakes
than those near land. First, the volume of the sea cools the
evaporations and overpowers them by its weight and so crushes
them. Then, currents and not shocks are produced in the sea by
the action of the winds. Again, it is so extensive that
evaporations do not collect in it but issue from it, and these
draw the evaporations from the earth after them. Islands near
the continent really form part of it: the intervening sea is not
enough to make any difference; but those in the open sea can
only be shaken if the whole of the sea that surrounds them is
shaken too.
1105
We have now explained earthquakes, their nature and cause,
and the most important of the circumstances attendant on
their appearance.
Let us go on to explain lightning and thunder, and further
whirlwind, fire-wind, and thunderbolts: for the cause of them
all is the same.
As we have said, there are two kinds of exhalation, moist and
dry, and the atmosphere contains them both potentially. It, as
we have said before, condenses into cloud, and the density of
the clouds is highest at their upper limit. (For they must be
denser and colder on the side where the heat escapes to the
upper region and leaves them. This explains why hurricanes
and thunderbolts and all analogous phenomena move
downwards in spite of the fact that everything hot has a natural
tendency upwards. Just as the pips that we squeeze between
our fingers are heavy but often jump upwards: so these things
are necessarily squeezed out away from the densest part of the
cloud.) Now the heat that escapes disperses to the up region.
But if any of the dry exhalation is caught in the process as the
air cools, it is squeezed out as the clouds contract, and collides
in its rapid course with the neighbouring clouds, and the sound
of this collision is what we call thunder. This collision is
analogous, to compare small with great, to the sound we hear in
a flame which men call the laughter or the threat of Hephaestus
or of Hestia. This occurs when the wood dries and cracks and
the exhalation rushes on the flame in a body. So in the clouds,
the exhalation is projected and its impact on dense clouds
causes thunder: the variety of the sound is due to the
1106
irregularity of the clouds and the hollows that intervene where
their density is interrupted. This then, is thunder, and this its
cause.
It usually happens that the exhalation that is ejected is
inflamed and burns with a thin and faint fire: this is what we
call lightning, where we see as it were the exhalation coloured
in the act of its ejection. It comes into existence after the
collision and the thunder, though we see it earlier because sight
is quicker than hearing. The rowing of triremes illustrates this:
the oars are going back again before the sound of their striking
the water reaches us.
However, there are some who maintain that there is actually
fire in the clouds. Empedocles says that it consists of some of
the sun's rays which are intercepted: Anaxagoras that it is part
of the upper ether (which he calls fire) which has descended
from above. Lightning, then, is the gleam of this fire, and
thunder the hissing noise of its extinction in the cloud.
But this involves the view that lightning actually is prior to
thunder and does not merely appear to be so. Again, this
intercepting of the fire is impossible on either theory, but
especially it is said to be drawn down from the upper ether.
Some reason ought to be given why that which naturally
ascends should descend, and why it should not always do so,
but only when it is cloudy. When the sky is clear there is no
lightning: to say that there is, is altogether wanton.
The view that the heat of the sun's rays intercepted in the
clouds is the cause of these phenomena is equally unattractive:
this, too, is a most careless explanation. Thunder, lightning, and
the rest must have a separate and determinate cause assigned
to them on which they ensue. But this theory does nothing of
the sort. It is like supposing that water, snow, and hail existed
all along and were produced when the time came and not
1107
generated at all, as if the atmosphere brought each to hand out
of its stock from time to time. They are concretions in the same
way as thunder and lightning are discretions, so that if it is true
of either that they are not generated but pre-exist, the same
must be true of the other. Again, how can any distinction be
made about the intercepting between this case and that of
interception in denser substances such as water? Water, too, is
heated by the sun and by fire: yet when it contracts again and
grows cold and freezes no such ejection as they describe occurs,
though it ought on their the. to take place on a proportionate
scale. Boiling is due to the exhalation generated by fire: but it is
impossible for it to exist in the water beforehand; and besides
they call the noise 'hissing', not 'boiling'. But hissing is really
boiling on a small scale: for when that which is brought into
contact with moisture and is in process of being extinguished
gets the better of it, then it boils and makes the noise in
question. Some - Cleidemus is one of them - say that lightning
is nothing objective but merely an appearance. They compare it
to what happens when you strike the sea with a rod by night
and the water is seen to shine. They say that the moisture in the
cloud is beaten about in the same way, and that lightning is the
appearance of brightness that ensues.
This theory is due to ignorance of the theory of reflection,
which is the real cause of that phenomenon. The water appears
to shine when struck because our sight is reflected from it to
some bright object: hence the phenomenon occurs mainly by
night: the appearance is not seen by day because the daylight is
too in, tense and obscures it.
These are the theories of others about thunder and lightning:
some maintaining that lightning is a reflection, the others that
lightning is fire shining through the cloud and thunder its
extinction, the fire not being generated in each case but existing
beforehand. We say that the same stuff is wind on the earth,
1108
and earthquake under it, and in the clouds thunder. The
essential constituent of all these phenomena is the same:
namely, the dry exhalation. If it flows in one direction it is wind,
in another it causes earthquakes; in the clouds, when they are
in a process of change and contract and condense into water, it
is ejected and causes thunder and lightning and the other
phenomena of the same nature.
So much for thunder and lightning.
Book III
Let us explain the remaining operations of this secretion in the
same way as we have treated the rest. When this exhalation is
secreted in small and scattered quantities and frequently, and is
transitory, and its constitution rare, it gives rise to thunder and
lightning. But if it is secreted in a body and is denser, that is,
less rare, we get a hurricane. The fact that it issues in body
explains its violence: it is due to the rapidity of the secretion.
Now when this secretion issues in a great and continuous
current the result corresponds to what we get when the
opposite development takes place and rain and a quantity of
water are produced. As far as the matter from which they are
developed goes both sets of phenomena are the same. As soon
as a stimulus to the development of either potentiality appears,
that of which there is the greater quantity present in the cloud
1109
is at once secreted from it, and there results either rain, or, if the
other exhalation prevails, a hurricane.
Sometimes the exhalation in the cloud, when it is being
secreted, collides with another under circumstances like those
found when a wind is forced from an open into a narrow space
in a gateway or a road. It often happens in such cases that the
first part of the moving body is deflected because of the
resistance due either to the narrowness or to a contrary current,
and so the wind forms a circle and eddy. It is prevented from
advancing in a straight line: at the same time it is pushed on
from behind; so it is compelled to move sideways in the
direction of least resistance. The same thing happens to the
next part, and the next, and so on, till the series becomes one,
that is, till a circle is formed: for if a figure is described by a
single motion that figure must itself be one. This is how eddies
are generated on the earth, and the case is the same in the
clouds as far as the beginning of them goes. Only here (as in the
case of the hurricane which shakes off the cloud without
cessation and becomes a continuous wind) the cloud follows
the exhalation unbroken, and the exhalation, failing to break
away from the cloud because of its density, first moves in a
circle for the reason given and then descends, because clouds
are always densest on the side where the heat escapes. This
phenomenon is called a whirlwind when it is colourless; and it
is a sort of undigested hurricane. There is never a whirlwind
when the weather is northerly, nor a hurricane when there is
snow. The reason is that all these phenomena are 'wind', and
wind is a dry and warm evaporation. Now frost and cold prevail
over this principle and quench it at its birth: that they do prevail
is clear or there could be no snow or northerly rain, since these
occur when the cold does prevail.
So the whirlwind originates in the failure of an incipient
hurricane to escape from its cloud: it is due to the resistance
1110
which generates the eddy, and it consists in the spiral which
descends to the earth and drags with it the cloud which it
cannot shake off. It moves things by its wind in the direction in
which it is blowing in a straight line, and whirls round by its
circular motion and forcibly snatches up whatever it meets.
When the cloud burns as it is drawn downwards, that is, when
the exhalation becomes rarer, it is called a fire-wind, for its fire
colours the neighbouring air and inflames it.
When there is a great quantity of exhalation and it is rare and is
squeezed out in the cloud itself we get a thunderbolt. If the
exhalation is exceedingly rare this rareness prevents the
thunderbolt from scorching and the poets call it 'bright': if the
rareness is less it does scorch and they call it 'smoky'. The
former moves rapidly because of its rareness, and because of its
rapidity passes through an object before setting fire to it or
dwelling on it so as to blacken it: the slower one does blacken
the object, but passes through it before it can actually burn it.
Further, resisting substances are affected, unresisting ones are
not. For instance, it has happened that the bronze of a shield
has been melted while the woodwork remained intact because
its texture was so loose that the exhalation filtered through
without affecting it. So it has passed through clothes, too,
without burning them, and has merely reduced them to shreds.
Such evidence is enough by itself to show that the exhalation is
at work in all these cases, but we sometimes get direct evidence
as well, as in the case of the conflagration of the temple at
Ephesus which we lately witnessed. There independent sheets
of flame left the main fire and were carried bodily in many
directions. Now that smoke is exhalation and that smoke burns
is certain, and has been stated in another place before; but
when the flame moves bodily, then we have ocular proof that
smoke is exhalation. On this occasion what is seen in small
1111
fires appeared on a much larger scale because of the quantity of
matter that was burning. The beams which were the source of
the exhalation split, and a quantity of it rushed in a body from
the place from which it issued forth and went up in a blaze: so
that the flame was actually seen moving through the air away
and falling on the houses. For we must recognize that
exhalation accompanies and precedes thunderbolts though it is
colourless and so invisible. Hence, where the thunderbolt is
going to strike, the object moves before it is struck, showing that
the exhalation leads the way and falls on the object first.
Thunder, too, splits things not by its noise but because the
exhalation that strikes the object and that which makes the
noise are ejected simultaneously. This exhalation splits the
thing it strikes but does not scorch it at all.
We have now explained thunder and lightning and hurricane,
and further firewinds, whirlwinds, and thunderbolts, and
shown that they are all of them forms of the same thing and
wherein they all differ.
Let us now explain the nature and cause of halo, rainbow, mock
suns, and rods, since the same account applies to them all.
We must first describe the phenomena and the circumstances
in which each of them occurs. The halo often appears as a
complete circle: it is seen round the sun and the moon and
bright stars, by night as well as by day, and at midday or in the
afternoon, more rarely about sunrise or sunset.
The rainbow never forms a full circle, nor any segment greater
than a semicircle. At sunset and sunrise the circle is smallest
1112
and the segment largest: as the sun rises higher the circle is
larger and the segment smaller. After the autumn equinox in
the shorter days it is seen at every hour of the day, in the
summer not about midday. There are never more than two
rainbows at one time. Each of them is three-coloured; the
colours are the same in both and their number is the same, but
in the outer rainbow they are fainter and their position is
reversed. In the inner rainbow the first and largest band is red;
in the outer rainbow the band that is nearest to this one and
smallest is of the same colour: the other bands correspond on
the same principle. These are almost the only colours which
painters cannot manufacture: for there are colours which they
create by mixing, but no mixing will give red, green, or purple.
These are the colours of the rainbow, though between the red
and the green an orange colour is often seen.
Mock suns and rods are always seen by the side of the sun, not
above or below it nor in the opposite quarter of the sky. They are
not seen at night but always in the neighbourhood of the sun,
either as it is rising or setting but more commonly towards
sunset. They have scarcely ever appeared when the sun was on
the meridian, though this once happened in Bosporus where
two mock suns rose with the sun and followed it all through the
day till sunset.
These are the facts about each of these phenomena: the cause
of them all is the same, for they are all reflections. But they are
different varieties, and are distinguished by the surface from
which and the way in which the reflection to the sun or some
other bright object takes place.
The rainbow is seen by day, and it was formerly thought that it
never appeared by night as a moon rainbow. This opinion was
due to the rarity of the occurrence: it was not observed, for
though it does happen it does so rarely. The reason is that the
1113
colours are not so easy to see in the dark and that many other
conditions must coincide, and all that in a single day in the
month. For if there is to be one it must be at full moon, and then
as the moon is either rising or setting. So we have only met with
two instances of a moon rainbow in more than fifty years.
We must accept from the theory of optics the fact that sight is
reflected from air and any object with a smooth surface just as
it is from water; also that in some mirrors the forms of things
are reflected, in others only their colours. Of the latter kind are
those mirrors which are so small as to be indivisible for sense. It
is impossible that the figure of a thing should be reflected in
them, for if it is the mirror will be sensibly divisible since
divisibility is involved in the notion of figure. But since
something must be reflected in them and figure cannot be, it
remains that colour alone should be reflected. The colour of a
bright object sometimes appears bright in the reflection, but it
sometimes, either owing to the admixture of the colour of the
mirror or to weakness of sight, gives rise to the appearance of
another colour.
However, we must accept the account we have given of these
things in the theory of sensation, and take some things for
granted while we explain others.
Let us begin by explaining the shape of the halo; why it is a
circle and why it appears round the sun or the moon or one of
the other stars: the explanation being in all these cases the
same.
1114
Sight is reflected in this way when air and vapour are
condensed into a cloud and the condensed matter is uniform
and consists of small parts. Hence in itself it is a sign of rain,
but if it fades away, of fine weather, if it is broken up, of wind.
For if it does not fade away and is not broken up but is allowed
to attain its normal state, it is naturally a sign of rain since it
shows that a process of condensation is proceeding which
must, when it is carried to an end, result in rain. For the same
reason these haloes are the darkest. It is a sign of wind when it
is broken up because its breaking up is due to a wind which
exists there but has not reached us. This view finds support in
the fact that the wind blows from the quarter in which the main
division appears in the halo. Its fading away is a sign of fine
weather because if the air is not yet in a state to get the better
of the heat it contains and proceed to condense into water, this
shows that the moist vapour has not yet separated from the dry
and firelike exhalation: and this is the cause of fine weather.
So much for the atmospheric conditions under which the
reflection takes place. The reflection is from the mist that forms
round the sun or the moon, and that is why the halo is not seen
opposite the sun like the rainbow.
Since the reflection takes place in the same way from every
point the result is necessarily a circle or a segment of a circle:
for if the lines start from the same point and end at the same
point and are equal, the points where they form an angle will
always lie on a circle.
Let AGB and AZB and ADB be lines each of which goes from the
point A to the point B and forms an angle. Let the lines AG, AZ,
AD be equal and those at B, GB, ZB, DB equal too. (See diagram.)
Draw the line AEB. Then the triangles are equal; for their base
AEB is equal. Draw perpendiculars to AEB from the angles; GE
from G, ZE from Z, DE from D. Then these perpendiculars are
1115
equal, being in equal triangles. And they are all in one plane,
being all at right angles to AEB and meeting at a single point E.
So if you draw the line it will be a circle and E its centre. Now B
is the sun, A the eye, and the circumference passing through the
points GZD the cloud from which the line of sight is reflected to
the sun.
The mirrors must be thought of as contiguous: each of them is
too small to be visible, but their contiguity makes the whole
made up of them all to seem one. The bright band is the sun,
which is seen as a circle, appearing successively in each of the
mirrors as a point indivisible to sense. The band of cloud next to
it is black, its colour being intensified by contrast with the
brightness of the halo. The halo is formed rather near the earth
because that is calmer: for where there is wind it is clear that
no halo can maintain its position.
Haloes are commoner round the moon because the greater heat
of the sun dissolves the condensations of the air more rapidly.
Haloes are formed round stars for the same reasons, but they
are not prognostic in the same way because the condensation
they imply is so insignificant as to be barren.
We have already stated that the rainbow is a reflection: we have
now to explain what sort of reflection it is, to describe its
various concomitants, and to assign their causes.
Sight is reflected from all smooth surfaces, such as are air and
water among others. Air must be condensed if it is to act as a
mirror, though it often gives a reflection even uncondensed
1116
when the sight is weak. Such was the case of a man whose sight
was faint and indistinct. He always saw an image in front of
him and facing him as he walked. This was because his sight
was reflected back to him. Its morbid condition made it so weak
and delicate that the air close by acted as a mirror, just as
distant and condensed air normally does, and his sight could
not push it back. So promontories in the sea 'loom' when there
is a south-east wind, and everything seems bigger, and in a
mist, too, things seem bigger: so, too, the sun and the stars
seem bigger when rising and setting than on the meridian. But
things are best reflected from water, and even in process of
formation it is a better mirror than air, for each of the particles,
the union of which constitutes a raindrop, is necessarily a better
mirror than mist. Now it is obvious and has already been stated
that a mirror of this kind renders the colour of an object only,
but not its shape. Hence it follows that when it is on the point of
raining and the air in the clouds is in process of forming into
raindrops but the rain is not yet actually there, if the sun is
opposite, or any other object bright enough to make the cloud a
mirror and cause the sight to be reflected to the object then the
reflection must render the colour of the object without its
shape. Since each of the mirrors is so small as to be invisible
and what we see is the continuous magnitude made up of them
all, the reflection necessarily gives us a continuous magnitude
made up of one colour; each of the mirrors contributing the
same colour to the whole. We may deduce that since these
conditions are realizable there will be an appearance due to
reflection whenever the sun and the cloud are related in the
way described and we are between them. But these are just the
conditions under which the rainbow appears. So it is clear that
the rainbow is a reflection of sight to the sun.
So the rainbow always appears opposite the sun whereas the
halo is round it. They are both reflections, but the rainbow is
distinguished by the variety of its colours. The reflection in the
1117
one case is from water which is dark and from a distance; in the
other from air which is nearer and lighter in colour. White light
through a dark medium or on a dark surface (it makes no
difference) looks red. We know how red the flame of green wood
is: this is because so much smoke is mixed with the bright
white firelight: so, too, the sun appears red through smoke and
mist. That is why in the rainbow reflection the outer
circumference is red (the reflection being from small particles of
water), but not in the case of the halo. The other colours shall be
explained later. Again, a condensation of this kind cannot
persist in the neighbourhood of the sun: it must either turn to
rain or be dissolved, but opposite to the sun there is an interval
during which the water is formed. If there were not this
distinction haloes would be coloured like the rainbow. Actually
no complete or circular halo presents this colour, only small and
fragmentary appearances called 'rods'. But if a haze due to
water or any other dark substance formed there we should have
had, as we maintain, a complete rainbow like that which we do
find lamps. A rainbow appears round these in winter, generally
with southerly winds. Persons whose eyes are moist see it most
clearly because their sight is weak and easily reflected. It is due
to the moistness of the air and the soot which the flame gives
off and which mixes with the air and makes it a mirror, and to
the blackness which that mirror derives from the smoky nature
of the soot. The light of the lamp appears as a circle which is
not white but purple. It shows the colours of the rainbow; but
because the sight that is reflected is too weak and the mirror
too dark, red is absent. The rainbow that is seen when oars are
raised out of the sea involves the same relative positions as that
in the sky, but its colour is more like that round the lamps,
being purple rather than red. The reflection is from very small
particles continuous with one another, and in this case the
particles are fully formed water. We get a rainbow, too, if a man
sprinkles fine drops in a room turned to the sun so that the sun
1118
is shining in part of the room and throwing a shadow in the
rest. Then if one man sprinkles in the room, another, standing
outside, sees a rainbow where the sun's rays cease and make
the shadow. Its nature and colour is like that from the oars and
its cause is the same, for the sprinkling hand corresponds to the
oar.
That the colours of the rainbow are those we described and how
the other colours come to appear in it will be clear from the
following considerations. We must recognize, as we have said,
and lay down: first, that white colour on a black surface or seen
through a black medium gives red; second, that sight when
strained to a distance becomes weaker and less; third, that
black is in a sort the negation of sight: an object is black because
sight fails; so everything at a distance looks blacker, because
sight does not reach it. The theory of these matters belongs to
the account of the senses, which are the proper subjects of such
an inquiry; we need only state about them what is necessary for
us. At all events, that is the reason why distant objects and
objects seen in a mirror look darker and smaller and smoother,
why the reflection of clouds in water is darker than the clouds
themselves. This latter is clearly the case: the reflection
diminishes the sight that reaches them. It makes no difference
whether the change is in the object seen or. in the sight, the
result being in either case the same. The following fact further
is worth noticing. When there is a cloud near the sun and we
look at it does not look coloured at all but white, but when we
look at the same cloud in water it shows a trace of rainbow
colouring. Clearly, then, when sight is reflected it is weakened
and, as it makes dark look darker, so it makes white look less
white, changing it and bringing it nearer to black. When the
sight is relatively strong the change is to red; the next stage is
green, and a further degree of weakness gives violet. No further
change is visible, but three completes the series of colours (as
we find three does in most other things), and the change into
1119
the rest is imperceptible to sense. Hence also the rainbow
appears with three colours; this is true of each of the two, but in
a contrary way. The outer band of the primary rainbow is red:
for the largest band reflects most sight to the sun, and the outer
band is largest. The middle band and the third go on the same
principle. So if the principles we laid down about the
appearance of colours are true the rainbow necessarily has
three colours, and these three and no others. The appearance of
yellow is due to contrast, for the red is whitened by its
juxtaposition with green. We can see this from the fact that the
rainbow is purest when the cloud is blackest; and then the red
shows most yellow. (Yellow in the rainbow comes between red
and green.) So the whole of the red shows white by contrast
with the blackness of the cloud around: for it is white compared
to the cloud and the green. Again, when the rainbow is fading
away and the red is dissolving, the white cloud is brought into
contact with the green and becomes yellow. But the moon
rainbow affords the best instance of this colour contrast. It
looks quite white: this is because it appears on the dark cloud
and at night. So, just as fire is intensified by added fire, black
beside black makes that which is in some degree white look
quite white. Bright dyes too show the effect of contrast. In
woven and embroidered stuffs the appearance of colours is
profoundly affected by their juxtaposition with one another
(purple, for instance, appears different on white and on black
wool), and also by differences of illumination. Thus
embroiderers say that they often make mistakes in their colours
when they work by lamplight, and use the wrong ones.
We have now shown why the rainbow has three colours and
that these are its only colours. The same cause explains the
double rainbow and the faintness of the colours in the outer
one and their inverted order. When sight is strained to a great
distance the appearance of the distant object is affected in a
certain way: and the same thing holds good here. So the
1120
reflection from the outer rainbow is weaker because it takes
place from a greater distance and less of it reaches the sun, and
so the colours seen are fainter. Their order is reversed because
more reflection reaches the sun from the smaller, inner band.
For that reflection is nearer to our sight which is reflected from
the band which is nearest to the primary rainbow. Now the
smallest band in the outer rainbow is that which is nearest, and
so it will be red; and the second and the third will follow the
same principle. Let B be the outer rainbow, A the inner one; let R
stand for the red colour, G for green, V for violet; yellow appears
at the point Y. Three rainbows or more are not found because
even the second is fainter, so that the third reflection can have
no strength whatever and cannot reach the sun at all. (See
diagram.)
The rainbow can never be a circle nor a segment of a circle
greater than a semicircle. The consideration of the diagram will
prove this and the other properties of the rainbow. (See
diagram.)
Let A be a hemisphere resting on the circle of the horizon, let its
centre be K and let H be another point appearing on the
horizon. Then, if the lines that fall in a cone from K have HK as
their axis, and, K and M being joined, the lines KM are reflected
from the hemisphere to H over the greater angle, the lines from
K will fall on the circumference of a circle. If the reflection takes
place when the luminous body is rising or setting the segment
of the circle above the earth which is cut off by the horizon will
be a semi-circle; if the luminous body is above the horizon it
will always be less than a semicircle, and it will be smallest
1121
when the luminous body culminates. First let the luminous
body be appearing on the horizon at the point H, and let KM be
reflected to H, and let the plane in which A is, determined by
the triangle HKM, be produced. Then the section of the sphere
will be a great circle. Let it be A (for it makes no difference
which of the planes passing through the line HK and
determined by the triangle KMH is produced). Now the lines
drawn from H and K to a point on the semicircle A are in a
certain ratio to one another, and no lines drawn from the same
points to another point on that semicircle can have the same
ratio. For since both the points H and K and the line KH are
given, the line MH will be given too; consequently the ratio of
the line MH to the line MK will be given too. So M will touch a
given circumference. Let this be NM. Then the intersection of
the circumferences is given, and the same ratio cannot hold
between lines in the same plane drawn from the same points to
any other circumference but MN.
Draw a line DB outside of the figure and divide it so that
D:B=MH:MK. But MH is greater than MK since the reflection of
the cone is over the greater angle (for it subtends the greater
angle of the triangle KMH). Therefore D is greater than B. Then
add to B a line Z such that B+Z:D=D:B. Then make another line
having the same ratio to B as KH has to Z, and join MI.
Then I is the pole of the circle on which the lines from K fall. For
the ratio of D to IM is the same as that of Z to KH and of B to KI.
If not, let D be in the same ratio to a line indifferently lesser or
greater than IM, and let this line be IP. Then HK and KI and IP
will have the same ratios to one another as Z, B, and D. But the
ratios between Z, B, and D were such that Z+B:D=D: B. Therefore
IH:IP=IP:IK. Now, if the points K, H be joined with the point P by
the lines HP, KP, these lines will be to one another as IH is to IP,
for the sides of the triangles HIP, KPI about the angle I are
homologous. Therefore, HP too will be to KP as HI is to IP. But
1122
this is also the ratio of MH to MK, for the ratio both of HI to IP
and of MH to MK is the same as that of D to B. Therefore, from
the points H, K there will have been drawn lines with the same
ratio to one another, not only to the circumference MN but to
another point as well, which is impossible. Since then D cannot
bear that ratio to any line either lesser or greater than IM (the
proof being in either case the same), it follows that it must
stand in that ratio to MI itself. Therefore as MI is to IK so IH will
be to MI and finally MH to MK.
If, then, a circle be described with I as pole at the distance MI it
will touch all the angles which the lines from H and K make by
their reflection. If not, it can be shown, as before, that lines
drawn to different points in the semicircle will have the same
ratio to one another, which was impossible. If, then, the
semicircle A be revolved about the diameter HKI, the lines
reflected from the points H, K at the point M will have the same
ratio, and will make the angle KMH equal, in every plane.
Further, the angle which HM and MI make with HI will always
be the same. So there are a number of triangles on HI and KI
equal to the triangles HMI and KMI. Their perpendiculars will
fall on HI at the same point and will be equal. Let be the point
on which they fall. Then is the centre of the circle, half of
which, MN, is cut off by the horizon. (See diagram.)
Next let the horizon be ABG but let H have risen above the
horizon. Let the axis now be HI. The proof will be the same for
the rest as before, but the pole I of the circle will be below the
horizon AG since the point H has risen above the horizon. But
the pole, and the centre of the circle, and the centre of that
circle (namely HI) which now determines the position of the sun
are on the same line. But since KH lies above the diameter AG,
the centre will be at on the line KI below the plane of the
circle AG determined the position of the sun before. So the
segment YX which is above the horizon will be less than a
1123
semicircle. For YXM was a semicircle and it has now been cut
off by the horizon AG. So part of it, YM, will be invisible when
the sun has risen above the horizon, and the segment visible
will be smallest when the sun is on the meridian; for the higher
H is the lower the pole and the centre of the circle will be.
In the shorter days after the autumn equinox there may be a
rainbow at any time of the day, but in the longer days from the
spring to the autumn equinox there cannot be a rainbow about
midday. The reason for this is that when the sun is north of the
equator the visible arcs of its course are all greater than a
semicircle, and go on increasing, while the invisible arc is small,
but when the sun is south of the equator the visible arc is small
and the invisible arc great, and the farther the sun moves south
of the equator the greater is the invisible arc. Consequently, in
the days near the summer solstice, the size of the visible arc is
such that before the point H reaches the middle of that arc, that
is its point of culmination, the point is well below the horizon;
the reason for this being the great size of the visible arc, and the
consequent distance of the point of culmination from the earth.
But in the days near the winter solstice the visible arcs are
small, and the contrary is necessarily the case: for the sun is on
the meridian before the point H has risen far.
Mock suns, and rods too, are due to the causes we have
described. A mock sun is caused by the reflection of sight to the
sun. Rods are seen when sight reaches the sun under
circumstances like those which we described, when there are
clouds near the sun and sight is reflected from some liquid
surface to the cloud. Here the clouds themselves are colourless
1124
when you look at them directly, but in the water they are full of
rods. The only difference is that in this latter case the colour of
the cloud seems to reside in the water, but in the case of rods
on the cloud itself. Rods appear when the composition of the
cloud is uneven, dense in part and in part rare, and more and
less watery in different parts. Then the sight is reflected to the
sun: the mirrors are too small for the shape of the sun to
appear, but, the bright white light of the sun, to which the sight
is reflected, being seen on the uneven mirror, its colour appears
partly red, partly green or yellow. It makes no difference
whether sight passes through or is reflected from a medium of
that kind; the colour is the same in both cases; if it is red in the
first case it must be the same in the other.
Rods then are occasioned by the unevenness of the mirror - as
regards colour, not form. The mock sun, on the contrary,
appears when the air is very uniform, and of the same density
throughout. This is why it is white: the uniform character of the
mirror gives the reflection in it a single colour, while the fact
that the sight is reflected in a body and is thrown on the sun all
together by the mist, which is dense and watery though not yet
quite water, causes the sun's true colour to appear just as it
does when the reflection is from the dense, smooth surface of
copper. So the sun's colour being white, the mock sun is white
too. This, too, is the reason why the mock sun is a surer sign of
rain than the rods; it indicates, more than they do, that the air is
ripe for the production of water. Further a mock sun to the
south is a surer sign of rain than one to the north, for the air in
the south is readier to turn into water than that in the north.
Mock suns and rods are found, as we stated, about sunset and
sunrise, not above the sun nor below it, but beside it. They are
not found very close to the sun, nor very far from it, for the sun
dissolves the cloud if it is near, but if it is far off the reflection
cannot take place, since sight weakens when it is reflected from
1125
a small mirror to a very distant object. (This is why a halo is
never found opposite to the sun.) If the cloud is above the sun
and close to it the sun will dissolve it; if it is above the sun but
at a distance the sight is too weak for the reflection to take
place, and so it will not reach the sun. But at the side of the sun,
it is possible for the mirror to be at such an interval that the sun
does not dissolve the cloud, and yet sight reaches it
undiminished because it moves close to the earth and is not
dissipated in the immensity of space. It cannot subsist below
the sun because close to the earth the sun's rays would dissolve
it, but if it were high up and the sun in the middle of the
heavens, sight would be dissipated. Indeed, even by the side of
the sun, it is not found when the sun is in the middle of the sky,
for then the line of vision is not close to the earth, and so but
little sight reaches the mirror and the reflection from it is
altogether feeble.
Some account has now been given of the effects of the secretion
above the surface of the earth; we must go on to describe its
operations below, when it is shut up in the parts of the earth.
Just as its twofold nature gives rise to various effects in the
upper region, so here it causes two varieties of bodies. We
maintain that there are two exhalations, one vaporous the other
smoky, and there correspond two kinds of bodies that originate
in the earth, 'fossiles' and metals. The heat of the dry exhalation
is the cause of all 'fossiles'. Such are the kinds of stones that
cannot be melted, and realgar, and ochre, and ruddle, and
sulphur, and the other things of that kind, most 'fossiles' being
either coloured lye or, like cinnabar, a stone compounded of it.
The vaporous exhalation is the cause of all metals, those bodies
which are either fusible or malleable such as iron, copper, gold.
All these originate from the imprisonment of the vaporous
exhalation in the earth, and especially in stones. Their dryness
compresses it, and it congeals just as dew or hoar-frost does
1126
when it has been separated off, though in the present case the
metals are generated before that segregation occurs. Hence,
they are water in a sense, and in a sense not. Their matter was
that which might have become water, but it can no longer do so:
nor are they, like savours, due to a qualitative change in actual
water. Copper and gold are not formed like that, but in every
case the evaporation congealed before water was formed.
Hence, they all (except gold) are affected by fire, and they
possess an admixture of earth; for they still contain the dry
exhalation.
This is the general theory of all these bodies, but we must take
up each kind of them and discuss it separately.
Book IV
We have explained that the qualities that constitute the
elements are four, and that their combinations determine the
number of the elements to be four.
Two of the qualities, the hot and the cold, are active; two, the
dry and the moist, passive. We can satisfy ourselves of this by
looking at instances. In every case heat and cold determine,
conjoin, and change things of the same kind and things of
different kinds, moistening, drying, hardening, and softening
them. Things dry and moist, on the other hand, both in isolation
1127
and when present together in the same body are the subjects of
that determination and of the other affections enumerated. The
account we give of the qualities when we define their character
shows this too. Hot and cold we describe as active, for
'congregating' is essentially a species of 'being active': moist
and dry are passive, for it is in virtue of its being acted upon in a
certain way that a thing is said to be 'easy to determine' or
'difficult to determine'. So it is clear that some of the qualities
are active and some passive.
Next we must describe the operations of the active qualities and
the forms taken by the passive. First of all, true becoming, that
is, natural change, is always the work of these powers and so is
the corresponding natural destruction; and this becoming and
this destruction are found in plants and animals and their
parts. True natural becoming is a change introduced by these
powers into the matter underlying a given thing when they are
in a certain ratio to that matter, which is the passive qualities
we have mentioned. When the hot and the cold are masters of
the matter they generate a thing: if they are not, and the failure
is partial, the object is imperfectly boiled or otherwise
unconcocted. But the strictest general opposite of true
becoming is putrefaction. All natural destruction is on the way
to it, as are, for instance, growing old or growing dry.
Putrescence is the end of all these things, that is of all natural
objects, except such as are destroyed by violence: you can burn,
for instance, flesh, bone, or anything else, but the natural course
of their destruction ends in putrefaction. Hence things that
putrefy begin by being moist and end by being dry. For the moist
and the dry were their matter, and the operation of the active
qualities caused the dry to be determined by the moist.
Destruction supervenes when the determined gets the better of
the determining by the help of the environment (though in a
special sense the word putrefaction is applied to partial
1128
destruction, when a thing's nature is perverted). Hence
everything, except fire, is liable to putrefy; for earth, water, and
air putrefy, being all of them matter relatively to fire. The
definition of putrefaction is: the destruction of the peculiar and
natural heat in any moist subject by external heat, that is, by
the heat of the environment. So since lack of heat is the ground
of this affection and everything in as far as it lacks heat is cold,
both heat and cold will be the causes of putrefaction, which will
be due indifferently to cold in the putrefying subject or to heat
in the environment.
This explains why everything that putrefies grows drier and
ends by becoming earth or dung. The subject's own heat departs
and causes the natural moisture to evaporate with it, and then
there is nothing left to draw in moisture, for it is a thing's
peculiar heat that attracts moisture and draws it in. Again,
putrefaction takes place less in cold that in hot seasons, for in
winter the surrounding air and water contain but little heat and
it has no power, but in summer there is more. Again, what is
frozen does not putrefy, for its cold is greater that the heat of
the air and so is not mastered, whereas what affects a thing
does master it. Nor does that which is boiling or hot putrefy, for
the heat in the air being less than that in the object does not
prevail over it or set up any change. So too anything that is
flowing or in motion is less apt to putrefy than a thing at rest,
for the motion set up by the heat in the air is weaker than that
pre-existing in the object, and so it causes no change. For the
same reason a great quantity of a thing putrefies less readily
than a little, for the greater quantity contains too much proper
fire and cold for the corresponding qualities in the environment
to get the better of. Hence, the sea putrefies quickly when
broken up into parts, but not as a whole; and all other waters
likewise. Animals too are generated in putrefying bodies,
because the heat that has been secreted, being natural,
organizes the particles secreted with it.
1129
So much for the nature of becoming and of destruction.
We must now describe the next kinds of processes which the
qualities already mentioned set up in actually existing natural
objects as matter.
Of these concoction is due to heat; its species are ripening,
boiling, broiling. Inconcoction is due to cold and its species are
rawness, imperfect boiling, imperfect broiling. (We must
recognize that the things are not properly denoted by these
words: the various classes of similar objects have no names
universally applicable to them; consequently we must think of
the species enumerated as being not what those words denote
but something like it.) Let us say what each of them is.
Concoction is a process in which the natural and proper heat of
an object perfects the corresponding passive qualities, which
are the proper matter of any given object. For when concoction
has taken place we say that a thing has been perfected and has
come to be itself. It is the proper heat of a thing that sets up this
perfecting, though external influences may contribute in some
degrees to its fulfilment. Baths, for instance, and other things of
the kind contribute to the digestion of food, but the primary
cause is the proper heat of the body. In some cases of
concoction the end of the process is the nature of the thing -
nature, that is, in the sense of the formal cause and essence. In
other cases it leads to some presupposed state which is
attained when the moisture has acquired certain properties or a
certain magnitude in the process of being broiled or boiled or of
putrefying, or however else it is being heated. This state is the
end, for when it has been reached the thing has some use and
1130
we say that concoction has taken place. Must is an instance of
this, and the matter in boils when it becomes purulent, and
tears when they become rheum, and so with the rest.
Concoction ensues whenever the matter, the moisture, is
mastered. For the matter is what is determined by the heat
connatural to the object, and as long as the ratio between them
exists in it a thing maintains its nature. Hence things like the
liquid and solid excreta and ejecta in general are signs of
health, and concoction is said to have taken place in them, for
they show that the proper heat has got the better of the
indeterminate matter.
Things that undergo a process of concoction necessarily
become thicker and hotter, for the action of heat is to make
things more compact, thicker, and drier.
This then is the nature of concoction: but inconcoction is an
imperfect state due to lack of proper heat, that is, to cold. That
of which the imperfect state is, is the corresponding passive
qualities which are the natural matter of anything.
So much for the definition of concoction and inconcoction.
Ripening is a sort of concoction; for we call it ripening when
there is a concoction of the nutriment in fruit. And since
concoction is a sort of perfecting, the process of ripening is
perfect when the seeds in fruit are able to reproduce the fruit in
which they are found; for in all other cases as well this is what
we mean by 'perfect'. This is what 'ripening' means when the
word is applied to fruit. However, many other things that have
1131
undergone concoction are said to be 'ripe', the general character
of the process being the same, though the word is applied by an
extension of meaning. The reason for this extension is, as we
explained before, that the various modes in which natural heat
and cold perfect the matter they determine have not special
names appropriated to them. In the case of boils and phlegm,
and the like, the process of ripening is the concoction of the
moisture in them by their natural heat, for only that which gets
the better of matter can determine it. So everything that ripens
is condensed from a spirituous into a watery state, and from a
watery into an earthy state, and in general from being rare
becomes dense. In this process the nature of the thing that is
ripening incorporates some of the matter in itself, and some it
rejects. So much for the definition of ripening.
Rawness is its opposite and is therefore an imperfect
concoction of the nutriment in the fruit, namely, of the
undetermined moisture. Consequently a raw thing is either
spirituous or watery or contains both spirit and water. Ripening
being a kind of perfecting, rawness will be an imperfect state,
and this state is due to a lack of natural heat and its
disproportion to the moisture that is undergoing the process of
ripening. (Nothing moist ripens without the admixture of some
dry matter: water alone of liquids does not thicken.) This
disproportion may be due either to defect of heat or to excess of
the matter to be determined: hence the juice of raw things is
thin, cold rather than hot, and unfit for food or drink. Rawness,
like ripening, is used to denote a variety of states. Thus the
liquid and solid excreta and catarrhs are called raw for the
same reason, for in every case the word is applied to things
because their heat has not got the mastery in them and
compacted them. If we go further, brick is called raw and so is
milk and many other things too when they are such as to admit
of being changed and compacted by heat but have remained
unaffected. Hence, while we speak of 'boiled' water, we cannot
1132
speak of raw water, since it does not thicken. We have now
defined ripening and rawness and assigned their causes.
Boiling is, in general, a concoction by moist heat of the
indeterminate matter contained in the moisture of the thing
boiled, and the word is strictly applicable only to things boiled
in the way of cooking. The indeterminate matter, as we said,
will be either spirituous or watery. The cause of the concoction
is the fire contained in the moisture; for what is cooked in a
frying-pan is broiled: it is the heat outside that affects it and, as
for the moisture in which it is contained, it dries this up and
draws it into itself. But a thing that is being boiled behaves in
the opposite way: the moisture contained in it is drawn out of it
by the heat in the liquid outside. Hence boiled meats are drier
than broiled; for, in boiling, things do not draw the moisture
into themselves, since the external heat gets the better of the
internal: if the internal heat had got the better it would have
drawn the moisture to itself. Not every body admits of the
process of boiling: if there is no moisture in it, it does not (for
instance, stones), nor does it if there is moisture in it but the
density of the body is too great for it to be mastered, as in the
case of wood. But only those bodies can be boiled that contain
moisture which can be acted on by the heat contained in the
liquid outside. It is true that gold and wood and many other
things are said to be 'boiled': but this is a stretch of the meaning
of the word, though the kind of thing intended is the same, the
reason for the usage being that the various cases have no
names appropriated to them. Liquids too, like milk and must,
are said to undergo a process of 'boiling' when the external fire
that surrounds and heats them changes the savour in the liquid
into a given form, the process being thus in a way like what we
have called boiling.
The end of the things that undergo boiling, or indeed any form
of concoction, is not always the same: some are meant to be
1133
eaten, some drunk, and some are intended for other uses; for
instance dyes, too, are said to be 'boiled'.
All those things then admit of 'boiling' which can grow denser,
smaller, or heavier; also those which do that with a part of
themselves and with a part do the opposite, dividing in such a
way that one portion thickens while the other grows thinner,
like milk when it divides into whey and curd. Oil by itself is
affected in none of these ways, and therefore cannot be said to
admit of 'boiling'. Such then is the pfcies of concoction known
as 'boiling', and the process is the same in an artificial and in a
natural instrument, for the cause will be the same in every case.
Imperfect boiling is the form of inconcoction opposed to boiling.
Now the opposite of boiling properly so called is an
inconcoction of the undetermined matter in a body due to lack
of heat in the surrounding liquid. (Lack of heat implies, as we
have pointed out, the presence of cold.) The motion which
causes imperfect boiling is different from that which causes
boiling, for the heat which operates the concoction is driven
out. The lack of heat is due either to the amount of cold in the
liquid or to the quantity of moisture in the object undergoing
the process of boiling. Where either of these conditions is
realized the heat in the surrounding liquid is too great to have
no effect at all, but too small to carry out the process of
concocting uniformly and thoroughly. Hence things are harder
when they are imperfectly boiled than when they are boiled,
and the moisture in them more distinct from the solid parts. So
much for the definition and causes of boiling and imperfect
boiling.
Broiling is concoction by dry foreign heat. Hence if a man were
to boil a thing but the change and concoction in it were due, not
to the heat of the liquid but to that of the fire, the thing will
have been broiled and not boiled when the process has been
1134
carried to completion: if the process has gone too far we use the
word 'scorched' to describe it. If the process leaves the thing
drier at the end the agent has been dry heat. Hence the outside
is drier than the inside, the opposite being true of things boiled.
Where the process is artificial, broiling is more difficult than
boiling, for it is difficult to heat the inside and the outside
uniformly, since the parts nearer to the fire are the first to get
dry and consequently get more intensely dry. In this way the
outer pores contract and the moisture in the thing cannot be
secreted but is shut in by the closing of the pores. Now broiling
and boiling are artificial processes, but the same general kind of
thing, as we said, is found in nature too. The affections
produced are similar though they lack a name; for art imitates
nature. For instance, the concoction of food in the body is like
boiling, for it takes place in a hot and moist medium and the
agent is the heat of the body. So, too, certain forms of
indigestion are like imperfect boiling. And it is not true that
animals are generated in the concoction of food, as some say.
Really they are generated in the excretion which putrefies in the
lower belly, and they ascend afterwards. For concoction goes on
in the upper belly but the excretion putrefies in the lower: the
reason for this has been explained elsewhere.
We have seen that the opposite of boiling is imperfect boiling:
now there is something correspondingly opposed to the species
of concoction called broiling, but it is more difficult to find a
name for it. It would be the kind of thing that would happen if
there were imperfect broiling instead of broiling proper through
lack of heat due to deficiency in the external fire or to the
quantity of water in the thing undergoing the process. For then
we should get too much heat for no effect to be produced, but
too little for concoction to take place.
We have now explained concoction and inconcoction, ripening
and rawness, boiling and broiling, and their opposites.
1135
We must now describe the forms taken by the passive qualities
the moist and the dry. The elements of bodies, that is, the
passive ones, are the moist and the dry; the bodies themselves
are compounded of them and whichever predominates
determines the nature of the body; thus some bodies partake
more of the dry, others of the moist. All the forms to be
described will exist either actually, or potentially and in their
opposite: for instance, there is actual melting and on the other
hand that which admits of being melted.
Since the moist is easily determined and the dry determined
with difficulty, their relation to one another is like that of a dish
and its condiments. The moist is what makes the dry
determinable, and each serves as a sort of glue to the other - as
Empedocles said in his poem on Nature, 'glueing meal together
by means of water.' Thus the determined body involves them
both. Of the elements earth is especially representative of the
dry, water of the moist, and therefore all determinate bodies in
our world involve earth and water. Every body shows the quality
of that element which predominates in it. It is because earth
and water are the material elements of all bodies that animals
live in them alone and not in air or fire.
Of the qualities of bodies hardness and softness are those
which must primarily belong to a determined thing, for
anything made up of the dry and the moist is necessarily either
hard or soft. Hard is that the surface of which does not yield
into itself; soft that which does yield but not by interchange of
place: water, for instance, is not soft, for its surface does not
yield to pressure or sink in but there is an interchange of place.
1136
Those things are absolutely hard and soft which satisfy the
definition absolutely, and those things relatively so which do so
compared with another thing. Now relatively to one another
hard and soft are indefinable, because it is a matter of degree,
but since all the objects of sense are determined by reference to
the faculty of sense it is clearly the relation to touch which
determines that which is hard and soft absolutely, and touch is
that which we use as a standard or mean. So we call that which
exceeds it hard and that which falls short of it soft.
A body determined by its own boundary must be either hard or
soft; for it either yields or does not.
It must also be concrete: or it could not be so determined. So
since everything that is determined and solid is either hard or
soft and these qualities are due to concretion, all composite and
determined bodies must involve concretion. Concretion
therefore must be discussed.
Now there are two causes besides matter, the agent and the
quality brought about, the agent being the efficient cause, the
quality the formal cause. Hence concretion and disaggregation,
drying and moistening, must have these two causes.
But since concretion is a form of drying let us speak of the latter
first.
As we have explained, the agent operates by means of two
qualities and the patient is acted on in virtue of two qualities:
action takes place by means of heat or cold, and the quality is
produced either by the presence or by the absence of heat or
1137
cold; but that which is acted upon is moist or dry or a
compound of both. Water is the element characterized by the
moist, earth that characterized by the dry, for these among the
elements that admit the qualities moist and dry are passive.
Therefore cold, too, being found in water and earth (both of
which we recognize to be cold), must be reckoned rather as a
passive quality. It is active only as contributing to destruction or
incidentally in the manner described before; for cold is
sometimes actually said to burn and to warm, but not in the
same way as heat does, but by collecting and concentrating
heat.
The subjects of drying are water and the various watery fluids
and those bodies which contain water either foreign or
connatural. By foreign I mean like the water in wool, by
connatural, like that in milk. The watery fluids are wine, urine,
whey, and in general those fluids which have no sediment or
only a little, except where this absence of sediment is due to
viscosity. For in some cases, in oil and pitch for instance, it is
the viscosity which prevents any sediment from appearing.
It is always a process of heating or cooling that dries things, but
the agent in both cases is heat, either internal or external. For
even when things are dried by cooling, like a garment, where
the moisture exists separately it is the internal heat that dries
them. It carries off the moisture in the shape of vapour (if there
is not too much of it), being itself driven out by the surrounding
cold. So everything is dried, as we have said, by a process either
of heating or cooling, but the agent is always heat, either
internal or external, carrying off the moisture in vapour. By
external heat I mean as where things are boiled: by internal
where the heat breathes out and takes away and uses up its
moisture. So much for drying.
1138
Liquefaction is, first, condensation into water; second, the
melting of a solidified body. The first, condensation, is due to
the cooling of vapour: what melting is will appear from the
account of solidification.
Whatever solidifies is either water or a mixture of earth and
water, and the agent is either dry heat or cold. Hence those of
the bodies solidified by heat or cold which are soluble at all are
dissolved by their opposites. Bodies solidified by the dry-hot are
dissolved by water, which is the moist-cold, while bodies
solidified by cold are dissolved by fire, which is hot. Some things
seem to be solidified by water, e.g. boiled honey, but really it is
not the water but the cold in the water which effects the
solidification. Aqueous bodies are not solidified by fire: for it is
fire that dissolves them, and the same cause in the same
relation cannot have opposite effects upon the same thing.
Again, water solidifies owing to the departure of heat; so it will
clearly be dissolved by the entry into it of heat: cold, therefore,
must be the agent in solidifying it.
Hence aqueous bodies do not thicken when they solidify; for
thickening occurs when the moisture goes off and the dry
matter comes together, but water is the only liquid that does
not thicken. Those bodies that are made up of both earth and
water are solidified both by fire and by cold and in either case
are thickened. The operation of the two is in a way the same
and in a way different. Heat acts by drawing off the moisture,
and as the moisture goes off in vapour the dry matter thickens
and collects. Cold acts by driving out the heat, which is
accompanied by the moisture as this goes off in vapour with it.
Bodies that are soft but not liquid do not thicken but solidify
when the moisture leaves them, e.g. potter's clay in process of
1139
baking: but those mixed bodies that are liquid thicken besides
solidifying, like milk. Those bodies which have first been
thickened or hardened by cold often begin by becoming moist:
thus potter's clay at first in the process of baking steams and
grows softer, and is liable to distortion in the ovens for that
reason.
Now of the bodies solidified by cold which are made up both of
earth and water but in which the earth preponderates, those
which solidify by the departure of heat melt by heat when it
enters into them again; this is the case with frozen mud. But
those which solidify by refrigeration, where all the moisture has
gone off in vapour with the heat, like iron and horn, cannot be
dissolved except by excessive heat, but they can be softened -
though manufactured iron does melt, to the point of becoming
fluid and then solidifying again. This is how steel is made. The
dross sinks to the bottom and is purged away: when this has
been done often and the metal is pure we have steel. The
process is not repeated often because the purification of the
metal involves great waste and loss of weight. But the iron that
has less dross is the better iron. The stone pyrimachus, too,
melts and forms into drops and becomes fluid; after having
been in a fluid state it solidifies and becomes hard again.
Millstones, too, melt and become fluid: when the fluid mass
begins to solidify it is black but its consistency comes to be like
that of lime, and earth, too
Of the bodies which are solidified by dry heat some are
insoluble, others are dissolved by liquid. Pottery and some kinds
of stone that are formed out of earth burnt up by fire, such as
millstones, cannot be dissolved. Natron and salt are soluble by
liquid, but not all liquid but only such as is cold. Hence water
and any of its varieties melt them, but oil does not. For the
opposite of the dry-hot is the cold-moist and what the one
1140
solidified the other will dissolve, and so opposites will have
opposite effects.
If a body contains more water than earth fire only thickens it: if
it contains more earth fire solidifies it. Hence natron and salt
and stone and potter's clay must contain more earth.
The nature of oil presents the greatest problem. If water
preponderated in it, cold ought to solidify it; if earth
preponderated, then fire ought to do so. Actually neither
solidifies, but both thicken it. The reason is that it is full of air
(hence it floats on the top of water, since air tends to rise). Cold
thickens it by turning the air in it into water, for any mixture of
oil and water is thicker than either. Fire and the lapse of time
thicken and whiten it. The whitening follows on the evaporation
of any water that may have been in it; the is due to the change
of the air into water as the heat in the oil is dissipated. The
effect in both cases is the same and the cause is the same, but
the manner of its operation is different. Both heat and cold
thicken it, but neither dries it (neither the sun nor cold dries oil),
not only because it is glutinous but because it contains air. Its
glutinous nature prevents it from giving off vapour and so fire
does not dry it or boil it off.
Those bodies which are made up of earth and water may be
classified according to the preponderance of either. There is a
kind of wine, for instance, which both solidifies and thickens by
boiling - I mean, must. All bodies of this kind lose their water as
they That it is their water may be seen from the fact that the
vapour from them condenses into water when collected. So
wherever some sediment is left this is of the nature of earth.
1141
Some of these bodies, as we have said, are also thickened and
dried by cold. For cold not only solidifies but also dries water,
and thickens things by turning air into water. (Solidifying, as we
have said, is a form of drying.) Now those things that are not
thickened by cold, but solidified, belong rather to water, e.g..
wine, urine, vinegar, lye, whey. But those things that are
thickened (not by evaporation due to fire) are made up either of
earth or of water and air: honey of earth, while oil contains air.
Milk and blood, too, are made up of both water and earth,
though earth generally predominates in them. So, too, are the
liquids out of which natron and salt are formed; and stones are
also formed from some mixtures of this kind. Hence, if the whey
has not been separated, it burns away if you boil it over a fire.
But the earthy element in milk can also be coagulated by the
help of fig-juice, if you boil it in a certain way as doctors do
when they treat it with fig-juice, and this is how the whey and
the cheese are commonly separated. Whey, once separated,
does not thicken, as the milk did, but boils away like water.
Sometimes, however, there is little or no cheese in milk, and
such milk is not nutritive and is more like water. The case of
blood is similar: cold dries and so solidifies it. Those kinds of
blood that do not solidify, like that of the stag, belong rather to
water and are very cold. Hence they contain no fibres: for the
fibres are of earth and solid, and blood from which they have
been removed does not solidify. This is because it cannot dry;
for what remains is water, just as what remains of milk when
cheese has been removed is water. The fact that diseased blood
will not solidify is evidence of the same thing, for such blood is
of the nature of serum and that is phlegm and water, the nature
of the animal having failed to get the better of it and digest it.
Some of these bodies are soluble, e.g. natron, some insoluble,
e.g. pottery: of the latter, some, like horn, can be softened by
heat, others, like pottery and stone, cannot. The reason is that
opposite causes have opposite effects: consequently, if
1142
solidification is due to two causes, the cold and the dry, solution
must be due to the hot and the moist, that is, to fire and to
water (these being opposites): water dissolving what was
solidified by fire alone, fire what was solidified by cold alone.
Consequently, if any things happen to be solidified by the action
of both, these are least apt to be soluble. Such a case we find
where things have been heated and are then solidified by cold.
When the heat in leaving them has caused most of the
moisture to evaporate, the cold so compacts these bodies
together again as to leave no entrance even for moisture.
Therefore heat does not dissolve them (for it only dissolves
those bodies that are solidified by cold alone), nor does water
(for it does not dissolve what cold solidifies, but only what is
solidified by dry heat). But iron is melted by heat and solidified
by cold. Wood consists of earth and air and is therefore
combustible but cannot be melted or softened by heat. (For the
same reason it floats in water - all except ebony. This does not,
for other kinds of wood contain a preponderance of air, but in
black ebony the air has escaped and so earth preponderates in
it.) Pottery consists of earth alone because it solidified gradually
in the process of drying. Water cannot get into it, for the pores
were only large enough to admit of vapour escaping: and seeing
that fire solidified it, that cannot dissolve it either.
So solidification and melting, their causes, and the kinds of
subjects in which they occur have been described.
8
All this makes it clear that bodies are formed by heat and cold
and that these agents operate by thickening and solidifying. It is
because these qualities fashion bodies that we find heat in all of
1143
them, and in some cold in so far as heat is absent. These
qualities, then, are present as active, and the moist and the dry-
as passive, and consequently all four are found in mixed bodies.
So water and earth are the constituents of homogeneous bodies
both in plants and in animals and of metals such as gold, silver,
and the rest - water and earth and their respective exhalations
shut up in the compound bodies, as we have explained
elsewhere.
All these mixed bodies are distinguished from one another,
firstly by the qualities special to the various senses, that is, by
their capacities of action. (For a thing is white, fragrant, sonant,
sweet, hot, cold in virtue of a power of acting on sense).
Secondly by other more characteristic affections which express
their aptitude to be affected: I mean, for instance, the aptitude
to melt or solidify or bend and so forth, all these qualities, like
moist and dry, being passive. These are the qualities that
differentiate bone, flesh, sinew, wood, bark, stone and all other
homogeneous natural bodies. Let us begin by enumerating
these qualities expressing the aptitude or inaptitude of a thing
to be affected in a certain way. They are as follows: to be apt or
inapt to solidify, melt, be softened by heat, be softened by water,
bend, break, be comminuted, impressed, moulded, squeezed; to
be tractile or non-tractile, malleable or non-malleable, to be
fissile or non-fissile, apt or inapt to be cut; to be viscous or
friable, compressible or incompressible, combustible or
incombustible; to be apt or inapt to give off fumes. These
affections differentiate most bodies from one another. Let us go
on to explain the nature of each of them. We have already given
a general account of that which is apt or inapt to solidify or to
melt, but let us return to them again now. Of all the bodies that
admit of solidification and hardening, some are brought into
this state by heat, others by cold. Heat does this by drying up
their moisture, cold by driving out their heat. Consequently
some bodies are affected in this way by defect of moisture,
1144
some by defect of heat: watery bodies by defect of heat, earthy
bodies of moisture. Now those bodies that are so affected by
defect of moisture are dissolved by water, unless like pottery
they have so contracted that their pores are too small for the
particles of water to enter. All those bodies in which this is not
the case are dissolved by water, e.g. natron, salt, dry mud. Those
bodies that solidified through defect of heat are melted by heat,
e.g. ice, lead, copper. So much for the bodies that admit of
solidification and of melting, and those that do not admit of
melting.
The bodies which do not admit of solidification are those which
contain no aqueous moisture and are not watery, but in which
heat and earth preponderate, like honey and must (for these are
in a sort of state of effervescence), and those which do possess
some water but have a preponderance of air, like oil and
quicksilver, and all viscous substances such as pitch and
birdlime.
Those bodies admit of softening which are not (like ice) made
up of water, but in which earth predominates. All their moisture
must not have left them (as in the case of natron and salt), nor
must the relation of dry to moist in them be incongruous (as in
the case of pottery). They must be tractile (without admitting
water) or malleable (without consisting of water), and the agent
in softening them is fire. Such are iron and horn.
Both of bodies that can melt and of bodies that cannot, some do
and some do not admit of softening in water. Copper, for
instance, which can be melted, cannot be softened in water,
whereas wool and earth can be softened in water, for they can
1145
be soaked. (It is true that though copper can be melted the
agent in its case is not water, but some of the bodies that can be
melted by water too such as natron and salt cannot be softened
in water: for nothing is said to be so affected unless the water
soaks into it and makes it softer.) Some things, on the other
hand, such as wool and grain, can be softened by water though
they cannot be melted. Any body that is to be softened by water
must be of earth and must have its pores larger than the
particles of water, and the pores themselves must be able to
resist the action of water, whereas bodies that can be 'melted'
by water must have pores throughout.
(Why is it that earth is both 'melted' and softened by moisture,
while natron is 'melted' but not softened? Because natron is
pervaded throughout by pores so that the parts are immediately
divided by the water, but earth has also pores which do not
connect and is therefore differently affected according as the
water enters by one or the other set of pores.)
Some bodies can be bent or straightened, like the reed or the
withy, some cannot, like pottery and stone. Those bodies are apt
to be bent and straightened which can change from being
curved to being straight and from being straight to being
curved, and bending and straightening consist in the change or
motion to the straight or to a curve, for a thing is said to be in
process of being bent whether it is being made to assume a
convex or a concave shape. So bending is defined as motion to
the convex or the concave without a change of length. For if we
added 'or to the straight', we should have a thing bent and
straight at once, and it is impossible for that which is straight to
be bent. And if all bending is a bending back or a bending down,
the former being a change to the convex, the latter to the
concave, a motion that leads to the straight cannot be called
bending, but bending and straightening are two different things.
1146
These, then, are the things that can, and those that cannot be
bent, and be straightened.
Some things can be both broken and comminuted, others admit
only one or the other. Wood, for instance, can be broken but not
comminuted, ice and stone can be comminuted but not broken,
while pottery may either be comminuted or broken. The
distinction is this: breaking is a division and separation into
large parts, comminution into parts of any size, but there must
be more of them than two. Now those solids that have many
pores not communicating with one another are comminuible
(for the limit to their subdivision is set by the pores), but those
whose pores stretch continuously for a long way are breakable,
while those which have pores of both kinds are both
comminuible and breakable.
Some things, e.g. copper and wax, are impressible, others, e.g.
pottery and water, are not. The process of being impressed is
the sinking of a part of the surface of a thing in response to
pressure or a blow, in general to contact. Such bodies are either
soft, like wax, where part of the surface is depressed while the
rest remains, or hard, like copper. Non-impressible bodies are
either hard, like pottery (its surface does not give way and sink
in), or liquid, like water (for though water does give way it is not
in a part of it, for there is a reciprocal change of place of all its
parts). Those impressibles that retain the shape impressed on
them and are easily moulded by the hand are called 'plastic';
those that are not easily moulded, such as stone or wood, or are
easily moulded but do not retain the shape impressed, like wool
or a sponge, are not plastic. The last group are said to be
'squeezable'. Things are 'squeezable' when they can contract
into themselves under pressure, their surface sinking in without
being broken and without the parts interchanging position as
happens in the case of water. (We speak of pressure when there
is movement and the motor remains in contact with the thing
1147
moved, of impact when the movement is due to the local
movement of the motor.) Those bodies are subject to squeezing
which have empty pores - empty, that is, of the stuff of which
the body itself consists - and that can sink upon the void spaces
within them, or rather upon their pores. For sometimes the
pores upon which a body sinks in are not empty (a wet sponge,
for instance, has its pores full). But the pores, if full, must be full
of something softer than the body itself which is to contract.
Examples of things squeezable are the sponge, wax, flesh. Those
things are not squeezable which cannot be made to contract
upon their own pores by pressure, either because they have no
pores or because their pores are full of something too hard.
Thus iron, stone, water and all liquids are incapable of being
squeezed.
Things are tractile when their surface can be made to elongate,
for being drawn out is a movement of the surface, remaining
unbroken, in the direction of the mover. Some things are
tractile, e.g. hair, thongs, sinew, dough, birdlime, and some are
not, e.g. water, stone. Some things are both tractile and
squeezable, e.g. wool; in other cases the two qualities do not
coincide; phlegm, for instance, is tractile but not squeezable,
and a sponge squeezable but not tractile.
Some things are malleable, like copper. Some are not, like stone
and wood. Things are malleable when their surface can be made
to move (but only in part) both downwards and sideways with
one and the same blow: when this is not possible a body is not
malleable. All malleable bodies are impressible, but not all
impressible bodies are malleable, e.g. wood, though on the
whole the two go together. Of squeezable things some are
malleable and some not: wax and mud are malleable, wool is
not. Some things are fissile, e.g. wood, some are not, e.g. potter's
clay. A thing is fissile when it is apt to divide in advance of the
instrument dividing it, for a body is said to split when it divides
1148
to a further point than that to which the dividing instrument
divides it and the act of division advances: which is not the case
with cutting. Those bodies which cannot behave like this are
non-fissile. Nothing soft is fissile (by soft I mean absolutely soft
and not relatively: for iron itself may be relatively soft); nor are
all hard things fissile, but only such as are neither liquid nor
impressible nor comminuible. Such are the bodies that have the
pores along which they cohere lengthwise and not crosswise.
Those hard or soft solids are apt to be cut which do not
necessarily either split in advance of the instrument or break
into minute fragments when they are being divided. Those that
necessarily do so and liquids cannot be cut. Some things can be
both split and cut, like wood, though generally it is lengthwise
that a thing can be split and crosswise that it can be cut. For, a
body being divided into many parts fin so far as its unity is
made up of many lengths it is apt to be split, in so far as it is
made up of many breadths it is apt to be cut.
A thing is viscous when, being moist or soft, it is tractile. Bodies
owe this property to the interlocking of their parts when they
are composed like chains, for then they can be drawn out to a
great length and contracted again. Bodies that are not like this
are friable. Bodies are compressible when they are squeezable
and retain the shape they have been squeezed into;
incompressible when they are either inapt to be squeezed at all
or do not retain the shape they have been squeezed into.
Some bodies are combustible and some are not. Wood, wool,
bone are combustible; stone, ice are not. Bodies are combustible
when their pores are such as to admit fire and their longitudinal
pores contain moisture weaker than fire. If they have no
moisture, or if, as in ice or very green wood, the moisture is
stronger than fire, they are not combustible.
1149
Those bodies give off fumes which contain moisture, but in
such a form that it does not go off separately in vapour when
they are exposed to fire. For vapour is a moist secretion tending
to the nature of air produced from a liquid by the agency of
burning heat. Bodies that give off fumes give off secretions of
the nature of air by the lapse of time: as they perish away they
dry up or become earth. But the kind of secretion we are
concerned with now differs from others in that it is not moist
nor does it become wind (which is a continuous flow of air in a
given direction). Fumes are common secretion of dry and moist
together caused by the agency of burning heat. Hence they do
not moisten things but rather colour them.
The fumes of a woody body are called smoke. (I mean to include
bones and hair and everything of this kind in the same class.
For there is no name common to all the objects that I mean, but,
for all that, these things are all in the same class by analogy.
Compare what Empedocles says: They are one and the same,
hair and leaves and the thick wings of birds and scales that
grow on stout limbs.) The fumes of fat are a sooty smoke and
those of oily substances a greasy steam. Oil does not boil away
or thicken by evaporation because it does not give off vapour
but fumes. Water on the other hand does not give off fumes, but
vapour. Sweet wine does give off fumes, for it contains fat and
behaves like oil. It does not solidify under the influence of cold
and it is apt to burn. Really it is not wine at all in spite of its
name: for it does not taste like wine and consequently does not
inebriate as ordinary wine does. It contains but little fumigable
stuff and consequently is inflammable.
All bodies are combustible that dissolve into ashes, and all
bodies do this that solidify under the influence either of heat or
of both heat and cold; for we find that all these bodies are
mastered by fire. Of stones the precious stone called carbuncle
is least amenable to fire.
1150
Of combustible bodies some are inflammable and some are not,
and some of the former are reduced to coals. Those are called
'inflammable' which produce flame and those which do not are
called 'non-inflammable'. Those fumigable bodies that are not
liquid are inflammable, but pitch, oil, wax are inflammable in
conjunction with other bodies rather than by themselves. Most
inflammable are those bodies that give off smoke. Of bodies of
this kind those that contain more earth than smoke are apt to
be reduced to coals. Some bodies that can be melted are not
inflammable, e.g. copper; and some bodies that cannot be
melted are inflammable, e.g. wood; and some bodies can be
melted and are also inflammable, e.g. frankincense. The reason
is that wood has its moisture all together and this is continuous
throughout and so it burns up: whereas copper has it in each
part but not continuous, and insufficient in quantity to give rise
to flame. In frankincense it is disposed in both of these ways.
Fumigable bodies are inflammable when earth predominates in
them and they are consequently such as to be unable to melt.
These are inflammable because they are dry like fire. When this
dry comes to be hot there is fire. This is why flame is burning
smoke or dry exhalation. The fumes of wood are smoke, those
of wax and frankincense and such-like, and pitch and whatever
contains pitch or such-like are sooty smoke, while the fumes of
oil and oily substances are a greasy steam; so are those of all
substances which are not at all combustible by themselves
because there is too little of the dry in them (the dry being the
means by which the transition to fire is effected), but burn very
readily in conjunction with something else. (For the fat is just
the conjunction of the oily with the dry.) So those bodies that
give off fumes, like oil and pitch, belong rather to the moist, but
those that burn to the dry.
1151
10
Homogeneous bodies differ to touch - by these affections and
differences, as we have said. They also differ in respect of their
smell, taste, and colour.
By homogeneous bodies I mean, for instance, 'metals', gold,
copper, silver, tin, iron, stone, and everything else of this kind
and the bodies that are extracted from them; also the
substances found in animals and plants, for instance, flesh,
bones, sinew, skin, viscera, hair, fibres, veins (these are the
elements of which the non-homogeneous bodies like the face, a
hand, a foot, and everything of that kind are made up), and in
plants, wood, bark, leaves, roots, and the rest like them.
The homogeneous bodies, it is true, are constituted by a
different cause, but the matter of which they are composed is
the dry and the moist, that is, water and earth (for these bodies
exhibit those qualities most clearly). The agents are the hot and
the cold, for they constitute and make concrete the
homogeneous bodies out of earth and water as matter. Let us
consider, then, which of the homogeneous bodies are made of
earth and which of water, and which of both.
Of organized bodies some are liquid, some soft, some hard. The
soft and the hard are constituted by a process of solidification,
as we have already explained.
Those liquids that go off in vapour are made of water, those
that do not are either of the nature of earth, or a mixture either
of earth and water, like milk, or of earth and air, like wood, or of
water and air, like oil. Those liquids which are thickened by heat
are a mixture. (Wine is a liquid which raises a difficulty: for it is
both liable to evaporation and it also thickens; for instance new
wine does. The reason is that the word 'wine' is ambiguous and
different 'wines' behave in different ways. New wine is more
1152
earthy than old, and for this reason it is more apt to be
thickened by heat and less apt to be congealed by cold. For it
contains much heat and a great proportion of earth, as in
Arcadia, where it is so dried up in its skins by the smoke that
you scrape it to drink. If all wine has some sediment in it then it
will belong to earth or to water according to the quantity of the
sediment it possesses.) The liquids that are thickened by cold
are of the nature of earth; those that are thickened either by
heat or by cold consist of more than one element, like oil and
honey, and 'sweet wine'.
Of solid bodies those that have been solidified by cold are of
water, e.g. ice, snow, hail, hoar-frost. Those solidified by heat are
of earth, e.g. pottery, cheese, natron, salt. Some bodies are
solidified by both heat and cold. Of this kind are those solidified
by refrigeration, that is by the privation both of heat and of the
moisture which departs with the heat. For salt and the bodies
that are purely of earth solidify by the privation of moisture
only, ice by that of heat only, these bodies by that of both. So
both the active qualities and both kinds of matter were involved
in the process. Of these bodies those from which all the
moisture has gone are all of them of earth, like pottery or
amber. (For amber, also, and the bodies called 'tears' are formed
by refrigeration, like myrrh, frankincense, gum. Amber, too,
appears to belong to this class of things: the animals enclosed
in it show that it is formed by solidification. The heat is driven
out of it by the cold of the river and causes the moisture to
evaporate with it, as in the case of honey when it has been
heated and is immersed in water.) Some of these bodies cannot
be melted or softened; for instance, amber and certain stones,
e.g. the stalactites in caves. (For these stalactites, too, are
formed in the same way: the agent is not fire, but cold which
drives out the heat, which, as it leaves the body, draws out the
moisture with it: in the other class of bodies the agent is
external fire.) In those from which the moisture has not wholly
1153
gone earth still preponderates, but they admit of softening by
heat, e.g. iron and horn.
Now since we must include among 'meltables' those bodies
which are melted by fire, these contain some water: indeed
some of them, like wax, are common to earth and water alike.
But those that are melted by water are of earth. Those that are
not melted either by fire or water are of earth, or of earth and
water.
Since, then, all bodies are either liquid or solid, and since the
things that display the affections we have enumerated belong to
these two classes and there is nothing intermediate, it follows
that we have given a complete account of the criteria for
distinguishing whether a body consists of earth or of water or of
more elements than one, and whether fire was the agent in its
formation, or cold, or both.
Gold, then, and silver and copper and tin and lead and glass and
many nameless stone are of water: for they are all melted by
heat. Of water, too, are some wines and urine and vinegar and
lye and whey and serum: for they are all congealed by cold. In
iron, horn, nails, bones, sinews, wood, hair, leaves, bark, earth
preponderates. So, too, in amber, myrrh, frankincense, and all
the substances called 'tears', and stalactites, and fruits, such as
leguminous plants and corn. For things of this kind are, to a
greater or less degree, of earth. For of all these bodies some
admit of softening by heat, the rest give off fumes and are
formed by refrigeration. So again in natron, salt, and those kinds
of stones that are not formed by refrigeration and cannot be
melted. Blood, on the other hand, and semen, are made up of
earth and water and air. If the blood contains fibres, earth
preponderates in it: consequently its solidifies by refrigeration
and is melted by liquids; if not, it is of water and therefore does
1154
not solidify. Semen solidifies by refrigeration, its moisture
leaving it together with its heat.
11
We must investigate in the light of the results we have arrived
at what solid or liquid bodies are hot and what cold.
Bodies consisting of water are commonly cold, unless (like lye,
urine, wine) they contain foreign heat. Bodies consisting of
earth, on the other hand, are commonly hot because heat was
active in forming them: for instance lime and ashes.
We must recognize that cold is in a sense the matter of bodies.
For the dry and the moist are matter (being passive) and earth
and water are the elements that primarily embody them, and
they are characterized by cold. Consequently cold must
predominate in every body that consists of one or other of the
elements simply, unless such a body contains foreign heat as
water does when it boils or when it has been strained through
ashes. This latter, too, has acquired heat from the ashes, for
everything that has been burnt contains more or less heat. This
explains the generation of animals in putrefying bodies: the
putrefying body contains the heat which destroyed its proper
heat.
Bodies made up of earth and water are hot, for most of them
derive their existence from concoction and heat, though some,
like the waste products of the body, are products of
putrefaction. Thus blood, semen, marrow, figjuice, and all things
of the kinds are hot as long as they are in their natural state, but
when they perish and fall away from that state they are so no
longer. For what is left of them is their matter and that is earth
1155
and water. Hence both views are held about them, some people
maintaining them to be cold and others to be warm; for they are
observed to be hot when they are in their natural state, but to
solidify when they have fallen away from it. That, then, is the
case of mixed bodies. However, the distinction we laid down
holds good: if its matter is predominantly water a body is cold
(water being the complete opposite of fire), but if earth or air it
tends to be warm.
It sometimes happens that the coldest bodies can be raised to
the highest temperature by foreign heat; for the most solid and
the hardest bodies are coldest when deprived of heat and most
burning after exposure to fire: thus water is more burning than
smoke and stone than water.
12
Having explained all this we must describe the nature of flesh,
bone, and the other homogeneous bodies severally.
Our account of the formation of the homogeneous bodies has
given us the elements out of which they are compounded and
the classes into which they fall, and has made it clear to which
class each of those bodies belongs. The homogeneous bodies
are made up of the elements, and all the works of nature in turn
of the homogeneous bodies as matter. All the homogeneous
bodies consist of the elements described, as matter, but their
essential nature is determined by their definition. This fact is
always clearer in the case of the later products of those, in fact,
that are instruments, as it were, and have an end: it is clearer,
for instance, that a dead man is a man only in name. And so the
hand of a dead man, too, will in the same way be a hand in
name only, just as stone flutes might still be called flutes: for
1156
these members, too, are instruments of a kind. But in the case
of flesh and bone the fact is not so clear to see, and in that of
fire and water even less. For the end is least obvious there
where matter predominates most. If you take the extremes,
matter is pure matter and the essence is pure definition; but the
bodies intermediate between the two are matter or definition in
proportion as they are near to either. For each of those elements
has an end and is not water or fire in any and every condition of
itself, just as flesh is not flesh nor viscera viscera, and the same
is true in a higher degree with face and hand. What a thing is
always determined by its function: a thing really is itself when it
can perform its function; an eye, for instance, when it can see.
When a thing cannot do so it is that thing only in name, like a
dead eye or one made of stone, just as a wooden saw is no more
a saw than one in a picture. The same, then, is true of flesh,
except that its function is less clear than that of the tongue. So,
too, with fire; but its function is perhaps even harder to specify
by physical inquiry than that of flesh. The parts of plants, and
inanimate bodies like copper and silver, are in the same case.
They all are what they are in virtue of a certain power of action
or passion - just like flesh and sinew. But we cannot state their
form accurately, and so it is not easy to tell when they are really
there and when they are not unless the body is thoroughly
corrupted and its shape only remains. So ancient corpses
suddenly become ashes in the grave and very old fruit preserves
its shape only but not its taste: so, too, with the solids that form
from milk.
Now heat and cold and the motions they set up as the bodies
are solidified by the hot and the cold are sufficient to form all
such parts as are the homogeneous bodies, flesh, bone, hair,
sinew, and the rest. For they are all of them differentiated by the
various qualities enumerated above, tension, tractility,
comminuibility, hardness, softness, and the rest of them: all of
which are derived from the hot and the cold and the mixture of
1157
their motions. But no one would go as far as to consider them
sufficient in the case of the non-homogeneous parts (like the
head, the hand, or the foot) which these homogeneous parts go
to make up. Cold and heat and their motion would be admitted
to account for the formation of copper or silver, but not for that
of a saw, a bowl, or a box. So here, save that in the examples
given the cause is art, but in the nonhomogeneous bodies
nature or some other cause.
Since, then, we know to what element each of the
homogeneous bodies belongs, we must now find the definition
of each of them, the answer, that is, to the question, 'what is'
flesh, semen, and the rest? For we know the cause of a thing
and its definition when we know the material or the formal or,
better, both the material and the formal conditions of its
generation and destruction, and the efficient cause of it.
After the homogeneous bodies have been explained we must
consider the non-homogeneous too, and lastly the bodies made
up of these, such as man, plants, and the rest.
1158
Aristotle - On the Soul
[Translated by J. A. Smith]
Book I
Holding as we do that, while knowledge of any kind is a thing to
be honoured and prized, one kind of it may, either by reason of
its greater exactness or of a higher dignity and greater
wonderfulness in its objects, be more honourable and precious
than another, on both accounts we should naturally be led to
place in the front rank the study of the soul. The knowledge of
the soul admittedly contributes greatly to the advance of truth
in general, and, above all, to our understanding of Nature, for
the soul is in some sense the principle of animal life. Our aim is
to grasp and understand, first its essential nature, and secondly
its properties; of these some are taught to be affections proper
to the soul itself, while others are considered to attach to the
animal owing to the presence within it of soul.
To attain any assured knowledge about the soul is one of the
most difficult things in the world. As the form of question
which here presents itself, viz. the question 'What is it?', recurs
in other fields, it might be supposed that there was some single
method of inquiry applicable to all objects whose essential
nature (as we are endeavouring to ascertain there is for derived
properties the single method of demonstration); in that case
what we should have to seek for would be this unique method.
But if there is no such single and general method for solving the
question of essence, our task becomes still more difficult; in the
1159
case of each different subject we shall have to determine the
appropriate process of investigation. If to this there be a clear
answer, e.g. that the process is demonstration or division, or
some known method, difficulties and hesitations still beset us -
with what facts shall we begin the inquiry? For the facts which
form the starting-points in different subjects must be different,
as e.g. in the case of numbers and surfaces.
First, no doubt, it is necessary to determine in which of the
summa genera soul lies, what it is; is it 'a this-somewhat, 'a
substance, or is it a quale or a quantum, or some other of the
remaining kinds of predicates which we have distinguished?
Further, does soul belong to the class of potential existents, or is
it not rather an actuality? Our answer to this question is of the
greatest importance.
We must consider also whether soul is divisible or is without
parts, and whether it is everywhere homogeneous or not; and if
not homogeneous, whether its various forms are different
specifically or generically: up to the present time those who
have discussed and investigated soul seem to have confined
themselves to the human soul. We must be careful not to ignore
the question whether soul can be defined in a single
unambiguous formula, as is the case with animal, or whether
we must not give a separate formula for each of it, as we do for
horse, dog, man, god (in the latter case the 'universal' animal -
and so too every other 'common predicate' - being treated
either as nothing at all or as a later product). Further, if what
exists is not a plurality of souls, but a plurality of parts of one
soul, which ought we to investigate first, the whole soul or its
parts? (It is also a difficult problem to decide which of these
parts are in nature distinct from one another.) Again, which
ought we to investigate first, these parts or their functions,
mind or thinking, the faculty or the act of sensation, and so on?
If the investigation of the functions precedes that of the parts,
1160
the further question suggests itself: ought we not before either
to consider the correlative objects, e.g. of sense or thought? It
seems not only useful for the discovery of the causes of the
derived properties of substances to be acquainted with the
essential nature of those substances (as in mathematics it is
useful for the understanding of the property of the equality of
the interior angles of a triangle to two right angles to know the
essential nature of the straight and the curved or of the line and
the plane) but also conversely, for the knowledge of the
essential nature of a substance is largely promoted by an
acquaintance with its properties: for, when we are able to give
an account conformable to experience of all or most of the
properties of a substance, we shall be in the most favourable
position to say something worth saying about the essential
nature of that subject; in all demonstration a definition of the
essence is required as a starting-point, so that definitions which
do not enable us to discover the derived properties, or which fail
to facilitate even a conjecture about them, must obviously, one
and all, be dialectical and futile.
A further problem presented by the affections of soul is this: are
they all affections of the complex of body and soul, or is there
any one among them peculiar to the soul by itself? To determine
this is indispensable but difficult. If we consider the majority of
them, there seems to be no case in which the soul can act or be
acted upon without involving the body; e.g. anger, courage,
appetite, and sensation generally. Thinking seems the most
probable exception; but if this too proves to be a form of
imagination or to be impossible without imagination, it too
requires a body as a condition of its existence. If there is any
way of acting or being acted upon proper to soul, soul will be
capable of separate existence; if there is none, its separate
existence is impossible. In the latter case, it will be like what is
straight, which has many properties arising from the
straightness in it, e.g. that of touching a bronze sphere at a
1161
point, though straightness divorced from the other constituents
of the straight thing cannot touch it in this way; it cannot be so
divorced at all, since it is always found in a body. It therefore
seems that all the affections of soul involve a body - passion,
gentleness, fear, pity, courage, joy, loving, and hating; in all these
there is a concurrent affection of the body. In support of this we
may point to the fact that, while sometimes on the occasion of
violent and striking occurrences there is no excitement or fear
felt, on others faint and feeble stimulations produce these
emotions, viz. when the body is already in a state of tension
resembling its condition when we are angry. Here is a still
clearer case: in the absence of any external cause of terror we
find ourselves experiencing the feelings of a man in terror. From
all this it is obvious that the affections of soul are enmattered
formulable essences.
Consequently their definitions ought to correspond, e.g. anger
should be defined as a certain mode of movement of such and
such a body (or part or faculty of a body) by this or that cause
and for this or that end. That is precisely why the study of the
soul must fall within the science of Nature, at least so far as in
its affections it manifests this double character. Hence a
physicist would define an affection of soul differently from a
dialectician; the latter would define e.g. anger as the appetite
for returning pain for pain, or something like that, while the
former would define it as a boiling of the blood or warm
substance surround the heart. The latter assigns the material
conditions, the former the form or formulable essence; for what
he states is the formulable essence of the fact, though for its
actual existence there must be embodiment of it in a material
such as is described by the other. Thus the essence of a house is
assigned in such a formula as 'a shelter against destruction by
wind, rain, and heat'; the physicist would describe it as 'stones,
bricks, and timbers'; but there is a third possible description
which would say that it was that form in that material with that
1162
purpose or end. Which, then, among these is entitled to be
regarded as the genuine physicist? The one who confines
himself to the material, or the one who restricts himself to the
formulable essence alone? Is it not rather the one who
combines both in a single formula? If this is so, how are we to
characterize the other two? Must we not say that there is no
type of thinker who concerns himself with those qualities or
attributes of the material which are in fact inseparable from the
material, and without attempting even in thought to separate
them? The physicist is he who concerns himself with all the
properties active and passive of bodies or materials thus or thus
defined; attributes not considered as being of this character he
leaves to others, in certain cases it may be to a specialist, e.g. a
carpenter or a physician, in others (a) where they are
inseparable in fact, but are separable from any particular kind of
body by an effort of abstraction, to the mathematician, (b)
where they are separate both in fact and in thought from body
altogether, to the First Philosopher or metaphysician. But we
must return from this digression, and repeat that the affections
of soul are inseparable from the material substratum of animal
life, to which we have seen that such affections, e.g. passion and
fear, attach, and have not the same mode of being as a line or a
plane.
For our study of soul it is necessary, while formulating the
problems of which in our further advance we are to find the
solutions, to call into council the views of those of our
predecessors who have declared any opinion on this subject, in
order that we may profit by whatever is sound in their
suggestions and avoid their errors.
1163
The starting-point of our inquiry is an exposition of those
characteristics which have chiefly been held to belong to soul in
its very nature. Two characteristic marks have above all others
been recognized as distinguishing that which has soul in it from
that which has not - movement and sensation. It may be said
that these two are what our predecessors have fixed upon as
characteristic of soul.
Some say that what originates movement is both pre-eminently
and primarily soul; believing that what is not itself moved
cannot originate movement in another, they arrived at the view
that soul belongs to the class of things in movement. This is
what led Democritus to say that soul is a sort of fire or hot
substance; his 'forms' or atoms are infinite in number; those
which are spherical he calls fire and soul, and compares them
to the motes in the air which we see in shafts of light coming
through windows; the mixture of seeds of all sorts he calls the
elements of the whole of Nature (Leucippus gives a similar
account); the spherical atoms are identified with soul because
atoms of that shape are most adapted to permeate everywhere,
and to set all the others moving by being themselves in
movement. This implies the view that soul is identical with
what produces movement in animals. That is why, further, they
regard respiration as the characteristic mark of life; as the
environment compresses the bodies of animals, and tends to
extrude those atoms which impart movement to them, because
they themselves are never at rest, there must be a
reinforcement of these by similar atoms coming in from
without in the act of respiration; for they prevent the extrusion
of those which are already within by counteracting the
compressing and consolidating force of the environment; and
animals continue to live only so long as they are able to
maintain this resistance.
1164
The doctrine of the Pythagoreans seems to rest upon the same
ideas; some of them declared the motes in air, others what
moved them, to be soul. These motes were referred to because
they are seen always in movement, even in a complete calm.
The same tendency is shown by those who define soul as that
which moves itself; all seem to hold the view that movement is
what is closest to the nature of soul, and that while all else is
moved by soul, it alone moves itself. This belief arises from their
never seeing anything originating movement which is not first
itself moved.
Similarly also Anaxagoras (and whoever agrees with him in
saying that mind set the whole in movement) declares the
moving cause of things to be soul. His position must, however,
be distinguished from that of Democritus. Democritus roundly
identifies soul and mind, for he identifies what appears with
what is true - that is why he commends Homer for the phrase
'Hector lay with thought distraught'; he does not employ mind
as a special faculty dealing with truth, but identifies soul and
mind. What Anaxagoras says about them is more obscure; in
many places he tells us that the cause of beauty and order is
mind, elsewhere that it is soul; it is found, he says, in all
animals, great and small, high and low, but mind (in the sense
of intelligence) appears not to belong alike to all animals, and
indeed not even to all human beings.
All those, then, who had special regard to the fact that what has
soul in it is moved, adopted the view that soul is to be identified
with what is eminently originative of movement. All, on the
other hand, who looked to the fact that what has soul in it
knows or perceives what is, identify soul with the principle or
principles of Nature, according as they admit several such
principles or one only. Thus Empedocles declares that it is
1165
formed out of all his elements, each of them also being soul; his
words are:
For 'tis by Earth we see Earth, by Water Water,
By Ether Ether divine, by Fire destructive Fire,
By Love Love, and Hate by cruel Hate.
In the same way Plato in the Timaeus fashions soul out of his
elements; for like, he holds, is known by like, and things are
formed out of the principles or elements, so that soul must be
so too. Similarly also in his lectures 'On Philosophy' it was set
forth that the Animal-itself is compounded of the Idea itself of
the One together with the primary length, breadth, and depth,
everything else, the objects of its perception, being similarly
constituted. Again he puts his view in yet other terms: Mind is
the monad, science or knowledge the dyad (because it goes
undeviatingly from one point to another), opinion the number
of the plane, sensation the number of the solid; the numbers
are by him expressly identified with the Forms themselves or
principles, and are formed out of the elements; now things are
apprehended either by mind or science or opinion or sensation,
and these same numbers are the Forms of things.
Some thinkers, accepting both premisses, viz. that the soul is
both originative of movement and cognitive, have compounded
it of both and declared the soul to be a self-moving number.
As to the nature and number of the first principles opinions
differ. The difference is greatest between those who regard
them as corporeal and those who regard them as incorporeal,
and from both dissent those who make a blend and draw their
principles from both sources. The number of principles is also in
dispute; some admit one only, others assert several. There is a
consequent diversity in their several accounts of soul; they
assume, naturally enough, that what is in its own nature
1166
originative of movement must be among what is primordial.
That has led some to regard it as fire, for fire is the subtlest of
the elements and nearest to incorporeality; further, in the most
primary sense, fire both is moved and originates movement in
all the others.
Democritus has expressed himself more ingeniously than the
rest on the grounds for ascribing each of these two characters to
soul; soul and mind are, he says, one and the same thing, and
this thing must be one of the primary and indivisible bodies,
and its power of originating movement must be due to its
fineness of grain and the shape of its atoms; he says that of all
the shapes the spherical is the most mobile, and that this is the
shape of the particles of fire and mind.
Anaxagoras, as we said above, seems to distinguish between
soul and mind, but in practice he treats them as a single
substance, except that it is mind that he specially posits as the
principle of all things; at any rate what he says is that mind
alone of all that is simple, unmixed, and pure. He assigns both
characteristics, knowing and origination of movement, to the
same principle, when he says that it was mind that set the
whole in movement.
Thales, too, to judge from what is recorded about him, seems to
have held soul to be a motive force, since he said that the
magnet has a soul in it because it moves the iron.
Diogenes (and others) held the soul to be air because he
believed air to be finest in grain and a first principle; therein lay
the grounds of the soul's powers of knowing and originating
movement. As the primordial principle from which all other
things are derived, it is cognitive; as finest in grain, it has the
power to originate movement.
1167
Heraclitus too says that the first principle - the 'warm
exhalation' of which, according to him, everything else is
composed - is soul; further, that this exhalation is most
incorporeal and in ceaseless flux; that what is in movement
requires that what knows it should be in movement; and that
all that is has its being essentially in movement (herein
agreeing with the majority).
Alcmaeon also seems to have held a similar view about soul; he
says that it is immortal because it resembles 'the immortals,'
and that this immortality belongs to it in virtue of its ceaseless
movement; for all the 'things divine,' moon, sun, the planets,
and the whole heavens, are in perpetual movement.
of More superficial writers, some, e.g. Hippo, have pronounced it
to be water; they seem to have argued from the fact that the
seed of all animals is fluid, for Hippo tries to refute those who
say that the soul is blood, on the ground that the seed, which is
the primordial soul, is not blood.
Another group (Critias, for example) did hold it to be blood; they
take perception to be the most characteristic attribute of soul,
and hold that perceptiveness is due to the nature of blood.
Each of the elements has thus found its partisan, except earth -
earth has found no supporter unless we count as such those
who have declared soul to be, or to be compounded of, all the
elements. All, then, it may be said, characterize the soul by three
marks, Movement, Sensation, Incorporeality, and each of these
is traced back to the first principles. That is why (with one
exception) all those who define the soul by its power of knowing
make it either an element or constructed out of the elements.
The language they all use is similar; like, they say, is known by
like; as the soul knows everything, they construct it out of all
the principles. Hence all those who admit but one cause or
element, make the soul also one (e.g. fire or air), while those
1168
who admit a multiplicity of principles make the soul also
multiple. The exception is Anaxagoras; he alone says that mind
is impassible and has nothing in common with anything else.
But, if this is so, how or in virtue of what cause can it know?
That Anaxagoras has not explained, nor can any answer be
inferred from his words. All who acknowledge pairs of opposites
among their principles, construct the soul also out of these
contraries, while those who admit as principles only one
contrary of each pair, e.g. either hot or cold, likewise make the
soul some one of these. That is why, also, they allow themselves
to be guided by the names; those who identify soul with the hot
argue that sen (to live) is derived from sein (to boil), while those
who identify it with the cold say that soul (psuche) is so called
from the process of respiration and (katapsuxis). Such are the
traditional opinions concerning soul, together with the grounds
on which they are maintained.
We must begin our examination with movement; for doubtless,
not only is it false that the essence of soul is correctly described
by those who say that it is what moves (or is capable of moving)
itself, but it is an impossibility that movement should be even
an attribute of it.
We have already pointed out that there is no necessity that
what originates movement should itself be moved. There are
two senses in which anything may be moved - either (a)
indirectly, owing to something other than itself, or (b) directly,
owing to itself. Things are 'indirectly moved' which are moved
as being contained in something which is moved, e.g. sailors in
a ship, for they are moved in a different sense from that in
1169
which the ship is moved; the ship is 'directly moved', they are
'indirectly moved', because they are in a moving vessel. This is
clear if we consider their limbs; the movement proper to the
legs (and so to man) is walking, and in this case the sailors tare
not walking. Recognizing the double sense of 'being moved',
what we have to consider now is whether the soul is 'directly
moved' and participates in such direct movement.
There are four species of movement - locomotion, alteration,
diminution, growth; consequently if the soul is moved, it must
be moved with one or several or all of these species of
movement. Now if its movement is not incidental, there must
be a movement natural to it, and, if so, as all the species
enumerated involve place, place must be natural to it. But if the
essence of soul be to move itself, its being moved cannot be
incidental to - as it is to what is white or three cubits long; they
too can be moved, but only incidentally - what is moved is that
of which 'white' and 'three cubits long' are the attributes, the
body in which they inhere; hence they have no place: but if the
soul naturally partakes in movement, it follows that it must
have a place.
Further, if there be a movement natural to the soul, there must
be a counter-movement unnatural to it, and conversely. The
same applies to rest as well as to movement; for the terminus
ad quern of a thing's natural movement is the place of its
natural rest, and similarly the terminus ad quern of its enforced
movement is the place of its enforced rest. But what meaning
can be attached to enforced movements or rests of the soul, it is
difficult even to imagine.
Further, if the natural movement of the soul be upward, the soul
must be fire; if downward, it must be earth; for upward and
downward movements are the definitory characteristics of
these bodies. The same reasoning applies to the intermediate
1170
movements, termini, and bodies. Further, since the soul is
observed to originate movement in the body, it is reasonable to
suppose that it transmits to the body the movements by which
it itself is moved, and so, reversing the order, we may infer from
the movements of the body back to similar movements of the
soul. Now the body is moved from place to place with
movements of locomotion. Hence it would follow that the soul
too must in accordance with the body change either its place as
a whole or the relative places of its parts. This carries with it the
possibility that the soul might even quit its body and re-enter it,
and with this would be involved the possibility of a resurrection
of animals from the dead. But, it may be contended, the soul
can be moved indirectly by something else; for an animal can be
pushed out of its course. Yes, but that to whose essence belongs
the power of being moved by itself, cannot be moved by
something else except incidentally, just as what is good by or in
itself cannot owe its goodness to something external to it or to
some end to which it is a means.
If the soul is moved, the most probable view is that what moves
it is sensible things.
We must note also that, if the soul moves itself, it must be the
mover itself that is moved, so that it follows that if movement is
in every case a displacement of that which is in movement, in
that respect in which it is said to be moved, the movement of
the soul must be a departure from its essential nature, at least if
its self-movement is essential to it, not incidental.
Some go so far as to hold that the movements which the soul
imparts to the body in which it is are the same in kind as those
with which it itself is moved. An example of this is Democritus,
who uses language like that of the comic dramatist Philippus,
who accounts for the movements that Daedalus imparted to his
wooden Aphrodite by saying that he poured quicksilver into it;
1171
similarly Democritus says that the spherical atoms which
according to him constitute soul, owing to their own ceaseless
movements draw the whole body after them and so produce its
movements. We must urge the question whether it is these very
same atoms which produce rest also - how they could do so, it
is difficult and even impossible to say. And, in general, we may
object that it is not in this way that the soul appears to originate
movement in animals - it is through intention or process of
thinking.
It is in the same fashion that the Timaeus also tries to give a
physical account of how the soul moves its body; the soul, it is
there said, is in movement, and so owing to their mutual
implication moves the body also. After compounding the soul-
substance out of the elements and dividing it in accordance
with the harmonic numbers, in order that it may possess a
connate sensibility for 'harmony' and that the whole may move
in movements well attuned, the Demiurge bent the straight line
into a circle; this single circle he divided into two circles united
at two common points; one of these he subdivided into seven
circles. All this implies that the movements of the soul are
identified with the local movements of the heavens.
Now, in the first place, it is a mistake to say that the soul is a
spatial magnitude. It is evident that Plato means the soul of the
whole to be like the sort of soul which is called mind not like
the sensitive or the desiderative soul, for the movements of
neither of these are circular. Now mind is one and continuous
in the sense in which the process of thinking is so, and thinking
is identical with the thoughts which are its parts; these have a
serial unity like that of number, not a unity like that of a spatial
magnitude. Hence mind cannot have that kind of unity either;
mind is either without parts or is continuous in some other way
than that which characterizes a spatial magnitude. How, indeed,
if it were a spatial magnitude, could mind possibly think? Will it
1172
think with any one indifferently of its parts? In this case, the
'part' must be understood either in the sense of a spatial
magnitude or in the sense of a point (if a point can be called a
part of a spatial magnitude). If we accept the latter alternative,
the points being infinite in number, obviously the mind can
never exhaustively traverse them; if the former, the mind must
think the same thing over and over again, indeed an infinite
number of times (whereas it is manifestly possible to think a
thing once only). If contact of any part whatsoever of itself with
the object is all that is required, why need mind move in a
circle, or indeed possess magnitude at all? On the other hand, if
contact with the whole circle is necessary, what meaning can be
given to the contact of the parts? Further, how could what has
no parts think what has parts, or what has parts think what has
none? We must identify the circle referred to with mind; for it is
mind whose movement is thinking, and it is the circle whose
movement is revolution, so that if thinking is a movement of
revolution, the circle which has this characteristic movement
must be mind.
If the circular movement is eternal, there must be something
which mind is always thinking - what can this be? For all
practical processes of thinking have limits - they all go on for
the sake of something outside the process, and all theoretical
processes come to a close in the same way as the phrases in
speech which express processes and results of thinking. Every
such linguistic phrase is either definitory or demonstrative.
Demonstration has both a starting-point and may be said to end
in a conclusion or inferred result; even if the process never
reaches final completion, at any rate it never returns upon itself
again to its starting-point, it goes on assuming a fresh middle
term or a fresh extreme, and moves straight forward, but
circular movement returns to its starting-point. Definitions, too,
are closed groups of terms.
1173
Further, if the same revolution is repeated, mind must
repeatedly think the same object.
Further, thinking has more resemblance to a coming to rest or
arrest than to a movement; the same may be said of inferring.
It might also be urged that what is difficult and enforced is
incompatible with blessedness; if the movement of the soul is
not of its essence, movement of the soul must be contrary to its
nature. It must also be painful for the soul to be inextricably
bound up with the body; nay more, if, as is frequently said and
widely accepted, it is better for mind not to be embodied, the
union must be for it undesirable.
Further, the cause of the revolution of the heavens is left
obscure. It is not the essence of soul which is the cause of this
circular movement - that movement is only incidental to soul -
nor is, a fortiori, the body its cause. Again, it is not even asserted
that it is better that soul should be so moved; and yet the
reason for which God caused the soul to move in a circle can
only have been that movement was better for it than rest, and
movement of this kind better than any other. But since this sort
of consideration is more appropriate to another field of
speculation, let us dismiss it for the present.
The view we have just been examining, in company with most
theories about the soul, involves the following absurdity: they
all join the soul to a body, or place it in a body, without adding
any specification of the reason of their union, or of the bodily
conditions required for it. Yet such explanation can scarcely be
omitted; for some community of nature is presupposed by the
fact that the one acts and the other is acted upon, the one
moves and the other is moved; interaction always implies a
special nature in the two interagents. All, however, that these
thinkers do is to describe the specific characteristics of the soul;
they do not try to determine anything about the body which is
1174
to contain it, as if it were possible, as in the Pythagorean myths,
that any soul could be clothed upon with any body - an absurd
view, for each body seems to have a form and shape of its own.
It is as absurd as to say that the art of carpentry could embody
itself in flutes; each art must use its tools, each soul its body.
There is yet another theory about soul, which has commended
itself to many as no less probable than any of those we have
hitherto mentioned, and has rendered public account of itself in
the court of popular discussion. Its supporters say that the soul
is a kind of harmony, for (a) harmony is a blend or composition
of contraries, and (b) the body is compounded out of contraries.
Harmony, however, is a certain proportion or composition of the
constituents blended, and soul can be neither the one nor the
other of these. Further, the power of originating movement
cannot belong to a harmony, while almost all concur in
regarding this as a principal attribute of soul. It is more
appropriate to call health (or generally one of the good states of
the body) a harmony than to predicate it of the soul. The
absurdity becomes most apparent when we try to attribute the
active and passive affections of the soul to a harmony; the
necessary readjustment of their conceptions is difficult. Further,
in using the word 'harmony' we have one or other of two cases
in our mind; the most proper sense is in relation to spatial
magnitudes which have motion and position, where harmony
means the disposition and cohesion of their parts in such a
manner as to prevent the introduction into the whole of
anything homogeneous with it, and the secondary sense,
derived from the former, is that in which it means the ratio
between the constituents so blended; in neither of these senses
1175
is it plausible to predicate it of soul. That soul is a harmony in
the sense of the mode of composition of the parts of the body is
a view easily refutable; for there are many composite parts and
those variously compounded; of what bodily part is mind or the
sensitive or the appetitive faculty the mode of composition?
And what is the mode of composition which constitutes each of
them? It is equally absurd to identify the soul with the ratio of
the mixture; for the mixture which makes flesh has a different
ratio between the elements from that which makes bone. The
consequence of this view will therefore be that distributed
throughout the whole body there will be many souls, since
every one of the bodily parts is a different mixture of the
elements, and the ratio of mixture is in each case a harmony, i.e.
a soul.
From Empedocles at any rate we might demand an answer to
the following question for he says that each of the parts of the
body is what it is in virtue of a ratio between the elements: is
the soul identical with this ratio, or is it not rather something
over and above this which is formed in the parts? Is love the
cause of any and every mixture, or only of those that are in the
right ratio? Is love this ratio itself, or is love something over and
above this? Such are the problems raised by this account. But,
on the other hand, if the soul is different from the mixture, why
does it disappear at one and the same moment with that
relation between the elements which constitutes flesh or the
other parts of the animal body? Further, if the soul is not
identical with the ratio of mixture, and it is consequently not
the case that each of the parts has a soul, what is that which
perishes when the soul quits the body?
That the soul cannot either be a harmony, or be moved in a
circle, is clear from what we have said. Yet that it can be moved
incidentally is, as we said above, possible, and even that in a
sense it can move itself, i.e. in the sense that the vehicle in
1176
which it is can be moved, and moved by it; in no other sense
can the soul be moved in space.
More legitimate doubts might remain as to its movement in
view of the following facts. We speak of the soul as being pained
or pleased, being bold or fearful, being angry, perceiving,
thinking. All these are regarded as modes of movement, and
hence it might be inferred that the soul is moved. This, however,
does not necessarily follow. We may admit to the full that being
pained or pleased, or thinking, are movements (each of them a
'being moved'), and that the movement is originated by the soul.
For example we may regard anger or fear as such and such
movements of the heart, and thinking as such and such another
movement of that organ, or of some other; these modifications
may arise either from changes of place in certain parts or from
qualitative alterations (the special nature of the parts and the
special modes of their changes being for our present purpose
irrelevant). Yet to say that it is the soul which is angry is as
inexact as it would be to say that it is the soul that weaves webs
or builds houses. It is doubtless better to avoid saying that the
soul pities or learns or thinks and rather to say that it is the
man who does this with his soul. What we mean is not that the
movement is in the soul, but that sometimes it terminates in
the soul and sometimes starts from it, sensation e.g. coming
from without inwards, and reminiscence starting from the soul
and terminating with the movements, actual or residual, in the
sense organs.
The case of mind is different; it seems to be an independent
substance implanted within the soul and to be incapable of
being destroyed. If it could be destroyed at all, it would be under
the blunting influence of old age. What really happens in
respect of mind in old age is, however, exactly parallel to what
happens in the case of the sense organs; if the old man could
recover the proper kind of eye, he would see just as well as the
1177
young man. The incapacity of old age is due to an affection not
of the soul but of its vehicle, as occurs in drunkenness or
disease. Thus it is that in old age the activity of mind or
intellectual apprehension declines only through the decay of
some other inward part; mind itself is impassible. Thinking,
loving, and hating are affections not of mind, but of that which
has mind, so far as it has it. That is why, when this vehicle
decays, memory and love cease; they were activities not of
mind, but of the composite which has perished; mind is, no
doubt, something more divine and impassible. That the soul
cannot be moved is therefore clear from what we have said, and
if it cannot be moved at all, manifestly it cannot be moved by
itself.
Of all the opinions we have enumerated, by far the most
unreasonable is that which declares the soul to be a self-moving
number; it involves in the first place all the impossibilities
which follow from regarding the soul as moved, and in the
second special absurdities which follow from calling it a
number. How we to imagine a unit being moved? By what
agency? What sort of movement can be attributed to what is
without parts or internal differences? If the unit is both
originative of movement and itself capable of being moved, it
must contain difference.
Further, since they say a moving line generates a surface and a
moving point a line, the movements of the psychic units must
be lines (for a point is a unit having position, and the number of
the soul is, of course, somewhere and has position).
Again, if from a number a number or a unit is subtracted, the
remainder is another number; but plants and many animals
when divided continue to live, and each segment is thought to
retain the same kind of soul.
1178
It must be all the same whether we speak of units or corpuscles;
for if the spherical atoms of Democritus became points, nothing
being retained but their being a quantum, there must remain in
each a moving and a moved part, just as there is in what is
continuous; what happens has nothing to do with the size of
the atoms, it depends solely upon their being a quantum. That
is why there must be something to originate movement in the
units. If in the animal what originates movement is the soul, so
also must it be in the case of the number, so that not the mover
and the moved together, but the mover only, will be the soul.
But how is it possible for one of the units to fulfil this function
of originating movement? There must be some difference
between such a unit and all the other units, and what difference
can there be between one placed unit and another except a
difference of position? If then, on the other hand, these psychic
units within the body are different from the points of the body,
there will be two sets of units both occupying the same place;
for each unit will occupy a point. And yet, if there can be two,
why cannot there be an infinite number? For if things can
occupy an indivisible lace, they must themselves be indivisible.
If, on the other hand, the points of the body are identical with
the units whose number is the soul, or if the number of the
points in the body is the soul, why have not all bodies souls? For
all bodies contain points or an infinity of points.
Further, how is it possible for these points to be isolated or
separated from their bodies, seeing that lines cannot be
resolved into points?
1179
The result is, as we have said, that this view, while on the one
side identical with that of those who maintain that soul is a
subtle kind of body, is on the other entangled in the absurdity
peculiar to Democritus' way of describing the manner in which
movement is originated by soul. For if the soul is present
throughout the whole percipient body, there must, if the soul be
a kind of body, be two bodies in the same place; and for those
who call it a number, there must be many points at one point,
or every body must have a soul, unless the soul be a different
sort of number - other, that is, than the sum of the points
existing in a body. Another consequence that follows is that the
animal must be moved by its number precisely in the way that
Democritus explained its being moved by his spherical psychic
atoms. What difference does it make whether we speak of small
spheres or of large units, or, quite simply, of units in movement?
One way or another, the movements of the animal must be due
to their movements. Hence those who combine movement and
number in the same subject lay themselves open to these and
many other similar absurdities. It is impossible not only that
these characters should give the definition of soul - it is
impossible that they should even be attributes of it. The point is
clear if the attempt be made to start from this as the account of
soul and explain from it the affections and actions of the soul,
e.g. reasoning, sensation, pleasure, pain, &c. For, to repeat what
we have said earlier, movement and number do not facilitate
even conjecture about the derivative properties of soul.
Such are the three ways in which soul has traditionally been
defined; one group of thinkers declared it to be that which is
most originative of movement because it moves itself, another
group to be the subtlest and most nearly incorporeal of all kinds
of body. We have now sufficiently set forth the difficulties and
inconsistencies to which these theories are exposed. It remains
1180
now to examine the doctrine that soul is composed of the
elements.
The reason assigned for this doctrine is that thus the soul may
perceive or come to know everything that is, but the theory
necessarily involves itself in many impossibilities. Its upholders
assume that like is known only by like, and imagine that by
declaring the soul to be composed of the elements they succeed
in identifying the soul with all the things it is capable of
apprehending. But the elements are not the only things it
knows; there are many others, or, more exactly, an infinite
number of others, formed out of the elements. Let us admit that
the soul knows or perceives the elements out of which each of
these composites is made up; but by what means will it know or
perceive the composite whole, e.g. what God, man, flesh, bone
(or any other compound) is? For each is, not merely the
elements of which it is composed, but those elements combined
in a determinate mode or ratio, as Empedocles himself says of
bone,
The kindly Earth in its broad-bosomed moulds
Won of clear Water two parts out of eight,
And four of Fire; and so white bones were formed.
Nothing, therefore, will be gained by the presence of the
elements in the soul, unless there be also present there the
various formulae of proportion and the various compositions in
accordance with them. Each element will indeed know its fellow
outside, but there will be no knowledge of bone or man, unless
they too are present in the constitution of the soul. The
impossibility of this needs no pointing out; for who would
suggest that stone or man could enter into the constitution of
the soul? The same applies to 'the good' and 'the not-good', and
so on.
1181
Further, the word 'is' has many meanings: it may be used of a
'this' or substance, or of a quantum, or of a quale, or of any
other of the kinds of predicates we have distinguished. Does the
soul consist of all of these or not? It does not appear that all
have common elements. Is the soul formed out of those
elements alone which enter into substances? so how will it be
able to know each of the other kinds of thing? Will it be said
that each kind of thing has elements or principles of its own,
and that the soul is formed out of the whole of these? In that
case, the soul must be a quantum and a quale and a substance.
But all that can be made out of the elements of a quantum is a
quantum, not a substance. These (and others like them) are the
consequences of the view that the soul is composed of all the
elements.
It is absurd, also, to say both (a) that like is not capable of being
affected by like, and (b) that like is perceived or known by like,
for perceiving, and also both thinking and knowing, are, on their
own assumption, ways of being affected or moved.
There are many puzzles and difficulties raised by saying, as
Empedocles does, that each set of things is known by means of
its corporeal elements and by reference to something in soul
which is like them, and additional testimony is furnished by
this new consideration; for all the parts of the animal body
which consist wholly of earth such as bones, sinews, and hair
seem to be wholly insensitive and consequently not perceptive
even of objects earthy like themselves, as they ought to have
been.
Further, each of the principles will have far more ignorance
than knowledge, for though each of them will know one thing,
there will be many of which it will be ignorant. Empedocles at
any rate must conclude that his God is the least intelligent of all
beings, for of him alone is it true that there is one thing, Strife,
1182
which he does not know, while there is nothing which mortal
beings do not know, for ere is nothing which does not enter into
their composition.
In general, we may ask, Why has not everything a soul, since
everything either is an element, or is formed out of one or
several or all of the elements? Each must certainly know one or
several or all.
The problem might also be raised, What is that which unifies
the elements into a soul? The elements correspond, it would
appear, to the matter; what unites them, whatever it is, is the
supremely important factor. But it is impossible that there
should be something superior to, and dominant over, the soul
(and a fortiori over the mind); it is reasonable to hold that mind
is by nature most primordial and dominant, while their
statement that it is the elements which are first of all that is.
All, both those who assert that the soul, because of its
knowledge or perception of what is compounded out of the
elements, and is those who assert that it is of all things the
most originative of movement, fail to take into consideration all
kinds of soul. In fact (1) not all beings that perceive can
originate movement; there appear to be certain animals which
stationary, and yet local movement is the only one, so it seems,
which the soul originates in animals. And (2) the same objection
holds against all those who construct mind and the perceptive
faculty out of the elements; for it appears that plants live, and
yet are not endowed with locomotion or perception, while a
large number of animals are without discourse of reason. Even
if these points were waived and mind admitted to be a part of
the soul (and so too the perceptive faculty), still, even so, there
would be kinds and parts of soul of which they had failed to
give any account.
1183
The same objection lies against the view expressed in the
'Orphic' poems: there it is said that the soul comes in from the
whole when breathing takes place, being borne in upon the
winds. Now this cannot take place in the case of plants, nor
indeed in the case of certain classes of animal, for not all
classes of animal breathe. This fact has escaped the notice of
the holders of this view.
If we must construct the soul out of the elements, there is no
necessity to suppose that all the elements enter into its
construction; one element in each pair of contraries will suffice
to enable it to know both that element itself and its contrary. By
means of the straight line we know both itself and the curved -
the carpenter's rule enables us to test both - but what is curved
does not enable us to distinguish either itself or the straight.
Certain thinkers say that soul is intermingled in the whole
universe, and it is perhaps for that reason that Thales came to
the opinion that all things are full of gods. This presents some
difficulties: Why does the soul when it resides in air or fire not
form an animal, while it does so when it resides in mixtures of
the elements, and that although it is held to be of higher quality
when contained in the former? (One might add the question,
why the soul in air is maintained to be higher and more
immortal than that in animals.) Both possible ways of replying
to the former question lead to absurdity or paradox; for it is
beyond paradox to say that fire or air is an animal, and it is
absurd to refuse the name of animal to what has soul in it. The
opinion that the elements have soul in them seems to have
arisen from the doctrine that a whole must be homogeneous
with its parts. If it is true that animals become animate by
drawing into themselves a portion of what surrounds them, the
partisans of this view are bound to say that the soul of the
Whole too is homogeneous with all its parts. If the air sucked in
is homogeneous, but soul heterogeneous, clearly while some
part of soul will exist in the inbreathed air, some other part will
1184
not. The soul must either be homogeneous, or such that there
are some parts of the Whole in which it is not to be found.
From what has been said it is now clear that knowing as an
attribute of soul cannot be explained by soul's being composed
of the elements, and that it is neither sound nor true to speak of
soul as moved. But since (a) knowing, perceiving, opining, and
further (b) desiring, wishing, and generally all other modes of
appetition, belong to soul, and (c) the local movements of
animals, and (d) growth, maturity, and decay are produced by
the soul, we must ask whether each of these is an attribute of
the soul as a whole, i.e. whether it is with the whole soul we
think, perceive, move ourselves, act or are acted upon, or
whether each of them requires a different part of the soul? So
too with regard to life. Does it depend on one of the parts of
soul? Or is it dependent on more than one? Or on all? Or has it
some quite other cause?
Some hold that the soul is divisible, and that one part thinks,
another desires. If, then, its nature admits of its being divided,
what can it be that holds the parts together? Surely not the
body; on the contrary it seems rather to be the soul that holds
the body together; at any rate when the soul departs the body
disintegrates and decays. If, then, there is something else which
makes the soul one, this unifying agency would have the best
right to the name of soul, and we shall have to repeat for it the
question: Is it one or multipartite? If it is one, why not at once
admit that 'the soul' is one? If it has parts, once more the
question must be put: What holds its parts together, and so ad
infinitum?
The question might also be raised about the parts of the soul:
What is the separate role of each in relation to the body? For, if
the whole soul holds together the whole body, we should expect
each part of the soul to hold together a part of the body. But this
1185
seems an impossibility; it is difficult even to imagine what sort
of bodily part mind will hold together, or how it will do this.
It is a fact of observation that plants and certain insects go on
living when divided into segments; this means that each of the
segments has a soul in it identical in species, though not
numerically identical in the different segments, for both of the
segments for a time possess the power of sensation and local
movement. That this does not last is not surprising, for they no
longer possess the organs necessary for self-maintenance. But,
all the same, in each of the bodily parts there are present all the
parts of soul, and the souls so present are homogeneous with
one another and with the whole; this means that the several
parts of the soul are indisseverable from one another, although
the whole soul is divisible. It seems also that the principle found
in plants is also a kind of soul; for this is the only principle
which is common to both animals and plants; and this exists in
isolation from the principle of sensation, though there nothing
which has the latter without the former.
Book II
Let the foregoing suffice as our account of the views concerning
the soul which have been handed on by our predecessors; let us
now dismiss them and make as it were a completely fresh start,
1186
endeavouring to give a precise answer to the question, What is
soul? i.e. to formulate the most general possible definition of it.
We are in the habit of recognizing, as one determinate kind of
what is, substance, and that in several senses, (a) in the sense of
matter or that which in itself is not 'a this', and (b) in the sense
of form or essence, which is that precisely in virtue of which a
thing is called 'a this', and thirdly (c) in the sense of that which
is compounded of both (a) and (b). Now matter is potentiality,
form actuality; of the latter there are two grades related to one
another as e.g. knowledge to the exercise of knowledge.
Among substances are by general consent reckoned bodies and
especially natural bodies; for they are the principles of all other
bodies. Of natural bodies some have life in them, others not; by
life we mean self-nutrition and growth (with its correlative
decay). It follows that every natural body which has life in it is a
substance in the sense of a composite.
But since it is also a body of such and such a kind, viz. having
life, the body cannot be soul; the body is the subject or matter,
not what is attributed to it. Hence the soul must be a substance
in the sense of the form of a natural body having life potentially
within it. But substance is actuality, and thus soul is the
actuality of a body as above characterized. Now the word
actuality has two senses corresponding respectively to the
possession of knowledge and the actual exercise of knowledge.
It is obvious that the soul is actuality in the first sense, viz. that
of knowledge as possessed, for both sleeping and waking
presuppose the existence of soul, and of these waking
corresponds to actual knowing, sleeping to knowledge
possessed but not employed, and, in the history of the
individual, knowledge comes before its employment or exercise.
That is why the soul is the first grade of actuality of a natural
body having life potentially in it. The body so described is a body
1187
which is organized. The parts of plants in spite of their extreme
simplicity are 'organs'; e.g. the leaf serves to shelter the
pericarp, the pericarp to shelter the fruit, while the roots of
plants are analogous to the mouth of animals, both serving for
the absorption of food. If, then, we have to give a general
formula applicable to all kinds of soul, we must describe it as
the first grade of actuality of a natural organized body. That is
why we can wholly dismiss as unnecessary the question
whether the soul and the body are one: it is as meaningless as
to ask whether the wax and the shape given to it by the stamp
are one, or generally the matter of a thing and that of which it is
the matter. Unity has many senses (as many as 'is' has), but the
most proper and fundamental sense of both is the relation of an
actuality to that of which it is the actuality. We have now given
an answer to the question, what is soul? - an answer which
applies to it in its full extent. It is substance in the sense which
corresponds to the definitive formula of a thing's essence. That
means that it is 'the essential whatness' of a body of the
character just assigned. Suppose that what is literally an 'organ',
like an axe, were a natural body, its 'essential whatness', would
have been its essence, and so its soul; if this disappeared from
it, it would have ceased to be an axe, except in name. As it is, it
is just an axe; it wants the character which is required to make
its whatness or formulable essence a soul; for that, it would
have had to be a natural body of a particular kind, viz. one
having in itself the power of setting itself in movement and
arresting itself. Next, apply this doctrine in the case of the
'parts' of the living body. Suppose that the eye were an animal-
sight would have been its soul, for sight is the substance or
essence of the eye which corresponds to the formula, the eye
being merely the matter of seeing; when seeing is removed the
eye is no longer an eye, except in name - it is no more a real eye
than the eye of a statue or of a painted figure. We must now
extend our consideration from the 'parts' to the whole living
1188
body; for what the departmental sense is to the bodily part
which is its organ, that the whole faculty of sense is to the
whole sensitive body as such.
We must not understand by that which is 'potentially capable of
living' what has lost the soul it had, but only what still retains
it; but seeds and fruits are bodies which possess the
qualification. Consequently, while waking is actuality in a sense
corresponding to the cutting and the seeing, the soul is
actuality in the sense corresponding to the power of sight and
the power in the tool; the body corresponds to what exists in
potentiality; as the pupil plus the power of sight constitutes the
eye, so the soul plus the body constitutes the animal.
From this it indubitably follows that the soul is inseparable from
its body, or at any rate that certain parts of it are (if it has parts)
for the actuality of some of them is nothing but the actualities
of their bodily parts. Yet some may be separable because they
are not the actualities of any body at all. Further, we have no
light on the problem whether the soul may not be the actuality
of its body in the sense in which the sailor is the actuality of the
ship.
This must suffice as our sketch or outline determination of the
nature of soul.
Since what is clear or logically more evident emerges from what
in itself is confused but more observable by us, we must
reconsider our results from this point of view. For it is not
enough for a definitive formula to express as most now do the
mere fact; it must include and exhibit the ground also. At
1189
present definitions are given in a form analogous to the
conclusion of a syllogism; e.g. What is squaring? The
construction of an equilateral rectangle equal to a given oblong
rectangle. Such a definition is in form equivalent to a
conclusion. One that tells us that squaring is the discovery of a
line which is a mean proportional between the two unequal
sides of the given rectangle discloses the ground of what is
defined.
We resume our inquiry from a fresh starting-point by calling
attention to the fact that what has soul in it differs from what
has not, in that the former displays life. Now this word has
more than one sense, and provided any one alone of these is
found in a thing we say that thing is living. Living, that is, may
mean thinking or perception or local movement and rest, or
movement in the sense of nutrition, decay and growth. Hence
we think of plants also as living, for they are observed to
possess in themselves an originative power through which they
increase or decrease in all spatial directions; they grow up and
down, and everything that grows increases its bulk alike in both
directions or indeed in all, and continues to live so long as it can
absorb nutriment.
This power of self-nutrition can be isolated from the other
powers mentioned, but not they from it - in mortal beings at
least. The fact is obvious in plants; for it is the only psychic
power they possess.
This is the originative power the possession of which leads us to
speak of things as living at all, but it is the possession of
sensation that leads us for the first time to speak of living
things as animals; for even those beings which possess no
power of local movement but do possess the power of sensation
we call animals and not merely living things.
1190
The primary form of sense is touch, which belongs to all
animals, just as the power of self-nutrition can be isolated from
touch and sensation generally, so touch can be isolated from all
other forms of sense. (By the power of self-nutrition we mean
that departmental power of the soul which is common to plants
and animals: all animals whatsoever are observed to have the
sense of touch.) What the explanation of these two facts is, we
must discuss later. At present we must confine ourselves to
saying that soul is the source of these phenomena and is
characterized by them, viz. by the powers of self-nutrition,
sensation, thinking, and motivity.
Is each of these a soul or a part of a soul? And if a part, a part in
what sense? A part merely distinguishable by definition or a
part distinct in local situation as well? In the case of certain of
these powers, the answers to these questions are easy, in the
case of others we are puzzled what to say. just as in the case of
plants which when divided are observed to continue to live
though removed to a distance from one another (thus showing
that in their case the soul of each individual plant before
division was actually one, potentially many), so we notice a
similar result in other varieties of soul, i.e. in insects which have
been cut in two; each of the segments possesses both sensation
and local movement; and if sensation, necessarily also
imagination and appetition; for, where there is sensation, there
is also pleasure and pain, and, where these, necessarily also
desire.
We have no evidence as yet about mind or the power to think; it
seems to be a widely different kind of soul, differing as what is
eternal from what is perishable; it alone is capable of existence
in isolation from all other psychic powers. All the other parts of
soul, it is evident from what we have said, are, in spite of certain
statements to the contrary, incapable of separate existence
though, of course, distinguishable by definition. If opining is
1191
distinct from perceiving, to be capable of opining and to be
capable of perceiving must be distinct, and so with all the other
forms of living above enumerated. Further, some animals
possess all these parts of soul, some certain of them only,
others one only (this is what enables us to classify animals); the
cause must be considered later.' A similar arrangement is found
also within the field of the senses; some classes of animals have
all the senses, some only certain of them, others only one, the
most indispensable, touch.
Since the expression 'that whereby we live and perceive' has
two meanings, just like the expression 'that whereby we know'
- that may mean either (a) knowledge or (b) the soul, for we can
speak of knowing by or with either, and similarly that whereby
we are in health may be either (a) health or (b) the body or some
part of the body; and since of the two terms thus contrasted
knowledge or health is the name of a form, essence, or ratio, or
if we so express it an actuality of a recipient matter - knowledge
of what is capable of knowing, health of what is capable of
being made healthy (for the operation of that which is capable
of originating change terminates and has its seat in what is
changed or altered); further, since it is the soul by or with which
primarily we live, perceive, and think: - it follows that the soul
must be a ratio or formulable essence, not a matter or subject.
For, as we said, word substance has three meanings form,
matter, and the complex of both and of these three what is
called matter is potentiality, what is called form actuality. Since
then the complex here is the living thing, the body cannot be
the actuality of the soul; it is the soul which is the actuality of a
certain kind of body. Hence the Tightness of the view that the
soul cannot be without a body, while it csnnot he a body; it is
not a body but something relative to a body. That is why it is in a
body, and a body of a definite kind. It was a mistake, therefore,
to do as former thinkers did, merely to fit it into a body without
adding a definite specification of the kind or character of that
1192
body. Reflection confirms the observed fact; the actuality of any
given thing can only be realized in what is already potentially
that thing, i.e. in a matter of its own appropriate to it. From all
this it follows that soul is an actuality or formulable essence of
something that possesses a potentiality of being besouled.
Of the psychic powers above enumerated some kinds of living
things, as we have said, possess all, some less than all, others
one only. Those we have mentioned are the nutritive, the
appetitive, the sensory, the locomotive, and the power of
thinking. Plants have none but the first, the nutritive, while
another order of living things has this plus the sensory. If any
order of living things has the sensory, it must also have the
appetitive; for appetite is the genus of which desire, passion,
and wish are the species; now all animals have one sense at
least, viz. touch, and whatever has a sense has the capacity for
pleasure and pain and therefore has pleasant and painful
objects present to it, and wherever these are present, there is
desire, for desire is just appetition of what is pleasant. Further,
all animals have the sense for food (for touch is the sense for
food); the food of all living things consists of what is dry, moist,
hot, cold, and these are the qualities apprehended by touch; all
other sensible qualities are apprehended by touch only
indirectly. Sounds, colours, and odours contribute nothing to
nutriment; flavours fall within the field of tangible qualities.
Hunger and thirst are forms of desire, hunger a desire for what
is dry and hot, thirst a desire for what is cold and moist; flavour
is a sort of seasoning added to both. We must later clear up
these points, but at present it may be enough to say that all
animals that possess the sense of touch have also appetition.
1193
The case of imagination is obscure; we must examine it later.
Certain kinds of animals possess in addition the power of
locomotion, and still another order of animate beings, i.e. man
and possibly another order like man or superior to him, the
power of thinking, i.e. mind. It is now evident that a single
definition can be given of soul only in the same sense as one
can be given of figure. For, as in that case there is no figure
distinguishable and apart from triangle, &c, so here there is no
soul apart from the forms of soul just enumerated. It is true that
a highly general definition can be given for figure which will fit
all figures without expressing the peculiar nature of any figure.
So here in the case of soul and its specific forms. Hence it is
absurd in this and similar cases to demand an absolutely
general definition which will fail to express the peculiar nature
of anything that is, or again, omitting this, to look for separate
definitions corresponding to each infima species. The cases of
figure and soul are exactly parallel; for the particulars
subsumed under the common name in both cases - figures and
living beings - constitute a series, each successive term of
which potentially contains its predecessor, e.g. the square the
triangle, the sensory power the self-nutritive. Hence we must
ask in the case of each order of living things, What is its soul, i.e.
What is the soul of plant, animal, man? Why the terms are
related in this serial way must form the subject of later
examination. But the facts are that the power of perception is
never found apart from the power of self-nutrition, while - in
plants - the latter is found isolated from the former. Again, no
sense is found apart from that of touch, while touch is found by
itself; many animals have neither sight, hearing, nor smell.
Again, among living things that possess sense some have the
power of locomotion, some not. Lastly, certain living beings - a
small minority - possess calculation and thought, for (among
mortal beings) those which possess calculation have all the
other powers above mentioned, while the converse does not
1194
hold - indeed some live by imagination alone, while others have
not even imagination. The mind that knows with immediate
intuition presents a different problem.
It is evident that the way to give the most adequate definition of
soul is to seek in the case of each of its forms for the most
appropriate definition.
It is necessary for the student of these forms of soul first to find
a definition of each, expressive of what it is, and then to
investigate its derivative properties, &c. But if we are to express
what each is, viz. what the thinking power is, or the perceptive,
or the nutritive, we must go farther back and first give an
account of thinking or perceiving, for in the order of
investigation the question of what an agent does precedes the
question, what enables it to do what it does. If this is correct, we
must on the same ground go yet another step farther back and
have some clear view of the objects of each; thus we must start
with these objects, e.g. with food, with what is perceptible, or
with what is intelligible.
It follows that first of all we must treat of nutrition and
reproduction, for the nutritive soul is found along with all the
others and is the most primitive and widely distributed power
of soul, being indeed that one in virtue of which all are said to
have life. The acts in which it manifests itself are reproduction
and the use of food - reproduction, I say, because for any living
thing that has reached its normal development and which is
unmutilated, and whose mode of generation is not
spontaneous, the most natural act is the production of another
like itself, an animal producing an animal, a plant a plant, in
1195
order that, as far as its nature allows, it may partake in the
eternal and divine. That is the goal towards which all things
strive, that for the sake of which they do whatsoever their
nature renders possible. The phrase 'for the sake of which' is
ambiguous; it may mean either (a) the end to achieve which, or
(b) the being in whose interest, the act is done. Since then no
living thing is able to partake in what is eternal and divine by
uninterrupted continuance (for nothing perishable can for ever
remain one and the same), it tries to achieve that end in the
only way possible to it, and success is possible in varying
degrees; so it remains not indeed as the self-same individual
but continues its existence in something like itself - not
numerically but specifically one.
The soul is the cause or source of the living body. The terms
cause and source have many senses. But the soul is the cause of
its body alike in all three senses which we explicitly recognize.
It is (a) the source or origin of movement, it is (b) the end, it is (c)
the essence of the whole living body.
That it is the last, is clear; for in everything the essence is
identical with the ground of its being, and here, in the case of
living things, their being is to live, and of their being and their
living the soul in them is the cause or source. Further, the
actuality of whatever is potential is identical with its formulable
essence.
It is manifest that the soul is also the final cause of its body. For
Nature, like mind, always does whatever it does for the sake of
something, which something is its end. To that something
corresponds in the case of animals the soul and in this it
follows the order of nature; all natural bodies are organs of the
soul. This is true of those that enter into the constitution of
plants as well as of those which enter into that of animals. This
shows that that the sake of which they are is soul. We must
1196
here recall the two senses of that for the sake of which', viz. (a)
the end to achieve which, and (b) the being in whose interest,
anything is or is done.
We must maintain, further, that the soul is also the cause of the
living body as the original source of local movement. The power
of locomotion is not found, however, in all living things. But
change of quality and change of quantity are also due to the
soul. Sensation is held to be a qualitative alteration, and
nothing except what has soul in it is capable of sensation. The
same holds of the quantitative changes which constitute
growth and decay; nothing grows or decays naturally except
what feeds itself, and nothing feeds itself except what has a
share of soul in it.
Empedocles is wrong in adding that growth in plants is to be
explained, the downward rooting by the natural tendency of
earth to travel downwards, and the upward branching by the
similar natural tendency of fire to travel upwards. For he
misinterprets up and down; up and down are not for all things
what they are for the whole Cosmos: if we are to distinguish
and identify organs according to their functions, the roots of
plants are analogous to the head in animals. Further, we must
ask what is the force that holds together the earth and the fire
which tend to travel in contrary directions; if there is no
counteracting force, they will be torn asunder; if there is, this
must be the soul and the cause of nutrition and growth. By
some the element of fire is held to be the cause of nutrition and
growth, for it alone of the primary bodies or elements is
observed to feed and increase itself. Hence the suggestion that
in both plants and animals it is it which is the operative force. A
concurrent cause in a sense it certainly is, but not the principal
cause, that is rather the soul; for while the growth of fire goes
on without limit so long as there is a supply of fuel, in the case
of all complex wholes formed in the course of nature there is a
1197
limit or ratio which determines their size and increase, and
limit and ratio are marks of soul but not of fire, and belong to
the side of formulable essence rather than that of matter.
Nutrition and reproduction are due to one and the same psychic
power. It is necessary first to give precision to our account of
food, for it is by this function of absorbing food that this psychic
power is distinguished from all the others. The current view is
that what serves as food to a living thing is what is contrary to
it - not that in every pair of contraries each is food to the other:
to be food a contrary must not only be transformable into the
other and vice versa, it must also in so doing increase the bulk
of the other. Many a contrary is transformed into its other and
vice versa, where neither is even a quantum and so cannot
increase in bulk, e.g. an invalid into a healthy subject. It is clear
that not even those contraries which satisfy both the conditions
mentioned above are food to one another in precisely the same
sense; water may be said to feed fire, but not fire water. Where
the members of the pair are elementary bodies only one of the
contraries, it would appear, can be said to feed the other. But
there is a difficulty here. One set of thinkers assert that like fed,
as well as increased in amount, by like. Another set, as we have
said, maintain the very reverse, viz. that what feeds and what is
fed are contrary to one another; like, they argue, is incapable of
being affected by like; but food is changed in the process of
digestion, and change is always to what is opposite or to what is
intermediate. Further, food is acted upon by what is nourished
by it, not the other way round, as timber is worked by a
carpenter and not conversely; there is a change in the carpenter
but it is merely a change from not-working to working. In
answering this problem it makes all the difference whether we
mean by 'the food' the 'finished' or the 'raw' product. If we use
the word food of both, viz. of the completely undigested and the
completely digested matter, we can justify both the rival
accounts of it; taking food in the sense of undigested matter, it
1198
is the contrary of what is fed by it, taking it as digested it is like
what is fed by it. Consequently it is clear that in a certain sense
we may say that both parties are right, both wrong.
Since nothing except what is alive can be fed, what is fed is the
besouled body and just because it has soul in it. Hence food is
essentially related to what has soul in it. Food has a power
which is other than the power to increase the bulk of what is
fed by it; so far forth as what has soul in it is a quantum, food
may increase its quantity, but it is only so far as what has soul
in it is a 'this-somewhat' or substance that food acts as food; in
that case it maintains the being of what is fed, and that
continues to be what it is so long as the process of nutrition
continues. Further, it is the agent in generation, i.e. not the
generation of the individual fed but the reproduction of another
like it; the substance of the individual fed is already in
existence; the existence of no substance is a self-generation but
only a self-maintenance.
Hence the psychic power which we are now studying may be
described as that which tends to maintain whatever has this
power in it of continuing such as it was, and food helps it to do
its work. That is why, if deprived of food, it must cease to be.
The process of nutrition involves three factors, (a) what is fed,
(b) that wherewith it is fed, (c) what does the feeding; of these
(c) is the first soul, (a) the body which has that soul in it, (b) the
food. But since it is right to call things after the ends they
realize, and the end of this soul is to generate another being like
that in which it is, the first soul ought to be named the
reproductive soul. The expression (b) 'wherewith it is fed' is
ambiguous just as is the expression 'wherewith the ship is
steered'; that may mean either (i) the hand or (ii) the rudder, i.e.
either (i) what is moved and sets in movement, or (ii) what is
merely moved. We can apply this analogy here if we recall that
1199
all food must be capable of being digested, and that what
produces digestion is warmth; that is why everything that has
soul in it possesses warmth.
We have now given an outline account of the nature of food;
further details must be given in the appropriate place.
Having made these distinctions let us now speak of sensation in
the widest sense. Sensation depends, as we have said, on a
process of movement or affection from without, for it is held to
be some sort of change of quality. Now some thinkers assert
that like is affected only by like; in what sense this is possible
and in what sense impossible, we have explained in our general
discussion of acting and being acted upon.
Here arises a problem: why do we not perceive the senses
themselves as well as the external objects of sense, or why
without the stimulation of external objects do they not produce
sensation, seeing that they contain in themselves fire, earth,
and all the other elements, which are the direct or indirect
objects is so of sense? It is clear that what is sensitive is only
potentially, not actually. The power of sense is parallel to what
is combustible, for that never ignites itself spontaneously, but
requires an agent which has the power of starting ignition;
otherwise it could have set itself on fire, and would not have
needed actual fire to set it ablaze.
In reply we must recall that we use the word 'perceive' in two
ways, for we say (a) that what has the power to hear or see,
'sees' or 'hears', even though it is at the moment asleep, and
also (b) that what is actually seeing or hearing, 'sees' or 'hears'.
1200
Hence 'sense' too must have two meanings, sense potential, and
sense actual. Similarly 'to be a sentient' means either (a) to have
a certain power or (b) to manifest a certain activity. To begin
with, for a time, let us speak as if there were no difference
between (i) being moved or affected, and (ii) being active, for
movement is a kind of activity - an imperfect kind, as has
elsewhere been explained. Everything that is acted upon or
moved is acted upon by an agent which is actually at work.
Hence it is that in one sense, as has already been stated, what
acts and what is acted upon are like, in another unlike, i.e. prior
to and during the change the two factors are unlike, after it like.
But we must now distinguish not only between what is
potential and what is actual but also different senses in which
things can be said to be potential or actual; up to now we have
been speaking as if each of these phrases had only one sense.
We can speak of something as 'a knower' either (a) as when we
say that man is a knower, meaning that man falls within the
class of beings that know or have knowledge, or (b) as when we
are speaking of a man who possesses a knowledge of grammar;
each of these is so called as having in him a certain potentiality,
but there is a difference between their respective potentialities,
the one (a) being a potential knower, because his kind or matter
is such and such, the other (b), because he can in the absence of
any external counteracting cause realize his knowledge in
actual knowing at will. This implies a third meaning of 'a
knower' (c), one who is already realizing his knowledge - he is a
knower in actuality and in the most proper sense is knowing,
e.g. this A. Both the former are potential knowers, who realize
their respective potentialities, the one (a) by change of quality,
i.e. repeated transitions from one state to its opposite under
instruction, the other (b) by the transition from the inactive
possession of sense or grammar to their active exercise. The two
kinds of transition are distinct.
1201
Also the expression 'to be acted upon' has more than one
meaning; it may mean either (a) the extinction of one of two
contraries by the other, or (b) the maintenance of what is
potential by the agency of what is actual and already like what
is acted upon, with such likeness as is compatible with one's
being actual and the other potential. For what possesses
knowledge becomes an actual knower by a transition which is
either not an alteration of it at all (being in reality a
development into its true self or actuality) or at least an
alteration in a quite different sense from the usual meaning.
Hence it is wrong to speak of a wise man as being 'altered'
when he uses his wisdom, just as it would be absurd to speak of
a builder as being altered when he is using his skill in building a
house.
What in the case of knowing or understanding leads from
potentiality to actuality ought not to be called teaching but
something else. That which starting with the power to know
learns or acquires knowledge through the agency of one who
actually knows and has the power of teaching either (a) ought
not to be said 'to be acted upon' at all or (b) we must recognize
two senses of alteration, viz. (i) the substitution of one quality
for another, the first being the contrary of the second, or (ii) the
development of an existent quality from potentiality in the
direction of fixity or nature.
In the case of what is to possess sense, the first transition is due
to the action of the male parent and takes place before birth so
that at birth the living thing is, in respect of sensation, at the
stage which corresponds to the possession of knowledge. Actual
sensation corresponds to the stage of the exercise of knowledge.
But between the two cases compared there is a difference; the
objects that excite the sensory powers to activity, the seen, the
heard, &c, are outside. The ground of this difference is that
1202
what actual sensation apprehends is individuals, while what
knowledge apprehends is universals, and these are in a sense
within the soul. That is why a man can exercise his knowledge
when he wishes, but his sensation does not depend upon
himself a sensible object must be there. A similar statement
must be made about our knowledge of what is sensible - on the
same ground, viz. that the sensible objects are individual and
external.
A later more appropriate occasion may be found thoroughly to
clear up all this. At present it must be enough to recognize the
distinctions already drawn; a thing may be said to be potential
in either of two senses, (a) in the sense in which we might say
of a boy that he may become a general or (b) in the sense in
which we might say the same of an adult, and there are two
corresponding senses of the term 'a potential sentient'. There
are no separate names for the two stages of potentiality; we
have pointed out that they are different and how they are
different. We cannot help using the incorrect terms 'being acted
upon or altered' of the two transitions involved. As we have
said, has the power of sensation is potentially like what the
perceived object is actually; that is, while at the beginning of the
process of its being acted upon the two interacting factors are
dissimilar, at the end the one acted upon is assimilated to the
other and is identical in quality with it.
In dealing with each of the senses we shall have first to speak of
the objects which are perceptible by each. The term 'object of
sense' covers three kinds of objects, two kinds of which are, in
our language, directly perceptible, while the remaining one is
1203
only incidentally perceptible. Of the first two kinds one (a)
consists of what is perceptible by a single sense, the other (b) of
what is perceptible by any and all of the senses. I call by the
name of special object of this or that sense that which cannot
be perceived by any other sense than that one and in respect of
which no error is possible; in this sense colour is the special
object of sight, sound of hearing, flavour of taste. Touch, indeed,
discriminates more than one set of different qualities. Each
sense has one kind of object which it discerns, and never errs in
reporting that what is before it is colour or sound (though it
may err as to what it is that is coloured or where that is, or what
it is that is sounding or where that is.) Such objects are what we
propose to call the special objects of this or that sense.
'Common sensibles' are movement, rest, number, figure,
magnitude; these are not peculiar to any one sense, but are
common to all. There are at any rate certain kinds of movement
which are perceptible both by touch and by sight.
We speak of an incidental object of sense where e.g. the white
object which we see is the son of Diares; here because 'being the
son of Diares' is incidental to the directly visible white patch we
speak of the son of Diares as being (incidentally) perceived or
seen by us. Because this is only incidentally an object of sense,
it in no way as such affects the senses. Of the two former kinds,
both of which are in their own nature perceptible by sense, the
first kind - that of special objects of the several senses -
constitute the objects of sense in the strictest sense of the term
and it is to them that in the nature of things the structure of
each several sense is adapted.
1204
The object of sight is the visible, and what is visible is (a) colour
and (b) a certain kind of object which can be described in words
but which has no single name; what we mean by (b) will be
abundantly clear as we proceed. Whatever is visible is colour
and colour is what lies upon what is in its own nature visible;
'in its own nature' here means not that visibility is involved in
the definition of what thus underlies colour, but that that
substratum contains in itself the cause of visibility. Every colour
has in it the power to set in movement what is actually
transparent; that power constitutes its very nature. That is why
it is not visible except with the help of light; it is only in light
that the colour of a thing is seen. Hence our first task is to
explain what light is.
Now there clearly is something which is transparent, and by
'transparent' I mean what is visible, and yet not visible in itself,
but rather owing its visibility to the colour of something else; of
this character are air, water, and many solid bodies. Neither air
nor water is transparent because it is air or water; they are
transparent because each of them has contained in it a certain
substance which is the same in both and is also found in the
eternal body which constitutes the uppermost shell of the
physical Cosmos. Of this substance light is the activity - the
activity of what is transparent so far forth as it has in it the
determinate power of becoming transparent; where this power
is present, there is also the potentiality of the contrary, viz.
darkness. Light is as it were the proper colour of what is
transparent, and exists whenever the potentially transparent is
excited to actuality by the influence of fire or something
resembling 'the uppermost body'; for fire too contains
something which is one and the same with the substance in
question.
1205
We have now explained what the transparent is and what light
is; light is neither fire nor any kind whatsoever of body nor an
efflux from any kind of body (if it were, it would again itself be a
kind of body) - it is the presence of fire or something resembling
fire in what is transparent. It is certainly not a body, for two
bodies cannot be present in the same place. The opposite of
light is darkness; darkness is the absence from what is
transparent of the corresponding positive state above
characterized; clearly therefore, light is just the presence of
that.
Empedocles (and with him all others who used the same forms
of expression) was wrong in speaking of light as 'travelling' or
being at a given moment between the earth and its envelope, its
movement being unobservable by us; that view is contrary both
to the clear evidence of argument and to the observed facts; if
the distance traversed were short, the movement might have
been unobservable, but where the distance is from extreme East
to extreme West, the draught upon our powers of belief is too
great.
What is capable of taking on colour is what in itself is
colourless, as what can take on sound is what is soundless;
what is colourless includes (a) what is transparent and (b) what
is invisible or scarcely visible, i.e. what is 'dark'. The latter (b) is
the same as what is transparent, when it is potentially, not of
course when it is actually transparent; it is the same substance
which is now darkness, now light.
Not everything that is visible depends upon light for its
visibility. This is only true of the 'proper' colour of things. Some
objects of sight which in light are invisible, in darkness
stimulate the sense; that is, things that appear fiery or shining.
This class of objects has no simple common name, but
instances of it are fungi, flesh, heads, scales, and eyes offish. In
1206
none of these is what is seen their own proper' colour. Why we
see these at all is another question. At present what is obvious
is that what is seen in light is always colour. That is why
without the help of light colour remains invisible. Its being
colour at all means precisely its having in it the power to set in
movement what is already actually transparent, and, as we have
seen, the actuality of what is transparent is just light.
The following experiment makes the necessity of a medium
clear. If what has colour is placed in immediate contact with the
eye, it cannot be seen. Colour sets in movement not the sense
organ but what is transparent, e.g. the air, and that, extending
continuously from the object to the organ, sets the latter in
movement. Democritus misrepresents the facts when he
expresses the opinion that if the interspace were empty one
could distinctly see an ant on the vault of the sky; that is an
impossibility. Seeing is due to an affection or change of what
has the perceptive faculty, and it cannot be affected by the seen
colour itself; it remains that it must be affected by what comes
between. Hence it is indispensable that there be something in
between - if there were nothing, so far from seeing with greater
distinctness, we should see nothing at all.
We have now explained the cause why colour cannot be seen
otherwise than in light. Fire on the other hand is seen both in
darkness and in light; this double possibility follows necessarily
from our theory, for it is just fire that makes what is potentially
transparent actually transparent.
The same account holds also of sound and smell; if the object of
either of these senses is in immediate contact with the organ no
sensation is produced. In both cases the object sets in
movement only what lies between, and this in turn sets the
organ in movement: if what sounds or smells is brought into
immediate contact with the organ, no sensation will be
1207
produced. The same, in spite of all appearances, applies also to
touch and taste; why there is this apparent difference will be
clear later. What comes between in the case of sounds is air; the
corresponding medium in the case of smell has no name. But,
corresponding to what is transparent in the case of colour, there
is a quality found both in air and water, which serves as a
medium for what has smell - I say 'in water' because animals
that live in water as well as those that live on land seem to
possess the sense of smell, and 'in air' because man and all
other land animals that breathe, perceive smells only when
they breathe air in. The explanation of this too will be given
later.
8
Now let us, to begin with, make certain distinctions about
sound and hearing.
Sound may mean either of two things (a) actual, and (b)
potential, sound. There are certain things which, as we say,
'have no sound', e.g. sponges or wool, others which have, e.g.
bronze and in general all things which are smooth and solid -
the latter are said to have a sound because they can make a
sound, i.e. can generate actual sound between themselves and
the organ of hearing.
Actual sound requires for its occurrence (i, ii) two such bodies
and (iii) a space between them; for it is generated by an impact.
Hence it is impossible for one body only to generate a sound -
there must be a body impinging and a body impinged upon;
what sounds does so by striking against something else, and
this is impossible without a movement from place to place.
1208
As we have said, not all bodies can by impact on one another
produce sound; impact on wool makes no sound, while the
impact on bronze or any body which is smooth and hollow
does. Bronze gives out a sound when struck because it is
smooth; bodies which are hollow owing to reflection repeat the
original impact over and over again, the body originally set in
movement being unable to escape from the concavity.
Further, we must remark that sound is heard both in air and in
water, though less distinctly in the latter. Yet neither air nor
water is the principal cause of sound. What is required for the
production of sound is an impact of two solids against one
another and against the air. The latter condition is satisfied
when the air impinged upon does not retreat before the blow,
i.e. is not dissipated by it.
That is why it must be struck with a sudden sharp blow, if it is
to sound - the movement of the whip must outrun the
dispersion of the air, just as one might get in a stroke at a heap
or whirl of sand as it was traveling rapidly past.
An echo occurs, when, a mass of air having been unified,
bounded, and prevented from dissipation by the containing
walls of a vessel, the air originally struck by the impinging body
and set in movement by it rebounds from this mass of air like a
ball from a wall. It is probable that in all generation of sound
echo takes place, though it is frequently only indistinctly heard.
What happens here must be analogous to what happens in the
case of light; light is always reflected - otherwise it would not
be diffused and outside what was directly illuminated by the
sun there would be blank darkness; but this reflected light is
not always strong enough, as it is when it is reflected from
water, bronze, and other smooth bodies, to cast a shadow, which
is the distinguishing mark by which we recognize light.
1209
It is rightly said that an empty space plays the chief part in the
production of hearing, for what people mean by 'the vacuum' is
the air, which is what causes hearing, when that air is set in
movement as one continuous mass; but owing to its friability it
emits no sound, being dissipated by impinging upon any
surface which is not smooth. When the surface on which it
impinges is quite smooth, what is produced by the original
impact is a united mass, a result due to the smoothness of the
surface with which the air is in contact at the other end.
What has the power of producing sound is what has the power
of setting in movement a single mass of air which is continuous
from the impinging body up to the organ of hearing. The organ
of hearing is physically united with air, and because it is in air,
the air inside is moved concurrently with the air outside. Hence
animals do not hear with all parts of their bodies, nor do all
parts admit of the entrance of air; for even the part which can
be moved and can sound has not air everywhere in it. Air in
itself is, owing to its friability, quite soundless; only when its
dissipation is prevented is its movement sound. The air in the
ear is built into a chamber just to prevent this dissipating
movement, in order that the animal may accurately apprehend
all varieties of the movements of the air outside. That is why we
hear also in water, viz. because the water cannot get into the air
chamber or even, owing to the spirals, into the outer ear. If this
does happen, hearing ceases, as it also does if the tympanic
membrane is damaged, just as sight ceases if the membrane
covering the pupil is damaged. It is also a test of deafness
whether the ear does or does not reverberate like a horn; the air
inside the ear has always a movement of its own, but the sound
we hear is always the sounding of something else, not of the
organ itself. That is why we say that we hear with what is
empty and echoes, viz. because what we hear with is a chamber
which contains a bounded mass of air.
1210
Which is it that 'sounds', the striking body or the struck? Is not
the answer 'it is both, but each in a different way? Sound is a
movement of what can rebound from a smooth surface when
struck against it. As we have explained' not everything sounds
when it strikes or is struck, e.g. if one needle is struck against
another, neither emits any sound. In order, therefore, that sound
may be generated, what is struck must be smooth, to enable the
air to rebound and be shaken off from it in one piece.
The distinctions between different sounding bodies show
themselves only in actual sound; as without the help of light
colours remain invisible, so without the help of actual sound
the distinctions between acute and grave sounds remain
inaudible. Acute and grave are here metaphors, transferred from
their proper sphere, viz. that of touch, where they mean
respectively (a) what moves the sense much in a short time, (b)
what moves the sense little in a long time. Not that what is
sharp really moves fast, and what is grave, slowly, but that the
difference in the qualities of the one and the other movement is
due to their respective speeds. There seems to be a sort of
parallelism between what is acute or grave to hearing and what
is sharp or blunt to touch; what is sharp as it were stabs, while
what is blunt pushes, the one producing its effect in a short, the
other in a long time, so that the one is quick, the other slow.
Let the foregoing suffice as an analysis of sound. Voice is a kind
of sound characteristic of what has soul in it; nothing that is
without soul utters voice, it being only by a metaphor that we
speak of the voice of the flute or the lyre or generally of what
(being without soul) possesses the power of producing a
succession of notes which differ in length and pitch and timbre.
The metaphor is based on the fact that all these differences are
found also in voice. Many animals are voiceless, e.g. all non-
sanuineous animals and among sanguineous animals fish. This
is just what we should expect, since voice is a certain
1211
movement of air. The fish, like those in the Achelous, which are
said to have voice, really make the sounds with their gills or
some similar organ. Voice is the sound made by an animal, and
that with a special organ. As we saw, everything that makes a
sound does so by the impact of something (a) against
something else, (b) across a space, (c) filled with air; hence it is
only to be expected that no animals utter voice except those
which take in air. Once air is inbreathed, Nature uses it for two
different purposes, as the tongue is used both for tasting and
for articulating; in that case of the two functions tasting is
necessary for the animal's existence (hence it is found more
widely distributed), while articulate speech is a luxury
subserving its possessor's well-being; similarly in the former
case Nature employs the breath both as an indispensable
means to the regulation of the inner temperature of the living
body and also as the matter of articulate voice, in the interests
of its possessor's well-being. Why its former use is
indispensable must be discussed elsewhere.
The organ of respiration is the windpipe, and the organ to
which this is related as means to end is the lungs. The latter is
the part of the body by which the temperature of land animals
is raised above that of all others. But what primarily requires
the air drawn in by respiration is not only this but the region
surrounding the heart. That is why when animals breathe the
air must penetrate inwards.
Voice then is the impact of the inbreathed air against the
'windpipe', and the agent that produces the impact is the soul
resident in these parts of the body. Not every sound, as we said,
made by an animal is voice (even with the tongue we may
merely make a sound which is not voice, or without the tongue
as in coughing); what produces the impact must have soul in it
and must be accompanied by an act of imagination, for voice is
a sound with a meaning, and is not merely the result of any
1212
impact of the breath as in coughing; in voice the breath in the
windpipe is used as an instrument to knock with against the
walls of the windpipe. This is confirmed by our inability to
speak when we are breathing either out or in - we can only do
so by holding our breath; we make the movements with the
breath so checked. It is clear also why fish are voiceless; they
have no windpipe. And they have no windpipe because they do
not breathe or take in air. Why they do not is a question
belonging to another inquiry.
Smell and its object are much less easy to determine than what
we have hitherto discussed; the distinguishing characteristic of
the object of smell is less obvious than those of sound or colour.
The ground of this is that our power of smell is less
discriminating and in general inferior to that of many species of
animals; men have a poor sense of smell and our apprehension
of its proper objects is inseparably bound up with and so
confused by pleasure and pain, which shows that in us the
organ is inaccurate. It is probable that there is a parallel failure
in the perception of colour by animals that have hard eyes:
probably they discriminate differences of colour only by the
presence or absence of what excites fear, and that it is thus that
human beings distinguish smells. It seems that there is an
analogy between smell and taste, and that the species of tastes
run parallel to those of smells - the only difference being that
our sense of taste is more discriminating than our sense of
smell, because the former is a modification of touch, which
reaches in man the maximum of discriminative accuracy. While
in respect of all the other senses we fall below many species of
animals, in respect of touch we far excel all other species in
1213
exactness of discrimination. That is why man is the most
intelligent of all animals. This is confirmed by the fact that it is
to differences in the organ of touch and to nothing else that the
differences between man and man in respect of natural
endowment are due; men whose flesh is hard are ill-endowed
by nature, men whose flesh is soft, wellendowed.
As flavours may be divided into (a) sweet, (b) bitter, so with
smells. In some things the flavour and the smell have the same
quality, i.e. both are sweet or both bitter, in others they diverge.
Similarly a smell, like a flavour, may be pungent, astringent,
acid, or succulent. But, as we said, because smells are much less
easy to discriminate than flavours, the names of these varieties
are applied to smells only metaphorically; for example 'sweet' is
extended from the taste to the smell of saffron or honey,
'pungent' to that of thyme, and so on.
In the same sense in which hearing has for its object both the
audible and the inaudible, sight both the visible and the
invisible, smell has for its object both the odorous and the
inodorous. 'Inodorous' may be either (a) what has no smell at
all, or (b) what has a small or feeble smell. The same ambiguity
lurks in the word 'tasteless'.
Smelling, like the operation of the senses previously examined,
takes place through a medium, i.e. through air or water - I add
water, because water-animals too (both sanguineous and non-
sanguineous) seem to smell just as much as land-animals; at
any rate some of them make directly for their food from a
distance if it has any scent. That is why the following facts
constitute a problem for us. All animals smell in the same way,
but man smells only when he inhales; if he exhales or holds his
breath, he ceases to smell, no difference being made whether
the odorous object is distant or near, or even placed inside the
nose and actually on the wall of the nostril; it is a disability
1214
common to all the senses not to perceive what is in immediate
contact with the organ of sense, but our failure to apprehend
what is odorous without the help of inhalation is peculiar (the
fact is obvious on making the experiment). Now since bloodless
animals do not breathe, they must, it might be argued, have
some novel sense not reckoned among the usual five. Our reply
must be that this is impossible, since it is scent that is
perceived; a sense that apprehends what is odorous and what
has a good or bad odour cannot be anything but smell. Further,
they are observed to be deleteriously effected by the same
strong odours as man is, e.g. bitumen, sulphur, and the like.
These animals must be able to smell without being able to
breathe. The probable explanation is that in man the organ of
smell has a certain superiority over that in all other animals just
as his eyes have over those of hard-eyed animals. Man's eyes
have in the eyelids a kind of shelter or envelope, which must be
shifted or drawn back in order that we may see, while hardeyed
animals have nothing of the kind, but at once see whatever
presents itself in the transparent medium. Similarly in certain
species of animals the organ of smell is like the eye of hard-
eyed animals, uncurtained, while in others which take in air it
probably has a curtain over it, which is drawn back in
inhalation, owing to the dilating of the veins or pores. That
explains also why such animals cannot smell under water; to
smell they must first inhale, and that they cannot do under
water.
Smells come from what is dry as flavours from what is moist.
Consequently the organ of smell is potentially dry.
1215
10
What can be tasted is always something that can be touched,
and just for that reason it cannot be perceived through an
interposed foreign body, for touch means the absence of any
intervening body. Further, the flavoured and tasteable body is
suspended in a liquid matter, and this is tangible. Hence, if we
lived in water, we should perceive a sweet object introduced
into the water, but the water would not be the medium through
which we perceived; our perception would be due to the
solution of the sweet substance in what we imbibed, just as if it
were mixed with some drink. There is no parallel here to the
perception of colour, which is due neither to any blending of
anything with anything, nor to any efflux of anything from
anything. In the case of taste, there is nothing corresponding to
the medium in the case of the senses previously discussed; but
as the object of sight is colour, so the object of taste is flavour.
But nothing excites a perception of flavour without the help of
liquid; what acts upon the sense of taste must be either actually
or potentially liquid like what is saline; it must be both (a) itself
easily dissolved, and (b) capable of dissolving along with itself
the tongue. Taste apprehends both (a) what has taste and (b)
what has no taste, if we mean by (b) what has only a slight or
feeble flavour or what tends to destroy the sense of taste. In this
it is exactly parallel to sight, which apprehends both what is
visible and what is invisible (for darkness is invisible and yet is
discriminated by sight; so is, in a different way, what is over
brilliant), and to hearing, which apprehends both sound and
silence, of which the one is audible and the other inaudible, and
also over-loud sound. This corresponds in the case of hearing to
over-bright light in the case of sight. As a faint sound is
'inaudible', so in a sense is a loud or violent sound. The word
'invisible' and similar privative terms cover not only (a) what is
simply without some power, but also (b) what is adapted by
nature to have it but has not it or has it only in a very low
1216
degree, as when we say that a species of swallow is 'footless' or
that a variety of fruit is 'stoneless'. So too taste has as its object
both what can be tasted and the tasteless - the latter in the
sense of what has little flavour or a bad flavour or one
destructive of taste. The difference between what is tasteless
and what is not seems to rest ultimately on that between what
is drinkable and what is undrinkable both are tasteable, but the
latter is bad and tends to destroy taste, while the former is the
normal stimulus of taste. What is drinkable is the common
object of both touch and taste.
Since what can be tasted is liquid, the organ for its perception
cannot be either (a) actually liquid or (b) incapable of becoming
liquid. Tasting means a being affected by what can be tasted as
such; hence the organ of taste must be liquefied, and so to start
with must be non-liquid but capable of liquefaction without
loss of its distinctive nature. This is confirmed by the fact that
the tongue cannot taste either when it is too dry or when it is
too moist; in the latter case what occurs is due to a contact with
the pre-existent moisture in the tongue itself, when after a
foretaste of some strong flavour we try to taste another flavour;
it is in this way that sick persons find everything they taste
bitter, viz. because, when they taste, their tongues are
overflowing with bitter moisture.
The species of flavour are, as in the case of colour, (a) simple, i.e.
the two contraries, the sweet and the bitter, (b) secondary, viz. (i)
on the side of the sweet, the succulent, (ii) on the side of the
bitter, the saline, (iii) between these come the pungent, the
harsh, the astringent, and the acid; these pretty well exhaust
the varieties of flavour. It follows that what has the power of
tasting is what is potentially of that kind, and that what is
tasteable is what has the power of making it actually what it
itself already is.
1217
11
Whatever can be said of what is tangible, can be said of touch,
and vice versa; if touch is not a single sense but a group of
senses, there must be several kinds of what is tangible. It is a
problem whether touch is a single sense or a group of senses. It
is also a problem, what is the organ of touch; is it or is it not the
flesh (including what in certain animals is homologous with
flesh)? On the second view, flesh is 'the medium' of touch, the
real organ being situated farther inward. The problem arises
because the field of each sense is according to the accepted
view determined as the range between a single pair of
contraries, white and black for sight, acute and grave for
hearing, bitter and sweet for taste; but in the field of what is
tangible we find several such pairs, hot cold, dry moist, hard
soft, &c. This problem finds a partial solution, when it is recalled
that in the case of the other senses more than one pair of
contraries are to be met with, e.g. in sound not only acute and
grave but loud and soft, smooth and rough, &c; there are
similar contrasts in the field of colour. Nevertheless we are
unable clearly to detect in the case of touch what the single
subject is which underlies the contrasted qualities and
corresponds to sound in the case of hearing.
To the question whether the organ of touch lies inward or not
(i.e. whether we need look any farther than the flesh), no
indication in favour of the second answer can be drawn from
the fact that if the object comes into contact with the flesh it is
at once perceived. For even under present conditions if the
experiment is made of making a web and stretching it tight over
the flesh, as soon as this web is touched the sensation is
reported in the same manner as before, yet it is clear that the or
1218
is gan is not in this membrane. If the membrane could be grown
on to the flesh, the report would travel still quicker. The flesh
plays in touch very much the same part as would be played in
the other senses by an air-envelope growing round our body;
had we such an envelope attached to us we should have
supposed that it was by a single organ that we perceived
sounds, colours, and smells, and we should have taken sight,
hearing, and smell to be a single sense. But as it is, because that
through which the different movements are transmitted is not
naturally attached to our bodies, the difference of the various
sense-organs is too plain to miss. But in the case of touch the
obscurity remains.
There must be such a naturally attached 'medium' as flesh, for
no living body could be constructed of air or water; it must be
something solid. Consequently it must be composed of earth
along with these, which is just what flesh and its analogue in
animals which have no true flesh tend to be. Hence of necessity
the medium through which are transmitted the manifoldly
contrasted tactual qualities must be a body naturally attached
to the organism. That they are manifold is clear when we
consider touching with the tongue; we apprehend at the tongue
all tangible qualities as well as flavour. Suppose all the rest of
our flesh was, like the tongue, sensitive to flavour, we should
have identified the sense of taste and the sense of touch; what
saves us from this identification is the fact that touch and taste
are not always found together in the same part of the body. The
following problem might be raised. Let us assume that every
body has depth, i.e. has three dimensions, and that if two bodies
have a third body between them they cannot be in contact with
one another; let us remember that what is liquid is a body and
must be or contain water, and that if two bodies touch one
another under water, their touching surfaces cannot be dry, but
must have water between, viz. the water which wets their
bounding surfaces; from all this it follows that in water two
1219
bodies cannot be in contact with one another. The same holds
of two bodies in air - air being to bodies in air precisely what
water is to bodies in water - but the facts are not so evident to
our observation, because we live in air, just as animals that live
in water would not notice that the things which touch one
another in water have wet surfaces. The problem, then, is: does
the perception of all objects of sense take place in the same
way, or does it not, e.g. taste and touch requiring contact (as
they are commonly thought to do), while all other senses
perceive over a distance? The distinction is unsound; we
perceive what is hard or soft, as well as the objects of hearing,
sight, and smell, through a 'medium', only that the latter are
perceived over a greater distance than the former; that is why
the facts escape our notice. For we do perceive everything
through a medium; but in these cases the fact escapes us. Yet,
to repeat what we said before, if the medium for touch were a
membrane separating us from the object without our observing
its existence, we should be relatively to it in the same condition
as we are now to air or water in which we are immersed; in
their case we fancy we can touch objects, nothing coming in
between us and them. But there remains this difference
between what can be touched and what can be seen or can
sound; in the latter two cases we perceive because the medium
produces a certain effect upon us, whereas in the perception of
objects of touch we are affected not by but along with the
medium; it is as if a man were struck through his shield, where
the shock is not first given to the shield and passed on to the
man, but the concussion of both is simultaneous.
In general, flesh and the tongue are related to the real organs of
touch and taste, as air and water are to those of sight, hearing,
and smell. Hence in neither the one case nor the other can
there be any perception of an object if it is placed immediately
upon the organ, e.g. if a white object is placed on the surface of
the eye. This again shows that what has the power of perceiving
1220
the tangible is seated inside. Only so would there be a complete
analogy with all the other senses. In their case if you place the
object on the organ it is not perceived, here if you place it on the
flesh it is perceived; therefore flesh is not the organ but the
medium of touch.
What can be touched are distinctive qualities of body as body;
by such differences I mean those which characterize the
elements, viz, hot cold, dry moist, of which we have spoken
earlier in our treatise on the elements. The organ for the
perception of these is that of touch - that part of the body in
which primarily the sense of touch resides. This is that part
which is potentially such as its object is actually: for all sense-
perception is a process of being so affected; so that that which
makes something such as it itself actually is makes the other
such because the other is already potentially such. That is why
when an object of touch is equally hot and cold or hard and soft
we cannot perceive; what we perceive must have a degree of the
sensible quality lying beyond the neutral point. This implies
that the sense itself is a 'mean' between any two opposite
qualities which determine the field of that sense. It is to this
that it owes its power of discerning the objects in that field.
What is 'in the middle' is fitted to discern; relatively to either
extreme it can put itself in the place of the other. As what is to
perceive both white and black must, to begin with, be actually
neither but potentially either (and so with all the other sense-
organs), so the organ of touch must be neither hot nor cold.
Further, as in a sense sight had for its object both what was
visible and what was invisible (and there was a parallel truth
about all the other senses discussed), so touch has for its object
both what is tangible and what is intangible. Here by 'intangible'
is meant (a) what like air possesses some quality of tangible
things in a very slight degree and (b) what possesses it in an
excessive degree, as destructive things do.
1221
We have now given an outline account of each of the several
senses.
12
The following results applying to any and every sense may now
be formulated.
(A) By a 'sense' is meant what has the power of receiving into
itself the sensible forms of things without the matter. This must
be conceived of as taking place in the way in which a piece of
wax takes on the impress of a signet-ring without the iron or
gold; we say that what produces the impression is a signet of
bronze or gold, but its particular metallic constitution makes no
difference: in a similar way the sense is affected by what is
coloured or flavoured or sounding, but it is indifferent what in
each case the substance is; what alone matters is what quality
it has, i.e. in what ratio its constituents are combined.
(B) By 'an organ of sense' is meant that in which ultimately such
a power is seated.
The sense and its organ are the same in fact, but their essence
is not the same. What perceives is, of course, a spatial
magnitude, but we must not admit that either the having the
power to perceive or the sense itself is a magnitude; what they
are is a certain ratio or power in a magnitude. This enables us to
explain why objects of sense which possess one of two opposite
sensible qualities in a degree largely in excess of the other
opposite destroy the organs of sense; if the movement set up by
an object is too strong for the organ, the equipoise of contrary
qualities in the organ, which just is its sensory power, is
disturbed; it is precisely as concord and tone are destroyed by
1222
too violently twanging the strings of a lyre. This explains also
why plants cannot perceive, in spite of their having a portion of
soul in them and obviously being affected by tangible objects
themselves; for undoubtedly their temperature can be lowered
or raised. The explanation is that they have no mean of contrary
qualities, and so no principle in them capable of taking on the
forms of sensible objects without their matter; in the case of
plants the affection is an affection by form-and-matter together.
The problem might be raised: Can what cannot smell be said to
be affected by smells or what cannot see by colours, and so on?
It might be said that a smell is just what can be smelt, and if it
produces any effect it can only be so as to make something
smell it, and it might be argued that what cannot smell cannot
be affected by smells and further that what can smell can be
affected by it only in so far as it has in it the power to smell
(similarly with the proper objects of all the other senses).
Indeed that this is so is made quite evident as follows. Light or
darkness, sounds and smells leave bodies quite unaffected;
what does affect bodies is not these but the bodies which are
their vehicles, e.g. what splits the trunk of a tree is not the
sound of the thunder but the air which accompanies thunder.
Yes, but, it may be objected, bodies are affected by what is
tangible and by flavours. If not, by what are things that are
without soul affected, i.e. altered in quality? Must we not, then,
admit that the objects of the other senses also may affect them?
Is not the true account this, that all bodies are capable of being
affected by smells and sounds, but that some on being acted
upon, having no boundaries of their own, disintegrate, as in the
instance of air, which does become odorous, showing that some
effect is produced on it by what is odorous? But smelling is
more than such an affection by what is odorous - what more? Is
not the answer that, while the air owing to the momentary
duration of the action upon it of what is odorous does itself
1223
become perceptible to the sense of smell, smelling is an
observing of the result produced?
Book III
That there is no sixth sense in addition to the five enumerated -
sight, hearing, smell, taste, touch - may be established by the
following considerations:
If we have actually sensation of everything of which touch can
give us sensation (for all the qualities of the tangible qua
tangible are perceived by us through touch); and if absence of a
sense necessarily involves absence of a sense-organ; and if (1)
all objects that we perceive by immediate contact with them are
perceptible by touch, which sense we actually possess, and (2)
all objects that we perceive through media, i.e. without
immediate contact, are perceptible by or through the simple
elements, e.g. air and water (and this is so arranged that (a) if
more than one kind of sensible object is perceivable through a
single medium, the possessor of a sense-organ homogeneous
with that medium has the power of perceiving both kinds of
objects; for example, if the sense-organ is made of air, and air is
a medium both for sound and for colour; and that (b) if more
than one medium can transmit the same kind of sensible
objects, as e.g. water as well as air can transmit colour, both
being transparent, then the possessor of either alone will be
1224
able to perceive the kind of objects transmissible through both);
and if of the simple elements two only, air and water, go to form
sense-organs (for the pupil is made of water, the organ of
hearing is made of air, and the organ of smell of one or other of
these two, while fire is found either in none or in all - warmth
being an essential condition of all sensibility - and earth either
in none or, if anywhere, specially mingled with the components
of the organ of touch; wherefore it would remain that there can
be no sense-organ formed of anything except water and air);
and if these sense-organs are actually found in certain animals;
- then all the possible senses are possessed by those animals
that are not imperfect or mutilated (for even the mole is
observed to have eyes beneath its skin); so that, if there is no
fifth element and no property other than those which belong to
the four elements of our world, no sense can be wanting to such
animals.
Further, there cannot be a special sense-organ for the common
sensibles either, i.e. the objects which we perceive incidentally
through this or that special sense, e.g. movement, rest, figure,
magnitude, number, unity; for all these we perceive by
movement, e.g. magnitude by movement, and therefore also
figure (for figure is a species of magnitude), what is at rest by
the absence of movement: number is perceived by the negation
of continuity, and by the special sensibles; for each sense
perceives one class of sensible objects. So that it is clearly
impossible that there should be a special sense for any one of
the common sensibles, e.g. movement; for, if that were so, our
perception of it would be exactly parallel to our present
perception of what is sweet by vision. That is so because we
have a sense for each of the two qualities, in virtue of which
when they happen to meet in one sensible object we are aware
of both contemporaneously. If it were not like this our
perception of the common qualities would always be incidental,
i.e. as is the perception of Cleon's son, where we perceive him
1225
not as Cleon's son but as white, and the white thing which we
really perceive happens to be Cleon's son.
But in the case of the common sensibles there is already in us a
general sensibility which enables us to perceive them directly;
there is therefore no special sense required for their perception:
if there were, our perception of them would have been exactly
like what has been above described.
The senses perceive each other's special objects incidentally;
not because the percipient sense is this or that special sense,
but because all form a unity: this incidental perception takes
place whenever sense is directed at one and the same moment
to two disparate qualities in one and the same object, e.g. to the
bitterness and the yellowness of bile, the assertion of the
identity of both cannot be the act of either of the senses; hence
the illusion of sense, e.g. the belief that if a thing is yellow it is
bile.
It might be asked why we have more senses than one. Is it to
prevent a failure to apprehend the common sensibles, e.g.
movement, magnitude, and number, which go along with the
special sensibles? Had we no sense but sight, and that sense no
object but white, they would have tended to escape our notice
and everything would have merged for us into an
indistinguishable identity because of the concomitance of
colour and magnitude. As it is, the fact that the common
sensibles are given in the objects of more than one sense
reveals their distinction from each and all of the special
sensibles.
1226
Since it is through sense that we are aware that we are seeing or
hearing, it must be either by sight that we are aware of seeing,
or by some sense other than sight. But the sense that gives us
this new sensation must perceive both sight and its object, viz.
colour: so that either (1) there will be two senses both percipient
of the same sensible object, or (2) the sense must be percipient
of itself. Further, even if the sense which perceives sight were
different from sight, we must either fall into an infinite regress,
or we must somewhere assume a sense which is aware of itself.
If so, we ought to do this in the first case.
This presents a difficulty: if to perceive by sight is just to see,
and what is seen is colour (or the coloured), then if we are to see
that which sees, that which sees originally must be coloured. It
is clear therefore that 'to perceive by sight' has more than one
meaning; for even when we are not seeing, it is by sight that we
discriminate darkness from light, though not in the same way
as we distinguish one colour from another. Further, in a sense
even that which sees is coloured; for in each case the sense-
organ is capable of receiving the sensible object without its
matter. That is why even when the sensible objects are gone the
sensings and imaginings continue to exist in the sense-organs.
The activity of the sensible object and that of the percipient
sense is one and the same activity, and yet the distinction
between their being remains. Take as illustration actual sound
and actual hearing: a man may have hearing and yet not be
hearing, and that which has a sound is not always sounding.
But when that which can hear is actively hearing and which can
sound is sounding, then the actual hearing and the actual
sound are merged in one (these one might call respectively
hearkening and sounding).
1227
If it is true that the movement, both the acting and the being
acted upon, is to be found in that which is acted upon, both the
sound and the hearing so far as it is actual must be found in
that which has the faculty of hearing; for it is in the passive
factor that the actuality of the active or motive factor is
realized; that is why that which causes movement may be at
rest. Now the actuality of that which can sound is just sound or
sounding, and the actuality of that which can hear is hearing or
hearkening; 'sound' and 'hearing' are both ambiguous. The
same account applies to the other senses and their objects. For
as the-acting-and-being-acted-upon is to be found in the
passive, not in the active factor, so also the actuality of the
sensible object and that of the sensitive subject are both
realized in the latter. But while in some cases each aspect of the
total actuality has a distinct name, e.g. sounding and
hearkening, in some one or other is nameless, e.g. the actuality
of sight is called seeing, but the actuality of colour has no name:
the actuality of the faculty of taste is called tasting, but the
actuality of flavour has no name. Since the actualities of the
sensible object and of the sensitive faculty are one actuality in
spite of the difference between their modes of being, actual
hearing and actual sounding appear and disappear from
existence at one and the same moment, and so actual savour
and actual tasting, &c, while as potentialities one of them may
exist without the other. The earlier students of nature were
mistaken in their view that without sight there was no white or
black, without taste no savour. This statement of theirs is partly
true, partly false: 'sense' and 'the sensible object' are ambiguous
terms, i.e. may denote either potentialities or actualities: the
statement is true of the latter, false of the former. This
ambiguity they wholly failed to notice.
If voice always implies a concord, and if the voice and the
hearing of it are in one sense one and the same, and if concord
always implies a ratio, hearing as well as what is heard must be
1228
a ratio. That is why the excess of either the sharp or the flat
destroys the hearing. (So also in the case of savours excess
destroys the sense of taste, and in the case of colours excessive
brightness or darkness destroys the sight, and in the case of
smell excess of strength whether in the direction of sweetness
or bitterness is destructive.) This shows that the sense is a ratio.
That is also why the objects of sense are (1) pleasant when the
sensible extremes such as acid or sweet or salt being pure and
unmixed are brought into the proper ratio; then they are
pleasant: and in general what is blended is more pleasant than
the sharp or the flat alone; or, to touch, that which is capable of
being either warmed or chilled: the sense and the ratio are
identical: while (2) in excess the sensible extremes are painful
or destructive.
Each sense then is relative to its particular group of sensible
qualities: it is found in a sense-organ as such and discriminates
the differences which exist within that group; e.g. sight
discriminates white and black, taste sweet and bitter, and so in
all cases. Since we also discriminate white from sweet, and
indeed each sensible quality from every other, with what do we
perceive that they are different? It must be by sense; for what is
before us is sensible objects. (Hence it is also obvious that the
flesh cannot be the ultimate sense-organ: if it were, the
discriminating power could not do its work without immediate
contact with the object.)
Therefore (1) discrimination between white and sweet cannot
be effected by two agencies which remain separate; both the
qualities discriminated must be present to something that is
one and single. On any other supposition even if I perceived
sweet and you perceived white, the difference between them
would be apparent. What says that two things are different
must be one; for sweet is different from white. Therefore what
1229
asserts this difference must be self-identical, and as what
asserts, so also what thinks or perceives. That it is not possible
by means of two agencies which remain separate to
discriminate two objects which are separate, is therefore
obvious; and that (it is not possible to do this in separate
movements of time may be seen' if we look at it as follows. For
as what asserts the difference between the good and the bad is
one and the same, so also the time at which it asserts the one to
be different and the other to be different is not accidental to the
assertion (as it is for instance when I now assert a difference
but do not assert that there is now a difference); it asserts thus -
both now and that the objects are different now; the objects
therefore must be present at one and the same moment. Both
the discriminating power and the time of its exercise must be
one and undivided.
But, it may be objected, it is impossible that what is self-
identical should be moved at me and the same time with
contrary movements in so far as it is undivided, and in an
undivided moment of time. For if what is sweet be the quality
perceived, it moves the sense or thought in this determinate
way, while what is bitter moves it in a contrary way, and what is
white in a different way. Is it the case then that what
discriminates, though both numerically one and indivisible, is at
the same time divided in its being? In one sense, it is what is
divided that perceives two separate objects at once, but in
another sense it does so qua undivided; for it is divisible in its
being but spatially and numerically undivided, is not this
impossible? For while it is true that what is self-identical and
undivided may be both contraries at once potentially, it cannot
be self-identical in its being - it must lose its unity by being put
into activity. It is not possible to be at once white and black, and
therefore it must also be impossible for a thing to be affected at
one and the same moment by the forms of both, assuming it to
1230
be the case that sensation and thinking are properly so
described.
The answer is that just as what is called a 'point' is, as being at
once one and two, properly said to be divisible, so here, that
which discriminates is qua undivided one, and active in a single
moment of time, while so far forth as it is divisible it twice over
uses the same dot at one and the same time. So far forth then
as it takes the limit as two' it discriminates two separate objects
with what in a sense is divided: while so far as it takes it as one,
it does so with what is one and occupies in its activity a single
moment of time.
About the principle in virtue of which we say that animals are
percipient, let this discussion suffice.
There are two distinctive peculiarities by reference to which we
characterize the soul (1) local movement and (2) thinking,
discriminating, and perceiving. Thinking both speculative and
practical is regarded as akin to a form of perceiving; for in the
one as well as the other the soul discriminates and is cognizant
of something which is. Indeed the ancients go so far as to
identify thinking and perceiving; e.g. Empedocles says 'For 'tis in
respect of what is present that man's wit is increased', and
again 'Whence it befalls them from time to time to think
diverse thoughts', and Homer's phrase 'For suchlike is man's
mind' means the same. They all look upon thinking as a bodily
process like perceiving, and hold that like is known as well as
perceived by like, as I explained at the beginning of our
discussion. Yet they ought at the same time to have accounted
for error also; for it is more intimately connected with animal
1231
existence and the soul continues longer in the state of error
than in that of truth. They cannot escape the dilemma: either (1)
whatever seems is true (and there are some who accept this) or
(2) error is contact with the unlike; for that is the opposite of the
knowing of like by like.
But it is a received principle that error as well as knowledge in
respect to contraries is one and the same.
That perceiving and practical thinking are not identical is
therefore obvious; for the former is universal in the animal
world, the latter is found in only a small division of it. Further,
speculative thinking is also distinct from perceiving - I mean
that in which we find Tightness and wrongness - rightness in
prudence, knowledge, true opinion, wrongness in their
opposites; for perception of the special objects of sense is
always free from error, and is found in all animals, while it is
possible to think falsely as well as truly, and thought is found
only where there is discourse of reason as well as sensibility. For
imagination is different from either perceiving or discursive
thinking, though it is not found without sensation, or
judgement without it. That this activity is not the same kind of
thinking as judgement is obvious. For imagining lies within our
own power whenever we wish (e.g. we can call up a picture, as
in the practice of mnemonics by the use of mental images), but
in forming opinions we are not free: we cannot escape the
alternative of falsehood or truth. Further, when we think
something to be fearful or threatening, emotion is immediately
produced, and so too with what is encouraging; but when we
merely imagine we remain as unaffected as persons who are
looking at a painting of some dreadful or encouraging scene.
Again within the field of judgement itself we find varieties,
knowledge, opinion, prudence, and their opposites; of the
differences between these I must speak elsewhere.
1232
Thinking is different from perceiving and is held to be in part
imagination, in part judgement: we must therefore first mark
off the sphere of imagination and then speak of judgement. If
then imagination is that in virtue of which an image arises for
us, excluding metaphorical uses of the term, is it a single faculty
or disposition relative to images, in virtue of which we
discriminate and are either in error or not? The faculties in
virtue of which we do this are sense, opinion, science,
intelligence.
That imagination is not sense is clear from the following
considerations: Sense is either a faculty or an activity, e.g. sight
or seeing: imagination takes place in the absence of both, as e.g.
in dreams. (Again, sense is always present, imagination not. If
actual imagination and actual sensation were the same,
imagination would be found in all the brutes: this is held not to
be the case; e.g. it is not found in ants or bees or grubs. (Again,
sensations are always true, imaginations are for the most part
false. (Once more, even in ordinary speech, we do not, when
sense functions precisely with regard to its object, say that we
imagine it to be a man, but rather when there is some failure of
accuracy in its exercise. And as we were saying before, visions
appear to us even when our eyes are shut. Neither is
imagination any of the things that are never in error: e.g.
knowledge or intelligence; for imagination may be false.
It remains therefore to see if it is opinion, for opinion may be
either true or false.
But opinion involves belief (for without belief in what we opine
we cannot have an opinion), and in the brutes though we often
find imagination we never find belief. Further, every opinion is
accompanied by belief, belief by conviction, and conviction by
discourse of reason: while there are some of the brutes in which
we find imagination, without discourse of reason. It is clear
1233
then that imagination cannot, again, be (1) opinion plus
sensation, or (2) opinion mediated by sensation, or (3) a blend of
opinion and sensation; this is impossible both for these reasons
and because the content of the supposed opinion cannot be
different from that of the sensation (I mean that imagination
must be the blending of the perception of white with the
opinion that it is white: it could scarcely be a blend of the
opinion that it is good with the perception that it is white): to
imagine is therefore (on this view) identical with the thinking of
exactly the same as what one in the strictest sense perceives.
But what we imagine is sometimes false though our
contemporaneous judgement about it is true; e.g. we imagine
the sun to be a foot in diameter though we are convinced that it
is larger than the inhabited part of the earth, and the following
dilemma presents itself. Either (a while the fact has not
changed and the (observer has neither forgotten nor lost belief
in the true opinion which he had, that opinion has disappeared,
or (b) if he retains it then his opinion is at once true and false. A
true opinion, however, becomes false only when the fact alters
without being noticed.
Imagination is therefore neither any one of the states
enumerated, nor compounded out of them.
But since when one thing has been set in motion another thing
may be moved by it, and imagination is held to be a movement
and to be impossible without sensation, i.e. to occur in beings
that are percipient and to have for its content what can be
perceived, and since movement may be produced by actual
sensation and that movement is necessarily similar in character
to the sensation itself, this movement must be (1) necessarily (a)
incapable of existing apart from sensation, (b) incapable of
existing except when we perceive, (such that in virtue of its
possession that in which it is found may present various
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phenomena both active and passive, and (such that it may be
either true or false.
The reason of the last characteristic is as follows. Perception (1)
of the special objects of sense is never in error or admits the
least possible amount of falsehood. (2) That of the
concomitance of the objects concomitant with the sensible
qualities comes next: in this case certainly we may be deceived;
for while the perception that there is white before us cannot be
false, the perception that what is white is this or that may be
false. (3) Third comes the perception of the universal attributes
which accompany the concomitant objects to which the special
sensibles attach (I mean e.g. of movement and magnitude); it is
in respect of these that the greatest amount of sense-illusion is
possible.
The motion which is due to the activity of sense in these three
modes of its exercise will differ from the activity of sense; (1)
the first kind of derived motion is free from error while the
sensation is present; (2) and (3) the others may be erroneous
whether it is present or absent, especially when the object of
perception is far off. If then imagination presents no other
features than those enumerated and is what we have described,
then imagination must be a movement resulting from an actual
exercise of a power of sense.
As sight is the most highly developed sense, the name
Phantasia (imagination) has been formed from Phaos (light)
because it is not possible to see without light.
And because imaginations remain in the organs of sense and
resemble sensations, animals in their actions are largely guided
by them, some (i.e. the brutes) because of the non-existence in
them of mind, others (i.e. men) because of the temporary
eclipse in them of mind by feeling or disease or sleep.
1235
About imagination, what it is and why it exists, let so much
suffice.
Turning now to the part of the soul with which the soul knows
and thinks (whether this is separable from the others in
definition only, or spatially as well) we have to inquire (1) what
differentiates this part, and (2) how thinking can take place.
If thinking is like perceiving, it must be either a process in
which the soul is acted upon by what is capable of being
thought, or a process different from but analogous to that. The
thinking part of the soul must therefore be, while impassible,
capable of receiving the form of an object; that is, must be
potentially identical in character with its object without being
the object. Mind must be related to what is thinkable, as sense
is to what is sensible.
Therefore, since everything is a possible object of thought, mind
in order, as Anaxagoras says, to dominate, that is, to know, must
be pure from all admixture; for the co-presence of what is alien
to its nature is a hindrance and a block: it follows that it too, like
the sensitive part, can have no nature of its own, other than
that of having a certain capacity. Thus that in the soul which is
called mind (by mind I mean that whereby the soul thinks and
judges) is, before it thinks, not actually any real thing. For this
reason it cannot reasonably be regarded as blended with the
body: if so, it would acquire some quality, e.g. warmth or cold, or
even have an organ like the sensitive faculty: as it is, it has
none. It was a good idea to call the soul 'the place of forms',
though (1) this description holds only of the intellective soul,
and (2) even this is the forms only potentially, not actually.
1236
Observation of the sense-organs and their employment reveals
a distinction between the impassibility of the sensitive and that
of the intellective faculty. After strong stimulation of a sense we
are less able to exercise it than before, as e.g. in the case of a
loud sound we cannot hear easily immediately after, or in the
case of a bright colour or a powerful odour we cannot see or
smell, but in the case of mind thought about an object that is
highly intelligible renders it more and not less able afterwards
to think objects that are less intelligible: the reason is that while
the faculty of sensation is dependent upon the body, mind is
separable from it.
Once the mind has become each set of its possible objects, as a
man of science has, when this phrase is used of one who is
actually a man of science (this happens when he is now able to
exercise the power on his own initiative), its condition is still
one of potentiality, but in a different sense from the potentiality
which preceded the acquisition of knowledge by learning or
discovery: the mind too is then able to think itself.
Since we can distinguish between a spatial magnitude and what
it is to be such, and between water and what it is to be water,
and so in many other cases (though not in all; for in certain
cases the thing and its form are identical), flesh and what it is
to be flesh are discriminated either by different faculties, or by
the same faculty in two different states: for flesh necessarily
involves matter and is like what is snub-nosed, a this in a this.
Now it is by means of the sensitive faculty that we discriminate
the hot and the cold, i.e. the factors which combined in a
certain ratio constitute flesh: the essential character of flesh is
apprehended by something different either wholly separate
from the sensitive faculty or related to it as a bent line to the
same line when it has been straightened out.
1237
Again in the case of abstract objects what is straight is
analogous to what is snub-nosed; for it necessarily implies a
continuum as its matter: its constitutive essence is different, if
we may distinguish between straightness and what is straight:
let us take it to be two-ness. It must be apprehended, therefore,
by a different power or by the same power in a different state.
To sum up, in so far as the realities it knows are capable of
being separated from their matter, so it is also with the powers
of mind.
The problem might be suggested: if thinking is a passive
affection, then if mind is simple and impassible and has
nothing in common with anything else, as Anaxagoras says,
how can it come to think at all? For interaction between two
factors is held to require a precedent community of nature
between the factors. Again it might be asked, is mind a possible
object of thought to itself? For if mind is thinkable per se and
what is thinkable is in kind one and the same, then either (a)
mind will belong to everything, or (b) mind will contain some
element common to it with all other realities which makes
them all thinkable.
(1) Have not we already disposed of the difficulty about
interaction involving a common element, when we said that
mind is in a sense potentially whatever is thinkable, though
actually it is nothing until it has thought? What it thinks must
be in it just as characters may be said to be on a writingtablet
on which as yet nothing actually stands written: this is exactly
what happens with mind.
(Mind is itself thinkable in exactly the same way as its objects
are. For (a) in the case of objects which involve no matter, what
thinks and what is thought are identical; for speculative
knowledge and its object are identical. (Why mind is not always
thinking we must consider later.) (b) In the case of those which
1238
contain matter each of the objects of thought is only potentially
present. It follows that while they will not have mind in them
(for mind is a potentiality of them only in so far as they are
capable of being disengaged from matter) mind may yet be
thinkable.
Since in every class of things, as in nature as a whole, we find
two factors involved, (1) a matter which is potentially all the
particulars included in the class, (2) a cause which is productive
in the sense that it makes them all (the latter standing to the
former, as e.g. an art to its material), these distinct elements
must likewise be found within the soul.
And in fact mind as we have described it is what it is what it is
by virtue of becoming all things, while there is another which is
what it is by virtue of making all things: this is a sort of positive
state like light; for in a sense light makes potential colours into
actual colours.
Mind in this sense of it is separable, impassible, unmixed, since
it is in its essential nature activity (for always the active is
superior to the passive factor, the originating force to the matter
which it forms).
Actual knowledge is identical with its object: in the individual,
potential knowledge is in time prior to actual knowledge, but in
the universe as a whole it is not prior even in time. Mind is not
at one time knowing and at another not. When mind is set free
from its present conditions it appears as just what it is and
nothing more: this alone is immortal and eternal (we do not,
however, remember its former activity because, while mind in
1239
this sense is impassible, mind as passive is destructible), and
without it nothing thinks.
The thinking then of the simple objects of thought is found in
those cases where falsehood is impossible: where the
alternative of true or false applies, there we always find a
putting together of objects of thought in a quasi-unity. As
Empedocles said that 'where heads of many a creature sprouted
without necks' they afterwards by Love's power were combined,
so here too objects of thought which were given separate are
combined, e.g. 'incommensurate' and 'diagonal': if the
combination be of objects past or future the combination of
thought includes in its content the date. For falsehood always
involves a synthesis; for even if you assert that what is white is
not white you have included not white in a synthesis. It is
possible also to call all these cases division as well as
combination. However that may be, there is not only the true or
false assertion that Cleon is white but also the true or false
assertion that he was or will he white. In each and every case
that which unifies is mind.
Since the word 'simple' has two senses, i.e. may mean either (a)
'not capable of being divided' or (b) 'not actually divided', there
is nothing to prevent mind from knowing what is undivided, e.g.
when it apprehends a length (which is actually undivided) and
that in an undivided time; for the time is divided or undivided
in the same manner as the line. It is not possible, then, to tell
what part of the line it was apprehending in each half of the
time: the object has no actual parts until it has been divided: if
in thought you think each half separately, then by the same act
1240
you divide the time also, the half-lines becoming as it were new
wholes of length. But if you think it as a whole consisting of
these two possible parts, then also you think it in a time which
corresponds to both parts together. (But what is not
quantitatively but qualitatively simple is thought in a simple
time and by a simple act of the soul.)
But that which mind thinks and the time in which it thinks are
in this case divisible only incidentally and not as such. For in
them too there is something indivisible (though, it may be, not
isolable) which gives unity to the time and the whole of length;
and this is found equally in every continuum whether temporal
or spatial.
Points and similar instances of things that divide, themselves
being indivisible, are realized in consciousness in the same
manner as privations.
A similar account may be given of all other cases, e.g. how evil
or black is cognized; they are cognized, in a sense, by means of
their contraries. That which cognizes must have an element of
potentiality in its being, and one of the contraries must be in it.
But if there is anything that has no contrary, then it knows itself
and is actually and possesses independent existence.
Assertion is the saying of something concerning something, e.g.
affirmation, and is in every case either true or false: this is not
always the case with mind: the thinking of the definition in the
sense of the constitutive essence is never in error nor is it the
assertion of something concerning something, but, just as while
the seeing of the special object of sight can never be in error, the
belief that the white object seen is a man may be mistaken, so
too in the case of objects which are without matter.
1241
Actual knowledge is identical with its object: potential
knowledge in the individual is in time prior to actual knowledge
but in the universe it has no priority even in time; for all things
that come into being arise from what actually is. In the case of
sense clearly the sensitive faculty already was potentially what
the object makes it to be actually; the faculty is not affected or
altered. This must therefore be a different kind from movement;
for movement is, as we saw, an activity of what is imperfect,
activity in the unqualified sense, i.e. that of what has been
perfected, is different from movement.
To perceive then is like bare asserting or knowing; but when the
object is pleasant or painful, the soul makes a quasi-affirmation
or negation, and pursues or avoids the object. To feel pleasure or
pain is to act with the sensitive mean towards what is good or
bad as such. Both avoidance and appetite when actual are
identical with this: the faculty of appetite and avoidance are not
different, either from one another or from the faculty of sense-
perception; but their being is different.
To the thinking soul images serve as if they were contents of
perception (and when it asserts or denies them to be good or
bad it avoids or pursues them). That is why the soul never
thinks without an image. The process is like that in which the
air modifies the pupil in this or that way and the pupil
transmits the modification to some third thing (and similarly in
hearing), while the ultimate point of arrival is one, a single
mean, with different manners of being.
With what part of itself the soul discriminates sweet from hot I
have explained before and must now describe again as follows:
That with which it does so is a sort of unity, but in the way just
mentioned, i.e. as a connecting term. And the two faculties it
connects, being one by analogy and numerically, are each to
1242
each as the qualities discerned are to one another (for what
difference does it make whether we raise the problem of
discrimination between disparates or between contraries, e.g.
white and black?). Let then C be to D as is to B: it follows
alternando that C: A:: D: B. If then C and D belong to one subject,
the case will be the same with them as with and B; and B form a
single identity with different modes of being; so too will the
former pair. The same reasoning holds if be sweet and B white.
The faculty of thinking then thinks the forms in the images,
and as in the former case what is to be pursued or avoided is
marked out for it, so where there is no sensation and it is
engaged upon the images it is moved to pursuit or avoidance.
E.g.. perceiving by sense that the beacon is fire, it recognizes in
virtue of the general faculty of sense that it signifies an enemy,
because it sees it moving; but sometimes by means of the
images or thoughts which are within the soul, just as if it were
seeing, it calculates and deliberates what is to come by
reference to what is present; and when it makes a
pronouncement, as in the case of sensation it pronounces the
object to be pleasant or painful, in this case it avoids or persues
and so generally in cases of action.
That too which involves no action, i.e. that which is true or
false, is in the same province with what is good or bad: yet they
differ in this, that the one set imply and the other do not a
reference to a particular person.
The so-called abstract objects the mind thinks just as, if one
had thought of the snubnosed not as snub-nosed but as hollow,
one would have thought of an actuality without the flesh in
which it is embodied: it is thus that the mind when it is
thinking the objects of Mathematics thinks as separate
elements which do not exist separate. In every case the mind
which is actively thinking is the objects which it thinks.
1243
Whether it is possible for it while not existing separate from
spatial conditions to think anything that is separate, or not, we
must consider later.
8
Let us now summarize our results about soul, and repeat that
the soul is in a way all existing things; for existing things are
either sensible or thinkable, and knowledge is in a way what is
knowable, and sensation is in a way what is sensible: in what
way we must inquire.
Knowledge and sensation are divided to correspond with the
realities, potential knowledge and sensation answering to
potentialities, actual knowledge and sensation to actualities.
Within the soul the faculties of knowledge and sensation are
potentially these objects, the one what is knowable, the other
what is sensible. They must be either the things themselves or
their forms. The former alternative is of course impossible: it is
not the stone which is present in the soul but its form.
It follows that the soul is analogous to the hand; for as the hand
is a tool of tools, so the mind is the form of forms and sense the
form of sensible things.
Since according to common agreement there is nothing outside
and separate in existence from sensible spatial magnitudes, the
objects of thought are in the sensible forms, viz. both the
abstract objects and all the states and affections of sensible
things. Hence (1) no one can learn or understand anything in
the absence of sense, and (when the mind is actively aware of
anything it is necessarily aware of it along with an image; for
1244
images are like sensuous contents except in that they contain
no matter.
Imagination is different from assertion and denial; for what is
true or false involves a synthesis of concepts. In what will the
primary concepts differ from images? Must we not say that
neither these nor even our other concepts are images, though
they necessarily involve them?
The soul of animals is characterized by two faculties, (a) the
faculty of discrimination which is the work of thought and
sense, and (b) the faculty of originating local movement. Sense
and mind we have now sufficiently examined. Let us next
consider what it is in the soul which originates movement. Is it
a single part of the soul separate either spatially or in
definition? Or is it the soul as a whole? If it is a part, is that part
different from those usually distinguished or already mentioned
by us, or is it one of them? The problem at once presents itself,
in what sense we are to speak of parts of the soul, or how many
we should distinguish. For in a sense there is an infinity of
parts: it is not enough to distinguish, with some thinkers, the
calculative, the passionate, and the desiderative, or with others
the rational and the irrational; for if we take the dividing lines
followed by these thinkers we shall find parts far more
distinctly separated from one another than these, namely those
we have just mentioned: (1) the nutritive, which belongs both to
plants and to all animals, and (2) the sensitive, which cannot
easily be classed as either irrational or rational; further (3) the
imaginative, which is, in its being, different from all, while it is
very hard to say with which of the others it is the same or not
1245
the same, supposing we determine to posit separate parts in the
soul; and lastly (4) the appetitive, which would seem to be
distinct both in definition and in power from all hitherto
enumerated.
It is absurd to break up the last-mentioned faculty: as these
thinkers do, for wish is found in the calculative part and desire
and passion in the irrational; and if the soul is tripartite
appetite will be found in all three parts. Turning our attention to
the present object of discussion, let us ask what that is which
originates local movement of the animal.
The movement of growth and decay, being found in all living
things, must be attributed to the faculty of reproduction and
nutrition, which is common to all: inspiration and expiration,
sleep and waking, we must consider later: these too present
much difficulty: at present we must consider local movement,
asking what it is that originates forward movement in the
animal.
That it is not the nutritive faculty is obvious; for this kind of
movement is always for an end and is accompanied either by
imagination or by appetite; for no animal moves except by
compulsion unless it has an impulse towards or away from an
object. Further, if it were the nutritive faculty, even plants would
have been capable of originating such movement and would
have possessed the organs necessary to carry it out. Similarly it
cannot be the sensitive faculty either; for there are many
animals which have sensibility but remain fast and immovable
throughout their lives.
If then Nature never makes anything without a purpose and
never leaves out what is necessary (except in the case of
mutilated or imperfect growths; and that here we have neither
mutilation nor imperfection may be argued from the facts that
such animals (a) can reproduce their species and (b) rise to
1246
completeness of nature and decay to an end), it follows that,
had they been capable of originating forward movement, they
would have possessed the organs necessary for that purpose.
Further, neither can the calculative faculty or what is called
'mind' be the cause of such movement; for mind as speculative
never thinks what is practicable, it never says anything about an
object to be avoided or pursued, while this movement is always
in something which is avoiding or pursuing an object. No, not
even when it is aware of such an object does it at once enjoin
pursuit or avoidance of it; e.g. the mind often thinks of
something terrifying or pleasant without enjoining the emotion
of fear. It is the heart that is moved (or in the case of a pleasant
object some other part). Further, even when the mind does
command and thought bids us pursue or avoid something,
sometimes no movement is produced; we act in accordance
with desire, as in the case of moral weakness. And, generally, we
observe that the possessor of medical knowledge is not
necessarily healing, which shows that something else is
required to produce action in accordance with knowledge; the
knowledge alone is not the cause. Lastly, appetite too is
incompetent to account fully for movement; for those who
successfully resist temptation have appetite and desire and yet
follow mind and refuse to enact that for which they have
appetite.
10
These two at all events appear to be sources of movement:
appetite and mind (if one may venture to regard imagination as
a kind of thinking; for many men follow their imaginations
contrary to knowledge, and in all animals other than man there
is no thinking or calculation but only imagination).
1247
Both of these then are capable of originating local movement,
mind and appetite: (1) mind, that is, which calculates means to
an end, i.e. mind practical (it differs from mind speculative in
the character of its end); while (2) appetite is in every form of it
relative to an end: for that which is the object of appetite is the
stimulant of mind practical; and that which is last in the
process of thinking is the beginning of the action. It follows that
there is a justification for regarding these two as the sources of
movement, i.e. appetite and practical thought; for the object of
appetite starts a movement and as a result of that thought gives
rise to movement, the object of appetite being it a source of
stimulation. So too when imagination originates movement, it
necessarily involves appetite.
That which moves therefore is a single faculty and the faculty
of appetite; for if there had been two sources of movement -
mind and appetite - they would have produced movement in
virtue of some common character. As it is, mind is never found
producing movement without appetite (for wish is a form of
appetite; and when movement is produced according to
calculation it is also according to wish), but appetite can
originate movement contrary to calculation, for desire is a form
of appetite. Now mind is always right, but appetite and
imagination may be either right or wrong. That is why, though
in any case it is the object of appetite which originates
movement, this object may be either the real or the apparent
good. To produce movement the object must be more than this:
it must be good that can be brought into being by action; and
only what can be otherwise than as it is can thus be brought
into being. That then such a power in the soul as has been
described, i.e. that called appetite, originates movement is clear.
Those who distinguish parts in the soul, if they distinguish and
divide in accordance with differences of power, find themselves
with a very large number of parts, a nutritive, a sensitive, an
intellective, a deliberative, and now an appetitive part; for these
1248
are more different from one another than the faculties of desire
and passion.
Since appetites run counter to one another, which happens
when a principle of reason and a desire are contrary and is
possible only in beings with a sense of time (for while mind bids
us hold back because of what is future, desire is influenced by
what is just at hand: a pleasant object which is just at hand
presents itself as both pleasant and good, without condition in
either case, because of want of foresight into what is farther
away in time), it follows that while that which originates
movement must be specifically one, viz. the faculty of appetite
as such (or rather farthest back of all the object of that faculty;
for it is it that itself remaining unmoved originates the
movement by being apprehended in thought or imagination),
the things that originate movement are numerically many.
All movement involves three factors, (1) that which originates
the movement, (2) that by means of which it originates it, and
(3) that which is moved. The expression 'that which originates
the movement' is ambiguous: it may mean either (a) something
which itself is unmoved or (b) that which at once moves and is
moved. Here that which moves without itself being moved is
the realizable good, that which at once moves and is moved is
the faculty of appetite (for that which is influenced by appetite
so far as it is actually so influenced is set in movement, and
appetite in the sense of actual appetite is a kind of movement),
while that which is in motion is the animal. The instrument
which appetite employs to produce movement is no longer
psychical but bodily: hence the examination of it falls within
the province of the functions common to body and soul. To state
the matter summarily at present, that which is the instrument
in the production of movement is to be found where a
beginning and an end coincide as e.g. in a ball and socket joint;
for there the convex and the concave sides are respectively an
1249
end and a beginning (that is why while the one remains at rest,
the other is moved): they are separate in definition but not
separable spatially. For everything is moved by pushing and
pulling. Hence just as in the case of a wheel, so here there must
be a point which remains at rest, and from that point the
movement must originate.
To sum up, then, and repeat what I have said, inasmuch as an
animal is capable of appetite it is capable of self-movement; it is
not capable of appetite without possessing imagination; and all
imagination is either (1) calculative or (2) sensitive. In the latter
an animals, and not only man, partake.
11
We must consider also in the case of imperfect animals, sc.
those which have no sense but touch, what it is that in them
originates movement. Can they have imagination or not? or
desire? Clearly they have feelings of pleasure and pain, and if
they have these they must have desire. But how can they have
imagination? Must not we say that, as their movements are
indefinite, they have imagination and desire, but indefinitely?
Sensitive imagination, as we have said, is found in all animals,
deliberative imagination only in those that are calculative: for
whether this or that shall be enacted is already a task requiring
calculation; and there must be a single standard to measure by,
for that is pursued which is greater. It follows that what acts in
this way must be able to make a unity out of several images.
This is the reason why imagination is held not to involve
opinion, in that it does not involve opinion based on inference,
though opinion involves imagination. Hence appetite contains
1250
no deliberative element. Sometimes it overpowers wish and sets
it in movement: at times wish acts thus upon appetite, like one
sphere imparting its movement to another, or appetite acts thus
upon appetite, i.e. in the condition of moral weakness (though
by nature the higher faculty is always more authoritative and
gives rise to movement). Thus three modes of movement are
possible.
The faculty of knowing is never moved but remains at rest.
Since the one premiss or judgement is universal and the other
deals with the particular (for the first tells us that such and
such a kind of man should do such and such a kind of act, and
the second that this is an act of the kind meant, and I a person
of the type intended), it is the latter opinion that really
originates movement, not the universal; or rather it is both, but
the one does so while it remains in a state more like rest, while
the other partakes in movement.
12
The nutritive soul then must be possessed by everything that is
alive, and every such thing is endowed with soul from its birth
to its death. For what has been born must grow, reach maturity,
and decay - all of which are impossible without nutrition.
Therefore the nutritive faculty must be found in everything that
grows and decays.
But sensation need not be found in all things that live. For it is
impossible for touch to belong either (1) to those whose body is
uncompounded or (2) to those which are incapable of taking in
the forms without their matter.
1251
But animals must be endowed with sensation, since Nature
does nothing in vain. For all things that exist by Nature are
means to an end, or will be concomitants of means to an end.
Every body capable of forward movement would, if unendowed
with sensation, perish and fail to reach its end, which is the aim
of Nature; for how could it obtain nutriment? Stationary living
things, it is true, have as their nutriment that from which they
have arisen; but it is not possible that a body which is not
stationary but produced by generation should have a soul and a
discerning mind without also having sensation. (Nor yet even if
it were not produced by generation. Why should it not have
sensation? Because it were better so either for the body or for
the soul? But clearly it would not be better for either: the
absence of sensation will not enable the one to think better or
the other to exist better.) Therefore no body which is not
stationary has soul without sensation.
But if a body has sensation, it must be either simple or
compound. And simple it cannot be; for then it could not have
touch, which is indispensable. This is clear from what follows.
An animal is a body with soul in it: every body is tangible, i.e.
perceptible by touch; hence necessarily, if an animal is to
survive, its body must have tactual sensation. All the other
senses, e.g. smell, sight, hearing, apprehend through media; but
where there is immediate contact the animal, if it has no
sensation, will be unable to avoid some things and take others,
and so will find it impossible to survive. That is why taste also is
a sort of touch; it is relative to nutriment, which is just tangible
body; whereas sound, colour, and odour are innutritious, and
further neither grow nor decay. Hence it is that taste also must
be a sort of touch, because it is the sense for what is tangible
and nutritious.
Both these senses, then, are indispensable to the animal, and it
is clear that without touch it is impossible for an animal to be.
1252
All the other senses subserve well-being and for that very
reason belong not to any and every kind of animal, but only to
some, e.g. those capable of forward movement must have them;
for, if they are to survive, they must perceive not only by
immediate contact but also at a distance from the object. This
will be possible if they can perceive through a medium, the
medium being affected and moved by the perceptible object,
and the animal by the medium, just as that which produces
local movement causes a change extending to a certain point,
and that which gave an impulse causes another to produce a
new impulse so that the movement traverses a medium the
first mover impelling without being impelled, the last moved
being impelled without impelling, while the medium (or media,
for there are many) is both - so is it also in the case of
alteration, except that the agent produces produces it without
the patient's changing its place. Thus if an object is dipped into
wax, the movement goes on until submersion has taken place,
and in stone it goes no distance at all, while in water the
disturbance goes far beyond the object dipped: in air the
disturbance is propagated farthest of all, the air acting and
being acted upon, so long as it maintains an unbroken unity.
That is why in the case of reflection it is better, instead of saying
that the sight issues from the eye and is reflected, to say that
the air, so long as it remains one, is affected by the shape and
colour. On a smooth surface the air possesses unity; hence it is
that it in turn sets the sight in motion, just as if the impression
on the wax were transmitted as far as the wax extends.
13
It is clear that the body of an animal cannot be simple, i.e.
consist of one element such as fire or air. For without touch it is
1253
impossible to have any other sense; for every body that has soul
in it must, as we have said, be capable of touch. All the other
elements with the exception of earth can constitute organs of
sense, but all of them bring about perception only through
something else, viz. through the media. Touch takes place by
direct contact with its objects, whence also its name. All the
other organs of sense, no doubt, perceive by contact, only the
contact is mediate: touch alone perceives by immediate contact.
Consequently no animal body can consist of these other
elements.
Nor can it consist solely of earth. For touch is as it were a mean
between all tangible qualities, and its organ is capable of
receiving not only all the specific qualities which characterize
earth, but also the hot and the cold and all other tangible
qualities whatsoever. That is why we have no sensation by
means of bones, hair, &c, because they consist of earth. So too
plants, because they consist of earth, have no sensation.
Without touch there can be no other sense, and the organ of
touch cannot consist of earth or of any other single element.
It is evident, therefore, that the loss of this one sense alone
must bring about the death of an animal. For as on the one
hand nothing which is not an animal can have this sense, so on
the other it is the only one which is indispensably necessary to
what is an animal. This explains, further, the following
difference between the other senses and touch. In the case of all
the others excess of intensity in the qualities which they
apprehend, i.e. excess of intensity in colour, sound, and smell,
destroys not the but only the organs of the sense (except
incidentally, as when the sound is accompanied by an impact or
shock, or where through the objects of sight or of smell certain
other things are set in motion, which destroy by contact);
flavour also destroys only in so far as it is at the same time
tangible. But excess of intensity in tangible qualities, e.g. heat,
1254
cold, or hardness, destroys the animal itself. As in the case of
every sensible quality excess destroys the organ, so here what is
tangible destroys touch, which is the essential mark of life; for it
has been shown that without touch it is impossible for an
animal to be. That is why excess in intensity of tangible
qualities destroys not merely the organ, but the animal itself,
because this is the only sense which it must have.
All the other senses are necessary to animals, as we have said,
not for their being, but for their well-being. Such, e.g. is sight,
which, since it lives in air or water, or generally in what is
pellucid, it must have in order to see, and taste because of what
is pleasant or painful to it, in order that it may perceive these
qualities in its nutriment and so may desire to be set in motion,
and hearing that it may have communication made to it, and a
tongue that it may communicate with its fellows.
1255
Aristotle - Parva Naturalia
[Translated by J. I. Beare and G.R.T. Ross]
On Sense and the Sensible
[translated by J. I. Beare]
Having now definitely considered the soul, by itself, and its
several faculties, we must next make a survey of animals and all
living things, in order to ascertain what functions are peculiar,
and what functions are common, to them. What has been
already determined respecting the soul [sc. by itself] must be
assumed throughout. The remaining parts [sc. the attributes of
soul and body conjointly] of our subject must be now dealt with,
and we may begin with those that come first.
The most important attributes of animals, whether common to
all or peculiar to some, are, manifestly, attributes of soul and
body in conjunction, e.g. sensation, memory, passion, appetite
and desire in general, and, in addition pleasure and pain. For
these may, in fact, be said to belong to all animals. But there are,
besides these, certain other attributes, of which some are
common to all living things, while others are peculiar to certain
species of animals. The most important of these may be
summed up in four pairs, viz. waking and sleeping, youth and
old age, inhalation and exhalation, life and death. We must
endeavour to arrive at a scientific conception of these,
1256
determining their respective natures, and the causes of their
occurrence.
But it behoves the Physical Philosopher to obtain also a clear
view of the first principles of health and disease, inasmuch as
neither health nor disease can exist in lifeless things. Indeed we
may say of most physical inquirers, and of those physicians
who study their art philosophically, that while the former
complete their works with a disquisition on medicine, the latter
usually base their medical theories on principles derived from
Physics.
That all the attributes above enumerated belong to soul and
body in conjunction, is obvious; for they all either imply
sensation as a concomitant, or have it as their medium. Some
are either affections or states of sensation, others, means of
defending and safe-guarding it, while others, again, involve its
destruction or negation. Now it is clear, alike by reasoning and
observation, that sensation is generated in the soul through the
medium of the body.
We have already, in our treatise On the Soul, explained the
nature of sensation and the act of perceiving by sense, and the
reason why this affection belongs to animals. Sensation must,
indeed, be attributed to all animals as such, for by its presence
or absence we distinguish essentially between what is and what
is not an animal.
But coming now to the special senses severally, we may say that
touch and taste necessarily appertain to all animals, touch, for
the reason given in On the Soul, and taste, because of nutrition.
It is by taste that one distinguishes in food the pleasant from
the unpleasant, so as to flee from the latter and pursue the
former: and savour in general is an affection of nutrient matter.
1257
The senses which operate through external media, viz. smelling,
hearing, seeing, are found in all animals which possess the
faculty of locomotion. To all that possess them they are a means
of preservation; their final cause being that such creatures may,
guided by antecedent perception, both pursue their food, and
shun things that are bad or destructive. But in animals which
have also intelligence they serve for the attainment of a higher
perfection. They bring in tidings of many distinctive qualities of
things, from which the knowledge of truth, speculative and
practical, is generated in the soul.
Of the two last mentioned, seeing, regarded as a supply for the
primary wants of life, and in its direct effects, is the superior
sense; but for developing intelligence, and in its indirect
consequences, hearing takes the precedence. The faculty of
seeing, thanks to the fact that all bodies are coloured, brings
tidings of multitudes of distinctive qualities of all sorts; whence
it is through this sense especially that we perceive the common
sensibles, viz. figure, magnitude, motion, number: while hearing
announces only the distinctive qualities of sound, and, to some
few animals, those also of voice, indirectly, however, it is
hearing that contributes most to the growth of intelligence. For
rational discourse is a cause of instruction in virtue of its being
audible, which it is, not directly, but indirectly; since it is
composed of words, and each word is a thought-symbol.
Accordingly, of persons destitute from birth of either sense, the
blind are more intelligent than the deaf and dumb.
Of the distinctive potency of each of the faculties of sense
enough has been said already.
1258
But as to the nature of the sensory organs, or parts of the body
in which each of the senses is naturally implanted, inquirers
now usually take as their guide the fundamental elements of
bodies. Not, however, finding it easy to coordinate five senses
with four elements, they are at a loss respecting the fifth sense.
But they hold the organ of sight to consist of fire, being
prompted to this view by a certain sensory affection of whose
true cause they are ignorant. This is that, when the eye is
pressed or moved, fire appears to flash from it. This naturally
takes place in darkness, or when the eyelids are closed, for then,
too, darkness is produced.
This theory, however, solves one question only to raise another;
for, unless on the hypothesis that a person who is in his full
senses can see an object of vision without being aware of it, the
eye must on this theory see itself. But then why does the above
affection not occur also when the eye is at rest? The true
explanation of this affection, which will contain the answer to
our question, and account for the current notion that the eye
consists of fire, must be determined in the following way:
Things which are smooth have the natural property of shining
in darkness, without, however, producing light. Now, the part of
the eye called 'the black', i.e. its central part, is manifestly
smooth. The phenomenon of the flash occurs only when the eye
is moved, because only then could it possibly occur that the
same one object should become as it were two. The rapidity of
the movement has the effect of making that which sees and
that which is seen seem different from one another. Hence the
phenomenon does not occur unless the motion is rapid and
takes place in darkness. For it is in the dark that that which is
smooth, e.g. the heads of certain fishes, and the sepia of the
cuttle-fish, naturally shines, and, when the movement of the
eye is slow, it is impossible that that which sees and that which
is seen should appear to be simultaneously two and one. But, in
1259
fact, the eye sees itself in the above phenomenon merely as it
does so in ordinary optical reflexion.
If the visual organ proper really were fire, which is the doctrine
of Empedocles, a doctrine taught also in the Timaeus, and if
vision were the result of light issuing from the eye as from a
lantern, why should the eye not have had the power of seeing
even in the dark? It is totally idle to say, as the Timaeus does,
that the visual ray coming forth in the darkness is quenched.
What is the meaning of this 'quenching' of light? That which,
like a fire of coals or an ordinary flame, is hot and dry is, indeed,
quenched by the moist or cold; but heat and dryness are
evidently not attributes of light. Or if they are attributes of it,
but belong to it in a degree so slight as to be imperceptible to us,
we should have expected that in the daytime the light of the
sun should be quenched when rain falls, and that darkness
should prevail in frosty weather. Flame, for example, and ignited
bodies are subject to such extinction, but experience shows that
nothing of this sort happens to the sunlight.
Empedocles at times seems to hold that vision is to be
explained as above stated by light issuing forth from the eye,
e.g. in the following passage: -
As when one who purposes going abroad prepares a lantern,
A gleam of fire blazing through the stormy night,
Adjusting thereto, to screen it from all sorts of winds,
transparent sides,
Which scatter the breath of the winds as they blow,
While, out through them leaping, the fire,
i.e. all the more subtile part of this,
1260
Shines along his threshold old incessant beams:
So [Divine love] embedded the round "lens", [viz.]
the primaeval fire fenced within the membranes,
In [its own] delicate tissues;
And these fended off the deep surrounding flood,
While leaping forth the fire, i.e. all its more subtile part. -
Sometimes he accounts for vision thus, but at other times he
explains it by emanations from the visible objects.
Democritus, on the other hand, is right in his opinion that the
eye is of water; not, however, when he goes on to explain seeing
as mere mirroring. The mirroring that takes place in an eye is
due to the fact that the eye is smooth, and it really has its seat
not in the eye which is seen, but in that which sees. For the case
is merely one of reflexion. But it would seem that even in his
time there was no scientific knowledge of the general subject of
the formation of images and the phenomena of reflexion. It is
strange too, that it never occurred to him to ask why, if his
theory be true, the eye alone sees, while none of the other
things in which images are reflected do so.
True, then, the visual organ proper is composed of water, yet
vision appertains to it not because it is so composed, but
because it is translucent - a property common alike to water
and to air. But water is more easily confined and more easily
condensed than air; wherefore it is that the pupil, i.e. the eye
proper, consists of water. That it does so is proved by facts of
actual experience. The substance which flows from eyes when
decomposing is seen to be water, and this in undeveloped
embryos is remarkably cold and glistening. In sanguineous
animals the white of the eye is fat and oily, in order that the
1261
moisture of the eye may be proof against freezing. Wherefore
the eye is of all parts of the body the least sensitive to cold: no
one ever feels cold in the part sheltered by the eyelids. The eyes
of bloodless animals are covered with a hard scale which gives
them similar protection.
It is, to state the matter generally, an irrational notion that the
eye should see in virtue of something issuing from it; that the
visual ray should extend itself all the way to the stars, or else go
out merely to a certain point, and there coalesce, as some say,
with rays which proceed from the object. It would be better to
suppose this coalescence to take place in the fundament of the
eye itself. But even this would be mere trifling. For what is
meant by the 'coalescence' of light with light? Or how is it
possible? Coalescence does not occur between any two things
taken at random. And how could the light within the eye
coalesce with that outside it? For the environing membrane
comes between them.
That without light vision is impossible has been stated
elsewhere; but, whether the medium between the eye and its
objects is air or light, vision is caused by a process through this
medium.
Accordingly, that the inner part of the eye consists of water is
easily intelligible, water being translucent.
Now, as vision outwardly is impossible without [extra-organic]
light, so also it is impossible inwardly [without light within the
organ]. There must, therefore, be some translucent medium
within the eye, and, as this is not air, it must be water. The soul
or its perceptive part is not situated at the external surface of
the eye, but obviously somewhere within: whence the necessity
of the interior of the eye being translucent, i.e. capable of
admitting light. And that it is so is plain from actual
occurrences. It is matter of experience that soldiers wounded in
1262
battle by a sword slash on the temple, so inflicted as to sever
the passages of [i.e. inward from] the eye, feel a sudden onset of
darkness, as if a lamp had gone out; because what is called the
pupil, i.e. the translucent, which is a sort of inner lamp, is then
cut off [from its connexion with the soul].
Hence, if the facts be at all as here stated, it is clear that - if one
should explain the nature of the sensory organs in this way, i.e.
by correlating each of them with one of the four elements, - we
must conceive that the part of the eye immediately concerned
in vision consists of water, that the part immediately concerned
in the perception of sound consists of air, and that the sense of
smell consists of fire. (I say the sense of smell, not the organ.)
For the organ of smell is only potentially that which the sense
of smell, as realized, is actually; since the object of sense is
what causes the actualization of each sense, so that it (the
sense) must (at the instant of actualization) be (actually) that
which before (the moment of actualization) it was potentially.
Now, odour is a smoke-like evaporation, and smoke-like
evaporation arises from fire. This also helps us to understand
why the olfactory organ has its proper seat in the environment
of the brain, for cold matter is potentially hot. In the same way
must the genesis of the eye be explained. Its structure is an
offshoot from the brain, because the latter is the moistest and
coldest of all the bodily parts.
The organ of touch proper consists of earth, and the faculty of
taste is a particular form of touch. This explains why the
sensory organ of both touch and taste is closely related to the
heart. For the heart as being the hottest of all the bodily parts, is
the counterpoise of the brain.
This then is the way in which the characteristics of the bodily
organs of sense must be determined.
1263
Of the sensibles corresponding to each sensory organ, viz.
colour, sound, odour, savour, touch, we have treated in On the
Soul in general terms, having there determined what their
function is, and what is implied in their becoming actualized in
relation to their respective organs. We must next consider what
account we are to give of any one of them; what, for example,
we should say colour is, or sound, or odour, or savour; and so
also respecting [the object of] touch. We begin with colour.
Now, each of them may be spoken of from two points of view,
i.e. either as actual or as potential. We have in On the Soul
explained in what sense the colour, or sound, regarded as
actualized [for sensation] is the same as, and in what sense it is
different from, the correlative sensation, the actual seeing or
hearing. The point of our present discussion is, therefore, to
determine what each sensible object must be in itself, in order
to be perceived as it is in actual consciousness.
We have already in On the Soul stated of Light that it is the
colour of the Translucent, [being so related to it] incidentally; for
whenever a fiery element is in a translucent medium presence
there is Light; while the privation of it is Darkness. But the
'Translucent', as we call it, is not something peculiar to air, or
water, or any other of the bodies usually called translucent, but
is a common 'nature' and power, capable of no separate
existence of its own, but residing in these, and subsisting
likewise in all other bodies in a greater or less degree. As the
bodies in which it subsists must have some extreme bounding
surface, so too must this. Here, then, we may say that Light is a
'nature' inhering in the Translucent when the latter is without
determinate boundary. But it is manifest that, when the
Translucent is in determinate bodies, its bounding extreme
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must be something real; and that colour is just this 'something'
we are plainly taught by facts - colour being actually either at
the external limit, or being itself that limit, in bodies. Hence it
was that the Pythagoreans named the superficies of a body its
'hue', for 'hue', indeed, lies at the limit of the body; but the limit
of the body; is not a real thing; rather we must suppose that the
same natural substance which, externally, is the vehicle of
colour exists [as such a possible vehicle] also in the interior of
the body.
Air and water, too [i.e. as well as determinately bounded bodies]
are seen to possess colour; for their brightness is of the nature
of colour. But the colour which air or sea presents, since the
body in which it resides is not determinately bounded, is not
the same when one approaches and views it close by as it is
when one regards it from a distance; whereas in determinate
bodies the colour presented is definitely fixed, unless, indeed,
when the atmospheric environment causes it to change. Hence
it is clear that that in them which is susceptible of colour is in
both cases the same. It is therefore the Translucent, according to
the degree to which it subsists in bodies (and it does so in all
more or less), that causes them to partake of colour. But since
the colour is at the extremity of the body, it must be at the
extremity of the Translucent in the body. Whence it follows that
we may define colour as the limit of the Translucent in
determinately bounded body. For whether we consider the
special class of bodies called translucent, as water and such
others, or determinate bodies, which appear to possess a fixed
colour of their own, it is at the exterior bounding surface that all
alike exhibit their colour.
Now, that which when present in air produces light may be
present also in the Translucent which pervades determinate
bodies; or again, it may not be present, but there may be a
privation of it. Accordingly, as in the case of air the one
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condition is light, the other darkness, in the same way the
colours White and Black are generated in determinate bodies.
We must now treat of the other colours, reviewing the several
hypotheses invented to explain their genesis.
(1) It is conceivable that the White and the Black should be
juxtaposed in quantities so minute that [a particle of] either
separately would be invisible, though the joint product [of two
particles, a black and a white] would be visible; and that they
should thus have the other colours for resultants. Their product
could, at all events, appear neither white nor black; and, as it
must have some colour, and can have neither of these, this
colour must be of a mixed character - in fact, a species of colour
different from either. Such, then, is a possible way of conceiving
the existence of a plurality of colours besides the White and
Black; and we may suppose that [of this 'plurality'] many are the
result of a [numerical] ratio; for the blacks and whites may be
juxtaposed in the ratio of 3 to 2 or of 3 to 4, or in ratios
expressible by other numbers; while some may be juxtaposed
according to no numerically expressible ratio, but according to
some relation of excess or defect in which the blacks and
whites involved would be incommensurable quantities; and,
accordingly, we may regard all these colours [viz. all those based
on numerical ratios] as analogous to the sounds that enter into
music, and suppose that those involving simple numerical
ratios, like the concords in music, may be those generally
regarded as most agreeable; as, for example, purple, crimson,
and some few such colours, their fewness being due to the
same causes which render the concords few. The other
compound colours may be those which are not based on
numbers. Or it may be that, while all colours whatever [except
black and white] are based on numbers, some are regular in this
respect, others irregular; and that the latter [though now
supposed to be all based on numbers], whenever they are not
1266
pure, owe this character to a corresponding impurity in [the
arrangement of] their numerical ratios. This then is one
conceivable hypothesis to explain the genesis of intermediate
colours.
(2) Another is that the Black and White appear the one through
the medium of the other, giving an effect like that sometimes
produced by painters overlaying a less vivid upon a more vivid
colour, as when they desire to represent an object appearing
under water or enveloped in a haze, and like that produced by
the sun, which in itself appears white, but takes a crimson hue
when beheld through a fog or a cloud of smoke. On this
hypothesis, too, a variety of colours may be conceived to arise in
the same way as that already described; for between those at
the surface and those underneath a definite ratio might
sometimes exist; in other cases they might stand in no
determinate ratio. To [introduce a theory of colour which would
set all these hypotheses aside, and] say with the ancients that
colours are emanations, and that the visibility of objects is due
to such a cause, is absurd. For they must, in any case, explain
sense-perception through Touch; so that it were better to say at
once that visual perception is due to a process set up by the
perceived object in the medium between this object and the
sensory organ; due, that is, to contact [with the medium
affected,] not to emanations.
If we accept the hypothesis of juxtaposition, we must assume
not only invisible magnitude, but also imperceptible time, in
order that the succession in the arrival of the stimulatory
movements may be unperceived, and that the compound colour
seen may appear to be one, owing to its successive parts
seeming to present themselves at once. On the hypothesis of
superposition, however, no such assumption is needful: the
stimulatory process produced in the medium by the upper
colour, when this is itself unaffected, will be different in kind
1267
from that produced by it when affected by the underlying
colour. Hence it presents itself as a different colour, i.e. as one
which is neither white nor black. So that, if it is impossible to
suppose any magnitude to be invisible, and we must assume
that there is some distance from which every magnitude is
visible, this superposition theory, too [i.e. as well as No. 3 infra],
might pass as a real theory of colour-mixture. Indeed, in the
previous case also there is no reason why, to persons at a
distance from the juxtaposed blacks and whites, some one
colour should not appear to present itself as a blend of both.
[But it would not be so on a nearer view], for it will be shown, in
a discussion to be undertaken later on, that there is no
magnitude absolutely invisible.
(3) There is a mixture of bodies, however, not merely such as
some suppose, i.e. by juxtaposition of their minimal parts,
which, owing to [the weakness of our] sense, are imperceptible
by us, but a mixture by which they [i.e. the 'matter' of which
they consist] are wholly blent together by interpenetration, as
we have described it in the treatise on Mixture, where we dealt
with this subject generally in its most comprehensive aspect.
For, on the supposition we are criticizing, the only totals capable
of being mixed are those which are divisible into minimal parts,
[e.g. genera into individuals] as men, horses, or the [various
kinds of] seeds. For of mankind as a whole the individual man is
such a least part; of horses [as an aggregate] the individual
horse. Hence by the juxtaposition of these we obtain a mixed
total, consisting [like a troop of cavalry] of both together; but we
do not say that by such a process any individual man has been
mixed with any individual horse. Not in this way, but by
complete interpenetration [of their matter], must we conceive
those things to be mixed which are not divisible into minima;
and it is in the case of these that natural mixture exhibits itself
in its most perfect form. We have explained already in our
discourse 'On Mixture' how such mixture is possible. This being
1268
the true nature of mixture, it is plain that when bodies are
mixed their colours also are necessarily mixed at the same
time; and [it is no less plain] that this is the real cause
determining the existence of a plurality of colours - not
superposition or juxtaposition. For when bodies are thus mixed,
their resultant colour presents itself as one and the same at all
distances alike; not varying as it is seen nearer or farther away.
Colours will thus, too [as well as on the former hypotheses], be
many in number on account of the fact that the ingredients
may be combined with one another in a multitude of ratios;
some will be based on determinate numerical ratios, while
others again will have as their basis a relation of quantitative
excess or defect not expressible in integers. And all else that
was said in reference to the colours, considered as juxtaposed
or superposed, may be said of them likewise when regarded as
mixed in the way just described.
Why colours, as well as savours and sounds, consist of species
determinate [in themselves] and not infinite [in number] is a
question which we shall discuss hereafter.
We have now explained what colour is, and the reason why
there are many colours; while before, in our work On the Soul,
we explained the nature of sound and voice. We have next to
speak of Odour and Savour, both of which are almost the same
physical affection, although they each have their being in
different things. Savours, as a class, display their nature more
clearly to us than Odours, the cause of which is that the
olfactory sense of man is inferior in acuteness to that of the
lower animals, and is, when compared with our other senses,
1269
the least perfect of Man's sense of Touch, on the contrary, excels
that of all other animals in fineness, and Taste is a modification
of Touch.
Now the natural substance water per se tends to be tasteless.
But [since without water tasting is impossible] either (a) we
must suppose that water contains in itself [uniformly diffused
through it] the various kinds of savour, already formed, though
in amounts so small as to be imperceptible, which is the
doctrine of Empedocles; or (b) the water must be a sort of
matter, qualified, as it were, to produce germs of savours of all
kinds, so that all kinds of savour are generated from the water,
though different kinds from its different parts, or else (c) the
water is in itself quite undifferentiated in respect of savour
[whether developed or undeveloped], but some agent, such for
example as one might conceive Heat or the Sun to be, is the
efficient cause of savour.
(a) Of these three hypotheses, the falsity of that held by
Empedocles is only too evident. For we see that when pericarpal
fruits are plucked [from the tree] and exposed in the sun, or
subjected to the action of fire, their sapid juices are changed by
the heat, which shows that their qualities are not due to their
drawing anything from the water in the ground, but to a change
which they undergo within the pericarp itself; and we see,
moreover, that these juices, when extracted and allowed to lie,
instead of sweet become by lapse of time harsh or bitter, or
acquire savours of any and every sort; and that, again, by the
process of boiling or fermentation they are made to assume
almost all kinds of new savours.
(b) It is likewise impossible that water should be a material
qualified to generate all kinds of Savour germs [so that different
savours should arise out of different parts of the water]; for we
1270
see different kinds of taste generated from the same water,
having it as their nutriment.
(C) It remains, therefore, to suppose that the water is changed
by passively receiving some affection from an external agent.
Now, it is manifest that water does not contract the quality of
sapidity from the agency of Heat alone. For water is of all liquids
the thinnest, thinner even than oil itself, though oil, owing to its
viscosity, is more ductile than water, the latter being uncohesive
in its particles; whence water is more difficult than oil to hold
in the hand without spilling. But since perfectly pure water does
not, when subjected to the action of Heat, show any tendency to
acquire consistency, we must infer that some other agency than
heat is the cause of sapidity. For all savours [i.e. sapid liquors]
exhibit a comparative consistency. Heat is, however, a coagent
in the matter.
Now the sapid juices found in pericarpal fruits evidently exist
also in the earth. Hence many of the old natural philosophers
assert that water has qualities like those of the earth through
which it flows, a fact especially manifest in the case of saline
springs, for salt is a form of earth. Hence also when liquids are
filtered through ashes, a bitter substance, the taste they yield is
bitter. There are many wells, too, of which some are bitter,
others acid, while others exhibit other tastes of all kinds.
As was to be anticipated, therefore, it is in the vegetable
kingdom that tastes occur in richest variety. For, like all things
else, the Moist, by nature's law, is affected only by its contrary;
and this contrary is the Dry. Thus we see why the Moist is
affected by Fire, which as a natural substance, is dry. Heat is,
however, the essential property of Fire, as Dryness is of Earth,
according to what has been said in our treatise on the elements.
Fire and Earth, therefore, taken absolutely as such, have no
natural power to affect, or be affected by, one another; nor have
1271
any other pair of substances. Any two things can affect, or be
affected by, one another only so far as contrariety to the other
resides in either of them.
As, therefore, persons washing Colours or Savours in a liquid
cause the water in which they wash to acquire such a quality
[as that of the colour or savour], so nature, too, by washing the
Dry and Earthy in the Moist, and by filtering the latter, that is,
moving it on by the agency of heat through the dry and earthy,
imparts to it a certain quality. This affection, wrought by the
aforesaid Dry in the Moist, capable of transforming the sense of
Taste from potentiality to actuality, is Savour. Savour brings into
actual exercise the perceptive faculty which pre-existed only in
potency. The activity of sense-perception in general is
analogous, not to the process of acquiring knowledge, but to
that of exercising knowledge already acquired.
That Savours, either as a quality or as the privation of a quality,
belong not to every form of the Dry but to the Nutrient, we shall
see by considering that neither the Dry without the Moist, nor
the Moist without the Dry, is nutrient. For no single element, but
only composite substance, constitutes nutriment for animals.
Now, among the perceptible elements of the food which
animals assimilate, the tangible are the efficient causes of
growth and decay; it is qua hot or cold that the food assimilated
causes these; for the heat or cold is the direct cause of growth
or decay. It is qua gustable, however, that the assimilated food
supplies nutrition. For all organisms are nourished by the Sweet
[i.e. the 'gustable' proper], either by itself or in combination with
other savours. Of this we must speak with more precise detail in
our work on Generation: for the present we need touch upon it
only so far as our subject here requires. Heat causes growth, and
fits the food-stuff for alimentation; it attracts [into the organic
system] that which is light [viz. the sweet], while the salt and
bitter it rejects because of their heaviness. In fact, whatever
1272
effects external heat produces in external bodies, the same are
produced by their internal heat in animal and vegetable
organisms. Hence it is [i.e. by the agency of heat as described]
that nourishment is effected by the sweet. The other savours are
introduced into and blended in food [naturally] on a principle
analogous to that on which the saline or the acid is used
artificially, i.e. for seasoning. These latter are used because they
counteract the tendency of the sweet to be too nutrient, and to
float on the stomach.
As the intermediate colours arise from the mixture of white and
black, so the intermediate savours arise from the Sweet and
Bitter; and these savours, too, severally involve either a definite
ratio, or else an indefinite relation of degree, between their
components, either having certain integral numbers at the basis
of their mixture, and, consequently, of their stimulative effect,
or else being mixed in proportions not arithmetically
expressible. The tastes which give pleasure in their combination
are those which have their components joined in a definite
ratio.
The sweet taste alone is Rich, [therefore the latter may be
regarded as a variety of the former], while [so far as both imply
privation of the Sweet] the Saline is fairly identical with the
Bitter. Between the extremes of sweet and bitter come the
Harsh, the Pungent, the Astringent, and the Acid. Savours and
Colours, it will be observed, contain respectively about the same
number of species. For there are seven species of each, if, as is
reasonable, we regard Dun [or Grey] as a variety of Black (for the
alternative is that Yellow should be classed with White, as Rich
with Sweet); while [the irreducible colours, viz.] Crimson, Violet,
leek-Green, and deep Blue, come between White and Black, and
from these all others are derived by mixture.
1273
Again, as Black is a privation of White in the Translucent, so
Saline or Bitter is a privation of Sweet in the Nutrient Moist.
This explains why the ash of all burnt things is bitter; for the
potable [sc. the sweet] moisture has been exuded from them.
Democritus and most of the natural philosophers who treat of
sense-perception proceed quite irrationally, for they represent
all objects of sense as objects of Touch. Yet, if this is really so, it
clearly follows that each of the other senses is a mode of Touch;
but one can see at a glance that this is impossible.
Again, they treat the percepts common to all senses as proper to
one. For [the qualities by which they explain taste viz.]
Magnitude and Figure, Roughness and Smoothness, and,
moreover, the Sharpness and Bluntness found in solid bodies,
are percepts common to all the senses, or if not to all, at least to
Sight and Touch. This explains why it is that the senses are
liable to err regarding them, while no such error arises
respecting their proper sensibles; e.g. the sense of Seeing is not
deceived as to Colour, nor is that of Hearing as to Sound.
On the other hand, they reduce the proper to common
sensibles, as Democritus does with White and Black; for he
asserts that the latter is [a mode of the] rough, and the former
[a mode of the] smooth, while he reduces Savours to the atomic
figures. Yet surely no one sense, or, if any, the sense of Sight
rather than any other, can discern the common sensibles. But if
we suppose that the sense of Taste is better able to do so, then -
since to discern the smallest objects in each kind is what marks
the acutest sense. - Taste should have been the sense which
best perceived the common sensibles generally, and showed the
most perfect power of discerning figures in general.
Again, all the sensibles involve contrariety; e.g. in Colour White
is contrary to Black, and in Savours Bitter is contrary to Sweet;
but no one figure is reckoned as contrary to any other figure.
1274
Else, to which of the possible polygonal figures [to which
Democritus reduces Bitter] is the spherical figure [to which he
reduces Sweet] contrary?
Again, since figures are infinite in number, savours also should
be infinite; [the possible rejoinder - 'that they are so, only that
some are not perceived' - cannot be sustained] for why should
one savour be perceived, and another not?
This completes our discussion of the object of Taste, i.e. Savour;
for the other affections of Savours are examined in their proper
place in connection with the natural history of Plants.
Our conception of the nature of Odours must be analogous to
that of Savours; inasmuch as the Sapid Dry effects in air and
water alike, but in a different province of sense, precisely what
the Dry effects in the Moist of water only. We customarily
predicate Translucency of both air and water in common; but it
is not qua translucent that either is a vehicle of odour, but qua
possessed of a power of washing or rinsing [and so imbibing]
the Sapid Dryness.
For the object of Smell exists not in air only: it also exists in
water. This is proved by the case of fishes and testacea, which
are seen to possess the faculty of smell, although water
contains no air (for whenever air is generated within water it
rises to the surface), and these creatures do not respire. Hence,
if one were to assume that air and water are both moist, it
would follow that Odour is the natural substance consisting of
the Sapid Dry diffused in the Moist, and whatever is of this kind
would be an object of Smell.
1275
That the property of odorousness is based upon the Sapid may
be seen by comparing the things which possess with those
which do not possess odour. The elements, viz. Fire, Air, Earth,
Water, are inodorous, because both the dry and the moist
among them are without sapidity, unless some added
ingredient produces it. This explains why sea-water possesses
odour, for [unlike 'elemental' water] it contains savour and
dryness. Salt, too, is more odorous than natron, as the oil which
exudes from the former proves, for natron is allied to
['elemental'] earth more nearly than salt. Again, a stone is
inodorous, just because it is tasteless, while, on the contrary,
wood is odorous, because it is sapid. The kinds of wood, too,
which contain more ['elemental'] water are less odorous than
others. Moreover, to take the case of metals, gold is inodorous
because it is without taste, but bronze and iron are odorous; and
when the [sapid] moisture has been burnt out of them, their
slag is, in all cases, less odorous the metals [than the metals
themselves]. Silver and tin are more odorous than the one class
of metals, less so than the other, inasmuch as they are water [to
a greater degree than the former, to a less degree than the
latter].
Some writers look upon Fumid exhalation, which is a
compound of Earth and Air, as the essence of Odour. [Indeed all
are inclined to rush to this theory of Odour.] Heraclitus implied
his adherence to it when he declared that if all existing things
were turned into Smoke, the nose would be the organ to discern
them with. All writers incline to refer odour to this cause [sc.
exhalation of some sort], but some regard it as aqueous, others
as fumid, exhalation; while others, again, hold it to be either.
Aqueous exhalation is merely a form of moisture, but fumid
exhalation is, as already remarked, composed of Air and Earth.
The former when condensed turns into water; the latter, in a
particular species of earth. Now, it is unlikely that odour is
either of these. For vaporous exhalation consists of mere water
1276
[which, being tasteless, is inodorous]; and fumid exhalation
cannot occur in water at all, though, as has been before stated,
aquatic creatures also have the sense of smell.
Again, the exhalation theory of odour is analogous to the theory
of emanations. If, therefore, the latter is untenable, so, too, is the
former.
It is clearly conceivable that the Moist, whether in air (for air,
too, is essentially moist) or in water, should imbibe the
influence of, and have effects wrought in it by, the Sapid
Dryness. Moreover, if the Dry produces in moist media, i.e.
water and air, an effect as of something washed out in them, it
is manifest that odours must be something analogous to
savours. Nay, indeed, this analogy is, in some instances, a fact
[registered in language]; for odours as well as savours are
spoken of as pungent, sweet, harsh, astringent rich [='savoury'];
and one might regard fetid smells as analogous to bitter tastes;
which explains why the former are offensive to inhalation as
the latter are to deglutition. It is clear, therefore, that Odour is in
both water and air what Savour is in water alone. This explains
why coldness and freezing render Savours dull, and abolish
odours altogether; for cooling and freezing tend to annul the
kinetic heat which helps to fabricate sapidity.
There are two species of the Odorous. For the statement of
certain writers that the odorous is not divisible into species is
false; it is so divisible. We must here define the sense in which
these species are to be admitted or denied.
One class of odours, then, is that which runs parallel, as has
been observed, to savours: to odours of this class their
pleasantness or unpleasantness belongs incidentally. For owing
to the fact that Savours are qualities of nutrient matter, the
odours connected with these [e.g. those of a certain food] are
agreeable as long as animals have an appetite for the food, but
1277
they are not agreeable to them when sated and no longer in
want of it; nor are they agreeable, either, to those animals that
do not like the food itself which yields the odours. Hence, as we
observed, these odours are pleasant or unpleasant incidentally,
and the same reasoning explains why it is that they are
perceptible to all animals in common.
The other class of odours consists of those agreeable in their
essential nature, e.g. those of flowers. For these do not in any
degree stimulate animals to food, nor do they contribute in any
way to appetite; their effect upon it, if any, is rather the
opposite. For the verse of Strattis ridiculing Euripides -
Use not perfumery to flavour soup, contains a truth.
Those who nowadays introduce such flavours into beverages
deforce our sense of pleasure by habituating us to them, until,
from two distinct kinds of sensations combined, pleasure arises
as it might from one simple kind.
Of this species of odour man alone is sensible; the other, viz.
that correlated with Tastes, is, as has been said before,
perceptible also to the lower animals. And odours of the latter
sort, since their pleasureableness depends upon taste, are
divided into as many species as there are different tastes; but
we cannot go on to say this of the former kind of odour, since its
nature is agreeable or disagreeable per se. The reason why the
perception of such odours is peculiar to man is found in the
characteristic state of man's brain. For his brain is naturally
cold, and the blood which it contains in its vessels is thin and
pure but easily cooled (whence it happens that the exhalation
arising from food, being cooled by the coldness of this region,
produces unhealthy rheums); therefore it is that odours of such
a species have been generated for human beings, as a safeguard
to health. This is their sole function, and that they perform it is
evident. For food, whether dry or moist, though sweet to taste, is
1278
often unwholesome; whereas the odour arising from what is
fragrant, that odour which is pleasant in its own right, is, so to
say, always beneficial to persons in any state of bodily health
whatever.
For this reason, too, the perception of odour [in general] effected
through respiration, not in all animals, but in man and certain
other sanguineous animals, e.g. quadrupeds, and all that
participate freely in the natural substance air; because when
odours, on account of the lightness of the heat in them, mount
to the brain, the health of this region is thereby promoted. For
odour, as a power, is naturally heat-giving. Thus Nature has
employed respiration for two purposes: primarily for the relief
thereby brought to the thorax, secondarily for the inhalation of
odour. For while an animal is inhaling, - odour moves in
through its nostrils, as it were 'from a side-entrance.'
But the perception of the second class of odours above
described [does not belong to all animal, but] is confined to
human beings, because man's brain is, in proportion to his
whole bulk, larger and moister than the brain of any other
animal. This is the reason of the further fact that man alone, so
to speak, among animals perceives and takes pleasure in the
odours of flowers and such things. For the heat and stimulation
set up by these odours are commensurate with the excess of
moisture and coldness in his cerebral region. On all the other
animals which have lungs, Nature has bestowed their due
perception of one of the two kinds of odour [i.e. that connected
with nutrition] through the act of respiration, guarding against
the needless creation of two organs of sense; for in the fact that
they respire the other animals have already sufficient provision
for their perception of the one species of odour only, as human
beings have for their perception of both.
1279
But that creatures which do not respire have the olfactory sense
is evident. For fishes, and all insects as a class, have, thanks to
the species of odour correlated with nutrition, a keen olfactory
sense of their proper food from a distance, even when they are
very far away from it; such is the case with bees, and also with
the class of small ants, which some denominate knipes. Among
marine animals, too, the murex and many other similar animals
have an acute perception of their food by its odour.
It is not equally certain what the organ is whereby they so
perceive. This question, of the organ whereby they perceive
odour, may well cause a difficulty, if we assume that smelling
takes place in animals only while respiring (for that this is the
fact is manifest in all the animals which do respire), whereas
none of those just mentioned respires, and yet they have the
sense of smell - unless, indeed, they have some other sense not
included in the ordinary five. This supposition is, however,
impossible. For any sense which perceives odour is a sense of
smell, and this they do perceive, though probably not in the
same way as creatures which respire, but when the latter are
respiring the current of breath removes something that is laid
like a lid upon the organ proper (which explains why they do
not perceive odours when not respiring); while in creatures
which do not respire this is always off: just as some animals
have eyelids on their eyes, and when these are not raised they
cannot see, whereas hard-eyed animals have no lids, and
consequently do not need, besides eyes, an agency to raise the
lids, but see straightway [without intermission] from the actual
moment at which it is first possible for them to do so [i.e. from
the moment when an object first comes within their field of
vision].
Consistently with what has been said above, not one of the
lower animals shows repugnance to the odour of things which
are essentially ill-smelling, unless one of the latter is positively
1280
pernicious. They are destroyed, however, by these things, just as
human beings are; i.e. as human beings get headaches from,
and are often asphyxiated by, the fumes of charcoal, so the
lower animals perish from the strong fumes of brimstone and
bituminous substances; and it is owing to experience of such
effects that they shun these. For the disagreeable odour in itself
they care nothing whatever (though the odours of many plants
are essentially disagreeable), unless, indeed, it has some effect
upon the taste of their food.
The senses making up an odd number, and an odd number
having always a middle unit, the sense of smell occupies in
itself as it were a middle position between the tactual senses,
i.e. Touch and Taste, and those which perceive through a
medium, i.e. Sight and Hearing. Hence the object of smell, too, is
an affection of nutrient substances (which fall within the class
of Tangibles), and is also an affection of the audible and the
visible; whence it is that creatures have the sense of smell both
in air and water. Accordingly, the object of smell is something
common to both of these provinces, i.e. it appertains both to the
tangible on the one hand, and on the other to the audible and
translucent. Hence the propriety of the figure by which it has
been described by us as an immersion or washing of dryness in
the Moist and Fluid. Such then must be our account of the sense
in which one is or is not entitled to speak of the odorous as
having species.
The theory held by certain of the Pythagoreans, that some
animals are nourished by odours alone, is unsound. For, in the
first place, we see that food must be composite, since the bodies
nourished by it are not simple. This explains why waste matter
is secreted from food, either within the organisms, or, as in
plants, outside them. But since even water by itself alone, that
is, when unmixed, will not suffice for food - for anything which
is to form a consistency must be corporeal - , it is still much less
1281
conceivable that air should be so corporealized [and thus fitted
to be food]. But, besides this, we see that all animals have a
receptacle for food, from which, when it has entered, the body
absorbs it. Now, the organ which perceives odour is in the head,
and odour enters with the inhalation of the breath; so that it
goes to the respiratory region. It is plain, therefore, that odour,
qua odour, does not contribute to nutrition; that, however, it is
serviceable to health is equally plain, as well by immediate
perception as from the arguments above employed; so that
odour is in relation to general health what savour is in the
province of nutrition and in relation to the bodies nourished.
This then must conclude our discussion of the several organs of
sense-perception.
One might ask: if every body is infinitely divisible, are its
sensible qualities - Colour, Savour, Odour, Sound, Weight, Cold
or Heat, [Heaviness or] Lightness, Hardness or Softness - also
infinitely divisible? Or, is this impossible?
[One might well ask this question], because each of them is
productive of sense-perception, since, in fact, all derive their
name [of 'sensible qualities'] from the very circumstance of
their being able to stimulate this. Hence, [if this is so] both our
perception of them should likewise be divisible to infinity, and
every part of a body [however small] should be a perceptible
magnitude. For it is impossible, e.g. to see a thing which is white
but not of a certain magnitude.
Since if it were not so, [if its sensible qualities were not divisible,
pari passu with body], we might conceive a body existing but
1282
having no colour, or weight, or any such quality; accordingly not
perceptible at all. For these qualities are the objects of sense-
perception. On this supposition, every perceptible object should
be regarded as composed not of perceptible [but of
imperceptible] parts. Yet it must [be really composed of
perceptible parts], since assuredly it does not consist of
mathematical [and therefore purely abstract and non-sensible]
quantities. Again, by what faculty should we discern and
cognize these [hypothetical real things without sensible
qualities]? Is it by Reason? But they are not objects of Reason;
nor does reason apprehend objects in space, except when it acts
in conjunction with sense-perception. At the same time, if this
be the case [that there are magnitudes, physically real, but
without sensible quality], it seems to tell in favour of the
atomistic hypothesis; for thus, indeed, [by accepting this
hypothesis], the question [with which this chapter begins]
might be solved [negatively]. But it is impossible [to accept this
hypothesis]. Our views on the subject of atoms are to be found
in our treatise on Movement.
The solution of these questions will bring with it also the
answer to the question why the species of Colour, Taste, Sound,
and other sensible qualities are limited. For in all classes of
things lying between extremes the intermediates must be
limited. But contraries are extremes, and every object of sense-
perception involves contrariety: e.g. in Colour, White x Black; in
Savour, Sweet x Bitter, and in all the other sensibles also the
contraries are extremes. Now, that which is continuous is
divisible into an infinite number of unequal parts, but into a
finite number of equal parts, while that which is not per se
continuous is divisible into species which are finite in number.
Since then, the several sensible qualities of things are to be
reckoned as species, while continuity always subsists in these,
we must take account of the difference between the Potential
and the Actual. It is owing to this difference that we do not
1283
[actually] see its ten-thousandth part in a grain of millet,
although sight has embraced the whole grain within its scope;
and it is owing to this, too, that the sound contained in a
quarter-tone escapes notice, and yet one hears the whole strain,
inasmuch as it is a continuum; but the interval between the
extreme sounds [that bound the quarter-tone] escapes the ear
[being only potentially audible, not actually]. So, in the case of
other objects of sense, extremely small constituents are
unnoticed; because they are only potentially not actually
[perceptible e.g.] visible, unless when they have been parted
from the wholes. So the footlength too exists potentially in the
two-foot length, but actually only when it has been separated
from the whole. But objective increments so small as those
above might well, if separated from their totals, [instead of
achieving 'actual' exisistence] be dissolved in their
environments, like a drop of sapid moisture poured out into the
sea. But even if this were not so [sc. with the objective
magnitude], still, since the [subjective] of sense-perception is
not perceptible in itself, nor capable of separate existence (since
it exists only potentially in the more distinctly perceivable
whole of sense-perception), so neither will it be possible to
perceive [actually] its correlatively small object [sc. its quantum
of pathema or sensible quality] when separated from the object-
total. But yet this [small object] is to be considered as
perceptible: for it is both potentially so already [i.e. even when
alone], and destined to be actually so when it has become part
of an aggregate. Thus, therefore, we have shown that some
magnitudes and their sensible qualities escape notice, and the
reason why they do so, as well as the manner in which they are
still perceptible or not perceptible in such cases. Accordingly
then when these [minutely subdivided] sensibles have once
again become aggregated in a whole in such a manner,
relatively to one another, as to be perceptible actually, and not
merely because they are in the whole, but even apart from it, it
1284
follows necessarily [from what has been already stated] that
their sensible qualities, whether colours or tastes or sounds, are
limited in number.
One might ask: - do the objects of sense-perception, or the
movements proceeding from them ([since movements there
are,] in whichever of the two ways [viz. by emanations or by
stimulatory kinesis] sense-perception takes place), when these
are actualized for perception, always arrive first at a spatial
middle point [between the sense-organ and its object], as Odour
evidently does, and also Sound? For he who is nearer [to the
odorous object] perceives the Odour sooner [than who is farther
away], and the Sound of a stroke reaches us some time after it
has been struck. Is it thus also with an object seen, and with
Light? Empedocles, for example, says that the Light from the
Sun arrives first in the intervening space before it comes to the
eye, or reaches the Earth. This might plausibly seem to be the
case. For whatever is moved [in space], is moved from one place
to another; hence there must be a corresponding interval of
time also in which it is moved from the one place to the other.
But any given time is divisible into parts; so that we should
assume a time when the sun's ray was not as yet seen, but was
still travelling in the middle space.
Now, even if it be true that the acts of 'hearing' and 'having
heard', and, generally, those of 'perceiving' and 'having
perceived', form co-instantaneous wholes, in other words, that
acts of sense-perception do not involve a process of becoming,
but have their being none the less without involving such a
process; yet, just as, [in the case of sound], though the stroke
which causes the Sound has been already struck, the Sound is
not yet at the ear (and that this last is a fact is further proved by
the transformation which the letters [viz. the consonants as
heard] undergo [in the case of words spoken from a distance],
implying that the local movement [involved in Sound] takes
1285
place in the space between [us and the speaker]; for the reason
why [persons addressed from a distance] do not succeed in
catching the sense of what is said is evidently that the air
[sound wave] in moving towards them has its form changed)
[granting this, then, the question arises]: is the same also true in
the case of Colour and Light? For certainly it is not true that the
beholder sees, and the object is seen, in virtue of some merely
abstract relationship between them, such as that between
equals. For if it were so, there would be no need [as there is] that
either [the beholder or the thing beheld] should occupy some
particular place; since to the equalization of things their being
near to, or far from, one another makes no difference.
Now this [travelling through successive positions in the
medium] may with good reason take place as regards Sound
and Odour, for these, like [their media] Air and Water, are
continuous, but the movement of both is divided into parts. This
too is the ground of the fact that the object which the person
first in order of proximity hears or smells is the same as that
which each subsequent person perceives, while yet it is not the
same.
Some, indeed, raise a question also on these very points; they
declare it impossible that one person should hear, or see, or
smell, the same object as another, urging the impossibility of
several persons in different places hearing or smelling [the
same object], for the one same thing would [thus] be divided
from itself. The answer is that, in perceiving the object which
first set up the motion - e.g. a bell, or frankincense, or fire - all
perceive an object numerically one and the same; while, of
course, in the special object perceived they perceive an object
numerically different for each, though specifically the same for
all; and this, accordingly, explains how it is that many persons
together see, or smell, or hear [the same object]. These things
[the odour or sound proper] are not bodies, but an affection or
1286
process of some kind (otherwise this [viz. simultaneous
perception of the one object by many] would not have been, as
it is, a fact of experience) though, on the other hand, they each
imply a body [as their cause].
But [though sound and odour may travel,] with regard to Light
the case is different. For Light has its raison d'etre in the being
[not becoming] of something, but it is not a movement. And in
general, even in qualitative change the case is different from
what it is in local movement [both being different species of
kinesis]. Local movements, of course, arrive first at a point
midway before reaching their goal (and Sound, it is currently
believed, is a movement of something locally moved), but we
cannot go on to assert this [arrival at a point midway] like
manner of things which undergo qualitative change. For this
kind of change may conceivably take place in a thing all at once,
without one half of it being changed before the other; e.g. it is
conceivable that water should be frozen simultaneously in
every part. But still, for all that, if the body which is heated or
frozen is extensive, each part of it successively is affected by the
part contiguous, while the part first changed in quality is so
changed by the cause itself which originates the change, and
thus the change throughout the whole need not take place
coinstantaneously and all at once. Tasting would have been as
smelling now is, if we lived in a liquid medium, and perceived
[the sapid object] at a distance, before touching it.
Naturally, then, the parts of media between a sensory organ and
its object are not all affected at once - except in the case of
Light [illumination] for the reason above stated, and also in the
case of seeing, for the same reason; for Light is an efficient
cause of seeing.
1287
Another question respecting sense-perception is as follows:
assuming, as is natural, that of two [simultaneous] sensory
stimuli the stronger always tends to extrude the weaker [from
consciousness], is it conceivable or not that one should be able
to discern two objects coinstantaneously in the same individual
time? The above assumption explains why persons do not
perceive what is brought before their eyes, if they are at the
time deep in thought, or in a fright, or listening to some loud
noise. This assumption, then, must be made, and also the
following: that it is easier to discern each object of sense when
in its simple form than when an ingredient in a mixture; easier,
for example, to discern wine when neat than when blended,
and so also honey, and [in other provinces] a colour, or to
discern the nete by itself alone, than [when sounded with the
hypate] in the octave; the reason being that component
elements tend to efface [the distinctive characteristics of] one
another. Such is the effect [on one another] of all ingredients of
which, when compounded, some one thing is formed.
If, then, the greater stimulus tends to expel the less, it
necessarily follows that, when they concur, this greater should
itself too be less distinctly perceptible than if it were alone,
since the less by blending with it has removed some of its
individuality, according to our assumption that simple objects
are in all cases more distinctly perceptible.
Now, if the two stimuli are equal but heterogeneous, no
perception of either will ensue; they will alike efface one
another's characteristics. But in such a case the perception of
either stimulus in its simple form is impossible. Hence either
there will then be no sense-perception at all, or there will be a
perception compounded of both and differing from either. The
latter is what actually seems to result from ingredients blended
1288
together, whatever may be the compound in which they are so
mixed.
Since, then, from some concurrent [sensory stimuli] a resultant
object is produced, while from others no such resultant is
produced, and of the latter sort are those things which belong to
different sense provinces (for only those things are capable of
mixture whose extremes are contraries, and no one compound
can be formed from, e.g. White and Sharp, except indirectly, i.e.
not as a concord is formed of Sharp and Grave); there follows
logically the impossibility of discerning such concurrent stimuli
coinstantaneously. For we must suppose that the stimuli, when
equal, tend alike to efface one another, since no one [form of
stimulus] results from them; while, if they are unequal, the
stronger alone is distinctly perceptible.
Again, the soul would be more likely to perceive
coinstantaneously, with one and the same sensory act, two
things in the same sensory province, such as the Grave and the
Sharp in sound; for the sensory stimulation in this one province
is more likely to be unitemporal than that involving two
different provinces, as Sight and Hearing. But it is impossible to
perceive two objects coinstantaneously in the same sensory act
unless they have been mixed, [when, however, they are no
longer two], for their amalgamation involves their becoming
one, and the sensory act related to one object is itself one, and
such act, when one, is, of course, coinstantaneous with itself.
Hence, when things are mixed we of necessity perceive them
coinstantaneously: for we perceive them by a perception
actually one. For an object numerically one means that which is
perceived by a perception actually one, whereas an object
specifically one means that which is perceived by a sensory act
potentially one [i.e. by an energeia of the same sensuous
faculty]. If then the actualized perception is one, it will declare
its data to be one object; they must, therefore, have been mixed.
1289
Accordingly, when they have not been mixed, the actualized
perceptions which perceive them will be two; but [if so, their
perception must be successive not coinstantaneous, for] in one
and the same faculty the perception actualized at any single
moment is necessarily one, only one stimulation or exertion of
a single faculty being possible at a single instant, and in the
case supposed here the faculty is one. It follows, therefore, that
we cannot conceive the possibility of perceiving two distinct
objects coinstantaneously with one and the same sense.
But if it be thus impossible to perceive coinstantaneously two
objects in the same province of sense if they are really two,
manifestly it is still less conceivable that we should perceive
coinstantaneously objects in two different sensory provinces, as
White and Sweet. For it appears that when the Soul predicates
numerical unity it does so in virtue of nothing else than such
coinstantaneous perception [of one object, in one instant, by
one energeia]: while it predicates specific unity in virtue of [the
unity of] the discriminating faculty of sense together with [the
unity of] the mode in which this operates. What I mean, for
example, is this; the same sense no doubt discerns White and
Black, [which are hence generically one] though specifically
different from one another, and so, too, a faculty of sense self-
identical, but different from the former, discerns Sweet and
Bitter; but while both these faculties differ from one another
[and each from itself] in their modes of discerning either of
their respective contraries, yet in perceiving the co-ordinates in
each province they proceed in manners analogous to one
another; for instance, as Taste perceives Sweet, so Sight
perceives White; and as the latter perceives Black, so the former
perceives Bitter.
Again, if the stimuli of sense derived from Contraries are
themselves Contrary, and if Contraries cannot be conceived as
subsisting together in the same individual subject, and if
1290
Contraries, e.g. Sweet and Bitter, come under one and the same
sense-faculty, we must conclude that it is impossible to discern
them coinstantaneously. It is likewise clearly impossible so to
discern such homogeneous sensibles as are not [indeed]
Contrary, [but are yet of different species]. For these are, [in the
sphere of colour, for instance], classed some with White, others
with Black, and so it is, likewise, in the other provinces of sense;
for example, of savours, some are classed with Sweet, and
others with Bitter. Nor can one discern the components in
compounds coinstantaneously (for these are ratios of
Contraries, as e.g. the Octave or the Fifth); unless, indeed, on
condition of perceiving them as one. For thus, and not
otherwise, the ratios of the extreme sounds are compounded
into one ratio: since we should have together the ratio, on the
one hand, of Many to Few or of Odd to Even, on the other, that
of Few to Many or of Even to Odd [and these, to be perceived
together, must be unified].
If, then, the sensibles denominated co-ordinates though in
different provinces of sense (e.g. I call Sweet and White co-
ordinates though in different provinces) stand yet more aloof,
and differ more, from one another than do any sensibles in the
same province; while Sweet differs from White even more than
Black does from White, it is still less conceivable that one
should discern them [viz. sensibles in different sensory
provinces whether co-ordinates or not] coinstantaneously than
sensibles which are in the same province. Therefore, if
coinstantaneous perception of the latter be impossible, that of
the former is a fortiori impossible.
Some of the writers who treat of concords assert that the
sounds combined in these do not reach us simultaneously, but
only appear to do so, their real successiveness being unnoticed
whenever the time it involves is [so small as to be]
imperceptible. Is this true or not? One might perhaps, following
1291
this up, go so far as to say that even the current opinion that
one sees and hears coinstantaneously is due merely to the fact
that the intervals of time [between the really successive
perceptions of sight and hearing] escape observation. But this
can scarcely be true, nor is it conceivable that any portion of
time should be [absolutely] imperceptible, or that any should be
absolutely unnoticeable; the truth being that it is possible to
perceive every instant of time. [This is so]; because, if it is
inconceivable that a person should, while perceiving himself or
aught else in a continuous time, be at any instant unaware of
his own existence; while, obviously, the assumption, that there
is in the time-continuum a time so small as to be absolutely
imperceptible, carries the implication that a person would,
during such time, be unaware of his own existence, as well as of
his seeing and perceiving; [this assumption must be false].
Again, if there is any magnitude, whether time or thing,
absolutely imperceptible owing to its smallness, it follows that
there would not be either a thing which one perceives, or a time
in which one perceives it, unless in the sense that in some part
of the given time he sees some part of the given thing. For [let
there be a line ab, divided into two parts at g, and let this line
represent a whole object and a corresponding whole time. Now,]
if one sees the whole line, and perceives it during a time which
forms one and the same continuum, only in the sense that he
does so in some portion of this time, let us suppose the part gb,
representing a time in which by supposition he was perceiving
nothing, cut off from the whole. Well, then, he perceives in a
certain part [viz. in the remainder] of the time, or perceives a
part [viz. the remainder] of the line, after the fashion in which
one sees the whole earth by seeing some given part of it, or
walks in a year by walking in some given part of the year. But
[by hypothesis] in the part bg he perceives nothing: therefore, in
fact, he is said to perceive the whole object and during the
whole time simply because he perceives [some part of the
1292
object] in some part of the time ab. But the same argument
holds also in the case of ag [the remainder, regarded in its turn
as a whole]; for it will be found [on this theory of vacant times
and imperceptible magnitudes] that one always perceives only
in some part of a given whole time, and perceives only some
part of a whole magnitude, and that it is impossible to perceive
any [really] whole [object in a really whole time; a conclusion
which is absurd, as it would logically annihilate the perception
of both Objects and Time].
Therefore we must conclude that all magnitudes are
perceptible, but their actual dimensions do not present
themselves immediately in their presentation as objects. One
sees the sun, or a four-cubit rod at a distance, as a magnitude,
but their exact dimensions are not given in their visual
presentation: nay, at times an object of sight appears indivisible,
but [vision like other special senses, is fallible respecting
'common sensibles', e.g. magnitude, and] nothing that one sees
is really indivisible. The reason of this has been previously
explained. It is clear then, from the above arguments, that no
portion of time is imperceptible.
But we must here return to the question proposed above for
discussion, whether it is possible or impossible to perceive
several objects coinstantaneously; by 'coinstantaneously' I
mean perceiving the several objects in a time one and
indivisible relatively to one another, i.e. indivisible in a sense
consistent with its being all a continuum.
First, then, is it conceivable that one should perceive the
different things coinstantaneously, but each with a different
part of the Soul? Or [must we object] that, in the first place, to
begin with the objects of one and the same sense, e.g. Sight, if
we assume it [the Soul qua exercising Sight] to perceive one
colour with one part, and another colour with a different part, it
1293
will have a plurality of parts the same in species, [as they must
be,] since the objects which it thus perceives fall within the
same genus?
Should any one [to illustrate how the Soul might have in it two
different parts specifically identical, each directed to a set of
aistheta the same in genus with that to which the other is
directed] urge that, as there are two eyes, so there may be in the
Soul something analogous, [the reply is] that of the eyes,
doubtless, some one organ is formed, and hence their
actualization in perception is one; but if this is so in the Soul,
then, in so far as what is formed of both [i.e. of any two
specifically identical parts as assumed] is one, the true
perceiving subject also will be one, [and the contradictory of the
above hypothesis (of different parts of Soul remaining engaged
in simultaneous perception with one sense) is what emerges
from the analogy]; while if the two parts of Soul remain
separate, the analogy of the eyes will fail, [for of these some one
is really formed].
Furthermore, [on the supposition of the need of different parts
of Soul, co-operating in each sense, to discern different objects
coinstantaneously], the senses will be each at the same time
one and many, as if we should say that they were each a set of
diverse sciences; for neither will an 'activity' exist without its
proper faculty, nor without activity will there be sensation.
But if the Soul does not, in the way suggested [i.e. with different
parts of itself acting simultaneously], perceive in one and the
same individual time sensibles of the same sense, a fortiori it is
not thus that it perceives sensibles of different senses. For it is,
as already stated, more conceivable that it should perceive a
plurality of the former together in this way than a plurality of
heterogeneous objects.
1294
If then, as is the fact, the Soul with one part perceives Sweet,
with another, White, either that which results from these is
some one part, or else there is no such one resultant. But there
must be such an one, inasmuch as the general faculty of sense-
perception is one. What one object, then, does that one faculty
[when perceiving an object, e.g. as both White and Sweet]
perceive? [None]; for assuredly no one object arises by
composition of these [heterogeneous objects, such as White and
Sweet]. We must conclude, therefore, that there is, as has been
stated before, some one faculty in the soul with which the latter
perceives all its percepts, though it perceives each different
genus of sensibles through a different organ.
May we not, then, conceive this faculty which perceives White
and Sweet to be one qua indivisible [sc. qua combining its
different simultaneous objects] in its actualization, but
different, when it has become divisible [sc. qua distinguishing
its different simultaneous objects] in its actualization?
Or is what occurs in the case of the perceiving Soul conceivably
analogous to what holds true in that of the things themselves?
For the same numerically one thing is white and sweet, and has
many other qualities, [while its numerical oneness is not
thereby prejudiced] if the fact is not that the qualities are really
separable in the object from one another, but that the being of
each quality is different [from that of every other]. In the same
way therefore we must assume also, in the case of the Soul, that
the faculty of perception in general is in itself numerically one
and the same, but different [differentiated] in its being;
different, that is to say, in genus as regards some of its objects,
in species as regards others. Hence too, we may conclude that
one can perceive [numerically different objects]
coinstantaneously with a faculty which is numerically one and
the same, but not the same in its relationship [sc. according as
the objects to which it is directed are not the same].
1295
That every sensible object is a magnitude, and that nothing
which it is possible to perceive is indivisible, may be thus
shown. The distance whence an object could not be seen is
indeterminate, but that whence it is visible is determinate. We
may say the same of the objects of Smelling and Hearing, and of
all sensibles not discerned by actual contact. Now, there is, in
the interval of distance, some extreme place, the last from
which the object is invisible, and the first from which it is
visible. This place, beyond which if the object be one cannot
perceive it, while if the object be on the hither side one must
perceive it, is, I presume, itself necessarily indivisible. Therefore,
if any sensible object be indivisible, such object, if set in the said
extreme place whence imperceptibility ends and perceptibility
begins, will have to be both visible and invisible their objects,
whether regarded in general or at the same time; but this is
impossible.
This concludes our survey of the characteristics of the organs of
Sense-perception and their objects, whether regarded in general
or in relation to each organ. Of the remaining subjects, we must
first consider that of memory and remembering.
1296
On Memory and Reminiscence
translated by J. I. Beare
We have, in the next place, to treat of Memory and
Remembering, considering its nature, its cause, and the part of
the soul to which this experience, as well as that of Recollecting,
belongs. For the persons who possess a retentive memory are
not identical with those who excel in power of recollection;
indeed, as a rule, slow people have a good memory, whereas
those who are quick-witted and clever are better at recollecting.
We must first form a true conception of these objects of
memory, a point on which mistakes are often made. Now to
remember the future is not possible, but this is an object of
opinion or expectation (and indeed there might be actually a
science of expectation, like that of divination, in which some
believe); nor is there memory of the present, but only sense-
perception. For by the latter we know not the future, nor the
past, but the present only. But memory relates to the past. No
one would say that he remembers the present, when it is
present, e.g. a given white object at the moment when he sees
it; nor would one say that he remembers an object of scientific
contemplation at the moment when he is actually
contemplating it, and has it full before his mind; - of the former
he would say only that he perceives it, of the latter only that he
knows it. But when one has scientific knowledge, or perception,
apart from the actualizations of the faculty concerned, he thus
'remembers' (that the angles of a triangle are together equal to
two right angles); as to the former, that he learned it, or thought
it out for himself, as to the latter, that he heard, or saw, it, or
1297
had some such sensible experience of it. For whenever one
exercises the faculty of remembering, he must say within
himself, 'I formerly heard (or otherwise perceived) this,' or 'I
formerly had this thought'.
Memory is, therefore, neither Perception nor Conception, but a
state or affection of one of these, conditioned by lapse of time.
As already observed, there is no such thing as memory of the
present while present, for the present is object only of
perception, and the future, of expectation, but the object of
memory is the past. All memory, therefore, implies a time
elapsed; consequently only those animals which perceive time
remember, and the organ whereby they perceive time is also
that whereby they remember.
The subject of 'presentation' has been already considered in our
work On the Soul. Without a presentation intellectual activity is
impossible. For there is in such activity an incidental affection
identical with one also incidental in geometrical
demonstrations. For in the latter case, though we do not for the
purpose of the proof make any use of the fact that the quantity
in the triangle (for example, which we have drawn) is
determinate, we nevertheless draw it determinate in quantity.
So likewise when one exerts the intellect (e.g. on the subject of
first principles), although the object may not be quantitative,
one envisages it as quantitative, though he thinks it in
abstraction from quantity; while, on the other hand, if the
object of the intellect is essentially of the class of things that are
quantitative, but indeterminate, one envisages it as if it had
determinate quantity, though subsequently, in thinking it, he
abstracts from its determinateness. Why we cannot exercise the
intellect on any object absolutely apart from the continuous, or
apply it even to non-temporal things unless in connexion with
time, is another question. Now, one must cognize magnitude
and motion by means of the same faculty by which one
1298
cognizes time (i.e. by that which is also the faculty of memory),
and the presentation (involved in such cognition) is an affection
of the sensus communis; whence this follows, viz. that the
cognition of these objects (magnitude, motion time) is effected
by the (said sensus communis, i.e. the) primary faculty of
perception. Accordingly, memory (not merely of sensible, but)
even of intellectual objects involves a presentation: hence we
may conclude that it belongs to the faculty of intelligence only
incidentally, while directly and essentially it belongs to the
primary faculty of sense-perception.
Hence not only human beings and the beings which possess
opinion or intelligence, but also certain other animals, possess
memory. If memory were a function of (pure) intellect, it would
not have been as it is an attribute of many of the lower animals,
but probably, in that case, no mortal beings would have had
memory; since, even as the case stands, it is not an attribute of
them all, just because all have not the faculty of perceiving
time. Whenever one actually remembers having seen or heard,
or learned, something, he includes in this act (as we have
already observed) the consciousness of 'formerly'; and the
distinction of 'former' and 'latter' is a distinction in time.
Accordingly if asked, of which among the parts of the soul
memory is a function, we reply: manifestly of that part to which
'presentation' appertains; and all objects capable of being
presented (viz. aistheta) are immediately and properly objects of
memory, while those (viz. noeta) which necessarily involve (but
only involve) presentation are objects of memory incidentally.
One might ask how it is possible that though the affection (the
presentation) alone is present, and the (related) fact absent, the
latter - that which is not present - is remembered. (The
question arises), because it is clear that we must conceive that
which is generated through sense-perception in the sentient
1299
soul, and in the part of the body which is its seat - viz. that
affection the state whereof we call memory - to be some such
thing as a picture. The process of movement (sensory
stimulation) involved the act of perception stamps in, as it were,
a sort of impression of the percept, just as persons do who
make an impression with a seal. This explains why, in those
who are strongly moved owing to passion, or time of life, no
mnemonic impression is formed; just as no impression would
be formed if the movement of the seal were to impinge on
running water; while there are others in whom, owing to the
receiving surface being frayed, as happens to (the stucco on) old
(chamber) walls, or owing to the hardness of the receiving
surface, the requisite impression is not implanted at all. Hence
both very young and very old persons are defective in memory;
they are in a state of flux, the former because of their growth,
the latter, owing to their decay. In like manner, also, both those
who are too quick and those who are too slow have bad
memories. The former are too soft, the latter too hard (in the
texture of their receiving organs), so that in the case of the
former the presented image (though imprinted) does not
remain in the soul, while on the latter it is not imprinted at all.
But then, if this truly describes what happens in the genesis of
memory, (the question stated above arises:) when one
remembers, is it this impressed affection that he remembers, or
is it the objective thing from which this was derived? If the
former, it would follow that we remember nothing which is
absent; if the latter, how is it possible that, though perceiving
directly only the impression, we remember that absent thing
which we do not perceive? Granted that there is in us
something like an impression or picture, why should the
perception of the mere impression be memory of something
else, instead of being related to this impression alone? For when
one actually remembers, this impression is what he
contemplates, and this is what he perceives. How then does he
1300
remember what is not present? One might as well suppose it
possible also to see or hear that which is not present. In reply,
we suggest that this very thing is quite conceivable, nay,
actually occurs in experience. A picture painted on a panel is at
once a picture and a likeness: that is, while one and the same, it
is both of these, although the 'being' of both is not the same,
and one may contemplate it either as a picture, or as a likeness.
Just in the same way we have to conceive that the mnemonic
presentation within us is something which by itself is merely an
object of contemplation, while, in-relation to something else, it
is also a presentation of that other thing. In so far as it is
regarded in itself, it is only an object of contemplation, or a
presentation; but when considered as relative to something
else, e.g. as its likeness, it is also a mnemonic token. Hence,
whenever the residual sensory process implied by it is
actualized in consciousness, if the soul perceives this in so far
as it is something absolute, it appears to occur as a mere
thought or presentation; but if the soul perceives it qua related
to something else, then, - just as when one contemplates the
painting in the picture as being a likeness, and without having
(at the moment) seen the actual Koriskos, contemplates it as a
likeness of Koriskos, and in that case the experience involved in
this contemplation of it (as relative) is different from what one
has when he contemplates it simply as a painted figure - (so in
the case of memory we have the analogous difference for), of
the objects in the soul, the one (the unrelated object) presents
itself simply as a thought, but the other (the related object) just
because, as in the painting, it is a likeness, presents itself as a
mnemonic token.
We can now understand why it is that sometimes, when we
have such processes, based on some former act of perception,
occurring in the soul, we do not know whether this really
implies our having had perceptions corresponding to them, and
we doubt whether the case is or is not one of memory. But
1301
occasionally it happens that (while thus doubting) we get a
sudden idea and recollect that we heard or saw something
formerly. This (occurrence of the 'sudden idea') happens
whenever, from contemplating a mental object as absolute, one
changes his point of view, and regards it as relative to
something else.
The opposite (sc. to the case of those who at first do not
recognize their phantasms as mnemonic) also occurs, as
happened in the cases of Antipheron of Oreus and others
suffering from mental derangement; for they were accustomed
to speak of their mere phantasms as facts of their past
experience, and as if remembering them. This takes place
whenever one contemplates what is not a likeness as if it were
a likeness.
Mnemonic exercises aim at preserving one's memory of
something by repeatedly reminding him of it; which implies
nothing else (on the learner's part) than the frequent
contemplation of something (viz. the 'mnemonic', whatever it
may be) as a likeness, and not as out of relation.
As regards the question, therefore, what memory or
remembering is, it has now been shown that it is the state of a
presentation, related as a likeness to that of which it is a
presentation; and as to the question of which of the faculties
within us memory is a function, (it has been shown) that it is a
function of the primary faculty of sense-perception, i.e. of that
faculty whereby we perceive time.
1302
Next comes the subject of Recollection, in dealing with which
we must assume as fundamental the truths elicited above in
our introductory discussions. For recollection is not the
'recovery' or 'acquisition' of memory; since at the instant when
one at first learns (a fact of science) or experiences (a particular
fact of sense), he does not thereby 'recover' a memory,
inasmuch as none has preceded, nor does he acquire one ab
initio. It is only at the instant when the aforesaid state or
affection (of the aisthesis or upolepsis) is implanted in the soul
that memory exists, and therefore memory is not itself
implanted concurrently with the continuous implantation of
the (original) sensory experience.
Further: at the very individual and concluding instant when
first (the sensory experience or scientific knowledge) has been
completely implanted, there is then already established in the
person affected the (sensory) affection, or the scientific
knowledge (if one ought to apply the term 'scientific knowledge'
to the (mnemonic) state or affection; and indeed one may well
remember, in the 'incidental' sense, some of the things (i.e. ta
katholou) which are properly objects of scientific knowledge);
but to remember, strictly and properly speaking, is an activity
which will not be immanent until the original experience has
undergone lapse of time. For one remembers now what one saw
or otherwise experienced formerly; the moment of the original
experience and the moment of the memory of it are never
identical.
Again, (even when time has elapsed, and one can be said really
to have acquired memory, this is not necessarily recollection, for
firstly) it is obviously possible, without any present act of
recollection, to remember as a continued consequence of the
original perception or other experience; whereas when (after an
1303
interval of obliviscence) one recovers some scientific knowledge
which he had before, or some perception, or some other
experience, the state of which we above declared to be memory,
it is then, and then only, that this recovery may amount to a
recollection of any of the things aforesaid. But, (though as
observed above, remembering does not necessarily imply
recollecting), recollecting always implies remembering, and
actualized memory follows (upon the successful act of
recollecting).
But secondly, even the assertion that recollection is the
reinstatement in consciousness of something which was there
before but had disappeared requires qualification. This
assertion may be true, but it may also be false; for the same
person may twice learn (from some teacher), or twice discover
(i.e. excogitate), the same fact. Accordingly, the act of
recollecting ought (in its definition) to be distinguished from
these acts; i.e. recollecting must imply in those who recollect
the presence of some spring over and above that from which
they originally learn.
Acts of recollection, as they occur in experience, are due to the
fact that one movement has by nature another that succeeds it
in regular order.
If this order be necessary, whenever a subject experiences the
former of two movements thus connected, it will (invariably)
experience the latter; if, however, the order be not necessary,
but customary, only in the majority of cases will the subject
experience the latter of the two movements. But it is a fact that
there are some movements, by a single experience of which
persons take the impress of custom more deeply than they do
by experiencing others many times; hence upon seeing some
things but once we remember them better than others which
we may have been frequently.
1304
Whenever therefore, we are recollecting, we are experiencing
certain of the antecedent movements until finally we
experience the one after which customarily comes that which
we seek. This explains why we hunt up the series (of kineseis)
having started in thought either from a present intuition or
some other, and from something either similar, or contrary, to
what we seek, or else from that which is contiguous with it.
Such is the empirical ground of the process of recollection; for
the mnemonic movements involved in these starting-points are
in some cases identical, in others, again, simultaneous, with
those of the idea we seek, while in others they comprise a
portion of them, so that the remnant which one experienced
after that portion (and which still requires to be excited in
memory) is comparatively small.
Thus, then, it is that persons seek to recollect, and thus, too, it is
that they recollect even without the effort of seeking to do so,
viz. when the movement implied in recollection has supervened
on some other which is its condition. For, as a rule, it is when
antecedent movements of the classes here described have first
been excited, that the particular movement implied in
recollection follows. We need not examine a series of which the
beginning and end lie far apart, in order to see how (by
recollection) we remember; one in which they lie near one
another will serve equally well. For it is clear that the method is
in each case the same, that is, one hunts up the objective series,
without any previous search or previous recollection. For (there
is, besides the natural order, viz. the order of the pralmata, or
events of the primary experience, also a customary order, and)
by the effect of custom the mnemonic movements tend to
succeed one another in a certain order. Accordingly, therefore,
when one wishes to recollect, this is what he will do: he will try
to obtain a beginning of movement whose sequel shall be the
movement which he desires to reawaken. This explains why
attempts at recollection succeed soonest and best when they
1305
start from a beginning (of some objective series). For, in order of
succession, the mnemonic movements are to one another as
the objective facts (from which they are derived). Accordingly,
things arranged in a fixed order, like the successive
demonstrations in geometry, are easy to remember (or recollect)
while badly arranged subjects are remembered with difficulty.
Recollecting differs also in this respect from relearning, that one
who recollects will be able, somehow, to move, solely by his own
effort, to the term next after the starting-point. When one
cannot do this of himself, but only by external assistance, he no
longer remembers (i.e. he has totally forgotten, and therefore of
course cannot recollect). It often happens that, though a person
cannot recollect at the moment, yet by seeking he can do so,
and discovers what he seeks. This he succeeds in doing by
setting up many movements, until finally he excites one of a
kind which will have for its sequel the fact he wishes to
recollect. For remembering (which is the condicio sine qua non
of recollecting) is the existence, potentially, in the mind of a
movement capable of stimulating it to the desired movement,
and this, as has been said, in such a way that the person should
be moved (prompted to recollection) from within himself, i.e. in
consequence of movements wholly contained within himself.
But one must get hold of a starting-point. This explains why it is
that persons are supposed to recollect sometimes by starting
from mnemonic loci. The cause is that they pass swiftly in
thought from one point to another, e.g. from milk to white, from
white to mist, and thence to moist, from which one remembers
Autumn (the 'season of mists'), if this be the season he is trying
to recollect.
It seems true in general that the middle point also among all
things is a good mnemonic starting-point from which to reach
any of them. For if one does not recollect before, he will do so
1306
when he has come to this, or, if not, nothing can help him; as,
e.g. if one were to have in mind the numerical series denoted by
the symbols A, B, G, D, E, Z, I, H, 0. For, if he does not remember
what he wants at E, then at E he remembers 0; because from E
movement in either direction is possible, to D or to Z. But, if it is
not for one of these that he is searching, he will remember
(what he is searching for) when he has come to G if he is
searching for H or I. But if (it is) not (for H or I that he is
searching, but for one of the terms that remain), he will
remember by going to A, and so in all cases (in which one starts
from a middle point). The cause of one's sometimes recollecting
and sometimes not, though starting from the same point, is,
that from the same starting-point a movement can be made in
several directions, as, for instance, from G to I or to D. If, then,
the mind has not (when starting from E) moved in an old path
(i.e. one in which it moved first having the objective experience,
and that, therefore, in which un-'ethized' phusis would have it
again move), it tends to move to the more customary; for (the
mind having, by chance or otherwise, missed moving in the 'old'
way) Custom now assumes the role of Nature. Hence the
rapidity with which we recollect what we frequently think
about. For as regular sequence of events is in accordance with
nature, so, too, regular sequence is observed in the actualization
of kinesis (in consciousness), and here frequency tends to
produce (the regularity of) nature. And since in the realm of
nature occurrences take place which are even contrary to
nature, or fortuitous, the same happens a fortiori in the sphere
swayed by custom, since in this sphere natural law is not
similarly established. Hence it is that (from the same starting-
point) the mind receives an impulse to move sometimes in the
required direction, and at other times otherwise, (doing the
latter) particularly when something else somehow deflects the
mind from the right direction and attracts it to itself. This last
consideration explains too how it happens that, when we want
1307
to remember a name, we remember one somewhat like it,
indeed, but blunder in reference to (i.e. in pronouncing) the one
we intended.
Thus, then, recollection takes place.
But the point of capital importance is that (for the purpose of
recollection) one should cognize, determinately or
indeterminately, the time-relation (of that which he wishes to
recollect). There is, let it be taken as a fact, something by which
one distinguishes a greater and a smaller time; and it is
reasonable to think that one does this in a way analogous to
that in which one discerns (spacial) magnitudes. For it is not by
the mind's reaching out towards them, as some say a visual ray
from the eye does (in seeing), that one thinks of large things at a
distance in space (for even if they are not there, one may
similarly think them); but one does so by a proportionate
mental movement. For there are in the mind the like figures
and movements (i.e. 'like' to those of objects and events).
Therefore, when one thinks the greater objects, in what will his
thinking those differ from his thinking the smaller? (In
nothing,) because all the internal though smaller are as it were
proportional to the external. Now, as we may assume within a
person something proportional to the forms (of distant
magnitudes), so, too, we may doubtless assume also something
else proportional to their distances. As, therefore, if one has
(psychically) the movement in AB, BE, he constructs in thought
(i.e. knows objectively) GD, since AG and GD bear equal ratios
respectively (to AB and BE), (so he who recollects also proceeds).
Why then does he construct GD rather than ZH? Is it not
because as AG is to AB, so is to I? These movements therefore
(sc. in AB, BE, and in 0:1) he has simultaneously. But if he wishes
to construct to thought ZH, he has in mind BE in like manner as
before (when constructing GD), but now, instead of (the
1308
movements of the ratio) 0:1, he has in mind (those of the ratio
K:L; for K:L::ZA:BA. (See diagram.)
When, therefore, the 'movement' corresponding to the object
and that corresponding to its time concur, then one actually
remembers. If one supposes (himself to move in these different
but concurrent ways) without really doing so, he supposes
himself to remember.
For one may be mistaken, and think that he remembers when
he really does not. But it is not possible, conversely, that when
one actually remembers he should not suppose himself to
remember, but should remember unconsciously. For
remembering, as we have conceived it, essentially implies
consciousness of itself. If, however, the movement
corresponding to the objective fact takes place without that
corresponding to the time, or, if the latter takes place without
the former, one does not remember.
The movement answering to the time is of two kinds.
Sometimes in remembering a fact one has no determinate time-
notion of it, no such notion as that e.g. he did something or
other on the day before yesterday; while in other cases he has a
determinate notion of the time. Still, even though one does not
remember with actual determination of the time, he genuinely
remembers, none the less. Persons are wont to say that they
remember (something), but yet do not know when (it occurred,
as happens) whenever they do not know determinately the
exact length of time implied in the 'when'.
It has been already stated that those who have a good memory
are not identical with those who are quick at recollecting. But
the act of recollecting differs from that of remembering, not
only chronologically, but also in this, that many also of the other
animals (as well as man) have memory, but, of all that we are
acquainted with, none, we venture to say, except man, shares in
1309
the faculty of recollection. The cause of this is that recollection
is, as it were a mode of inference. For he who endeavours to
recollect infers that he formerly saw, or heard, or had some such
experience, and the process (by which he succeeds in
recollecting) is, as it were, a sort of investigation. But to
investigate in this way belongs naturally to those animals alone
which are also endowed with the faculty of deliberation; (which
proves what was said above), for deliberation is a form of
inference.
That the affection is corporeal, i.e. that recollection is a
searching for an 'image' in a corporeal substrate, is proved by
the fact that in some persons, when, despite the most
strenuous application of thought, they have been unable to
recollect, it (viz. the anamnesis = the effort at recollection)
excites a feeling of discomfort, which, even though they
abandon the effort at recollection, persists in them none the
less; and especially in persons of melancholic temperament. For
these are most powerfully moved by presentations. The reason
why the effort of recollection is not under the control of their
will is that, as those who throw a stone cannot stop it at their
will when thrown, so he who tries to recollect and 'hunts' (after
an idea) sets up a process in a material part, (that) in which
resides the affection. Those who have moisture around that part
which is the centre of sense-perception suffer most discomfort
of this kind. For when once the moisture has been set in motion
it is not easily brought to rest, until the idea which was sought
for has again presented itself, and thus the movement has
found a straight course. For a similar reason bursts of anger or
fits of terror, when once they have excited such motions, are not
at once allayed, even though the angry or terrified persons (by
efforts of will) set up counter motions, but the passions
continue to move them on, in the same direction as at first, in
opposition to such counter motions. The affection resembles
also that in the case of words, tunes, or sayings, whenever one
1310
of them has become inveterate on the lips. People give them up
and resolve to avoid them; yet again they find themselves
humming the forbidden air, or using the prohibited word. Those
whose upper parts are abnormally large, as. is the case with
dwarfs, have abnormally weak memory, as compared with their
opposites, because of the great weight which they have resting
upon the organ of perception, and because their mnemonic
movements are, from the very first, not able to keep true to a
course, but are dispersed, and because, in the effort at
recollection, these movements do not easily find a direct
onward path. Infants and very old persons have bad memories,
owing to the amount of movement going on within them; for
the latter are in process of rapid decay, the former in process of
vigorous growth; and we may add that children, until
considerably advanced in years, are dwarf-like in their bodily
structure. Such then is our theory as regards memory and
remembering their nature, and the particular organ of the soul
by which animals remember; also as regards recollection, its
formal definition, and the manner and causes of its
performance.
1311
On Sleep And Sleeplessness
translated by J. I. Beare
With regard to sleep and waking, we must consider what they
are: whether they are peculiar to soul or to body, or common to
both; and if common, to what part of soul or body they
appertain: further, from what cause it arises that they are
attributes of animals, and whether all animals share in them
both, or some partake of the one only, others of the other only,
or some partake of neither and some of both.
Further, in addition to these questions, we must also inquire
what the dream is, and from what cause sleepers sometimes
dream, and sometimes do not; or whether the truth is that
sleepers always dream but do not always remember (their
dream); and if this occurs, what its explanation is.
Again, [we must inquire] whether it is possible or not to foresee
the future (in dreams), and if it be possible, in what manner;
further, whether, supposing it possible, it extends only to things
to be accomplished by the agency of Man, or to those also of
which the cause lies in supra-human agency, and which result
from the workings of Nature, or of Spontaneity.
First, then, this much is clear, that waking and sleep appertain
to the same part of an animal, inasmuch as they are opposites,
and sleep is evidently a privation of waking. For contraries, in
natural as well as in all other matters, are seen always to
present themselves in the same subject, and to be affections of
the same: examples are - health and sickness, beauty and
1312
ugliness, strength and weakness, sight and blindness, hearing
and deafness. This is also clear from the following
considerations. The criterion by which we know the waking
person to be awake is identical with that by which we know the
sleeper to be asleep; for we assume that one who is exercising
sense-perception is awake, and that every one who is awake
perceives either some external movement or else some
movement in his own consciousness. If waking, then, consists
in nothing else than the exercise of sense-perception, the
inference is clear, that the organ, in virtue of which animals
perceive, is that by which they wake, when they are awake, or
sleep, when they are awake, or sleep, when they are asleep.
But since the exercise of sense-perception does not belong to
soul or body exclusively, then (since the subject of actuality is in
every case identical with that of potentiality, and what is called
sense-perception, as actuality, is a movement of the soul
through the body) it is clear that its affection is not an affection
of soul exclusively, and that a soulless body has not the
potentiality of perception. [Thus sleep and waking are not
attributes of pure intelligence, on the one hand, or of inanimate
bodies, on the other.]
Now, whereas we have already elsewhere distinguished what
are called the parts of the soul, and whereas the nutrient is, in
all living bodies, capable of existing without the other parts,
while none of the others can exist without the nutrient; it is
clear that sleep and waking are not affections of such living
things as partake only of growth and decay, e.g. not of plants,
because these have not the faculty of sense-perception,
whether or not this be capable of separate existence; in its
potentiality, indeed, and in its relationships, it is separable.
Likewise it is clear that [of those which either sleep or wake]
there is no animal which is always awake or always asleep, but
1313
that both these affections belong [alternately] to the same
animals. For if there be an animal not endued with sense-
perception, it is impossible that this should either sleep or
wake; since both these are affections of the activity of the
primary faculty of sense-perception. But it is equally impossible
also that either of these two affections should perpetually
attach itself to the same animal, e.g. that some species of
animal should be always asleep or always awake, without
intermission; for all organs which have a natural function must
lose power when they work beyond the natural time-limit of
their working period; for instance, the eyes [must lose power]
from [too long continued] seeing, and must give it up; and so it
is with the hand and every other member which has a function.
Now, if sense-perception is the function of a special organ, this
also, if it continues perceiving beyond the appointed time-limit
of its continuous working period, will lose its power, and will do
its work no longer. Accordingly, if the waking period is
determined by this fact, that in it sense-perception is free; if in
the case of some contraries one of the two must be present,
while in the case of others this is not necessary; if waking is the
contrary of sleeping, and one of these two must be present to
every animal: it must follow that the state of sleeping is
necessary. Finally, if such affection is Sleep, and this is a state of
powerlessness arising from excess of waking, and excess of
waking is in its origin sometimes morbid, sometimes not, so
that the powerlessness or dissolution of activity will be so or
not; it is inevitable that every creature which wakes must also
be capable of sleeping, since it is impossible that it should
continue actualizing its powers perpetually.
So, also, it is impossible for any animal to continue always
sleeping. For sleep is an affection of the organ of sense-
perception - a sort of tie or inhibition of function imposed on it,
so that every creature that sleeps must needs have the organ of
sense-perception. Now, that alone which is capable of sense-
1314
perception in actuality has the faculty of sense-perception; but
to realize this faculty, in the proper and unqualified sense, is
impossible while one is asleep. All sleep, therefore, must be
susceptible of awakening. Accordingly, almost all other animals
are clearly observed to partake in sleep, whether they are
aquatic, aerial, or terrestrial, since fishes of all kinds, and
molluscs, as well as all others which have eyes, have been seen
sleeping. 'Hard-eyed' creatures and insects manifestly assume
the posture of sleep; but the sleep of all such creatures is of
brief duration, so that often it might well baffle one's
observation to decide whether they sleep or not. Of testaceous
animals, on the contrary, no direct sensible evidence is as yet
forthcoming to determine whether they sleep, but if the above
reasoning be convincing to any one, he who follows it will admit
this [viz. that they do so.]
That, therefore, all animals sleep may be gathered from these
considerations. For an animal is defined as such by its
possessing sense-perception; and we assert that sleep is, in a
certain way, an inhibition of function, or, as it were, a tie,
imposed on sense-perception, while its loosening or remission
constitutes the being awake. But no plant can partake in either
of these affections, for without sense-perception there is
neither sleeping nor waking. But creatures which have sense-
perception have likewise the feeling of pain and pleasure, while
those which have these have appetite as well; but plants have
none of these affections. A mark of this is that the nutrient part
does its own work better when (the animal) is asleep than when
it is awake. Nutrition and growth are then especially promoted,
a fact which implies that creatures do not need sense-
perception to assist these processes.
1315
We must now proceed to inquire into the cause why one sleeps
and wakes, and into the particular nature of the sense-
perception, or sense-perceptions, if there be several, on which
these affections depend. Since, then, some animals possess all
the modes of sense-perception, and some not all, not, for
example, sight, while all possess touch and taste, except such
animals as are imperfectly developed, a class of which we have
already treated in our work on the soul; and since an animal
when asleep is unable to exercise, in the simple sense any
particular sensory faculty whatever, it follows that in the state
called sleep the same affection must extend to all the special
senses; because, if it attaches itself to one of them but not to
another, then an animal while asleep may perceive with the
latter; but this is impossible.
Now, since every sense has something peculiar, and also
something common; peculiar, as, e.g. seeing is to the sense of
sight, hearing to the auditory sense, and so on with the other
senses severally; while all are accompanied by a common
power, in virtue whereof a person perceives that he sees or
hears (for, assuredly, it is not by the special sense of sight that
one sees that he sees; and it is not by mere taste, or sight, or
both together that one discerns, and has the faculty of
discerning, that sweet things are different from white things,
but by a faculty connected in common with all the organs of
sense; for there is one sensory function, and the controlling
sensory faculty is one, though differing as a faculty of
perception in relation to each genus of sensibles, e.g. sound or
colour); and since this [common sensory activity] subsists in
association chiefly with the faculty of touch (for this can exist
apart from all the other organs of sense, but none of them can
exist apart from it - a subject of which we have treated in our
speculations concerning the Soul); it is therefore evident that
1316
waking and sleeping are an affection of this [common and
controlling organ of sense-perception]. This explains why they
belong to all animals, for touch [with which this common organ
is chiefly connected], alone, [is common] to all [animals].
For if sleeping were caused by the special senses having each
and all undergone some affection, it would be strange that
these senses, for which it is neither necessary nor in a manner
possible to realize their powers simultaneously, should
necessarily all go idle and become motionless simultaneously.
For the contrary experience, viz. that they should not go to rest
altogether, would have been more reasonably anticipated. But,
according to the explanation just given, all is quite clear
regarding those also. For, when the sense organ which controls
all the others, and to which all the others are tributary, has been
in some way affected, that these others should be all affected at
the same time is inevitable, whereas, if one of the tributaries
becomes powerless, that the controlling organ should also
become powerless need in no wise follow.
It is indeed evident from many considerations that sleep does
not consist in the mere fact that the special senses do not
function or that one does not employ them; and that it does not
consist merely in an inability to exercise the sense-perceptions;
for such is what happens in cases of swooning. A swoon means
just such impotence of perception, and certain other cases of
unconsciousness also are of this nature. Moreover, persons who
have the bloodvessels in the neck compressed become
insensible. But sleep supervenes when such incapacity of
exercise has neither arisen in some casual organ of sense, nor
from some chance cause, but when, as has been just stated, it
has its seat in the primary organ with which one perceives
objects in general. For when this has become powerless all the
other sensory organs also must lack power to perceive; but
1317
when one of them has become powerless, it is not necessary for
this also to lose its power.
We must next state the cause to which it is due, and its quality
as an affection. Now, since there are several types of cause (for
we assign equally the 'final', the 'efficient', the 'material', and
the 'formal' as causes), in the first place, then, as we assert that
Nature operates for the sake of an end, and that this end is a
good; and that to every creature which is endowed by nature
with the power to move, but cannot with pleasure to itself move
always and continuously, rest is necessary and beneficial; and
since, taught by experience, men apply to sleep this
metaphorical term, calling it a 'rest' [from the strain of
movement implied in sense-perception]: we conclude that its
end is the conservation of animals. But the waking state is for
an animal its highest end, since the exercise of sense-
perception or of thought is the highest end for all beings to
which either of these appertains; inasmuch as these are best,
and the highest end is what is best: whence it follows that sleep
belongs of necessity to each animal. I use the term 'necessity' in
its conditional sense, meaning that if an animal is to exist and
have its own proper nature, it must have certain endowments;
and, if these are to belong to it, certain others likewise must
belong to it [as their condition.]
The next question to be discussed is that of the kind of
movement or action, taking place within their bodies, from
which the affection of waking or sleeping arises in animals.
Now, we must assume that the causes of this affection in all
other animals are identical with, or analogous to, those which
operate in sanguineous animals; and that the causes operating
in sanguineous animals generally are identical with those
operating in man. Hence we must consider the entire subject in
the light of these instances [afforded by sanguineous animals,
especially man]. Now, it has been definitely settled already in
1318
another work that sense-perception in animals originates ill the
same part of the organism in which movement originates. This
locus of origination is one of three determinate loci, viz. that
which lies midway between the head and the abdomen. This is
sanguineous animals is the region of the heart; for all
sanguineous animals have a heart; and from this it is that both
motion and the controlling sense-perception originate. Now, as
regards movement, it is obvious that that of breathing and of
the cooling process generally takes its rise there; and it is with a
view to the conservation of the [due amount of] heat in this part
that nature has formed as she has both the animals which
respire, and those which cool themselves by moisture. Of this
[cooling process] per se we shall treat hereafter. In bloodless
animals, and insects, and such as do not respire, the 'connatural
spirit' is seen alternately puffed up and subsiding in the part
which is in them analogous [to the region of the heart in
sanguineous animals]. This is clearly observable in the
holoptera [insects with undivided wings] as wasps and bees;
also in flies and such creatures. And since to move anything, or
do anything, is impossible without strength, and holding the
breath produces strength - in creatures which inhale, the
holding of that breath which comes from without, but, in
creatures which do not respire, of that which is connatural
(which explains why winged insects of the class holoptera,
when they move, are perceived to make a humming noise, due
to the friction of the connatural spirit colliding with the
diaphragm); and since movement is, in every animal, attended
with some sense-perception, either internal or external, in the
primary organ of sense, [we conclude] accordingly that if
sleeping and waking are affections of this organ, the place in
which, or the organ in which, sleep and waking originate, is self-
evident [being that in which movement and sense-perception
originate, viz. the heart].
1319
Some persons move in their sleep, and perform many acts like
waking acts, but not without a phantasm or an exercise of
sense-perception; for a dream is in a certain way a sense-
impression. But of them we have to speak later on. Why it is
that persons when aroused remember their dreams, but do not
remember these acts which are like waking acts, has been
already explained in the work 'Of Problems'.
The point for consideration next in order to the preceding is: -
What are the processes in which the affection of waking and
sleeping originates, and whence do they arise? Now, since it is
when it has sense-perception that an animal must first take
food and receive growth, and in all cases food in its ultimate
form is, in sanguineous animals, the natural substance blood,
or, in bloodless animals, that which is analogous to this; and
since the veins are the place of the blood, while the origin of
these is the heart - an assertion which is proved by anatomy - it
is manifest that, when the external nutriment enters the parts
fitted for its reception, the evaporation arising from it enters
into the veins, and there, undergoing a change, is converted into
blood, and makes its way to their source [the heart]. We have
treated of all this when discussing the subject of nutrition, but
must here recapitulate what was there said, in order that we
may obtain a scientific view of the beginnings of the process,
and come to know what exactly happens to the primary organ
of sense-perception to account for the occurrence of waking
and sleep. For sleep, as has been shown, is not any given
impotence of the perceptive faculty; for unconsciousness, a
certain form of asphyxia, and swooning, all produce such
impotence. Moreover it is an established fact that some persons
1320
in a profound trance have still had the imaginative faculty in
play. This last point, indeed, gives rise to a difficulty; for if it is
conceivable that one who had swooned should in this state fall
asleep, the phantasm also which then presented itself to his
mind might be regarded as a dream. Persons, too, who have
fallen into a deep trance, and have come to be regarded as dead,
say many things while in this condition. The same view,
however, is to be taken of all these cases, [i.e. that they are not
cases of sleeping or dreaming].
As we observed above, sleep is not co-extensive with any and
every impotence of the perceptive faculty, but this affection is
one which arises from the evaporation attendant upon the
process of nutrition. The matter evaporated must be driven
onwards to a certain point, then turn back, and change its
current to and fro, like a tide-race in a narrow strait. Now, in
every animal the hot naturally tends to move [and carry other
things] upwards, but when it has reached the parts above
[becoming cool], it turns back again, and moves downwards in a
mass. This explains why fits of drowsiness are especially apt to
come on after meals; for the matter, both the liquid and the
corporeal, which is borne upwards in a mass, is then of
considerable quantity. When, therefore, this comes to a stand it
weighs a person down and causes him to nod, but when it has
actually sunk downwards, and by its return has repulsed the
hot, sleep comes on, and the animal so affected is presently
asleep. A confirmation of this appears from considering the
things which induce sleep; they all, whether potable or edible,
for instance poppy, mandragora, wine, darnel, produce a
heaviness in the head; and persons borne down [by sleepiness]
and nodding [drowsily] all seem affected in this way, i.e. they
are unable to lift up the head or the eye-lids. And it is after
meals especially that sleep comes on like this, for the
evaporation from the foods eaten is then copious. It also follows
certain forms of fatigue; for fatigue operates as a solvent, and
1321
the dissolved matter acts, if not cold, like food prior to digestion.
Moreover, some kinds of illness have this same effect; those
arising from moist and hot secretions, as happens with fever-
patients and in cases of lethargy. Extreme youth also has this
effect; infants, for example, sleep a great deal, because of the
food being all borne upwards - a mark whereof appears in the
disproportionately large size of the upper parts compared with
the lower during infancy, which is due to the fact that growth
predominates in the direction of the former. Hence also they are
subject to epileptic seizures; for sleep is like epilepsy, and, in a
sense, actually is a seizure of this sort. Accordingly, the
beginning of this malady takes place with many during sleep,
and their subsequent habitual seizures occur in sleep, not in
waking hours. For when the spirit [evaporation] moves upwards
in a volume, on its return downwards it distends the veins, and
forcibly compresses the passage through which respiration is
effected. This explains why wines are not good for infants or for
wet nurses (for it makes no difference, doubtless, whether the
infants themselves, or their nurses, drink them), but such
persons should drink them [if at all] diluted with water and in
small quantity. For wine is spirituous, and of all wines the dark
more so than any other. The upper parts, in infants, are so filled
with nutriment that within five months [after birth] they do not
even turn the neck [sc. to raise the head]; for in them, as in
persons deeply intoxicated, there is ever a large quantity of
moisture ascending. It is reasonable, too, to think that this
affection is the cause of the embryo's remaining at rest in the
womb at first. Also, as a general rule, persons whose veins are
inconspicuous, as well as those who are dwarf-like, or have
abnormally large heads, are addicted to sleep. For in the former
the veins are narrow, so that it is not easy for the moisture to
flow down through them; while in the case of dwarfs and those
whose heads are abnormally large, the impetus of the
evaporation upwards is excessive. Those [on the contrary]
1322
whose veins are large are, thanks to the easy flow through the
veins, not addicted to sleep, unless, indeed, they labour under
some other affection which counteracts [this easy flow]. Nor are
the 'atrabilious' addicted to sleep, for in them the inward region
is cooled so that the quantity of evaporation in their case is not
great. For this reason they have large appetites, though spare
and lean; for their bodily condition is as if they derived no
benefit from what they eat. The dark bile, too, being itself
naturally cold, cools also the nutrient tract, and the other parts
wheresoever such secretion is potentially present [i.e. tends to
be formed].
Hence it is plain from what has been said that sleep is a sort of
concentration, or natural recoil, of the hot matter inwards
[towards its centre], due to the cause above mentioned. Hence
restless movement is a marked feature in the case of a person
when drowsy. But where it [the heat in the upper and outer
parts] begins to fail, he grows cool, and owing to this cooling
process his eye-lids droop. Accordingly [in sleep] the upper and
outward parts are cool, but the inward and lower, i.e. the parts
at the feet and in the interior of the body, are hot.
Yet one might found a difficulty on the facts that sleep is most
oppressive in its onset after meals, and that wine, and other
such things, though they possess heating properties, are
productive of sleep, for it is not probable that sleep should be a
process of cooling while the things that cause sleeping are
themselves hot. Is the explanation of this, then, to be found in
the fact that, as the stomach when empty is hot, while
replenishment cools it by the movement it occasions, so the
passages and tracts in the head are cooled as the 'evaporation'
ascends thither? Or, as those who have hot water poured on
them feel a sudden shiver of cold, just so in the case before us,
may it be that, when the hot substance ascends, the cold
rallying to meet it cools [the aforesaid parts] deprives their
1323
native heat of all its power, and compels it to retire? Moreover,
when much food is taken, which [i.e. the nutrient evaporation
from which] the hot substance carries upwards, this latter, like a
fire when fresh logs are laid upon it, is itself cooled, until the
food has been digested.
For, as has been observed elsewhere, sleep comes on when the
corporeal element [in the 'evaporation'] conveyed upwards by
the hot, along the veins, to the head. But when that which has
been thus carried up can no longer ascend, but is too great in
quantity [to do so], it forces the hot back again and flows
downwards. Hence it is that men sink down [as they do in sleep]
when the heat which tends to keep them erect (man alone,
among animals, being naturally erect) is withdrawn; and this,
when it befalls them, causes unconsciousness, and afterwards
phantasy.
Or are the solutions thus proposed barely conceivable accounts
of the refrigeration which takes place, while, as a matter of fact,
the region of the brain is, as stated elsewhere, the main
determinant of the matter? For the brain, or in creatures
without a brain that which corresponds to it, is of all parts of
the body the coolest. Therefore, as moisture turned into vapour
by the sun's heat is, when it has ascended to the upper regions,
cooled by the coldness of the latter, and becoming condensed, is
carried downwards, and turned into water once more; just so
the excrementitious evaporation, when carried up by the heat to
the region of the brain, is condensed into a 'phlegm' (which
explains why catarrhs are seen to proceed from the head); while
that evaporation which is nutrient and not unwholesome,
becoming condensed, descends and cools the hot. The tenuity
or narrowness of the veins about the brain itself contributes to
its being kept cool, and to its not readily admitting the
evaporation. This, then, is a sufficient explanation of the cooling
1324
which takes place, despite the fact that the evaporation is
exceedingly hot.
A person awakes from sleep when digestion is completed: when
the heat, which had been previously forced together in large
quantity within a small compass from out the surrounding part,
has once more prevailed, and when a separation has been
effected between the more corporeal and the purer blood. The
finest and purest blood is that contained in the head, while the
thickest and most turbid is that in the lower parts. The source of
all the blood is, as has been stated both here and elsewhere, the
heart. Now of the chambers in the heart the central
communicates with each of the two others. Each of the latter
again acts as receiver from each, respectively, of the two vessels,
called the 'great' and the 'aorta'. It is in the central chamber that
the [above-mentioned] separation takes place. To go into these
matters in detail would, however, be more properly the business
of a different treatise from the present. Owing to the fact that
the blood formed after the assimilation of food is especially in
need of separation, sleep [then especially] occurs [and lasts]
until the purest part of this blood has been separated off into
the upper parts of the body, and the most turbid into the lower
parts. When this has taken place animals awake from sleep,
being released from the heaviness consequent on taking food.
We have now stated the cause of sleeping, viz. that it consists in
the recoil by the corporeal element, upborne by the connatural
heat, in a mass upon the primary sense-organ; we have also
stated what sleep is, having shown that it is a seizure of the
primary sense-organ, rendering it unable to actualize its
powers; arising of necessity (for it is impossible for an animal to
exist if the conditions which render it an animal be not
fulfilled), i.e. for the sake of its conservation; since remission of
movement tends to the conservation of animals.
1325
On Dreams
translated by J. I. Beare
We must, in the next place, investigate the subject of the dream,
and first inquire to which of the faculties of the soul it presents
itself, i.e. whether the affection is one which pertains to the
faculty of intelligence or to that of sense-perception; for these
are the only faculties within us by which we acquire knowledge.
If, then, the exercise of the faculty of sight is actual seeing, that
of the auditory faculty, hearing, and, in general that of the
faculty of sense-perception, perceiving; and if there are some
perceptions common to the senses, such as figure, magnitude,
motion, &c, while there are others, as colour, sound, taste,
peculiar [each to its own sense]; and further, if all creatures,
when the eyes are closed in sleep, are unable to see, and the
analogous statement is true of the other senses, so that
manifestly we perceive nothing when asleep; we may conclude
that it is not by sense-perception we perceive a dream.
But neither is it by opinion that we do so. For [in dreams] we not
only assert, e.g. that some object approaching is a man or a
horse [which would be an exercise of opinion], but that the
object is white or beautiful, points on which opinion without
sense-perception asserts nothing either truly or falsely. It is,
however, a fact that the soul makes such assertions in sleep. We
seem to see equally well that the approaching figure is a man,
1326
and that it is white. [In dreams], too, we think something else,
over and above the dream presentation, just as we do in waking
moments when we perceive something; for we often also
reason about that which we perceive. So, too, in sleep we
sometimes have thoughts other than the mere phantasms
immediately before our minds. This would be manifest to any
one who should attend and try, immediately on arising from
sleep, to remember [his dreaming experience]. There are cases
of persons who have seen such dreams, those, for example, who
believe themselves to be mentally arranging a given list of
subjects according to the mnemonic rule. They frequently find
themselves engaged in something else besides the dream, viz.
in setting a phantasm which they envisage into its mnemonic
position. Hence it is plain that not every 'phantasm' in sleep is a
mere dream-image, and that the further thinking which we
perform then is due to an exercise of the faculty of opinion.
So much at least is plain on all these points, viz. that the faculty
by which, in waking hours, we are subject to illusion when
affected by disease, is identical with that which produces
illusory effects in sleep. So, even when persons are in excellent
health, and know the facts of the case perfectly well, the sun,
nevertheless, appears to them to be only a foot wide. Now,
whether the presentative faculty of the soul be identical with, or
different from, the faculty of sense-perception, in either case
the illusion does not occur without our actually seeing or
[otherwise] perceiving something. Even to see wrongly or to
hear wrongly can happen only to one who sees or hears
something real, though not exactly what he supposes. But we
have assumed that in sleep one neither sees, nor hears, nor
exercises any sense whatever. Perhaps we may regard it as true
that the dreamer sees nothing, yet as false that his faculty of
sense-perception is unaffected, the fact being that the sense of
seeing and the other senses may possibly be then in a certain
way affected, while each of these affections, as duly as when he
1327
is awake, gives its impulse in a certain manner to his [primary]
faculty of sense, though not in precisely the same manner as
when he is awake. Sometimes, too, opinion says [to dreamers]
just as to those who are awake, that the object seen is an
illusion; at other times it is inhibited, and becomes a mere
follower of the phantasm.
It is plain therefore that this affection, which we name
'dreaming', is no mere exercise of opinion or intelligence, but
yet is not an affection of the faculty of perception in the simple
sense. If it were the latter it would be possible [when asleep] to
hear and see in the simple sense.
How then, and in what manner, it takes place, is what we have
to examine. Let us assume, what is indeed clear enough, that
the affection [of dreaming] pertains to sense-perception as
surely as sleep itself does. For sleep does not pertain to one
organ in animals and dreaming to another; both pertain to the
same organ.
But since we have, in our work On the Soul, treated of
presentation, and the faculty of presentation is identical with
that of sense-perception, though the essential notion of a
faculty of presentation is different from that of a faculty of
sense-perception; and since presentation is the movement set
up by a sensory faculty when actually discharging its function,
while a dream appears to be a presentation (for a presentation
which occurs in sleep - whether simply or in some particular
way - is what we call a dream): it manifestly follows that
dreaming is an activity of the faculty of sense-perception, but
belongs to this faculty qua presentative.
1328
We can best obtain a scientific view of the nature of the dream
and the manner in which it originates by regarding it in the
light of the circumstances attending sleep. The objects of sense-
perception corresponding to each sensory organ produce sense-
perception in us, and the affection due to their operation is
present in the organs of sense not only when the perceptions
are actualized, but even when they have departed.
What happens in these cases may be compared with what
happens in the case of projectiles moving in space. For in the
case of these the movement continues even when that which
set up the movement is no longer in contact [with the things
that are moved]. For that which set them in motion moves a
certain portion of air, and this, in turn, being moved excites
motion in another portion; and so, accordingly, it is in this way
that [the bodies], whether in air or in liquids, continue moving,
until they come to a standstill.
This we must likewise assume to happen in the case of
qualitative change; for that part which [for example] has been
heated by something hot, heats [in turn] the part next to it, and
this propagates the affection continuously onwards until the
process has come round to its oint of origination. This must also
happen in the organ wherein the exercise of sense-perception
takes place, since sense-perception, as realized in actual
perceiving, is a mode of qualitative change. This explains why
the affection continues in the sensory organs, both in their
deeper and in their more superficial parts, not merely while
they are actually engaged in perceiving, but even after they have
ceased to do so. That they do this, indeed, is obvious in cases
where we continue for some time engaged in a particular form
of perception, for then, when we shift the scene of our
perceptive activity, the previous affection remains; for instance,
1329
when we have turned our gaze from sunlight into darkness. For
the result of this is that one sees nothing, owing to the excited
by the light still subsisting in our eyes. Also, when we have
looked steadily for a long while at one colour, e.g. at white or
green, that to which we next transfer our gaze appears to be of
the same colour. Again if, after having looked at the sun or
some other brilliant object, we close the eyes, then, if we watch
carefully, it appears in a right line with the direction of vision
(whatever this may be), at first in its own colour; then it changes
to crimson, next to purple, until it becomes black and
disappears. And also when persons turn away from looking at
objects in motion, e.g. rivers, and especially those which flow
very rapidly, they find that the visual stimulations still present
themselves, for the things really at rest are then seen moving:
persons become very deaf after hearing loud noises, and after
smelling very strong odours their power of smelling is impaired;
and similarly in other cases. These phenomena manifestly take
place in the way above described.
That the sensory organs are acutely sensitive to even a slight
qualitative difference [in their objects] is shown by what
happens in the case of mirrors; a subject to which, even taking
it independently, one might devote close consideration and
inquiry. At the same time it becomes plain from them that as
the eye [in seeing] is affected [by the object seen], so also it
produces a certain effect upon it. If a woman chances during
her menstrual period to look into a highly polished mirror, the
surface of it will grow cloudy with a blood-coloured haze. It is
very hard to remove this stain from a new mirror, but easier to
remove from an older mirror. As we have said before, the cause
of this lies in the fact that in the act of sight there occurs not
only a passion in the sense organ acted on by the polished
surface, but the organ, as an agent, also produces an action, as
is proper to a brilliant object. For sight is the property of an
organ possessing brilliance and colour. The eyes, therefore, have
1330
their proper action as have other parts of the body. Because it is
natural to the eye to be filled with blood-vessels, a woman's
eyes, during the period of menstrual flux and inflammation, will
undergo a change, although her husband will not note this
since his seed is of the same nature as that of his wife. The
surrounding atmosphere, through which operates the action of
sight, and which surrounds the mirror also, will undergo a
change of the same sort that occurred shortly before in the
woman's eyes, and hence the surface of the mirror is likewise
affected. And as in the case of a garment, the cleaner it is the
more quickly it is soiled, so the same holds true in the case of
the mirror. For anything that is clean will show quite clearly a
stain that it chances to receive, and the cleanest object shows
up even the slightest stain. A bronze mirror, because of its
shininess, is especially sensitive to any sort of contact (the
movement of the surrounding air acts upon it like a rubbing or
pressing or wiping); on that account, therefore, what is clean
will show up clearly the slightest touch on its surface. It is hard
to cleanse smudges off new mirrors because the stain
penetrates deeply and is suffused to all parts; it penetrates
deeply because the mirror is not a dense medium, and is
suffused widely because of the smoothness of the object. On the
other hand, in the case of old mirrors, stains do not remain
because they do not penetrate deeply, but only smudge the
surface.
From this therefore it is plain that stimulatory motion is set up
even by slight differences, and that sense-perception is quick to
respond to it; and further that the organ which perceives colour
is not only affected by its object, but also reacts upon it. Further
evidence to the same point is afforded by what takes place in
wines, and in the manufacture of unguents. For both oil, when
prepared, and wine become rapidly infected by the odours of
the things near them; they not only acquire the odours of the
things thrown into or mixed with them, but also those of the
1331
things which are placed, or which grow, near the vessels
containing them.
In order to answer our original question, let us now, therefore,
assume one proposition, which is clear from what precedes, viz.
that even when the external object of perception has departed,
the impressions it has made persist, and are themselves objects
of perception: and [let us assume], besides, that we are easily
deceived respecting the operations of sense-perception when
we are excited by emotions, and different persons according to
their different emotions; for example, the coward when excited
by fear, the amorous person by amorous desire; so that, with but
little resemblance to go upon, the former thinks he sees his foes
approaching, the latter, that he sees the object of his desire; and
the more deeply one is under the influence of the emotion, the
less similarity is required to give rise to these illusory
impressions. Thus too, both in fits of anger, and also in all states
of appetite, all men become easily deceived, and more so the
more their emotions are excited. This is the reason too why
persons in the delirium of fever sometimes think they see
animals on their chamber walls, an illusion arising from the
faint resemblance to animals of the markings thereon when put
together in patterns; and this sometimes corresponds with the
emotional states of the sufferers, in such a way that, if the latter
be not very ill, they know well enough that it is an illusion; but
if the illness is more severe they actually move according to the
appearances. The cause of these occurrences is that the faculty
in virtue of which the controlling sense judges is not identical
with that in virtue of which presentations come before the
mind. A proof of this is, that the sun presents itself as only a
foot in diameter, though often something else gainsays the
presentation. Again, when the fingers are crossed, the one
object [placed between them] is felt [by the touch] as two; but
yet we deny that it is two; for sight is more authoritative than
touch. Yet, if touch stood alone, we should actually have
1332
pronounced the one object to be two. The ground of such false
judgements is that any appearances whatever present
themselves, not only when its object stimulates a sense, but
also when the sense by itself alone is stimulated, provided only
it be stimulated in the same manner as it is by the object. For
example, to persons sailing past the land seems to move, when
it is really the eye that is being moved by something else [the
moving ship.]
From this it is manifest that the stimulatory movements based
upon sensory impressions, whether the latter are derived from
external objects or from causes within the body, present
themselves not only when persons are awake, but also then,
when this affection which is called sleep has come upon them,
with even greater impressiveness. For by day, while the senses
and the intellect are working together, they (i.e. such
movements) are extruded from consciousness or obscured, just
as a smaller is beside a larger fire, or as small beside great pains
or pleasures, though, as soon as the latter have ceased, even
those which are trifling emerge into notice. But by night [i.e. in
sleep] owing to the inaction of the particular senses, and their
powerlessness to realize themselves, which arises from the
reflux of the hot from the exterior parts to the interior, they [i.e.
the above 'movements'] are borne in to the head quarters of
sense-perception, and there display themselves as the
disturbance (of waking life) subsides. We must suppose that,
like the little eddies which are being ever formed in rivers, so
the sensory movements are each a continuous process, often
remaining like what they were when first started, but often, too,
broken into other forms by collisions with obstacles. This [last
1333
mentioned point], moreover, gives the reason why no dreams
occur in sleep immediately after meals, or to sleepers who are
extremely young, e.g. to infants. The internal movement in such
cases is excessive, owing to the heat generated from the food.
Hence, just as in a liquid, if one vehemently disturbs it,
sometimes no reflected image appears, while at other times one
appears, indeed, but utterly distorted, so as to seem quite unlike
its original; while, when once the motion has ceased, the
reflected images are clear and plain; in the same manner during
sleep the phantasms, or residuary movements, which are based
upon the sensory impressions, become sometimes quite
obliterated by the above described motion when too violent;
while at other times the sights are indeed seen, but confused
and weird, and the dreams [which then appear] are unhealthy,
like those of persons who are atrabilious, or feverish, or
intoxicated with wine. For all such affections, being spirituous,
cause much commotion and disturbance. In sanguineous
animals, in proportion as the blood becomes calm, and as its
purer are separated from its less pure elements, the fact that
the movement, based on impressions derived from each of the
organs of sense, is preserved in its integrity, renders the dreams
healthy, causes a [clear] image to present itself, and makes the
dreamer think, owing to the effects borne in from the organ of
sight, that he actually sees, and owing to those which come
from the organ of hearing, that he really hears; and so on with
those also which proceed from the other sensory organs. For it
is owing to the fact that the movement which reaches the
primary organ of sense comes from them, that one even when
awake believes himself to see, or hear, or otherwise perceive;
just as it is from a belief that the organ of sight is being
stimulated, though in reality not so stimulated, that we
sometimes erroneously declare ourselves to see, or that, from
the fact that touch announces two movements, we think that
the one object is two. For, as a rule, the governing sense affirms
1334
the report of each particular sense, unless another particular
sense, more authoritative, makes a contradictory report. In
every case an appearance presents itself, but what appears does
not in every case seem real, unless when the deciding faculty is
inhibited, or does not move with its proper motion. Moreover, as
we said that different men are subject to illusions, each
according to the different emotion present in him, so it is that
the sleeper, owing to sleep, and to the movements then going
on in his sensory organs, as well as to the other facts of the
sensory process, [is liable to illusion], so that the dream
presentation, though but little like it, appears as some actual
given thing. For when one is asleep, in proportion as most of the
blood sinks inwards to its fountain [the heart], the internal
[sensory] movements, some potential, others actual accompany
it inwards. They are so related [in general] that, if anything
move the blood, some one sensory movement will emerge from
it, while if this perishes another will take its place; while to one
another also they are related in the same way as the artificial
frogs in water which severally rise [in fixed succesion] to the
surface in the order in which the salt [which keeps them down]
becomes dissolved. The residuary movements are like these:
they are within the soul potentially, but actualize themselves
only when the impediment to their doing so has been relaxed;
and according as they are thus set free, they begin to move in
the blood which remains in the sensory organs, and which is
now but scanty, while they possess verisimilitude after the
manner of cloud-shapes, which in their rapid metamorphoses
one compares now to human beings and a moment afterwards
to centaurs. Each of them is however, as has been said, the
remnant of a sensory impression taken when sense was
actualizing itself; and when this, the true impression, has
departed, its remnant is still immanent, and it is correct to say
of it, that though not actually Koriskos, it is like Koriskos. For
when the person was actually perceiving, his controlling and
1335
judging sensory faculty did not call it Koriskos, but, prompted
by this [impression], called the genuine person yonder Koriskos.
Accordingly, this sensory impulse, which, when actually
perceiving, it [the controlling faculty] describes (unless
completely inhibited by the blood), it now [in dreams] when
quasi-perceiving, receives from the movements persisting in the
sense-organs, and mistakes it - an impulse that is merely like
the true [objective] impression - for the true impression itself,
while the effect of sleep is so great that it causes this mistake to
pass unnoticed. Accordingly, just as if a finger be inserted
beneath the eyeball without being observed, one object will not
only present two visual images, but will create an opinion of its
being two objects; while if it [the finger] be observed, the
presentation will be the same, but the same opinion will not be
formed of it; exactly so it is in states of sleep: if the sleeper
perceives that he is asleep, and is conscious of the sleeping
state during which the perception comes before his mind, it
presents itself still, but something within him speaks to this
effect: 'the image of Koriskos presents itself, but the real
Koriskos is not present'; for often, when one is asleep, there is
something in consciousness which declares that what then
presents itself is but a dream. If, however, he is not aware of
being asleep, there is nothing which will contradict the
testimony of the bare presentation.
That what we here urge is true, i.e. that there are such
presentative movements in the sensory organs, any one may
convince himself, if he attends to and tries to remember the
affections we experience when sinking into slumber or when
being awakened. He will sometimes, in the moment of
awakening, surprise the images which present themselves to
him in sleep, and find that they are really but movements
lurking in the organs of sense. And indeed some very young
persons, if it is dark, though looking with wide open eyes, see
1336
multitudes of phantom figures moving before them, so that
they often cover up their heads in terror.
From all this, then, the conclusion to be drawn is, that the
dream is a sort of presentation, and, more particularly, one
which occurs in sleep; since the phantoms just mentioned are
not dreams, nor is any other a dream which presents itself
when the sense-perceptions are in a state of freedom. Nor is
every presentation which occurs in sleep necessarily a dream.
For in the first place, some persons [when asleep] actually, in a
certain way, perceive sounds, light, savour, and contact; feebly,
however, and, as it were, remotely. For there have been cases in
which persons while asleep, but with the eyes partly open, saw
faintly in their sleep (as they supposed) the light of a lamp, and
afterwards, on being awakened, straightway recognized it as the
actual light of a real lamp; while, in other cases, persons who
faintly heard the crowing of cocks or the barking of dogs
identified these clearly with the real sounds as soon as they
awoke. Some persons, too, return answers to questions put to
them in sleep. For it is quite possible that, of waking or sleeping,
while the one is present in the ordinary sense, the other also
should be present in a certain way. But none of these
occurrences should be called a dream. Nor should the true
thoughts, as distinct from the mere presentations, which occur
in sleep [be called dreams]. The dream proper is a presentation
based on the movement of sense impressions, when such
presentation occurs during sleep, taking sleep in the strict sense
of the term.
There are cases of persons who in their whole lives have never
had a dream, while others dream when considerably advanced
in years, having never dreamed before. The cause of their not
having dreams appears somewhat like that which operates in
the case of infants, and [that which operates] immediately after
meals. It is intelligible enough that no dream-presentation
1337
should occur to persons whose natural constitution is such that
in them copious evaporation is borne upwards, which, when
borne back downwards, causes a large quantity of motion. But it
is not surprising that, as age advances, a dream should at length
appear to them. Indeed, it is inevitable that, as a change is
wrought in them in proportion to age or emotional experience,
this reversal [from non-dreaming to dreaming] should occur
also.
On Prophesying by Dreams
translated by J. I. Beare
As to the divination which takes place in sleep, and is said to be
based on dreams, we cannot lightly either dismiss it with
contempt or give it implicit confidence. The fact that all
persons, or many, suppose dreams to possess a special
significance, tends to inspire us with belief in it [such
divination], as founded on the testimony of experience; and
indeed that divination in dreams should, as regards some
subjects, be genuine, is not incredible, for it has a show of
reason; from which one might form a like opinion also
respecting all other dreams. Yet the fact of our seeing no
probable cause to account for such divination tends to inspire
us with distrust. For, in addition to its further unreasonableness,
it is absurd to combine the idea that the sender of such dreams
1338
should be God with the fact that those to whom he sends them
are not the best and wisest, but merely commonplace persons.
If, however, we abstract from the causality of God, none of the
other causes assigned appears probable. For that certain
persons should have foresight in dreams concerning things
destined to take place at the Pillars of Hercules, or on the banks
of the Borysthenes, seems to be something to discover the
explanation of which surpasses the wit of man. Well then, the
dreams in question must be regarded either as causes, or as
tokens, of the events, or else as coincidences; either as all, or
some, of these, or as one only. I use the word 'cause' in the
sense in which the moon is [the cause] of an eclipse of the sun,
or in which fatigue is [a cause] of fever; 'token' [in the sense in
which] the entrance of a star [into the shadow] is a token of the
eclipse, or [in which] roughness of the tongue [is a token] of
fever; while by 'coincidence' I mean, for example, the
occurrence of an eclipse of the sun while some one is taking a
walk; for the walking is neither a token nor a cause of the
eclipse, nor the eclipse [a cause or token] of the walking. For this
reason no coincidence takes place according to a universal or
general rule. Are we then to say that some dreams are causes,
others tokens, e.g. of events taking place in the bodily
organism? At all events, even scientific physicians tell us that
one should pay diligent attention to dreams, and to hold this
view is reasonable also for those who are not practitioners, but
speculative philosophers. For the movements which occur in
the daytime [within the body] are, unless very great and violent,
lost sight of in contrast with the waking movements, which are
more impressive. In sleep the opposite takes place, for then
even trifling movements seem considerable. This is plain in
what often happens during sleep; for example, dreamers fancy
that they are affected by thunder and lightning, when in fact
there are only faint ringings in their ears; or that they are
enjoying honey or other sweet savours, when only a tiny drop of
1339
phlegm is flowing down [the oesophagus]; or that they are
walking through fire, and feeling intense heat, when there is
only a slight warmth affecting certain parts of the body. When
they are awakened, these things appear to them in this their
true character. But since the beginnings of all events are small,
so, it is clear, are those also of the diseases or other affections
about to occur in our bodies. In conclusion, it is manifest that
these beginnings must be more evident in sleeping than in
waking moments.
Nay, indeed, it is not improbable that some of the presentations
which come before the mind in sleep may even be causes of the
actions cognate to each of them. For as when we are about to
act [in waking hours], or are engaged in any course of action, or
have already performed certain actions, we often find ourselves
concerned with these actions, or performing them, in a vivid
dream; the cause whereof is that the dream-movement has had
a way paved for it from the original movements set up in the
daytime; exactly so, but conversely, it must happen that the
movements set up first in sleep should also prove to be starting-
points of actions to be performed in the daytime, since the
recurrence by day of the thought of these actions also has had
its way paved for it in the images before the mind at night. Thus
then it is quite conceivable that some dreams may be tokens
and causes [of future events].
Most [so-called prophetic] dreams are, however, to be classed as
mere coincidences, especially all such as are extravagant, and
those in the fulfilment of which the dreamers have no initiative,
such as in the case of a sea-fight, or of things taking place far
away. As regards these it is natural that the fact should stand as
it does whenever a person, on mentioning something, finds the
very thing mentioned come to pass. Why, indeed, should this
not happen also in sleep? The probability is, rather, that many
such things should happen. As, then, one's mentioning a
1340
particular person is neither token nor cause of this person's
presenting himself, so, in the parallel instance, the dream is, to
him who has seen it, neither token nor cause of its [so-called]
fulfilment, but a mere coincidence. Hence the fact that many
dreams have no 'fulfilment', for coincidence do not occur
according to any universal or general law.
On the whole, forasmuch as certain of the lower animals also
dream, it may be concluded that dreams are not sent by God,
nor are they designed for this purpose [to reveal the future].
They have a divine aspect, however, for Nature [their cause] is
divinely planned, though not itself divine. A special proof [of
their not being sent by God] is this: the power of foreseeing the
future and of having vivid dreams is found in persons of inferior
type, which implies that God does not send their dreams; but
merely that all those whose physical temperament is, as it were,
garrulous and excitable, see sights of all descriptions; for,
inasmuch as they experience many movements of every kind,
they just chance to have visions resembling objective facts, their
luck in these matters being merely like that of persons who play
at even and odd. For the principle which is expressed in the
gambler's maxim: 'If you make many throws your luck must
change,' holds in their case also.
That many dreams have no fulfilment is not strange, for it is so
too with many bodily toms and weather-signs, e.g. those of train
or wind. For if another movement occurs more influential than
that from which, while [the event to which it pointed was] still
future, the given token was derived, the event [to which such
token pointed] does not take place. So, of the things which
1341
ought to be accomplished by human agency, many, though well-
planned are by the operation of other principles more powerful
[than man's agency] brought to nought. For, speaking generally,
that which was about to happen is not in every case what now
is happening, nor is that which shall hereafter he identical with
that which is now going to be. Still, however, we must hold that
the beginnings from which, as we said, no consummation
follows, are real beginnings, and these constitute natural tokens
of certain events, even though the events do not come to pass.
As for [prophetic] dreams which involve not such beginnings
[sc. of future events] as we have here described, but such as are
extravagant in times, or places, or magnitudes; or those
involving beginnings which are not extravagant in any of these
respects, while yet the persons who see the dream hold not in
their own hands the beginnings [of the event to which it points]:
unless the foresight which such dreams give is the result of
pure coincidence, the following would be a better explanation of
it than that proposed by Democritus, who alleges 'images' and
'emanations' as its cause. As, when something has caused
motion in water or air, this [the portion of water or air], and,
though the cause has ceased to operate, such motion
propagates itself to a certain point, though there the prime
movement is not present; just so it may well be that a
movement and a consequent sense-perception should reach
sleeping souls from the objects from which Democritus
represents 'images' and 'emanations' coming; that such
movements, in whatever way they arrive, should be more
perceptible at night [than by day], because when proceeding
thus in the daytime they are more liable to dissolution (since at
night the air is less disturbed, there being then less wind); and
that they shall be perceived within the body owing to sleep,
since persons are more sensitive even to slight sensory
movements when asleep than when awake. It is these
movements then that cause 'presentations', as a result of which
1342
sleepers foresee the future even relatively to such events as
those referred to above. These considerations also explain why
this experience befalls commonplace persons and not the most
intelligent. For it would have regularly occurred both in the
daytime and to the wise had it been God who sent it; but, as we
have explained the matter, it is quite natural that commonplace
persons should be those who have foresight [in dreams]. For the
mind of such persons is not given to thinking, but, as it were,
derelict, or totally vacant, and, when once set moving, is borne
passively on in the direction taken by that which moves it. With
regard to the fact that some persons who are liable to
derangement have this foresight, its explanation is that their
normal mental movements do not impede [the alien
movements], but are beaten off by the latter. Therefore it is that
they have an especially keen perception of the alien
movements.
That certain persons in particular should have vivid dreams, e.g.
that familiar friends should thus have foresight in a special
degree respecting one another, is due to the fact that such
friends are most solicitous on one another's behalf. For as
acquaintances in particular recognize and perceive one another
a long way off, so also they do as regards the sensory
movements respecting one another; for sensory movements
which refer to persons familiarly known are themselves more
familiar. Atrabilious persons, owing to their impetuosity, are,
when they, as it were, shoot from a distance, expert at hitting;
while, owing to their mutability, the series of movements
deploys quickly before their minds. For even as the insane
recite, or con over in thought, the poems of Philaegides, e.g. the
Aphrodite, whose parts succeed in order of similitude, just so do
they [the 'atrabilious'] go on and on stringing sensory
movements together. Moreover, owing to their aforesaid
impetuosity, one movement within them is not liable to be
knocked out of its course by some other movement.
1343
The most skilful interpreter of dreams is he who has the faculty
of observing resemblances. Any one may interpret dreams
which are vivid and plain. But, speaking of 'resemblances', I
mean that dream presentations are analogous to the forms
reflected in water, as indeed we have already stated. In the
latter case, if the motion in the water be great, the reflexion has
no resemblance to its original, nor do the forms resemble the
real objects. Skilful, indeed, would he be in interpreting such
reflexions who could rapidly discern, and at a glance
comprehend, the scattered and distorted fragments of such
forms, so as to perceive that one of them represents a man, or a
horse, Or anything whatever. Accordingly, in the other case also,
in a similar way, some such thing as this [blurred image] is all
that a dream amounts to; for the internal movement effaces the
clearness of the dream.
The questions, therefore, which we proposed as to the nature of
sleep and the dream, and the cause to which each of them is
due, and also as to divination as a result of dreams, in every
form of it, have now been discussed.
1344
On Longevity and Shortness of Life
translated by G. R. T. Ross
The reasons for some animals being long-lived and others
short-lived, and, in a word, causes of the length and brevity of
life call for investigation.
The necessary beginning to our inquiry is a statement of the
difficulties about these points. For it is not clear whether in
animals and plants universally it is a single or diverse cause
that makes some to be long-lived, others short-lived. Plants too
have in some cases a long life, while in others it lasts but for a
year.
Further, in a natural structure are longevity and a sound
constitution coincident, or is shortness of life independent of
unhealthiness? Perhaps in the case of certain maladies a
diseased state of the body and shortness of life are
interchangeable, while in the case of others ill-health is
perfectly compatible with long life.
Of sleep and waking we have already treated; about life and
death we shall speak later on, and likewise about health and
disease, in so far as it belongs to the science of nature to do so.
But at present we have to investigate the causes of some
creatures being long-lived, and others short-lived. We find this
distinction affecting not only entire genera opposed as wholes
to one another, but applying also to contrasted sets of
individuals within the same species. As an instance of the
difference applying to the genus I give man and horse (for
1345
mankind has a longer life than the horse), while within the
species there is the difference between man and man; for of
men also some are long-lived, others short-lived, differing from
each other in respect of the different regions in which they
dwell. Races inhabiting warm countries have longer life, those
living in a cold climate live a shorter time. Likewise there are
similar differences among individuals occupying the same
locality.
In order to find premisses for our argument, we must answer
the question, What is that which, in natural objects, makes
them easily destroyed, or the reverse? Since fire and water, and
whatsoever is akin thereto, do not possess identical powers they
are reciprocal causes of generation and decay. Hence it is
natural to infer that everything else arising from them and
composed of them should share in the same nature, in all cases
where things are not, like a house, a composite unity formed by
the synthesis of many things.
In other matters a different account must be given; for in many
things their mode of dissolution is something peculiar to
themselves, e.g. in knowledge and health and disease. These
pass away even though the medium in which they are found is
not destroyed but continues to exist; for example, take the
termination of ignorance, which is recollection or learning,
while knowledge passes away into forgetfulness, or error. But
accidentally the disintegration of a natural object is
accompanied by the destruction of the non-physical reality; for,
when the animal dies, the health or knowledge resident in it
passes away too. Hence from these considerations we may draw
1346
a conclusion about the soul too; for, if the inherence of soul in
body is not a matter of nature but like that of knowledge in the
soul, there would be another mode of dissolution pertaining to
it besides that which occurs when the body is destroyed. But
since evidently it does not admit of this dual dissolution, the
soul must stand in a different case in respect of its union with
the body.
Perhaps one might reasonably raise the question whether there
is any place where what is corruptible becomes incorruptible, as
fire does in the upper regions where it meets with no opposite.
Opposites destroy each other, and hence accidentally, by their
destruction, whatsoever is attributed to them is destroyed. But
no opposite in a real substance is accidentally destroyed,
because real substance is not predicated of any subject. Hence a
thing which has no opposite, or which is situated where it has
no opposite, cannot be destroyed. For what will that be which
can destroy it, if destruction comes only through contraries, but
no contrary to it exists either absolutely or in the particular
place where it is? But perhaps this is in one sense true, in
another sense not true, for it is impossible that anything
containing matter should not have in any sense an opposite.
Heat and straightness can be present in every part of a thing,
but it is impossible that the thing should be nothing but hot or
white or straight; for, if that were so, attributes would have an
independent existence. Hence if, in all cases, whenever the
active and the passive exist together, the one acts and the other
is acted on, it is impossible that no change should occur.
Further, this is so if a waste product is an opposite, and waste
must always be produced; for opposition is always the source of
1347
change, and refuse is what remains of the previous opposite.
But, after expelling everything of a nature actually opposed,
would an object in this case also be imperishable? No, it would
be destroyed by the environment.
If then that is so, what we have said sufficiently accounts for
the change; but, if not, we must assume that something of
actually opposite character is in the changing object, and refuse
is produced.
Hence accidentally a lesser flame is consumed by a greater one,
for the nutriment, to wit the smoke, which the former takes a
long period to expend, is used up by the big flame quickly.
Hence [too] all things are at all times in a state of transition and
are coming into being and passing away. The environment acts
on them either favourably or antagonistically, and, owing to
this, things that change their situation become more or less
enduring than their nature warrants, but never are they eternal
when they contain contrary qualities; for their matter is an
immediate source of contrariety, so that if it involves locality
they show change of situation, if quantity, increase and
diminution, while if it involves qualitative affection we find
alteration of character.
We find that a superior immunity from decay attaches neither
to the largest animals (the horse has shorter life than man) nor
to those that are small (for most insects live but for a year). Nor
are plants as a whole less liable to perish than animals (many
plants are annuals), nor have sanguineous animals the pre-
eminence (for the bee is longer-lived than certain sanguineous
1348
animals). Neither is it the bloodless animals that live longest
(for molluscs live only a year, though bloodless), nor terrestrial
organisms (there are both plants and terrestrial animals of
which a single year is the period), nor the occupants of the sea
(for there we find the crustaceans and the molluscs, which are
short-lived).
Speaking generally, the longest-lived things occur among the
plants, e.g. the date-palm. Next in order we find them among
the sanguineous animals rather than among the bloodless, and
among those with feet rather than among the denizens of the
water. Hence, taking these two characters together, the longest-
lived animals fall among sanguineous animals which have feet,
e.g. man and elephant. As a matter of fact also it is a general
rule that the larger live longer than the smaller, for the other
long-lived animals too happen to be of a large size, as are also
those I have mentioned.
The following considerations may enable us to understand the
reasons for all these facts. We must remember that an animal is
by nature humid and warm, and to live is to be of such a
constitution, while old age is dry and cold, and so is a corpse.
This is plain to observation. But the material constituting the
bodies of all things consists of the following - the hot and the
cold, the dry and the moist. Hence when they age they must
become dry, and therefore the fluid in them requires to be not
easily dried up. Thus we explain why fat things are not liable to
decay. The reason is that they contain air; now air relatively to
the other elements is fire, and fire never becomes corrupted.
1349
Again the humid element in animals must not be small in
quantity, for a small quantity is easily dried up. This is why both
plants and animals that are large are, as a general rule, longer-
lived than the rest, as was said before; it is to be expected that
the larger should contain more moisture. But it is not merely
this that makes them longer lived; for the cause is twofold, to
wit, the quality as well as the quantity of the fluid. Hence the
moisture must be not only great in amount but also warm, in
order to be neither easily congealed nor easily dried up.
It is for this reason also that man lives longer than some
animals which are larger; for animals live longer though there is
a deficiency in the amount of their moisture, if the ratio of its
qualitative superiority exceeds that of its quantitative
deficiency.
In some creatures the warm element is their fatty substance,
which prevents at once desiccation and congelation; but in
others it assumes a different flavour. Further, that which is
designed to be not easily destroyed should not yield waste
products. Anything of such a nature causes death either by
disease or naturally, for the potency of the waste product works
adversely and destroys now the entire constitution, now a
particular member.
This is why salacious animals and those abounding in seed age
quickly; the seed is a residue, and further, by being lost, it
produces dryness. Hence the mule lives longer than either the
horse or the ass from which it sprang, and females live longer
than males if the males are salacious. Accordingly cock-
sparrows have a shorter life than the females. Again males
subject to great toil are short-lived and age more quickly owing
to the labour; toil produces dryness and old age is dry. But by
natural constitution and as a general rule males live longer than
1350
females, and the reason is that the male is an animal with more
warmth than the female.
The same kind of animals are longer-lived in warm than in cold
climates for the same reason, on account of which they are of
larger size. The size of animals of cold constitution illustrates
this particularly well, and hence snakes and lizards and scaly
reptiles are of great size in warm localities, as also are testacea
in the Red Sea: the warm humidity there is the cause equally of
their augmented size and of their life. But in cold countries the
humidity in animals is more of a watery nature, and hence is
readily congealed. Consequently it happens that animals with
little or no blood are in northerly regions either entirely absent
(both the land animals with feet and the water creatures whose
home is the sea) or, when they do occur, they are smaller and
have shorter life; for the frost prevents growth.
Both plants and animals perish if not fed, for in that case they
consume themselves; just as a large flame consumes and burns
up a small one by using up its nutriment, so the natural warmth
which is the primary cause of digestion consumes the material
in which it is located.
Water animals have a shorter life than terrestrial creatures, not
strictly because they are humid, but because they are watery,
and watery moisture is easily destroyed, since it is cold and
readily congealed. For the same reason bloodless animals perish
readily unless protected by great size, for there is neither
fatness nor sweetness about them. In animals fat is sweet, and
hence bees are longer-lived than other animals of larger size.
1351
It is amongst the plants that we find the longest life - more
than among the animals, for, in the first place, they are less
watery and hence less easily frozen. Further they have an
oiliness and a viscosity which makes them retain their moisture
in a form not easily dried up, even though they are dry and
earthy.
But we must discover the reason why trees are of an enduring
constitution, for it is peculiar to them and is not found in any
animals except the insects.
Plants continually renew themselves and hence last for a long
time. New shoots continually come and the others grow old,
and with the roots the same thing happens. But both processes
do not occur together. Rather it happens that at one time the
trunk and the branches alone die and new ones grow up beside
them, and it is only when this has taken place that the fresh
roots spring from the surviving part. Thus it continues, one part
dying and the other growing, and hence also it lives a long time.
There is a similarity, as has been already said, between plants
and insects, for they live, though divided, and two or more may
be derived from a single one. Insects, however, though
managing to live, are not able to do so long, for they do not
possess organs; nor can the principle resident in each of the
separated parts create organs. In the case of a plant, however, it
can do so; every part of a plant contains potentially both root
and stem. Hence it is from this source that issues that
continued growth when one part is renewed and the other
grows old; it is practically a case of longevity. The taking of slips
furnishes a similar instance, for we might say that, in a way,
when we take a slip the same thing happens; the shoot cut off
is part of the plant. Thus in taking slips this perpetuation of life
occurs though their connexion with the plant is severed, but in
1352
the former case it is the continuity that is operative. The reason
is that the life principle potentially belonging to them is present
in every part.
Identical phenomena are found both in plants and in animals.
For in animals the males are, in general, the longer-lived. They
have their upper parts larger than the lower (the male is more
of the dwarf type of build than the female), and it is in the
upper part that warmth resides, in the lower cold. In plants also
those with great heads are longer-lived, and such are those that
are not annual but of the tree-type, for the roots are the head
and upper part of a plant, and among the annuals growth
occurs in the direction of their lower parts and the fruit.
These matters however will be specially investigated in the
work On Plants. But this is our account of the reasons for the
duration of life and for short life in animals. It remains for us to
discuss youth and age, and life and death. To come to a definite
understanding about these matters would complete our course
of study on animals.
1353
On Youth and Old Age, On Breathing, On Life and Death
translated by G. R. T. Ross
We must now treat of youth and old age and life and death. We
must probably also at the same time state the causes of
respiration as well, since in some cases living and the reverse
depend on this.
We have elsewhere given a precise account of the soul, and
while it is clear that its essential reality cannot be corporeal, yet
manifestly it must exist in some bodily part which must be one
of those possessing control over the members. Let us for the
present set aside the other divisions or faculties of the soul
(whichever of the two be the correct name). But as to being
what is called an animal and a living thing, we find that in all
beings endowed with both characteristics (viz. being an animal
and being alive) there must be a single identical part in virtue of
which they live and are called animals; for an animal qua
animal cannot avoid being alive. But a thing need not, though
alive, be animal, for plants live without having sensation, and it
is by sensation that we distinguish animal from what is not
animal.
This organ, then, must be numerically one and the same and
yet possess multiple and disparate aspects, for being animal
and living are not identical. Since then the organs of special
sensation have one common organ in which the senses when
functioning must meet, and this must be situated midway
between what is called before and behind (we call 'before' the
direction from which sensation comes, 'behind' the opposite),
1354
further, since in all living things the body is divided into upper
and lower (they all have upper and lower parts, so that this is
true of plants as well), clearly the nutritive principle must be
situated midway between these regions. That part where food
enters we call upper, considering it by itself and not relatively to
the surrounding universe, while downward is that part by which
the primary excrement is discharged.
Plants are the reverse of animals in this respect. To man in
particular among the animals, on account of his erect stature,
belongs the characteristic of having his upper parts pointing
upwards in the sense in which that applies to the universe,
while in the others these are in an intermediate position. But in
plants, owing to their being stationary and drawing their
sustenance from the ground, the upper part must always be
down; for there is a correspondence between the roots in a
plant and what is called the mouth in animals, by means of
which they take in their food, whether the source of supply be
the earth or each other's bodies.
All perfectly formed animals are to be divided into three parts,
one that by which food is taken in, one that by which excrement
is discharged, and the third the region intermediate between
them. In the largest animals this latter is called the chest and in
the others something corresponding; in some also it is more
distinctly marked off than in others. All those also that are
capable of progression have additional members subservient to
this purpose, by means of which they bear the whole trunk, to
wit legs and feet and whatever parts are possessed of the same
powers. Now it is evident both by observation and by inference
1355
that the source of the nutritive soul is in the midst of the three
parts. For many animals, when either part - the head or the
receptacle of the food - is cut off, retain life in that member to
which the middle remains attached. This can be seen to occur
in many insects, e.g. wasps and bees, and many animals also
besides insects can, though divided, continue to live by means
of the part connected with nutrition.
While this member is indeed in actuality single, yet potentially
it is multiple, for these animals have a constitution similar to
that of Plants; plants when cut into sections continue to live,
and a number of trees can be derived from one single source. A
separate account will be given of the reason why some plants
cannot live when divided, while others can be propagated by
the taking of slips. In this respect, however, plants and insects
are alike.
It is true that the nutritive soul, in beings possessing it, while
actually single must be potentially plural. And it is too with the
principle of sensation, for evidently the divided segments of
these animals have sensation. They are unable, however, to
preserve their constitution, as plants can, not possessing the
organs on which the continuance of life depends, for some lack
the means for seizing, others for receiving their food; or again
they may be destitute of other organs as well.
Divisible animals are like a number of animals grown together,
but animals of superior construction behave differently because
their constitution is a unity of the highest possible kind. Hence
some of the organs on division display slight sensitiveness
because they retain some psychical susceptibility; the animals
continue to move after the vitals have been abstracted:
tortoises, for example, do so even after the heart has been
removed.
1356
The same phenomenon is evident both in plants and in
animals, and in plants we note it both in their propagation by
seed and in grafts and cuttings. Genesis from seeds always
starts from the middle. All seeds are bivalvular, and the place of
junction is situated at the point of attachment (to the plant), an
intermediate part belonging to both halves. It is from this part
that both root and stem of growing things emerge; the starting-
point is in a central position between them. In the case of grafts
and cuttings this is particularly true of the buds; for the bud is
in a way the starting-point of the branch, but at the same time
it is in a central position. Hence it is either this that is cut off, or
into this that the new shoot is inserted, when we wish either a
new branch or a new root to spring from it; which proves that
the point of origin in growth is intermediate between stem and
root.
Likewise in sanguineous animals the heart is the first organ
developed; this is evident from what has been observed in those
cases where observation of their growth is possible. Hence in
bloodless animals also what corresponds to the heart must
develop first. We have already asserted in our treatise on The
Parts of Animals that it is from the heart that the veins issue,
and that in sanguineous animals the blood is the final
nutriment from which the members are formed. Hence it is
clear that there is one function in nutrition which the mouth
has the faculty of performing, and a different one appertaining
to the stomach. But it is the heart that has supreme control,
exercising an additional and completing function. Hence in
sanguineous animals the source both of the sensitive and of the
nutritive soul must be in the heart, for the functions relative to
nutrition exercised by the other parts are ancillary to the
1357
activity of the heart. It is the part of the dominating organ to
achieve the final result, as of the physician's efforts to be
directed towards health, and not to be occupied with
subordinate offices.
Certainly, however, all saguineous animals have the supreme
organ of the sensefaculties in the heart, for it is here that we
must look for the common sensorium belonging to all the
sense-organs. These in two cases, taste and touch, can be
clearly seen to extend to the heart, and hence the others also
must lead to it, for in it the other organs may possibly initiate
changes, whereas with the upper region of the body taste and
touch have no connexion. Apart from these considerations, if
the life is always located in this part, evidently the principle of
sensation must be situated there too, for it is qua animal that
an animal is said to be a living thing, and it is called animal
because endowed with sensation. Elsewhere in other works we
have stated the reasons why some of the sense-organs are, as is
evident, connected with the heart, while others are situated in
the head. (It is this fact that causes some people to think that it
is in virtue of the brain that the function of perception belongs
to animals.)
Thus if, on the one hand, we look to the observed facts, what we
have said makes it clear that the source of the sensitive soul,
together with that connected with growth and nutrition, is
situated in this organ and in the central one of the three
divisions of the body. But it follows by deduction also; for we see
that in every case, when several results are open to her, Nature
always brings to pass the best. Now if both principles are
1358
located in the midst of the substance, the two parts of the body,
viz. that which elaborates and that which receives the
nutriment in its final form will best perform their appropriate
function; for the soul will then be close to each, and the central
situation which it will, as such, occupy is the position of a
dominating power.
Further, that which employs an instrument and the instrument
it employs must be distinct (and must be spatially diverse too, if
possible, as in capacity), just as the flute and that which plays it
- the hand - are diverse. Thus if animal is defined by the
possession of sensitive soul, this soul must in the sanguineous
animals be in the heart, and, in the bloodless ones, in the
corresponding part of their body. But in animals all the
members and the whole body possess some connate warmth of
constitution, and hence when alive they are observed to be
warm, but when dead and deprived of life they are the opposite.
Indeed, the source of this warmth must be in the heart in
sanguineous animals, and in the case of bloodless animals in
the corresponding organ, for, though all parts of the body by
means of their natural heat elaborate and concoct the
nutriment, the governing organ takes the chief share in this
process. Hence, though the other members become cold, life
remains; but when the warmth here is quenched, death always
ensues, because the source of heat in all the other members
depends on this, and the soul is, as it were, set aglow with fire
in this part, which in sanguineous animals is the heart and in
the bloodless order the analogous member. Hence, of necessity,
life must be coincident with the maintenance of heat, and what
we call death is its destruction.
1359
However, it is to be noticed that there are two ways in which fire
ceases to exist; it may go out either by exhaustion or by
extinction. That which is self-caused we call exhaustion, that
due to its opposites extinction. [The former is that due to old
age, the latter to violence.] But either of these ways in which fire
ceases to be may be brought about by the same cause, for, when
there is a deficiency of nutriment and the warmth can obtain no
maintenance, the fire fails; and the reason is that the opposite,
checking digestion, prevents the fire from being fed. But in other
cases the result is exhaustion, when the heat accumulates
excessively owing to lack of respiration and of refrigeration. For
in this case what happens is that the heat, accumulating in
great quantity, quickly uses up its nutriment and consumes it
all before more is sent up by evaporation. Hence not only is a
smaller fire readily put out by a large one, but of itself the
candle flame is consumed when inserted in a large blaze just as
is the case with any other combustible. The reason is that the
nutriment in the flame is seized by the larger one before fresh
fuel can be added, for fire is ever coming into being and rushing
just like a river, but so speedily as to elude observation.
Clearly therefore, if the bodily heat must be conserved (as is
necessary if life is to continue), there must be some way of
cooling the heat resident in the source of warmth. Take as an
illustration what occurs when coals are confined in a brazier. If
they are kept covered up continuously by the so-called 'choker',
they are quickly extinguished, but, if the lid is in rapid
alternation lifted up and put on again they remain glowing for a
long time. Banking up a fire also keeps it in, for the ashes, being
porous, do not prevent the passage of air, and again they enable
it to resist extinction by the surrounding air by means of the
supply of heat which it possesses. However, we have stated in
The Problems the reasons why these operations, namely
1360
banking up and covering up a fire, have the opposite effects (in
the one case the fire goes out, in the other it continues alive for
a considerable time).
Everything living has soul, and it, as we have said, cannot exist
without the presence of heat in the constitution. In plants the
natural heat is sufficiently well kept alive by the aid which their
nutriment and the surrounding air supply. For the food has a
cooling effect [as it enters, just as it has in man] when first it is
taken in, whereas abstinence from food produces heat and
thirst. The air, if it be motionless, becomes hot, but by the entry
of food a motion is set up which lasts until digestion is
completed and so cools it. If the surrounding air is excessively
cold owing to the time of year, there being severe frost, plants
shrivel, or if, in the extreme heats of summer the moisture
drawn from the ground cannot produce its cooling effect, the
heat comes to an end by exhaustion. Trees suffering at such
seasons are said to be blighted or star-stricken. Hence the
practice of laying beneath the roots stones of certain species or
water in pots, for the purpose of cooling the roots of the plants.
Some animals pass their life in the water, others in the air, and
therefore these media furnish the source and means of
refrigeration, water in the one case, air in the other. We must
proceed - and it will require further application on our part - to
give an account of the way and manner in which this
refrigeration occurs.
1361
A few of the previous physical philosophers have spoken of
respiration. The reason, however, why it exists in animals they
have either not declared or, when they have, their statements
are not correct and show a comparative lack of acquaintance
with the facts. Moreover they assert that all animals respire -
which is untrue. Hence these points must first claim our
attention, in order that we may not be thought to make
unsubstantiated charges against authors no longer alive.
First then, it is evident that all animals with lungs breathe, but
in some cases breathing animals have a bloodless and spongy
lung, and then there is less need for respiration. These animals
can remain under water for a time, which relatively to their
bodily strength, is considerable. All oviparous animals, e.g. the
frog-tribe, have a spongy lung. Also hemydes and tortoises can
remain for a long time immersed in water; for their lung,
containing little blood, has not much heat. Hence, when once it
is inflated, it itself, by means of its motion, produces a cooling
effect and enables the animal to remain immersed for a long
time. Suffocation, however, always ensues if the animal is
forced to hold its breath for too long a time, for none of this
class take in water in the way fishes do. On the other hand,
animals which have the lung charged with blood have greater
need of respiration on account of the amount of their heat,
while none at all of the others which do not possess lungs
breathe.
8
Democritus of Abdera and certain others who have treated of
respiration, while saying nothing definite about the lungless
1362
animals, nevertheless seem to speak as if all breathed. But
Anaxagoras and Diogenes both maintain that all breathe, and
state the manner in which fishes and oysters respire.
Anaxagoras says that when fishes discharge water through
their gills, air is formed in the mouth, for there can be no
vacuum, and that it is by drawing in this that they respire.
Diogenes' statement is that, when they discharge water through
their gills, they suck the air out of the water surrounding the
mouth by means of the vacuum formed in the mouth, for he
believes there is air in the water.
But these theories are untenable. Firstly, they state only what is
the common element in both operations and so leave out the
half of the matter. For what goes by the name of respiration
consists, on the one hand, of inhalation, and, on the other, of
the exhalation of breath; but, about the latter they say nothing,
nor do they describe how such animals emit their breath.
Indeed, explanation is for them impossible for, when the
creatures respire, they must discharge their breath by the same
passage as that by which they draw it in, and this must happen
in alternation. Hence, as a result, they must take the water into
their mouth at the same time as they breathe out. But the air
and the water must meet and obstruct each other. Further,
when they discharge the water they must emit their breath by
the mouth or the gills, and the result will be that they will
breathe in and breathe out at the same time, for it is at that
moment that respiration is said to occur. But it is impossible
that they should do both at the same time. Hence, if respiring
creatures must both exhale and inhale the air, and if none of
these animals can breathe out, evidently none can respire at all.
1363
Further, the assertion that they draw in air out of the mouth or
out of the water by means of the mouth is an impossibility, for,
not having a lung, they have no windpipe; rather the stomach is
closely juxtaposed to the mouth, so that they must do the
sucking with the stomach. But in that case the other animals
would do so also, which is not the truth; and the water-animals
also would be seen to do it when out of the water, whereas
quite evidently they do not. Further, in all animals that respire
and draw breath there is to be observed a certain motion in the
part of the body which draws in the air, but in the fishes this
does not occur. Fishes do not appear to move any of the parts in
the region of the stomach, except the gills alone, and these
move both when they are in the water and when they are
thrown on to dry land and gasp. Moreover, always when
respiring animals are killed by being suffocated in water,
bubbles are formed of the air which is forcibly discharged, as
happens, e.g. when one forces a tortoise or a frog or any other
animal of a similar class to stay beneath water. But with fishes
this result never occurs, in whatsoever way we try to obtain it,
since they do not contain air drawn from an external source.
Again, the manner of respiration said to exist in them might
occur in the case of men also when they are under water. For if
fishes draw in air out of the surrounding water by means of
their mouth why should not men too and other animals do so
also; they should also, in the same way as fishes, draw in air out
of the mouth. If in the former case it were possible, so also
should it be in the latter. But, since in the one it is not so,
neither does it occur in the other. Furthermore, why do fishes, if
they respire, die in the air and gasp (as can be seen) as in
suffocation? It is not want of food that produces this effect
upon them, and the reason given by Diogenes is foolish, for he
says that in air they take in too much air and hence die, but in
the water they take in a moderate amount. But that should be a
1364
possible occurrence with land animals also; as facts are,
however, no land animal seems to be suffocated by excessive
respiration. Again, if all animals breathe, insects must do so
also, many of them seem to live though divided not merely into
two, but into several parts, e.g. the class called Scolopendra. But
how can they, when thus divided, breathe, and what is the
organ they employ? The main reason why these writers have
not given a good account of these facts is that they have no
acquaintance with the internal organs, and that they did not
accept the doctrine that there is a final cause for whatever
Nature does. If they had asked for what purpose respiration
exists in animals, and had considered this with reference to the
organs, e.g. the gills and the lungs, they would have discovered
the reason more speedily.
10
Democritus, however, does teach that in the breathing animals
there is a certain result produced by respiration; he asserts that
it prevents the soul from being extruded from the body.
Nevertheless, he by no means asserts that it is for this purpose
that Nature so contrives it, for he, like the other physical
philosophers, altogether fails to attain to any such explanation.
His statement is that the soul and the hot element are identical,
being the primary forms among the spherical particles. Hence,
when these are being crushed together by the surrounding
atmosphere thrusting them out, respiration, according to his
account, comes in to succour them. For in the air there are
many of those particles which he calls mind and soul. Hence,
when we breathe and the air enters, these enter along with it,
and by their action cancel the pressure, thus preventing the
expulsion of the soul which resides in the animal.
1365
This explains why life and death are bound up with the taking
in and letting out of the breath; for death occurs when the
compression by the surrounding air gains the upper hand, and,
the animal being unable to respire, the air from outside can no
longer enter and counteract the compression. Death is the
departure of those forms owing to the expulsive pressure
exerted by the surrounding air. Death, however, occurs not by
haphazard but, when natural, owing to old age, and, when
unnatural, to violence.
But the reason for this and why all must die Democritus has by
no means made clear. And yet, since evidently death occurs at
one time of life and not at another, he should have said whether
the cause is external or internal. Neither does he assign the
cause of the beginning of respiration, nor say whether it is
internal or external. Indeed, it is not the case that the external
mind superintends the reinforcement; rather the origin of
breathing and of the respiratory motion must be within: it is not
due to pressure from around. It is absurd also that what
surrounds should compress and at the same time by entering
dilate. This then is practically his theory, and how he puts it.
But if we must consider that our previous account is true, and
that respiration does not occur in every animal, we must deem
that this explains death not universally, but only in respiring
animals. Yet neither is it a good account of these even, as may
clearly be seen from the facts and phenomena of which we all
have experience. For in hot weather we grow warmer, and,
having more need of respiration, we always breathe faster. But,
when the air around is cold and contracts and solidifies the
body, retardation of the breathing results. Yet this was just the
time when the external air should enter and annul the
expulsive movement, whereas it is the opposite that occurs. For
when the breath is not let out and the heat accumulates too
much then we need to respire, and to respire we must draw in
1366
the breath. When hot, people breathe rapidly, because they
must do so in order to cool themselves, just when the theory of
Democritus would make them add fire to fire.
11
The theory found in the Timaeus, of the passing round of the
breath by pushing, by no means determines how, in the case of
the animals other than land-animals, their heat is preserved,
and whether it is due to the same or a different cause. For if
respiration occurs only in land-animals we should be told what
is the reason of that. Likewise, if it is found in others also, but in
a different form, this form of respiration, if they all can breathe,
must also be described.
Further, the method of explaining involves a fiction. It is said
that when the hot air issues from the mouth it pushes the
surrounding air, which being carried on enters the very place
whence the internal warmth issued, through the interstices of
the porous flesh; and this reciprocal replacement is due to the
fact that a vacuum cannot exist. But when it has become hot
the air passes out again by the same route, and pushes back
inwards through the mouth the air that had been discharged in
a warm condition. It is said that it is this action which goes on
continuously when the breath is taken in and let out.
But according to this way of thinking it will follow that we
breathe out before we breathe in. But the opposite is the case, as
evidence shows, for though these two functions go on in
alternation, yet the last act when life comes to a close is the
letting out of the breath, and hence its admission must have
been the beginning of the process.
1367
Once more, those who give this kind of explanation by no
means state the final cause of the presence in animals of this
function (to wit the admission and emission of the breath), but
treat it as though it were a contingent accompaniment of life.
Yet it evidently has control over life and death, for it results
synchronously that when respiring animals are unable to
breathe they perish. Again, it is absurd that the passage of the
hot air out through the mouth and back again should be quite
perceptible, while we were not able to detect the thoracic influx
and the return outwards once more of the heated breath. It is
also nonsense that respiration should consist in the entrance of
heat, for the evidence is to the contrary effect; what is breathed
out is hot, and what is breathed in is cold. When it is hot we
pant in breathing, for, because what enters does not adequately
perform its cooling function, we have as a consequence to draw
the breath frequently.
12
It is certain, however, that we must not entertain the notion
that it is for purposes of nutrition that respiration is designed,
and believe that the internal fire is fed by the breath;
respiration, as it were, adding fuel to the fire, while the feeding
of the flame results in the outward passage of the breath. To
combat this doctrine I shall repeat what I said in opposition to
the previous theories. This, or something analogous to it, should
occur in the other animals also (on this theory), for all possess
vital heat. Further, how are we to describe this fictitious process
of the generation of heat from the breath? Observation shows
rather that it is a product of the food. A consequence also of this
theory is that the nutriment would enter and the refuse be
1368
discharged by the same channel, but this does not appear to
occur in the other instances.
13
Empedocles also gives an account of respiration without,
however, making clear what its purpose is, or whether or not it
is universal in animals. Also when dealing with respiration by
means of the nostrils he imagines he is dealing with what is the
primary kind of respiration. Even the breath which passes
through the nostrils passes through the windpipe out of the
chest as well, and without the latter the nostrils cannot act.
Again, when animals are bereft of respiration through the
nostrils, no detrimental result ensues, but, when prevented
from breathing through the windpipe, they die. Nature employs
respiration through the nostrils as a secondary function in
certain animals in order to enable them to smell. But the reason
why it exists in some only is that though almost all animals are
endowed with the sense of smell, the sense-organ is not the
same in all.
A more precise account has been given about this elsewhere.
Empedocles, however, explains the passage inwards and
outwards of the breath, by the theory that there are certain
blood-vessels, which, while containing blood, are not filled by it,
but have passages leading to the outer air, the calibre of which
is fine in contrast to the size of the solid particles, but large
relatively to those in the air. Hence, since it is the nature of the
blood to move upwards and downwards, when it moves down
the air rushes in and inspiration occurs; when the blood rises,
the air is forced out and the outward motion of the breath
results. He compares this process to what occurs in a clepsydra.
1369
Thus all things outwards breathe and in; - their flesh has tubes
Bloodless, that stretch towards the body's outmost edge,
Which, at their mouths, full many frequent channels pierce,
Cleaving the extreme nostrils through; thus, while the gore
Lies hid, for air is cut a thoroughfare most plain.
And thence, whenever shrinks away the tender blood,
Enters the blustering wind with swelling billow wild.
But when the blood leaps up, backward it breathes. As when
With water-clock of polished bronze a maiden sporting,
Sets on her comely hand the narrow of the tube
And dips it in the frail-formed water's silvery sheen;
Not then the flood the vessel enters, but the air,
Until she frees the crowded stream. But then indeed
Upon the escape runs in the water meet.
So also when within the vessel's deeps the water
Remains, the opening by the hand of flesh being closed,
The outer air that entrance craves restrains the flood
At the gates of the sounding narrow,
upon the surface pressing,
Until the maid withdraws her hand. But then in contrariwise
Once more the air comes in and water meet flows out.
1370
Thus to the to the subtle blood, surging throughout the limbs,
Whene'er it shrinks away into the far recesses
Admits a stream of air rushing with swelling wave,
But, when it backward leaps, in like bulk air flows out.
This then is what he says of respiration. But, as we said, all
animals that evidently respire do so by means of the windpipe,
when they breathe either through the mouth or through the
nostrils. Hence, if it is of this kind of respiration that he is
talking, we must ask how it tallies with the explanation given.
But the facts seem to be quite opposed. The chest is raised in
the manner of a forge-bellows when the breath is drawn in - it
is quite reasonable that it should be heat which raises up and
that the blood should occupy the hot region - but it collapses
and sinks down, like the bellows once more, when the breath is
let out. The difference is that in a bellows it is not by the same
channel that the air is taken in and let out, but in breathing it is.
But, if Empedocles is accounting only for respiration through
the nostrils, he is much in error, for that does not involve the
nostrils alone, but passes by the channel beside the uvula where
the extremity of the roof of the mouth is, some of the air going
this way through the apertures of the nostrils and some
through the mouth, both when it enters and when it passes out.
Such then is the nature and magnitude of the difficulties
besetting the theories of other writers concerning respiration.
14
We have already stated that life and the presence of soul
involve a certain heat. Not even the digesting process to which
1371
is due the nutrition of animals occurs apart from soul and
warmth, for it is to fire that in all cases elaboration is due. It is
for this reason, precisely, that the primary nutritive soul also
must be located in that part of the body and in that division of
this region which is the immediate vehicle of this principle. The
region in question is intermediate between that where food
enters and that where excrement is discharged. In bloodless
animals it has no name, but in the sanguineous class this organ
is called the heart. The blood constitutes the nutriment from
which the organs of the animal are directly formed. Likewise
the bloodvessels must have the same originating source, since
the one exists for the other's behoof - as a vessel or receptacle
for it. In sanguineous animals the heart is the starting-point of
the veins; they do not traverse it, but are found to stretch out
from it, as dissections enable us to see.
Now the other psychical faculties cannot exist apart from the
power of nutrition (the reason has already been stated in the
treatise On the Soul), and this depends on the natural fire, by
the union with which Nature has set it aglow. But fire, as we
have already stated, is destroyed in two ways, either by
extinction or by exhaustion. It suffers extinction from its
opposites. Hence it can be extinguished by the surrounding cold
both when in mass and (though more speedily) when scattered.
Now this way of perishing is due to violence equally in living
and in lifeless objects, for the division of an animal by
instruments and consequent congelation by excess of cold
cause death. But exhaustion is due to excess of heat; if there is
too much heat close at hand and the thing burning does not
have a fresh supply of fuel added to it, it goes out by exhaustion,
not by the action of cold. Hence, if it is going to continue it must
be cooled, for cold is a preventive against this form of
extinction.
1372
15
Some animals occupy the water, others live on land, and, that
being so, in the case of those which are very small and
bloodless the refrigeration due to the surrounding water or air is
sufficient to prevent destruction from this cause. Having little
heat, they require little cold to combat it. Hence too such
animals are almost all short-lived, for, being small, they have
less scope for deflection towards either extreme. But some
insects are longer-lived though bloodless, like all the others),
and these have a deep indentation beneath the waist, in order
to secure cooling through the membrane, which there is
thinner. They are warmer animals and hence require more
refrigeration, and such are bees (some of which live as long as
seven years) and all that make a humming noise, like wasps,
cockchafers, and crickets. They make a sound as if of panting by
means of air, for, in the middle section itself, the air which
exists internally and is involved in their construction, causing a
rising and falling movement, produces friction against the
membrane. The way in which they move this region is like the
motion due to the lungs in animals that breathe the outer air, or
to the gills in fishes. What occurs is comparable to the
suffocation of a respiring animal by holding its mouth, for then
the lung causes a heaving motion of this kind. In the case of
these animals this internal motion is not sufficient for
refrigeration, but in insects it is. It is by friction against the
membrane that they produce the humming sound, as we said,
in the way that children do by blowing through the holes of a
reed covered by a fine membrane. It is thus that the singing
crickets too produce their song; they possess greater warmth
and are indented at the waist, but the songless variety have no
fissure there.
1373
Animals also which are sanguineous and possess a lung, though
that contains little blood and is spongy, can in some cases,
owing to the latter fact, live a long time without breathing; for
the lung, containing little blood or fluid, can rise a long way: its
own motion can for a long time produce sufficient refrigeration.
But at last it ceases to suffice, and the animal dies of suffocation
if it does not respire - as we have already said. For of exhaustion
that kind which is destruction due to lack of refrigeration is
called suffocation, and whatsoever is thus destroyed is said to
be suffocated.
We have already stated that among animals insects do not
respire, and the fact is open to observation in the case of even
small creatures like flies and bees, for they can swim about in a
fluid for a long time if it is not too hot or too cold. Yet animals
with little strength tend to breathe more frequently. These,
however, die of what is called suffocation when the stomach
becomes filled and the heat in the central segment is destroyed.
This explains also why they revive after being among ashes for
a time.
Again among water-animals those that are bloodless remain
alive longer in air than those that have blood and admit the sea-
water, as, for example, fishes. Since it is a small quantity of heat
they possess, the air is for a long time adequate for the
purposes of refrigeration in such animals as the Crustacea and
the polyps. It does not however suffice, owing to their want of
heat, to keep them finally in life, for most fishes also live though
among earth, yet in a motionless state, and are to be found by
digging. For all animals that have no lung at all or have a
bloodless one require less refrigeration.
1374
16
Concerning the bloodless animals we have declared that in
some cases it is the surrounding air, in others fluid, that aids
the maintenance of life. But in the case of animals possessing
blood and heart, all which have a lung admit the air and
produce the cooling effect by breathing in and out. All animals
have a lung that are viviparous and are so internally, not
externally merely (the Selachia are viviparous, but not
internally), and of the oviparous class those that have wings,
e.g. birds, and those with scales, e.g. tortoises, lizards, and
snakes. The former class have a lung charged with blood, but in
the most part of the latter it is spongy. Hence they employ
respiration more sparingly as already said. The function is
found also in all that frequent and pass their life in the water,
e.g. the class of water-snakes and frogs and crocodiles and
hemydes, both sea - and land-tortoises, and seals.
All these and similar animals both bring forth on land and sleep
on shore or, when they do so in the water, keep the head above
the surface in order to respire. But all with gills produce
refrigeration by taking in water; the Selachia and all other
footless animals have gills. Fish are footless, and the limbs they
have get their name (pterugion) from their similarity to wings
(pterux). But of those with feet one only, so far as observed, has
gills. It is called the tadpole.
No animal yet has been seen to possess both lungs and gills,
and the reason for this is that the lung is designed for the
purpose of refrigeration by means of the air (it seems to have
derived its name (pneumon) from its function as a receptacle of
the breath (pneuma)), while gills are relevant to refrigeration by
water. Now for one purpose one organ is adapted and one single
means of refrigeration is sufficient in every case. Hence, since
we see that Nature does nothing in vain, and if there were two
1375
organs one would be purposeless, this is the reason why some
animals have gills, others lungs, but none possess both.
17
Every animal in order to exist requires nutriment, in order to
prevent itself from dying, refrigeration; and so Nature employs
the same organ for both purposes. For, as in some cases the
tongue serves both for discerning tastes and for speech, so in
animals with lungs the mouth is employed both in working up
the food and in the passage of the breath outwards and
inwards. In lungless and non-respiring animals it is employed in
working up the food, while in those of them that require
refrigeration it is the gills that are created for this purpose.
We shall state further on how it is that these organs have the
faculty of producing refrigeration. But to prevent their food from
impeding these operations there is a similar contrivance in the
respiring animals and in those that admit water. At the moment
of respiration they do not take in food, for otherwise suffocation
results owing to the food, whether liquid or dry, slipping in
through the windpipe and lying on the lung. The windpipe is
situated before the oesophagus, through which food passes into
what is called the stomach, but in quadrupeds which are
sanguineous there is, as it were, a lid over the windpipe - the
epiglottis. In birds and oviparous quadrupeds this covering is
absent, but its office is discharged by a contraction of the
windpipe. The latter class contract the windpipe when
swallowing their food; the former close down the epiglottis.
When the food has passed, the epiglottis is in the one case
raised, and in the other the windpipe is expanded, and the air
enters to effect refrigeration. In animals with gills the water is
1376
first discharged through them and then the food passes in
through the mouth; they have no windpipe and hence can take
no harm from liquid lodging in this organ, only from its
entering the stomach. For these reasons the expulsion of water
and the seizing of their food is rapid, and their teeth are sharp
and in almost all cases arranged in a saw-like fashion, for they
are debarred from chewing their food.
18
Among water-animals the cetaceans may give rise to some
perplexity, though they too can be rationally explained.
Examples of such animals are dolphins and whales, and all
others that have a blowhole. They have no feet, yet possess a
lung though admitting the sea-water. The reason for possessing
a lung is that which we have now stated [refrigeration]; the
admission of water is not for the purpose of refrigeration. That
is effected by respiration, for they have a lung. Hence they sleep
with their head out of the water, and dolphins, at any rate,
snore. Further, if they are entangled in nets they soon die of
suffocation owing to lack of respiration, and hence they can be
seen to come to the surface owing to the necessity of breathing.
But, since they have to feed in the water, they must admit it,
and it is in order to discharge this that they all have a blow-
hole; after admitting the water they expel it through the blow-
hole as the fishes do through the gills. The position of the blow-
hole is an indication of this, for it leads to none of the organs
which are charged with blood; but it lies before the brain and
thence discharges water.
It is for the very same reason that molluscs and crustaceans
admit water - I mean such animals as Carabi and Carcini. For
1377
none of these is refrigeration a necessity, for in every case they
have little heat and are bloodless, and hence are sufficiently
cooled by the surrounding water. But in feeding they admit
water, and hence must expel it in order to prevent its being
swallowed simultaneously with the food. Thus crustaceans, like
the Carcini and Carabi, discharge water through the folds beside
their shaggy parts, while cuttlefish and the polyps employ for
this purpose the hollow above the head. There is, however, a
more precise account of these in the History of Animals.
Thus it has been explained that the cause of the admission of
the water is refrigeration, and the fact that animals constituted
for a life in water must feed in it.
19
An account must next be given of refrigeration and the manner
in which it occurs in respiring animals and those possessed of
gills. We have already said that all animals with lungs respire.
The reason why some creatures have this organ, and why those
having it need respiration, is that the higher animals have a
greater proportion of heat, for at the same time they must have
been assigned a higher soul and they have a higher nature than
plants. Hence too those with most blood and most warmth in
the lung are of greater size, and animal in which the blood in
the lung is purest and most plentiful is the most erect, namely
man; and the reason why he alone has his upper part directed
to the upper part of the universe is that he possesses such a
lung. Hence this organ as much as any other must be assigned
to the essence of the animal both in man and in other cases.
This then is the purpose of refrigeration. As for the constraining
and efficient cause, we must believe that it created animals like
1378
this, just as it created many others also not of this constitution.
For some have a greater proportion of earth in their
composition, like plants, and others, e.g. aquatic animals,
contain a larger amount of water; while winged and terrestrial
animals have an excess of air and fire respectively. It is always
in the region proper to the element preponderating in the
scheme of their constitution that things exist.
20
Empedocles is then in error when he says that those animals
which have the most warmth and fire live in the water to
counterbalance the excess of heat in their constitution, in order
that, since they are deficient in cold and fluid, they may be kept
in life by the contrary character of the region they occupy; for
water has less heat than air. But it is wholly absurd that the
water-animals should in every case originate on dry land, and
afterwards change their place of abode to the water; for they are
almost all footless. He, however, when describing their original
structure says that, though originating on dry land, they have
abandoned it and migrated to the water. But again it is evident
that they are not warmer than land-animals, for in some cases
they have no blood at all, in others little.
The question, however, as to what sorts of animals should be
called warm and what cold, has in each special case received
consideration. Though in one respect there is reason in the
explanation which Empedocles aims at establishing, yet his
account is not correct. Excess in a bodily state is cured by a
situation or season of opposite character, but the constitution is
best maintained by an environment akin to it. There is a
difference between the material of which any animal is
1379
constituted and the states and dispositions of that material. For
example, if nature were to constitute a thing of wax or of ice,
she would not preserve it by putting it in a hot place, for the
opposing quality would quickly destroy it, seeing that heat
dissolves that which cold congeals. Again, a thing composed of
salt or nitre would not be taken and placed in water, for fluid
dissolves that of which the consistency is due to the hot and
the dry.
Hence if the fluid and the dry supply the material for all bodies,
it is reasonable that things the composition of which is due to
the fluid and the cold should have liquid for their medium [and,
if they are cold, they will exist in the cold], while that which is
due to the dry will be found in the dry. Thus trees grow not in
water but on dry land. But the same theory would relegate them
to the water, on account of their excess of dryness, just as it
does the things that are excessively fiery. They would migrate
thither not on account of its cold but owing to its fluidity.
Thus the natural character of the material of objects is of the
same nature as the region in which they exist; the liquid is
found in liquid, the dry on land, the warm in air. With regard,
however, to states of body, a cold situation has, on the other
hand, a beneficial effect on excess of heat, and a warm
environment on excess of cold, for the region reduces to a mean
the excess in the bodily condition. The regions appropriate to
each material and the revolutions of the seasons which all
experience supply the means which must be sought in order to
correct such excesses; but, while states of the body can be
opposed in character to the environment, the material of which
it is composed can never be so. This, then, is a sufficient
explanation of why it is not owing to the heat in their
constitution that some animals are aquatic, others terrestrial, as
Empedocles maintains, and of why some possess lungs and
others do not.
1380
21
The explanation of the admission of air and respiration in those
animals in which a lung is found, and especially in those in
which it is full of blood, is to be found in the fact that it is of a
spongy nature and full of tubes, and that it is the most fully
charged with blood of all the visceral organs. All animals with a
full-blooded lung require rapid refrigeration because there is
little scope for deviation from the normal amount of their vital
fire; the air also must penetrate all through it on account of the
large quantity of blood and heat it contains. But both these
operations can be easily performed by air, for, being of a subtle
nature, it penetrates everywhere and that rapidly, and so
performs its cooling function; but water has the opposite
characteristics.
The reason why animals with a full-blooded lung respire most
is hence manifest; the more heat there is, the greater is the
need for refrigeration, and at the same time breath can easily
pass to the source of heat in the heart.
22
In order to understand the way in which the heart is connected
with the lung by means of passages, we must consult both
dissections and the account in the History of Animals. The
universal cause of the need which the animal has for
refrigeration, is the union of the soul with fire that takes place
in the heart. Respiration is the means of effecting refrigeration,
1381
of which those animals make use that possess a lung as well as
a heart. But when they, as for example the fishes, which on
account of their aquatic nature have no lung, possess the latter
organ without the former, the cooling is effected through the
gills by means of water. For ocular evidence as to how the heart
is situated relatively to the gills we must employ dissections,
and for precise details we must refer to Natural History. As a
summarizing statement, however, and for present purposes, the
following is the account of the matter.
It might appear that the heart has not the same position in
terrestrial animals and fishes, but the position really is
identical, for the apex of the heart is in the direction in which
they incline their heads. But it is towards the mouth in fishes
that the apex of the heart points, seeing that they do not incline
their heads in the same direction as land-animals do. Now from
the extremity of the heart a tube of a sinewy, arterial character
runs to the centre where the gills all join. This then is the
largest of those ducts, but on either side of the heart others also
issue and run to the extremity of each gill, and by means of the
ceaseless flow of water through the gills, effect the cooling
which passes to the heart.
In similar fashion as the fish move their gills, respiring animals
with rapid action raise and let fall the chest according as the
breath is admitted or expelled. If air is limited in amount and
unchanged they are suffocated, for either medium, owing to
contact with the blood, rapidly becomes hot. The heat of the
blood counteracts the refrigeration and, when respiring animals
can no longer move the lung aquatic animals their gills,
whether owing to disease or old age, their death ensues.
1382
23
To be born and to die are common to all animals, but there are
specifically diverse ways in which these phenomena occur; of
destruction there are different types, though yet something is
common to them all. There is violent death and again natural
death, and the former occurs when the cause of death is
external, the latter when it is internal, and involved from the
beginning in the constitution of the organ, and not an affection
derived from a foreign source. In the case of plants the name
given to this is withering, in animals senility. Death and decay
pertain to all things that are not imperfectly developed; to the
imperfect also they may be ascribed in nearly the same but not
an identical sense. Under the imperfect I class eggs and seeds of
plants as they are before the root appears.
It is always to some lack of heat that death is due, and in perfect
creatures the cause is its failure in the organ containing the
source of the creature's essential nature. This member is situate,
as has been said, at the junction of the upper and lower parts;
in plants it is intermediate between the root and the stem, in
sanguineous animals it is the heart, and in those that are
bloodless the corresponding part of their body. But some of
these animals have potentially many sources of life, though in
actuality they possess only one. This is why some insects live
when divided, and why, even among sanguineous animals, all
whose vitality is not intense live for a long time after the heart
has been removed. Tortoises, for example, do so and make
movements with their feet, so long as the shell is left, a fact to
be explained by the natural inferiority of their constitution, as it
is in insects also.
The source of life is lost to its possessors when the heat with
which it is bound up is no longer tempered by cooling, for, as I
have often remarked, it is consumed by itself. Hence when,
1383
owing to lapse of time, the lung in the one class and the gills in
the other get dried up, these organs become hard and earthy
and incapable of movement, and cannot be expanded or
contracted. Finally things come to a climax, and the fire goes
out from exhaustion.
Hence a small disturbance will speedily cause death in old age.
Little heat remains, for the most of it has been breathed away in
the long period of life preceding, and hence any increase of
strain on the organ quickly causes extinction. It is just as
though the heart contained a tiny feeble flame which the
slightest movement puts out. Hence in old age death is painless,
for no violent disturbance is required to cause death, and there
is an entire absence of feeling when the soul's connexion is
severed. All diseases which harden the lung by forming tumours
or waste residues, or by excess of morbid heat, as happens in
fevers, accelerate the breathing owing to the inability of the
lung to move far either upwards or downwards. Finally, when
motion is no longer possible, the breath is given out and death
ensues.
24
Generation is the initial participation, mediated by warm
substance, in the nutritive soul, and life is the maintenance of
this participation. Youth is the period of the growth of the
primary organ of refrigeration, old age of its decay, while the
intervening time is the prime of life.
A violent death or dissolution consists in the extinction or
exhaustion of the vital heat (for either of these may cause
dissolution), while natural death is the exhaustion of the heat
owing to lapse of time, and occurring at the end of life. In plants
1384
this is to wither, in animals to die. Death, in old age, is the
exhaustion due to inability on the part of the organ, owing to
old age, to produce refrigeration. This then is our account of
generation and life and death, and the reason for their
occurrence in animals.
25
It is hence also clear why respiring animals are suffocated in
water and fishes in air. For it is by water in the latter class, by
air in the former that refrigeration is effected, and either of
these means of performing the function is removed by a change
of environment.
There is also to be explained in either case the cause of the
cause of the motion of the gills and of the lungs, the rise and
fall of which effects the admission and expulsion of the breath
or of water. The following, moreover, is the manner of the
constitution of the organ.
26
In connexion with the heart there are three phenomena, which,
though apparently of the same nature, are really not so, namely
palpitation, pulsation, and respiration.
Palpitation is the rushing together of the hot substance in the
heart owing to the chilling influence of residual or waste
products. It occurs, for example, in the ailment known as
'spasms' and in other diseases. It occurs also in fear, for when
1385
one is afraid the upper parts become cold, and the hot
substance, fleeing away, by its concentration in the heart
produces palpitation. It is crushed into so small a space that
sometimes life is extinguished, and the animals die of the fright
and morbid disturbance.
The beating of the heart, which, as can be seen, goes on
continuously, is similar to the throbbing of an abscess. That,
however, is accompanied by pain, because the change produced
in the blood is unnatural, and it goes on until the matter formed
by concoction is discharged. There is a similarity between this
phenomenon and that of boiling; for boiling is due to the
volatilization of fluid by heat and the expansion consequent on
increase of bulk. But in an abscess, if there is no evaporation
through the walls, the process terminates in suppuration due to
the thickening of the liquid, while in boiling it ends in the
escape of the fluid out of the containing vessel.
In the heart the beating is produced by the heat expanding the
fluid, of which the food furnishes a constant supply. It occurs
when the fluid rises to the outer wall of the heart, and it goes on
continuously; for there is a constant flow of the fluid that goes
to constitute the blood, it being in the heart that the blood
receives its primary elaboration. That this is so we can perceive
in the initial stages of generation, for the heart can be seen to
contain blood before the veins become distinct. This explains
why pulsation in youth exceeds that in older people, for in the
young the formation of vapour is more abundant.
All the veins pulse, and do so simultaneously with each other,
owing to their connexion with the heart. The heart always
beats, and hence they also beat continuously and
simultaneously with each other and with it.
1386
Palpitation, then, is the recoil of the heart against the
compression due to cold; and pulsation is the volatilization of
the heated fluid.
27
Respiration takes place when the hot substance which is the
seat of the nutritive principle increases. For it, like the rest of
the body, requires nutrition, and more so than the members, for
it is through it that they are nourished. But when it increases it
necessarily causes the organ to rise. This organ we must to be
constructed like the bellows in a smithy, for both heart and
lungs conform pretty well to this shape. Such a structure must
be double, for the nutritive principle must be situated in the
centre of the natural force.
Thus on increase of bulk expansion results, which necessarily
causes the surrounding parts to rise. Now this can be seen to
occur when people respire; they raise their chest because the
motive principle of the organ described resident within the
chest causes an identical expansion of this organ. When it
dilates the outer air must rush in as into a bellows, and, being
cold, by its chilling influence reduces by extinction the excess of
the fire. But, as the increase of bulk causes the organ to dilate,
so diminution causes contraction, and when it collapses the air
which entered must pass out again. When it enters the air is
cold, but on issuing it is warm owing to its contact with the heat
resident in this organ, and this is specially the case in those
animals that possess a full-blooded lung. The numerous canal-
like ducts in the lung, into which it passes, have each a blood-
vessel lying alongside, so that the whole lung is thought to be
full of blood. The inward passage of the air is called respiration,
1387
the outward expiration, and this double movement goes on
continuously just so long as the animal lives and keeps this
organ in continuous motion; it is for this reason that life is
bound up with the passage of the breath outwards and inwards.
It is in the same way that the motion of the gills in fishes takes
place. When the hot substance in the blood throughout the
members rises, the gills rise too, and let the water pass through,
but when it is chilled and retreats through its channels to the
heart, they contract and eject the water. Continually as the heat
in the heart rises, continually on being chilled it returns thither
again. Hence, as in respiring animals life and death are bound
up with respiration, so in the other animals class they depend
on the admission of water.
Our discussion of life and death and kindred topics is now
practically complete. But health and disease also claim the
attention of the scientist, and not merely of the physician, in so
far as an account of their causes is concerned. The extent to
which these two differ and investigate diverse provinces must
not escape us, since facts show that their inquiries are, to a
certain extent, at least conterminous. For physicians of culture
and refinement make some mention of natural science, and
claim to derive their principles from it, while the most
accomplished investigators into nature generally push their
studies so far as to conclude with an account of medical
principles.
1388
Aristotle - History of Animals
[Translated by D'Arcy Wentworth Thompson]
Book I
Of the parts of animals some are simple: to wit, all such as
divide into parts uniform with themselves, as flesh into flesh;
others are composite, such as divide into parts not uniform with
themselves, as, for instance, the hand does not divide into
hands nor the face into faces.
And of such as these, some are called not parts merely, but
limbs or members. Such are those parts that, while entire in
themselves, have within themselves other diverse parts: as for
instance, the head, foot, hand, the arm as a whole, the chest; for
these are all in themselves entire parts, and there are other
diverse parts belonging to them.
All those parts that do not subdivide into parts uniform with
themselves are composed of parts that do so subdivide, for
instance, hand is composed of flesh, sinews, and bones. Of
animals, some resemble one another in all their parts, while
others have parts wherein they differ. Sometimes the parts are
identical in form or species, as, for instance, one man's nose or
eye resembles another man's nose or eye, flesh flesh, and bone
bone; and in like manner with a horse, and with all other
animals which we reckon to be of one and the same species: for
as the whole is to the whole, so each to each are the parts
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severally. In other cases the parts are identical, save only for a
difference in the way of excess or defect, as is the case in such
animals as are of one and the same genus. By 'genus' I mean,
for instance, Bird or Fish, for each of these is subject to
difference in respect of its genus, and there are many species of
fishes and of birds.
Within the limits of genera, most of the parts as a rule exhibit
differences through contrast of the property or accident, such as
colour and shape, to which they are subject: in that some are
more and some in a less degree the subject of the same
property or accident; and also in the way of multitude or
fewness, magnitude or parvitude, in short in the way of excess
or defect. Thus in some the texture of the flesh is soft, in others
firm; some have a long bill, others a short one; some have
abundance of feathers, others have only a small quantity. It
happens further that some have parts that others have not: for
instance, some have spurs and others not, some have crests and
others not; but as a general rule, most parts and those that go to
make up the bulk of the body are either identical with one
another, or differ from one another in the way of contrast and of
excess and defect. For 'the more' and 'the less' may be
represented as 'excess' or 'defect'.
Once again, we may have to do with animals whose parts are
neither identical in form nor yet identical save for differences in
the way of excess or defect: but they are the same only in the
way of analogy, as, for instance, bone is only analogous to fish-
bone, nail to hoof, hand to claw, and scale to feather; for what
the feather is in a bird, the scale is in a fish.
The parts, then, which animals severally possess are diverse
from, or identical with, one another in the fashion above
described. And they are so furthermore in the way of local
disposition: for many animals have identical organs that differ
1390
in position; for instance, some have teats in the breast, others
close to the thighs.
Of the substances that are composed of parts uniform (or
homogeneous) with themselves, some are soft and moist,
others are dry and solid. The soft and moist are such either
absolutely or so long as they are in their natural conditions, as,
for instance, blood, serum, lard, suet, marrow, sperm, gall, milk
in such as have it flesh and the like; and also, in a different way,
the superfluities, as phlegm and the excretions of the belly and
the bladder. The dry and solid are such as sinew, skin, vein, hair,
bone, gristle, nail, horn (a term which as applied to the part
involves an ambiguity, since the whole also by virtue of its form
is designated horn), and such parts as present an analogy to
these.
Animals differ from one another in their modes of subsistence,
in their actions, in their habits, and in their parts. Concerning
these differences we shall first speak in broad and general
terms, and subsequently we shall treat of the same with close
reference to each particular genus.
Differences are manifested in modes of subsistence, in habits,
in actions performed. For instance, some animals live in water
and others on land. And of those that live in water some do so
in one way, and some in another: that is to say, some live and
feed in the water, take in and emit water, and cannot live if
deprived of water, as is the case with the great majority of
fishes; others get their food and spend their days in the water,
but do not take in water but air, nor do they bring forth in the
water. Many of these creatures are furnished with feet, as the
otter, the beaver, and the crocodile; some are furnished with
wings, as the diver and the grebe; some are destitute of feet, as
the water-snake. Some creatures get their living in the water
and cannot exist outside it: but for all that do not take in either
1391
air or water, as, for instance, the sea-nettle and the oyster. And
of creatures that live in the water some live in the sea, some in
rivers, some in lakes, and some in marshes, as the frog and the
newt.
Of animals that live on dry land some take in air and emit it,
which phenomena are termed 'inhalation' and 'exhalation'; as,
for instance, man and all such land animals as are furnished
with lungs. Others, again, do not inhale air, yet live and find
their sustenance on dry land; as, for instance, the wasp, the bee,
and all other insects. And by 'insects' I mean such creatures as
have nicks or notches on their bodies, either on their bellies or
on both backs and bellies.
And of land animals many, as has been said, derive their
subsistence from the water; but of creatures that live in and
inhale water not a single one derives its subsistence from dry
land.
Some animals at first live in water, and by and by change their
shape and live out of water, as is the case with river worms, for
out of these the gadfly develops.
Furthermore, some animals are stationary, and some are erratic.
Stationary animals are found in water, but no such creature is
found on dry land. In the water are many creatures that live in
close adhesion to an external object, as is the case with several
kinds of oyster. And, by the way, the sponge appears to be
endowed with a certain sensibility: as a proof of which it is
alleged that the difficulty in detaching it from its moorings is
increased if the movement to detach it be not covertly applied.
Other creatures adhere at one time to an object and detach
themselves from it at other times, as is the case with a species
of the so-called sea-nettle; for some of these creatures seek
their food in the night-time loose and unattached.
1392
Many creatures are unattached but motionless, as is the case
with oysters and the so-called holothuria. Some can swim, as,
for instance, fishes, molluscs, and crustaceans, such as the
crawfish. But some of these last move by walking, as the crab,
for it is the nature of the creature, though it lives in water, to
move by walking.
Of land animals some are furnished with wings, such as birds
and bees, and these are so furnished in different ways one from
another; others are furnished with feet. Of the animals that are
furnished with feet some walk, some creep, and some wriggle.
But no creature is able only to move by flying, as the fish is able
only to swim, for the animals with leathern wings can walk; the
bat has feet and the seal has imperfect feet.
Some birds have feet of little power, and are therefore called
Apodes. This little bird is powerful on the wing; and, as a rule,
birds that resemble it are weak-footed and strong winged, such
as the swallow and the drepanis or (?) Alpine swift; for all these
birds resemble one another in their habits and in their plumage,
and may easily be mistaken one for another. (The apus is to be
seen at all seasons, but the drepanis only after rainy weather in
summer; for this is the time when it is seen and captured,
though, as a general rule, it is a rare bird.)
Again, some animals move by walking on the ground as well as
by swimming in water.
Furthermore, the following differences are manifest in their
modes of living and in their actions. Some are gregarious, some
are solitary, whether they be furnished with feet or wings or be
fitted for a life in the water; and some partake of both
characters, the solitary and the gregarious. And of the
gregarious, some are disposed to combine for social purposes,
others to live each for its own self.
1393
Gregarious creatures are, among birds, such as the pigeon, the
crane, and the swan; and, by the way, no bird furnished with
crooked talons is gregarious. Of creatures that live in water
many kinds of fishes are gregarious, such as the so-called
migrants, the tunny, the pelamys, and the bonito.
Man, by the way, presents a mixture of the two characters, the
gregarious and the solitary.
Social creatures are such as have some one common object in
view; and this property is not common to all creatures that are
gregarious. Such social creatures are man, the bee, the wasp, the
ant, and the crane.
Again, of these social creatures some submit to a ruler, others
are subject to no governance: as, for instance, the crane and the
several sorts of bee submit to a ruler, whereas ants and
numerous other creatures are every one his own master.
And again, both of gregarious and of solitary animals, some are
attached to a fixed home and others are erratic or nomad.
Also, some are carnivorous, some graminivorous, some
omnivorous: whilst some feed on a peculiar diet, as for instance
the bees and the spiders, for the bee lives on honey and certain
other sweets, and the spider lives by catching flies; and some
creatures live on fish. Again, some creatures catch their food,
others treasure it up; whereas others do not so.
Some creatures provide themselves with a dwelling, others go
without one: of the former kind are the mole, the mouse, the
ant, the bee; of the latter kind are many insects and
quadrupeds. Further, in respect to locality of dwelling place,
some creatures dwell under ground, as the lizard and the snake;
others live on the surface of the ground, as the horse and the
dog. make to themselves holes, others do not
1394
Some are nocturnal, as the owl and the bat; others live in the
daylight.
Moreover, some creatures are tame and some are wild: some are
at all times tame, as man and the mule; others are at all times
savage, as the leopard and the wolf; and some creatures can be
rapidly tamed, as the elephant.
Again, we may regard animals in another light. For, whenever a
race of animals is found domesticated, the same is always to be
found in a wild condition; as we find to be the case with horses,
kine, swine, (men), sheep, goats, and dogs.
Further, some animals emit sound while others are mute, and
some are endowed with voice: of these latter some have
articulate speech, while others are inarticulate; some are given
to continual chirping and twittering some are prone to silence;
some are musical, and some unmusical; but all animals without
exception exercise their power of singing or chattering chiefly in
connexion with the intercourse of the sexes.
Again, some creatures live in the fields, as the cushat; some on
the mountains, as the hoopoe; some frequent the abodes of
men, as the pigeon.
Some, again, are peculiarly salacious, as the partridge, the barn-
door cock and their congeners; others are inclined to chastity, as
the whole tribe of crows, for birds of this kind indulge but rarely
in sexual intercourse.
Of marine animals, again, some live in the open seas, some near
the shore, some on rocks.
Furthermore, some are combative under offence; others are
provident for defence. Of the former kind are such as act as
aggressors upon others or retaliate when subjected to ill usage,
1395
and of the latter kind are such as merely have some means of
guarding themselves against attack.
Animals also differ from one another in regard to character in
the following respects. Some are good-tempered, sluggish, and
little prone to ferocity, as the ox; others are quick tempered,
ferocious and unteachable, as the wild boar; some are
intelligent and timid, as the stag and the hare; others are mean
and treacherous, as the snake; others are noble and courageous
and high-bred, as the lion; others are thorough-bred and wild
and treacherous, as the wolf: for, by the way, an animal is
highbred if it come from a noble stock, and an animal is
thorough-bred if it does not deflect from its racial
characteristics.
Further, some are crafty and mischievous, as the fox; some are
spirited and affectionate and fawning, as the dog; others are
easy-tempered and easily domesticated, as the elephant; others
are cautious and watchful, as the goose; others are jealous and
self-conceited, as the peacock. But of all animals man alone is
capable of deliberation.
Many animals have memory, and are capable of instruction; but
no other creature except man can recall the past at will.
With regard to the several genera of animals, particulars as to
their habits of life and modes of existence will be discussed
more fully by and by.
Common to all animals are the organs whereby they take food
and the organs where into they take it; and these are either
1396
identical with one another, or are diverse in the ways above
specified: to wit, either identical in form, or varying in respect of
excess or defect, or resembling one another analogically, or
differing in position.
Furthermore, the great majority of animals have other organs
besides these in common, whereby they discharge the residuum
of their food: I say, the great majority, for this statement does
not apply to all. And, by the way, the organ whereby food is
taken in is called the mouth, and the organ whereinto it is
taken, the belly; the remainder of the alimentary system has a
great variety of names.
Now the residuum of food is twofold in kind, wet and dry, and
such creatures as have organs receptive of wet residuum are
invariably found with organs receptive of dry residuum; but
such as have organs receptive of dry residuum need not possess
organs receptive of wet residuum. In other words, an animal has
a bowel or intestine if it have a bladder; but an animal may have
a bowel and be without a bladder. And, by the way, I may here
remark that the organ receptive of wet residuum is termed
'bladder', and the organ receptive of dry residuum 'intestine or
'bowel'.
Of animals otherwise, a great many have, besides the organs
above-mentioned, an organ for excretion of the sperm: and of
animals capable of generation one secretes into another, and
the other into itself. The latter is termed 'female', and the
former 'male'; but some animals have neither male nor female.
Consequently, the organs connected with this function differ in
1397
form, for some animals have a womb and others an organ
analogous thereto.
The above-mentioned organs, then, are the most indispensable
parts of animals; and with some of them all animals without
exception, and with others animals for the most part, must
needs be provided.
One sense, and one alone, is common to all animals - the sense
of touch. Consequently, there is no special name for the organ
in which it has its seat; for in some groups of animals the organ
is identical, in others it is only analogous.
Every animal is supplied with moisture, and, if the animal be
deprived of the same by natural causes or artificial means,
death ensues: further, every animal has another part in which
the moisture is contained. These parts are blood and vein, and
in other animals there is something to correspond; but in these
latter the parts are imperfect, being merely fibre and serum or
lymph.
Touch has its seat in a part uniform and homogeneous, as in
the flesh or something of the kind, and generally, with animals
supplied with blood, in the parts charged with blood. In other
animals it has its seat in parts analogous to the parts charged
with blood; but in all cases it is seated in parts that in their
texture are homogeneous.
The active faculties, on the contrary, are seated in the parts that
are heterogeneous: as, for instance, the business of preparing
1398
the food is seated in the mouth, and the office of locomotion in
the feet, the wings, or in organs to correspond.
Again, some animals are supplied with blood, as man, the horse,
and all such animals as are, when full-grown, either destitute of
feet, or two-footed, or four-footed; other animals are bloodless,
such as the bee and the wasp, and, of marine animals, the
cuttle-fish, the crawfish, and all such animals as have more
than four feet.
Again, some animals are viviparous, others oviparous, others
vermiparous or 'grub-bearing'. Some are viviparous, such as
man, the horse, the seal, and all other animals that are hair-
coated, and, of marine animals, the cetaceans, as the dolphin,
and the so-called Selachia. (Of these latter animals, some have a
tubular air-passage and no gills, as the dolphin and the whale:
the dolphin with the air-passage going through its back, the
whale with the air-passage in its forehead; others have
uncovered gills, as the Selachia, the sharks and rays.)
What we term an egg is a certain completed result of
conception out of which the animal that is to be develops, and
in such a way that in respect to its primitive germ it comes from
part only of the egg, while the rest serves for food as the germ
develops. A 'grub' on the other hand is a thing out of which in
its entirety the animal in its entirety develops, by differentiation
and growth of the embryo.
Of viviparous animals, some hatch eggs in their own interior, as
creatures of the shark kind; others engender in their interior a
live foetus, as man and the horse. When the result of
1399
conception is perfected, with some animals a living creature is
brought forth, with others an egg is brought to light, with others
a grub. Of the eggs, some have egg-shells and are of two
different colours within, such as birds' eggs; others are soft-
skinned and of uniform colour, as the eggs of animals of the
shark kind. Of the grubs, some are from the first capable of
movement, others are motionless. However, with regard to
these phenomena we shall speak precisely hereafter when we
come to treat of Generation.
Furthermore, some animals have feet and some are destitute
thereof. Of such as have feet some animals have two, as is the
case with men and birds, and with men and birds only; some
have four, as the lizard and the dog; some have more, as the
centipede and the bee; but allsoever that have feet have an even
number of them.
Of swimming creatures that are destitute of feet, some have
winglets or fins, as fishes: and of these some have four fins, two
above on the back, two below on the belly, as the gilthead and
the basse; some have two only, to wit, such as are exceedingly
long and smooth, as the eel and the conger; some have none at
all, as the muraena, but use the sea just as snakes use dry
ground - and by the way, snakes swim in water in just the same
way. Of the shark-kind some have no fins, such as those that are
flat and long-tailed, as the ray and the sting-ray, but these fishes
swim actually by the undulatory motion of their flat bodies; the
fishing frog, however, has fins, and so likewise have all such
fishes as have not their flat surfaces thinned off to a sharp edge.
Of those swimming creatures that appear to have feet, as is the
case with the molluscs, these creatures swim by the aid of their
feet and their fins as well, and they swim most rapidly
backwards in the direction of the trunk, as is the case with the
1400
cuttle-fish or sepia and the calamary; and, by the way, neither of
these latter can walk as the poulpe or octopus can.
The hard-skinned or crustaceous animals, like the crawfish,
swim by the instrumentality of their tail-parts; and they swim
most rapidly tail foremost, by the aid of the fins developed upon
that member. The newt swims by means of its feet and tail; and
its tail resembles that of the sheatfish, to compare little with
great.
Of animals that can fly some are furnished with feathered
wings, as the eagle and the hawk; some are furnished with
membranous wings, as the bee and the cockchafer; others are
furnished with leathern wings, as the flying fox and the bat. All
flying creatures possessed of blood have feathered wings or
leathern wings; the bloodless creatures have membranous
wings, as insects. The creatures that have feathered wings or
leathern wings have either two feet or no feet at all: for there
are said to be certain flying serpents in Ethiopia that are
destitute of feet.
Creatures that have feathered wings are classed as a genus
under the name of 'bird'; the other two genera, the leathern-
winged and membrane-winged, are as yet without a generic
title.
Of creatures that can fly and are bloodless some are
coleopterous or sheath-winged, for they have their wings in a
sheath or shard, like the cockchafer and the dung-beetle; others
are sheathless, and of these latter some are dipterous and some
tetrapterous: tetrapterous, such as are comparatively large or
have their stings in the tail, dipterous, such as are
comparatively small or have their stings in front. The coleoptera
are, without exception, devoid of stings; the diptera have the
sting in front, as the fly, the horsefly, the gadfly, and the gnat.
1401
Bloodless animals as a general rule are inferior in point of size
to blooded animals; though, by the way, there are found in the
sea some few bloodless creatures of abnormal size, as in the
case of certain molluscs. And of these bloodless genera, those
are the largest that dwell in milder climates, and those that
inhabit the sea are larger than those living on dry land or in
fresh water.
All creatures that are capable of motion move with four or more
points of motion; the blooded animals with four only: as, for
instance, man with two hands and two feet, birds with two
wings and two feet, quadrupeds and fishes severally with four
feet and four fins. Creatures that have two winglets or fins, or
that have none at all like serpents, move all the same with not
less than four points of motion; for there are four bends in their
bodies as they move, or two bends together with their fins.
Bloodless and many footed animals, whether furnished with
wings or feet, move with more than four points of motion; as,
for instance, the dayfly moves with four feet and four wings:
and, I may observe in passing, this creature is exceptional not
only in regard to the duration of its existence, whence it
receives its name, but also because though a quadruped it has
wings also.
All animals move alike, four-footed and many-footed; in other
words, they all move cross-corner-wise. And animals in general
have two feet in advance; the crab alone has four.
Very extensive genera of animals, into which other subdivisions
fall, are the following: one, of birds; one, of fishes; and another,
of cetaceans. Now all these creatures are blooded.
1402
There is another genus of the hard-shell kind, which is called
oyster; another of the soft-shell kind, not as yet designated by a
single term, such as the spiny crawfish and the various kinds of
crabs and lobsters; and another of molluscs, as the two kinds of
calamary and the cuttle-fish; that of insects is different. All
these latter creatures are bloodless, and such of them as have
feet have a goodly number of them; and of the insects some
have wings as well as feet.
Of the other animals the genera are not extensive. For in them
one species does not comprehend many species; but in one
case, as man, the species is simple, admitting of no
differentiation, while other cases admit of differentiation, but
the forms lack particular designations.
So, for instance, creatures that are qudapedal and unprovided
with wings are blooded without exception, but some of them
are viviparous, and some oviparous. Such as are viviparous are
hair-coated, and such as are oviparous are covered with a kind
of tessellated hard substance; and the tessellated bits of this
substance are, as it were, similar in regard to position to a scale.
An animal that is blooded and capable of movement on dry
land, but is naturally unprovided with feet, belongs to the
serpent genus; and animals of this genus are coated with the
tessellated horny substance. Serpents in general are oviparous;
the adder, an exceptional case, is viviparous: for not all
viviparous animals are hair-coated, and some fishes also are
viviparous.
All animals, however, that are hair-coated are viviparous. For, by
the way, one must regard as a kind of hair such prickly hairs as
hedgehogs and porcupines carry; for these spines perform the
office of hair, and not of feet as is the case with similar parts of
sea-urchins.
1403
In the genus that combines all viviparous quadrupeds are many
species, but under no common appellation. They are only
named as it were one by one, as we say man, lion, stag, horse,
dog, and so on; though, by the way, there is a sort of genus that
embraces all creatures that have bushy manes and bushy tails,
such as the horse, the ass, the mule, the jennet, and the animals
that are called Hemioni in Syria, from their externally
resembling mules, though they are not strictly of the same
species. And that they are not so is proved by the fact that they
mate with and breed from one another. For all these reasons, we
must take animals species by species, and discuss their
peculiarities severally.
These preceding statements, then, have been put forward thus
in a general way, as a kind of foretaste of the number of subjects
and of the properties that we have to consider in order that we
may first get a clear notion of distinctive character and common
properties. By and by we shall discuss these matters with
greater minuteness.
After this we shall pass on to the discussion of causes. For to do
this when the investigation of the details is complete is the
proper and natural method, and that whereby the subjects and
the premisses of our argument will afterwards be rendered
plain.
In the first place we must look to the constituent parts of
animals. For it is in a way relative to these parts, first and
foremost, that animals in their entirety differ from one another:
either in the fact that some have this or that, while they have
not that or this; or by peculiarities of position or of
arrangement; or by the differences that have been previously
mentioned, depending upon diversity of form, or excess or
defect in this or that particular, on analogy, or on contrasts of
the accidental qualities.
1404
To begin with, we must take into consideration the parts of
Man. For, just as each nation is wont to reckon by that monetary
standard with which it is most familiar, so must we do in other
matters. And, of course, man is the animal with which we are
all of us the most familiar.
Now the parts are obvious enough to physical perception.
However, with the view of observing due order and sequence
and of combining rational notions with physical perception, we
shall proceed to enumerate the parts: firstly, the organic, and
afterwards the simple or non-composite.
The chief parts into which the body as a whole is subdivided,
are the head, the neck, the trunk (extending from the neck to
the privy parts), which is called the thorax, two arms and two
legs.
Of the parts of which the head is composed the hair-covered
portion is called the 'skull'. The front portion of it is termed
'bregma' or 'sinciput', developed after birth - for it is the last of
all the bones in the body to acquire solidity, - the hinder part is
termed the 'occiput', and the part intervening between the
sinciput and the occiput is the 'crown'. The brain lies
underneath the sinciput; the occiput is hollow. The skull
consists entirely of thin bone, rounded in shape, and contained
within a wrapper of fleshless skin.
The skull has sutures: one, of circular form, in the case of
women; in the case of men, as a general rule, three meeting at a
point. Instances have been known of a man's skull devoid of
suture altogether. In the skull the middle line, where the hair
1405
parts, is called the crown or vertex. In some cases the parting is
double; that is to say, some men are double crowned, not in
regard to the bony skull, but in consequence of the double fall
or set of the hair.
8
The part that lies under the skull is called the 'face': but in the
case of man only, for the term is not applied to a fish or to an
ox. In the face the part below the sinciput and between the eyes
is termed the forehead. When men have large foreheads, they
are slow to move; when they have small ones, they are fickle;
when they have broad ones, they are apt to be distraught; when
they have foreheads rounded or bulging out, they are quick-
tempered.
Underneath the forehead are two eyebrows. Straight eyebrows
are a sign of softness of disposition; such as curve in towards
the nose, of harshness; such as curve out towards the temples,
of humour and dissimulation; such as are drawn in towards one
another, of jealousy.
Under the eyebrows come the eyes. These are naturally two in
number. Each of them has an upper and a lower eyelid, and the
hairs on the edges of these are termed 'eyelashes'. The central
part of the eye includes the moist part whereby vision is
effected, termed the 'pupil', and the part surrounding it called
the 'black'; the part outside this is the 'white'. A part common to
1406
the upper and lower eyelid is a pair of nicks or corners, one in
the direction of the nose, and the other in the direction of the
temples. When these are long they are a sign of bad disposition;
if the side toward the nostril be fleshy and comb-like, they are a
sign of dishonesty.
All animals, as a general rule, are provided with eyes, excepting
the ostracoderms and other imperfect creatures; at all events,
all viviparous animals have eyes, with the exception of the
mole. And yet one might assert that, though the mole has not
eyes in the full sense, yet it has eyes in a kind of a way. For in
point of absolute fact it cannot see, and has no eyes visible
externally; but when the outer skin is removed, it is found to
have the place where eyes are usually situated, and the black
parts of the eyes rightly situated, and all the place that is
usually devoted on the outside to eyes: showing that the parts
are stunted in development, and the skin allowed to grow over.
10
Of the eye the white is pretty much the same in all creatures;
but what is called the black differs in various animals. Some
have the rim black, some distinctly blue, some greyish-blue,
some greenish; and this last colour is the sign of an excellent
disposition, and is particularly well adapted for sharpness of
vision. Man is the only, or nearly the only, creature, that has
eyes of diverse colours. Animals, as a rule, have eyes of one
colour only. Some horses have blue eyes.
Of eyes, some are large, some small, some medium-sized; of
these, the medium-sized are the best. Moreover, eyes
sometimes protrude, sometimes recede, sometimes are neither
protruding nor receding. Of these, the receding eye is in all
1407
animals the most acute; but the last kind are the sign of the
best disposition. Again, eyes are sometimes inclined to wink
under observation, sometimes to remain open and staring, and
sometimes are disposed neither to wink nor stare. The last kind
are the sign of the best nature, and of the others, the latter kind
indicates impudence, and the former indecision.
11
Furthermore, there is a portion of the head, whereby an animal
hears, a part incapable of breathing, the 'ear'. I say 'incapable of
breathing', for Alcmaeon is mistaken when he says that goats
inspire through their ears. Of the ear one part is unnamed, the
other part is called the 'lobe'; and it is entirely composed of
gristle and flesh. The ear is constructed internally like the
trumpet-shell, and the innermost bone is like the ear itself, and
into it at the end the sound makes its way, as into the bottom of
a jar. This receptacle does not communicate by any passage
with the brain, but does so with the palate, and a vein extends
from the brain towards it. The eyes also are connected with the
brain, and each of them lies at the end of a little vein. Of
animals possessed of ears man is the only one that cannot
move this organ. Of creatures possessed of hearing, some have
ears, whilst others have none, but merely have the passages for
ears visible, as, for example, feathered animals or animals
coated with horny tessellates.
Viviparous animals, with the exception of the seal, the dolphin,
and those others which after a similar fashion to these are
cetaceans, are all provided with ears; for, by the way, the shark-
kind are also viviparous. Now, the seal has the passages visible
whereby it hears; but the dolphin can hear, but has no ears, nor
1408
yet any passages visible. But man alone is unable to move his
ears, and all other animals can move them. And the ears lie,
with man, in the same horizontal plane with the eyes, and not
in a plane above them as is the case with some quadrupeds. Of
ears, some are fine, some are coarse, and some are of medium
texture; the last kind are best for hearing, but they serve in no
way to indicate character. Some ears are large, some small,
some medium-sized; again, some stand out far, some lie in
close and tight, and some take up a medium position; of these
such as are of medium size and of medium position are
indications of the best disposition, while the large and
outstanding ones indicate a tendency to irrelevant talk or
chattering. The part intercepted between the eye, the ear, and
the crown is termed the 'temple'. Again, there is a part of the
countenance that serves as a passage for the breath, the 'nose'.
For a man inhales and exhales by this organ, and sneezing is
effected by its means: which last is an outward rush of collected
breath, and is the only mode of breath used as an omen and
regarded as supernatural. Both inhalation and exhalation go
right on from the nose towards the chest; and with the nostrils
alone and separately it is impossible to inhale or exhale, owing
to the fact that the inspiration and respiration take place from
the chest along the windpipe, and not by any portion connected
with the head; and indeed it is possible for a creature to live
without using this process of nasal respiration.
Again, smelling takes place by means of the nose, - smelling, or
the sensible discrimination of odour. And the nostril admits of
easy motion, and is not, like the ear, intrinsically immovable. A
part of it, composed of gristle, constitutes, a septum or partition,
and part is an open passage; for the nostril consists of two
separate channels. The nostril (or nose) of the elephant is long
and strong, and the animal uses it like a hand; for by means of
this organ it draws objects towards it, and takes hold of them,
1409
and introduces its food into its mouth, whether liquid or dry
food, and it is the only living creature that does so.
Furthermore, there are two jaws; the front part of them
constitutes the chin, and the hinder part the cheek. All animals
move the lower jaw, with the exception of the river crocodile;
this creature moves the upper jaw only.
Next after the nose come two lips, composed of flesh, and facile
of motion. The mouth lies inside the jaws and lips. Parts of the
mouth are the roof or palate and the pharynx.
The part that is sensible of taste is the tongue. The sensation
has its seat at the tip of the tongue; if the object to be tasted be
placed on the flat surface of the organ, the taste is less sensibly
experienced. The tongue is sensitive in all other ways wherein
flesh in general is so: that is, it can appreciate hardness, or
warmth and cold, in any part of it, just as it can appreciate taste.
The tongue is sometimes broad, sometimes narrow, and
sometimes of medium width; the last kind is the best and the
clearest in its discrimination of taste. Moreover, the tongue is
sometimes loosely hung, and sometimes fastened: as in the
case of those who mumble and who lisp.
The tongue consists of flesh, soft and spongy, and the so-called
'epiglottis' is a part of this organ.
That part of the mouth that splits into two bits is called the
'tonsils'; that part that splits into many bits, the 'gums'. Both
the tonsils and the gums are composed of flesh. In the gums are
teeth, composed of bone.
Inside the mouth is another part, shaped like a bunch of grapes,
a pillar streaked with veins. If this pillar gets relaxed and
inflamed it is called 'uvula' or 'bunch of grapes', and it then has
a tendency to bring about suffocation.
1410
12
The neck is the part between the face and the trunk. Of this the
front part is the larynx land the back part the ur The front part,
composed of gristle, through which respiration and speech is
effected, is termed the 'windpipe'; the part that is fleshy is the
oesophagus, inside just in front of the chine. The part to the
back of the neck is the epomis, or 'shoulder-point'.
These then are the parts to be met with before you come to the
thorax.
To the trunk there is a front part and a back part. Next after the
neck in the front part is the chest, with a pair of breasts. To each
of the breasts is attached a teat or nipple, through which in the
case of females the milk percolates; and the breast is of a
spongy texture. Milk, by the way, is found at times in the male;
but with the male the flesh of the breast is tough, with the
female it is soft and porous.
13
Next after the thorax and in front comes the 'belly', and its root
the 'navel'. Underneath this root the bilateral part is the 'flank':
the undivided part below the navel, the 'abdomen', the
extremity of which is the region of the 'pubes'; above the navel
the 'hypochondrium'; the cavity common to the hypochondrium
and the flank is the gut-cavity.
1411
Serving as a brace girdle to the hinder parts is the pelvis, and
hence it gets its name (osphus), for it is symmetrical (isophues)
in appearance; of the fundament the part for resting on is
termed the 'rump', and the part whereon the thigh pivots is
termed the 'socket' (or acetabulum).
The 'womb' is a part peculiar to the female; and the 'penis' is
peculiar to the male. This latter organ is external and situated at
the extremity of the trunk; it is composed of two separate parts:
of which the extreme part is fleshy, does not alter in size, and is
called the glans; and round about it is a skin devoid of any
specific title, which integument if it be cut asunder never grows
together again, any more than does the jaw or the eyelid. And
the connexion between the latter and the glans is called the
frenum. The remaining part of the penis is composed of gristle;
it is easily susceptible of enlargement; and it protrudes and
recedes in the reverse directions to what is observable in the
identical organ in cats. Underneath the penis are two 'testicles',
and the integument of these is a skin that is termed the
'scrotum'.
Testicles are not identical with flesh, and are not altogether
diverse from it. But by and by we shall treat in an exhaustive
way regarding all such parts.
14
The privy part of the female is in character opposite to that of
the male. In other words, the part under the pubes is hollow or
receding, and not, like the male organ, protruding. Further, there
is an 'urethra' outside the womb; which organ serves as a
passage for the sperm of the male, and as an outlet for liquid
excretion to both sexes).
1412
The part common to the neck and chest is the 'throat'; the
'armpit' is common to side, arm, and shoulder; and the 'groin' is
common to thigh and abdomen. The part inside the thigh and
buttocks is the 'perineum', and the part outside the thigh and
buttocks is the 'hypoglutis'.
The front parts of the trunk have now been enumerated.
The part behind the chest is termed the 'back'.
15
Parts of the back are a pair of 'shoulderblades', the 'back-bone',
and, underneath on a level with the belly in the trunk, the
'loins'. Common to the upper and lower part of the trunk are
the 'ribs', eight on either side, for as to the so-called seven-
ribbed Ligyans we have not received any trustworthy evidence.
Man, then, has an upper and a lower part, a front and a back
part, a right and a left side. Now the right and the left side are
pretty well alike in their parts and identical throughout, except
that the left side is the weaker of the two; but the back parts do
not resemble the front ones, neither do the lower ones the
upper: only that these upper and lower parts may be said to
resemble one another thus far, that, if the face be plump or
meagre, the abdomen is plump or meagre to correspond; and
that the legs correspond to the arms, and where the upper arm
is short the thigh is usually short also, and where the feet are
small the hands are small correspondingly.
Of the limbs, one set, forming a pair, is 'arms'. To the arm belong
the 'shoulder', 'upper-arm', 'elbow', 'fore-arm', and 'hand'. To the
hand belong the 'palm', and the five 'fingers'. The part of the
1413
finger that bends is termed 'knuckle', the part that is inflexible
is termed the 'phalanx'. The big finger or thumb is single-
jointed, the other fingers are double jointed. The bending both
of the arm and of the finger takes place from without inwards
in all cases; and the arm bends at the elbow. The inner part of
the hand is termed the palm', and is fleshy and divided by joints
or lines: in the case of long-lived people by one or two
extending right across, in the case of the short-lived by two, not
so extending. The joint between hand and arm is termed the
'wrist'. The outside or back of the hand is sinewy, and has no
specific designation.
There is another duplicate limb, the 'leg'. Of this limb the
double-knobbed part is termed the 'thigh-bone', the sliding part
of the 'kneecap', the double-boned part the 'leg'; the front part
of this latter is termed the 'shin', and the part behind it the
'calf, wherein the flesh is sinewy and venous, in some cases
drawn upwards towards the hollow behind the knee, as in the
case of people with large hips, and in other cases drawn
downwards. The lower extremity of the shin is the 'ankle',
duplicate in either leg. The part of the limb that contains a
multiplicity of bones is the 'foot'. The hinder part of the foot is
the 'heel'; at the front of it the divided part consists of 'toes',
five in number; the fleshy part underneath is the 'ball'; the
upper part or back of the foot is sinewy and has no particular
appellation; of the toe, one portion is the 'nail' and another the
'joint', and the nail is in all cases at the extremity; and toes are
without exception single jointed. Men that have the inside or
sole of the foot clumsy and not arched, that is, that walk resting
on the entire under-surface of their feet, are prone to roguery.
The joint common to thigh and shin is the 'knee'.
These, then, are the parts common to the male and the female
sex. The relative position of the parts as to up and down, or to
front and back, or to right and left, all this as regards externals
1414
might safely be left to mere ordinary perception. But for all that,
we must treat of them for the same reason as the one
previously brought forward; that is to say, we must refer to them
in order that a due and regular sequence may be observed in
our exposition, and in order that by the enumeration of these
obvious facts due attention may be subsequently given to those
parts in men and other animals that are diverse in any way
from one another.
In man, above all other animals, the terms 'upper' and 'lower'
are used in harmony with their natural positions; for in him,
upper and lower have the same meaning as when they are
applied to the universe as a whole. In like manner the terms, 'in
front', 'behind', 'right' and 'left', are used in accordance with
their natural sense. But in regard to other animals, in some
cases these distinctions do not exist, and in others they do so,
but in a vague way. For instance, the head with all animals is up
and above in respect to their bodies; but man alone, as has been
said, has, in maturity, this part uppermost in respect to the
material universe.
Next after the head comes the neck, and then the chest and the
back: the one in front and the other behind. Next after these
come the belly, the loins, the sexual parts, and the haunches;
then the thigh and shin; and, lastly, the feet.
The legs bend frontwards, in the direction of actual progression,
and frontwards also lies that part of the foot which is the most
effective of motion, and the flexure of that part; but the heel lies
at the back, and the anklebones lie laterally, earwise. The arms
are situated to right and left, and bend inwards: so that the
convexities formed by bent arms and legs are practically face to
face with one another in the case of man.
As for the senses and for the organs of sensation, the eyes, the
nostrils, and the tongue, all alike are situated frontwards; the
1415
sense of hearing, and the organ of hearing, the ear, is situated
sideways, on the same horizontal plane with the eyes. The eyes
in man are, in proportion to his size, nearer to one another than
in any other animal.
Of the senses man has the sense of touch more refined than
any animal, and so also, but in less degree, the sense of taste; in
the development of the other senses he is surpassed by a great
number of animals.
16
The parts, then, that are externally visible are arranged in the
way above stated, and as a rule have their special designations,
and from use and wont are known familiarly to all; but this is
not the case with the inner parts. For the fact is that the inner
parts of man are to a very great extent unknown, and the
consequence is that we must have recourse to an examination
of the inner parts of other animals whose nature in any way
resembles that of man.
In the first place then, the brain lies in the front part of the
head. And this holds alike with all animals possessed of a brain;
and all blooded animals are possessed thereof, and, by the way,
molluscs as well. But, taking size for size of animal, the largest
brain, and the moistest, is that of man. Two membranes enclose
it: the stronger one near the bone of the skull; the inner one,
round the brain itself, is finer. The brain in all cases is bilateral.
Behind this, right at the back, comes what is termed the
'cerebellum', differing in form from the brain as we may both
feel and see.
1416
The back of the head is with all animals empty and hollow,
whatever be its size in the different animals. For some creatures
have big heads while the face below is small in proportion, as is
the case with round-faced animals; some have little heads and
long jaws, as is the case, without exception, among animals of
the mane-and-tail species.
The brain in all animals is bloodless, devoid of veins, and
naturally cold to the touch; in the great majority of animals it
has a small hollow in its centre. The brain-caul around it is
reticulated with veins; and this brain-caul is that skin-like
membrane which closely surrounds the brain. Above the brain
is the thinnest and weakest bone of the head, which is termed
or 'sinciput'.
From the eye there go three ducts to the brain: the largest and
the medium-sized to the cerebellum, the least to the brain
itself; and the least is the one situated nearest to the nostril.
The two largest ones, then, run side by side and do not meet;
the medium-sized ones meet - and this is particularly visible in
fishes, - for they lie nearer than the large ones to the brain; the
smallest pair are the most widely separate from one another,
and do not meet.
Inside the neck is what is termed the oesophagus (whose other
name is derived oesophagus from its length and narrowness),
and the windpipe. The windpipe is situated in front of the
oesophagus in all animals that have a windpipe, and all animals
have one that are furnished with lungs. The windpipe is made
up of gristle, is sparingly supplied with blood, and is streaked all
round with numerous minute veins; it is situated, in its upper
part, near the mouth, below the aperture formed by the nostrils
into the mouth - an aperture through which, when men, in
drinking, inhale any of the liquid, this liquid finds its way out
through the nostrils. In betwixt the two openings comes the so-
1417
called epiglottis, an organ capable of being drawn over and
covering the orifice of the windpipe communicating with the
mouth; the end of the tongue is attached to the epiglottis. In the
other direction the windpipe extends to the interval between
the lungs, and hereupon bifurcates into each of the two
divisions of the lung; for the lung in all animals possessed of
the organ has a tendency to be double. In viviparous animals,
however, the duplication is not so plainly discernible as in other
species, and the duplication is least discernible in man. And in
man the organ is not split into many parts, as is the case with
some vivipara, neither is it smooth, but its surface is uneven.
In the case of the ovipara, such as birds and oviparous
quadrupeds, the two parts of the organ are separated to a
distance from one another, so that the creatures appear to be
furnished with a pair of lungs; and from the windpipe, itself
single, there branch off two separate parts extending to each of
the two divisions of the lung. It is attached also to the great vein
and to what is designated the 'aorta'. When the windpipe is
charged with air, the air passes on to the hollow parts of the
lung. These parts have divisions, composed of gristle, which
meet at an acute angle; from the divisions run passages through
the entire lung, giving off smaller and smaller ramifications.
The heart also is attached to the windpipe, by connexions of fat,
gristle, and sinew; and at the point of juncture there is a hollow.
When the windpipe is charged with air, the entrance of the air
into the heart, though imperceptible in some animals, is
perceptible enough in the larger ones. Such are the properties of
the windpipe, and it takes in and throws out air only, and takes
in nothing else either dry or liquid, or else it causes you pain
until you shall have coughed up whatever may have gone down.
The oesophagus communicates at the top with the mouth, close
to the windpipe, and is attached to the backbone and the
windpipe by membranous ligaments, and at last finds its way
1418
through the midriff into the belly. It is composed of flesh-like
substance, and is elastic both lengthways and breadthways.
The stomach of man resembles that of a dog; for it is not much
bigger than the bowel, but is somewhat like a bowel of more
than usual width; then comes the bowel, single, convoluted,
moderately wide. The lower part of the gut is like that of a pig;
for it is broad, and the part from it to the buttocks is thick and
short. The caul, or great omentum, is attached to the middle of
the stomach, and consists of a fatty membrane, as is the case
with all other animals whose stomachs are single and which
have teeth in both jaws.
The mesentery is over the bowels; this also is membranous and
broad, and turns to fat. It is attached to the great vein and the
aorta, and there run through it a number of veins closely packed
together, extending towards the region of the bowels, beginning
above and ending below.
So much for the properties of the oesophagus, the windpipe,
and the stomach.
17
The heart has three cavities, and is situated above the lung at
the division of the windpipe, and is provided with a fatty and
thick membrane where it fastens on to the great vein and the
aorta. It lies with its tapering portion upon the aorta, and this
portion is similarly situated in relation to the chest in all
animals that have a chest. In all animals alike, in those that
have a chest and in those that have none, the apex of the heart
points forwards, although this fact might possibly escape notice
by a change of position under dissection. The rounded end of
1419
the heart is at the top. The apex is to a great extent fleshy and
close in texture, and in the cavities of the heart are sinews. As a
rule the heart is situated in the middle of the chest in animals
that have a chest, and in man it is situated a little to the left-
hand side, leaning a little way from the division of the breasts
towards the left breast in the upper part of the chest.
The heart is not large, and in its general shape it is not
elongated; in fact, it is somewhat round in form: only, be it
remembered, it is sharp-pointed at the bottom. It has three
cavities, as has been said: the right-hand one the largest of the
three, the left-hand one the least, and the middle one
intermediate in size. All these cavities, even the two small ones,
are connected by passages with the lung, and this fact is
rendered quite plain in one of the cavities. And below, at the
point of attachment, in the largest cavity there is a connexion
with the great vein (near which the mesentery lies); and in the
middle one there is a connexion with the aorta.
Canals lead from the heart into the lung, and branch off just as
the windpipe does, running all over the lung parallel with the
passages from the windpipe. The canals from the heart are
uppermost; and there is no common passage, but the passages
through their having a common wall receive the breath and
pass it on to the heart; and one of the passages conveys it to the
right cavity, and the other to the left.
With regard to the great vein and the aorta we shall, by and by,
treat of them together in a discussion devoted to them and to
them alone. In all animals that are furnished with a lung, and
that are both internally and externally viviparous, the lung is of
all organs the most richly supplied with blood; for the lung is
throughout spongy in texture, and along by every single pore in
it go branches from the great vein. Those who imagine it to be
empty are altogether mistaken; and they are led into their error
1420
by their observation of lungs removed from animals under
dissection, out of which organs the blood had all escaped
immediately after death.
Of the other internal organs the heart alone contains blood. And
the lung has blood not in itself but in its veins, but the heart has
blood in itself; for in each of its three cavities it has blood, but
the thinnest blood is what it has in its central cavity.
Under the lung comes the thoracic diaphragm or midriff,
attached to the ribs, the hypochondria and the backbone, with a
thin membrane in the middle of it. It has veins running through
it; and the diaphragm in the case of man is thicker in
proportion to the size of his frame than in other animals.
Under the diaphragm on the right-hand side lies the 'liver', and
on the left-hand side the 'spleen', alike in all animals that are
provided with these organs in an ordinary and not preternatural
way; for, be it observed, in some quadrupeds these organs have
been found in a transposed position. These organs are
connected with the stomach by the caul.
To outward view the spleen of man is narrow and long,
resembling the self-same organ in the pig. The liver in the great
majority of animals is not provided with a 'gall-bladder'; but the
latter is present in some. The liver of a man is round-shaped,
and resembles the same organ in the ox. And, by the way, the
absence above referred to of a gall-bladder is at times met with
in the practice of augury. For instance, in a certain district of the
Chalcidic settlement in Euboea the sheep are devoid of gall-
bladders; and in Naxos nearly all the quadrupeds have one so
large that foreigners when they offer sacrifice with such victims
are bewildered with fright, under the impression that the
phenomenon is not due to natural causes, but bodes some
mischief to the individual offerers of the sacrifice.
1421
Again, the liver is attached to the great vein, but it has no
communication with the aorta; for the vein that goes off from
the great vein goes right through the liver, at a point where are
the so-called 'portals' of the liver. The spleen also is connected
only with the great vein, for a vein extends to the spleen off
from it.
After these organs come the 'kidneys', and these are placed
close to the backbone, and resemble in character the same
organ in kine. In all animals that are provided with this organ,
the right kidney is situated higher up than the other. It has also
less fatty substance than the left-hand one and is less moist.
And this phenomenon also is observable in all the other
animals alike.
Furthermore, passages or ducts lead into the kidneys both from
the great vein and from the aorta, only not into the cavity. For,
by the way, there is a cavity in the middle of the kidney, bigger
in some creatures and less in others; but there is none in the
case of the seal. This latter animal has kidneys resembling in
shape the identical organ in kine, but in its case the organs are
more solid than in any other known creature. The ducts that
lead into the kidneys lose themselves in the substance of the
kidneys themselves; and the proof that they extend no farther
rests on the fact that they contain no blood, nor is any clot
found therein. The kidneys, however, have, as has been said, a
small cavity. From this cavity in the kidney there lead two
considerable ducts or ureters into the bladder; and others spring
from the aorta, strong and continuous. And to the middle of
each of the two kidneys is attached a hollow sinewy vein,
stretching right along the spine through the narrows; by and by
these veins are lost in either loin, and again become visible
extending to the flank. And these off-branchings of the veins
terminate in the bladder. For the bladder lies at the extremity,
and is held in position by the ducts stretching from the kidneys,
1422
along the stalk that extends to the urethra; and pretty well all
round it is fastened by fine sinewy membranes, that resemble to
some extent the thoracic diaphragm. The bladder in man is,
proportionately to his size, tolerably large.
To the stalk of the bladder the private part is attached, the
external orifices coalescing; but a little lower down, one of the
openings communicates with the testicles and the other with
the bladder. The penis is gristly and sinewy in its texture. With it
are connected the testicles in male animals, and the properties
of these organs we shall discuss in our general account of the
said organ.
All these organs are similar in the female; for there is no
difference in regard to the internal organs, except in respect to
the womb, and with reference to the appearance of this organ I
must refer the reader to diagrams in my 'Anatomy'. The womb,
however, is situated over the bowel, and the bladder lies over
the womb. But we must treat by and by in our pages of the
womb of all female animals viewed generally. For the wombs of
all female animals are not identical, neither do their local
dispositions coincide.
These are the organs, internal and external, of man, and such is
their nature and such their local disposition.
1423
Book II
With regard to animals in general, some parts or organs are
common to all, as has been said, and some are common only to
particular genera; the parts, moreover, are identical with or
different from one another on the lines already repeatedly laid
down. For as a general rule all animals that are generically
distinct have the majority of their parts or organs different in
form or species; and some of them they have only analogically
similar and diverse in kind or genus, while they have others
that are alike in kind but specifically diverse; and many parts or
organs exist in some animals, but not in others.
For instance, viviparous quadrupeds have all a head and a neck,
and all the parts or organs of the head, but they differ each from
other in the shapes of the parts. The lion has its neck composed
of one single bone instead of vertebrae; but, when dissected, the
animal is found in all internal characters to resemble the dog.
The quadrupedal vivipara instead of arms have forelegs. This is
true of all quadrupeds, but such of them as have toes have,
practically speaking, organs analogous to hands; at all events,
they use these fore-limbs for many purposes as hands. And they
have the limbs on the left-hand side less distinct from those on
the right than man.
The fore-limbs then serve more or less the purpose of hands in
quadrupeds, with the exception of the elephant. This latter
animal has its toes somewhat indistinctly defined, and its front
legs are much bigger than its hinder ones; it is five-toed, and
has short ankles to its hind feet. But it has a nose such in
1424
properties and such in size as to allow of its using the same for
a hand. For it eats and drinks by lifting up its food with the aid
of this organ into its mouth, and with the same organ it lifts up
articles to the driver on its back; with this organ it can pluck up
trees by the roots, and when walking through water it spouts
the water up by means of it; and this organ is capable of being
crooked or coiled at the tip, but not of flexing like a joint, for it is
composed of gristle.
Of all animals man alone can learn to make equal use of both
hands.
All animals have a part analogous to the chest in man, but not
similar to his; for the chest in man is broad, but that of all other
animals is narrow. Moreover, no other animal but man has
breasts in front; the elephant, certainly, has two breasts, not
however in the chest, but near it.
Moreover, also, animals have the flexions of their fore and hind
limbs in directions opposite to one another, and in directions
the reverse of those observed in the arms and legs of man; with
the exception of the elephant. In other words, with the
viviparous quadrupeds the front legs bend forwards and the
hind ones backwards, and the concavities of the two pairs of
limbs thus face one another.
The elephant does not sleep standing, as some were wont to
assert, but it bends its legs and settles down; only that in
consequence of its weight it cannot bend its leg on both sides
simultaneously, but falls into a recumbent position on one side
or the other, and in this position it goes to sleep. And it bends
its hind legs just as a man bends his legs.
In the case of the ovipara, as the crocodile and the lizard and
the like, both pairs of legs, fore and hind, bend forwards, with a
slight swerve on one side. The flexion is similar in the case of
1425
the multipeds; only that the legs in between the extreme ends
always move in a manner intermediate between that of those in
front and those behind, and accordingly bend sideways rather
than backwards or forwards. But man bends his arms and his
legs towards the same point, and therefore in opposite ways:
that is to say, he bends his arms backwards, with just a slight
inclination inwards, and his legs frontwards. No animal bends
both its fore-limbs and hind-limbs backwards; but in the case of
all animals the flexion of the shoulders is in the opposite
direction to that of the elbows or the joints of the forelegs, and
the flexure in the hips to that of the knees of the hind-legs: so
that since man differs from other animals in flexion, those
animals that possess such parts as these move them
contrariwise to man.
Birds have the flexions of their limbs like those of the
quadrupeds; for, although bipeds, they bend their legs
backwards, and instead of arms or front legs have wings which
bend frontwards.
The seal is a kind of imperfect or crippled quadruped; for just
behind the shoulder-blade its front feet are placed, resembling
hands, like the front paws of the bear; for they are furnished
with five toes, and each of the toes has three flexions and a nail
of inconsiderable size. The hind feet are also furnished with five
toes; in their flexions and nails they resemble the front feet, and
in shape they resemble a fish's tail.
The movements of animals, quadruped and multiped, are
crosswise, or in diagonals, and their equilibrium in standing
posture is maintained crosswise; and it is always the limb on
the right-hand side that is the first to move. The lion, however,
and the two species of camels, both the Bactrian and the
Arabian, progress by an amble; and the action so called is when
1426
the animal never overpasses the right with the left, but always
follows close upon it.
Whatever parts men have in front, these parts quadrupeds have
below, in or on the belly; and whatever parts men have behind,
these parts quadrupeds have above on their backs. Most
quadrupeds have a tail; for even the seal has a tiny one
resembling that of the stag. Regarding the tails of the pithecoids
we must give their distinctive properties by and by animal
All viviparous quadrupeds are hair-coated, whereas man has
only a few short hairs excepting on the head, but, so far as the
head is concerned, he is hairier than any other animal. Further,
of hair-coated animals, the back is hairier than the belly, which
latter is either comparatively void of hair or smooth and void of
hair altogether. With man the reverse is the case.
Man also has upper and lower eyelashes, and hair under the
armpits and on the pubes. No other animal has hair in either of
these localities, or has an under eyelash; though in the case of
some animals a few straggling hairs grow under the eyelid.
Of hair-coated quadrupeds some are hairy all over the body, as
the pig, the bear, and the dog; others are especially hairy on the
neck and all round about it, as is the case with animals that
have a shaggy mane, such as the lion; others again are
especially hairy on the upper surface of the neck from the head
as far as the withers, namely, such as have a crested mane, as in
the case with the horse, the mule, and, among the
undomesticated horned animals, the bison.
The so-called hippelaphus also has a mane on its withers, and
the animal called pardion, in either case a thin mane extending
from the head to the withers; the hippelaphus has,
exceptionally, a beard by the larynx. Both these animals have
horns and are cloven-footed; the female, however, of the
1427
hippelaphus has no horns. This latter animal resembles the stag
in size; it is found in the territory of the Arachotae, where the
wild cattle also are found. Wild cattle differ from their
domesticated congeners just as the wild boar differs from the
domesticated one. That is to say they are black, strong looking,
with a hook-nosed muzzle, and with horns lying more over the
back. The horns of the hippelaphus resemble those of the
gazelle.
The elephant, by the way, is the least hairy of all quadrupeds.
With animals, as a general rule, the tail corresponds with the
body as regards thickness or thinness of hair-coating; that is,
with animals that have long tails, for some creatures have tails
of altogether insignificant size.
Camels have an exceptional organ wherein they differ from all
other animals, and that is the so-called 'hump' on their back.
The Bactrian camel differs from the Arabian; for the former has
two humps and the latter only one, though it has, by the way, a
kind of a hump below like the one above, on which, when it
kneels, the weight of the whole body rests. The camel has four
teats like the cow, a tail like that of an ass, and the privy parts of
the male are directed backwards. It has one knee in each leg,
and the flexures of the limb are not manifold, as some say,
although they appear to be so from the constricted shape of the
region of the belly. It has a huckle-bone like that of kine, but
meagre and small in proportion to its bulk. It is cloven-footed,
and has not got teeth in both jaws; and it is cloven footed in the
following way: at the back there is a slight cleft extending as far
up as the second joint of the toes; and in front there are small
hooves on the tip of the first joint of the toes; and a sort of web
passes across the cleft, as in geese. The foot is fleshy
underneath, like that of the bear; so that, when the animal goes
to war, they protect its feet, when they get sore, with sandals.
1428
The legs of all quadrupeds are bony, sinewy, and fleshless; and
in point of fact such is the case with all animals that are
furnished with feet, with the exception of man. They are also
unfurnished with buttocks; and this last point is plain in an
especial degree in birds. It is the reverse with man; for there is
scarcely any part of the body in which man is so fleshy as in the
buttock, the thigh, and the calf; for the part of the leg called
gastroenemia or is fleshy.
Of blooded and viviparous quadrupeds some have the foot
cloven into many parts, as is the case with the hands and feet of
man (for some animals, by the way, are many-toed, as the lion,
the dog, and the pard); others have feet cloven in twain, and
instead of nails have hooves, as the sheep, the goat, the deer,
and the hippopotamus; others are uncloven of foot, such for
instance as the solid-hooved animals, the horse and the mule.
Swine are either cloven-footed or uncloven-footed; for there are
in Illyria and in Paeonia and elsewhere solid-hooved swine. The
cloven-footed animals have two clefts behind; in the solid-
hooved this part is continuous and undivided.
Furthermore, of animals some are horned, and some are not so.
The great majority of the horned animals are cloven-footed, as
the ox, the stag, the goat; and a solid-hooved animal with a pair
of horns has never yet been met with. But a few animals are
known to be singled-horned and single-hooved, as the Indian
ass; and one, to wit the oryx, is single horned and cloven-
hooved.
Of all solid-hooved animals the Indian ass alone has an
astragalus or huckle-bone; for the pig, as was said above, is
either solid-hooved or cloven-footed, and consequently has no
well-formed huckle-bone. Of the cloven footed many are
provided with a huckle-bone. Of the many-fingered or many-
toed, no single one has been observed to have a huckle-bone,
1429
none of the others any more than man. The lynx, however, has
something like a hemiastragal, and the lion something
resembling the sculptor's 'labyrinth'. All the animals that have a
huckle-bone have it in the hinder legs. They have also the bone
placed straight up in the joint; the upper part, outside; the lower
part, inside; the sides called Coa turned towards one another,
the sides called Chia outside, and the keraiae or 'horns' on the
top. This, then, is the position of the hucklebone in the case of
all animals provided with the part.
Some animals are, at one and the same time, furnished with a
mane and furnished also with a pair of horns bent in towards
one another, as is the bison (or aurochs), which is found in
Paeonia and Maedica. But all animals that are horned are
quadrupedal, except in cases where a creature is said
metaphorically, or by a figure of speech, to have horns; just as
the Egyptians describe the serpents found in the neighbourhood
of Thebes, while in point of fact the creatures have merely
protuberances on the head sufficiently large to suggest such an
epithet.
Of horned animals the deer alone has a horn, or antler, hard
and solid throughout. The horns of other animals are hollow for
a certain distance, and solid towards the extremity. The hollow
part is derived from the skin, but the core round which this is
wrapped - the hard part - is derived from the bones; as is the
case with the horns of oxen. The deer is the only animal that
sheds its horns, and it does so annually, after reaching the age
of two years, and again renews them. All other animals retain
their horns permanently, unless the horns be damaged by
accident.
Again, with regard to the breasts and the generative organs,
animals differ widely from one another and from man. For
instance, the breasts of some animals are situated in front,
1430
either in the chest or near to it, and there are in such cases two
breasts and two teats, as is the case with man and the elephant,
as previously stated. For the elephant has two breasts in the
region of the axillae; and the female elephant has two breasts
insignificant in size and in no way proportionate to the bulk of
the entire frame, in fact, so insignificant as to be invisible in a
sideways view; the males also have breasts, like the females,
exceedingly small. The she-bear has four breasts. Some animals
have two breasts, but situated near the thighs, and teats,
likewise two in number, as the sheep; others have four teats, as
the cow. Some have breasts neither in the chest nor at the
thighs, but in the belly, as the dog and pig; and they have a
considerable number of breasts or dugs, but not all of equal size.
Thus the shepard has four dugs in the belly, the lioness two, and
others more. The she-camel, also, has two dugs and four teats,
like the cow. Of solid-hooved animals the males have no dugs,
excepting in the case of males that take after the mother, which
phenomenon is observable in horses.
Of male animals the genitals of some are external, as is the case
with man, the horse, and most other creatures; some are
internal, as with the dolphin. With those that have the organ
externally placed, the organ in some cases is situated in front,
as in the cases already mentioned, and of these some have the
organ detached, both penis and testicles, as man; others have
penis and testicles closely attached to the belly, some more
closely, some less; for this organ is not detached in the wild
boar nor in the horse.
The penis of the elephant resembles that of the horse;
compared with the size of the animal it is disproportionately
small; the testicles are not visible, but are concealed inside in
the vicinity of the kidneys; and for this reason the male speedily
gives over in the act of intercourse. The genitals of the female
are situated where the udder is in sheep; when she is in heat,
1431
she draws the organ back and exposes it externally, to facilitate
the act of intercourse for the male; and the organ opens out to a
considerable extent.
With most animals the genitals have the position above
assigned; but some animals discharge their urine backwards, as
the lynx, the lion, the camel, and the hare. Male animals differ
from one another, as has been said, in this particular, but all
female animals are retromingent: even the female elephant like
other animals, though she has the privy part below the thighs.
In the male organ itself there is a great diversity. For in some
cases the organ is composed of flesh and gristle, as in man; in
such cases, the fleshy part does not become inflated, but the
gristly part is subject to enlargement. In other cases, the organ
is composed of fibrous tissue, as with the camel and the deer; in
other cases it is bony, as with the fox, the wolf, the marten, and
the weasel; for this organ in the weasel has a bone.
When man has arrived at maturity, his upper part is smaller
than the lower one, but with all other blooded animals the
reverse holds good. By the 'upper' part we mean all extending
from the head down to the parts used for excretion of residuum,
and by the 'lower' part else. With animals that have feet the
hind legs are to be rated as the lower part in our comparison of
magnitudes, and with animals devoid of feet, the tail, and the
like.
When animals arrive at maturity, their properties are as above
stated; but they differ greatly from one another in their growth
towards maturity. For instance, man, when young, has his upper
part larger than the lower, but in course of growth he comes to
reverse this condition; and it is owing to this circumstance that
- an exceptional instance, by the way - he does not progress in
early life as he does at maturity, but in infancy creeps on all
fours; but some animals, in growth, retain the relative
1432
proportion of the parts, as the dog. Some animals at first have
the upper part smaller and the lower part larger, and in course
of growth the upper part gets to be the larger, as is the case with
the bushy-tailed animals such as the horse; for in their case
there is never, subsequently to birth, any increase in the part
extending from the hoof to the haunch.
Again, in respect to the teeth, animals differ greatly both from
one another and from man. All animals that are quadrupedal,
blooded and viviparous, are furnished with teeth; but, to begin
with, some are double-toothed (or fully furnished with teeth in
both jaws), and some are not. For instance, horned quadrupeds
are not double-toothed; for they have not got the front teeth in
the upper jaw; and some hornless animals, also, are not double
toothed, as the camel. Some animals have tusks, like the boar,
and some have not. Further, some animals are saw-toothed,
such as the lion, the pard, and the dog; and some have teeth
that do not interlock but have flat opposing crowns, as the
horse and the ox; and by 'saw-toothed' we mean such animals
as interlock the sharp-pointed teeth in one jaw between the
sharp-pointed ones in the other. No animal is there that
possesses both tusks and horns, nor yet do either of these
structures exist in any animal possessed of 'saw-teeth'. The
front teeth are usually sharp, and the back ones blunt. The seal
is saw-toothed throughout, inasmuch as he is a sort of link with
the class of fishes; for fishes are almost all saw-toothed.
No animal of these genera is provided with double rows of
teeth. There is, however, an animal of the sort, if we are to
believe Ctesias. He assures us that the Indian wild beast called
the 'martichoras' has a triple row of teeth in both upper and
lower jaw; that it is as big as a lion and equally hairy, and that
its feet resemble those of the lion; that it resembles man in its
face and ears; that its eyes are blue, and its colour vermilion;
that its tail is like that of the land-scorpion; that it has a sting in
1433
the tail, and has the faculty of shooting off arrow-wise the
spines that are attached to the tail; that the sound of its voice is
a something between the sound of a pan-pipe and that of a
trumpet; that it can run as swiftly as deer, and that it is savage
and a man-eater.
Man sheds his teeth, and so do other animals, as the horse, the
mule, and the ass. And man sheds his front teeth; but there is
no instance of an animal that sheds its molars. The pig sheds
none of its teeth at all.
With regard to dogs some doubts are entertained, as some
contend that they shed no teeth whatever, and others that they
shed the canines, but those alone; the fact being, that they do
shed their teeth like man, but that the circumstance escapes
observation, owing to the fact that they never shed them until
equivalent teeth have grown within the gums to take the place
of the shed ones. We shall be justified in supposing that the
case is similar with wild beasts in general; for they are said to
shed their canines only. Dogs can be distinguished from one
another, the young from the old, by their teeth; for the teeth in
young dogs are white and sharp-pointed; in old dogs, black and
blunt.
1434
In this particular, the horse differs entirely from animals in
general: for, generally speaking, as animals grow older their
teeth get blacker, but the horse's teeth grow whiter with age.
The so-called 'canines' come in between the sharp teeth and
the broad or blunt ones, partaking of the form of both kinds; for
they are broad at the base and sharp at the tip.
Males have more teeth than females in the case of men, sheep,
goats, and swine; in the case of other animals observations have
not yet been made: but the more teeth they have the more long-
lived are they, as a rule, while those are short-lived in
proportion that have teeth fewer in number and thinly set.
The last teeth to come in man are molars called 'wisdom-teeth',
which come at the age of twenty years, in the case of both
sexes. Cases have been known in women upwards, of eighty
years old where at the very close of life the wisdom-teeth have
come up, causing great pain in their coming; and cases have
been known of the like phenomenon in men too. This happens,
when it does happen, in the case of people where the wisdom-
teeth have not come up in early years.
1435
The elephant has four teeth on either side, by which it munches
its food, grinding it like so much barley-meal, and, quite apart
from these, it has its great teeth, or tusks, two in number. In the
male these tusks are comparatively large and curved upwards;
in the female, they are comparatively small and point in the
opposite direction; that is, they look downwards towards the
ground. The elephant is furnished with teeth at birth, but the
tusks are not then visible.
The tongue of the elephant is exceedingly small, and situated
far back in the mouth, so that it is difficult to get a sight of it.
Furthermore, animals differ from one another in the relative
size of their mouths. In some animals the mouth opens wide, as
is the case with the dog, the lion, and with all the saw-toothed
animals; other animals have small mouths, as man; and others
have mouths of medium capacity, as the pig and his congeners.
(The Egyptian hippopotamus has a mane like a horse, is cloven-
footed like an ox, and is snub-nosed. It has a huckle-bone like
cloven-footed animals, and tusks just visible; it has the tail of a
pig, the neigh of a horse, and the dimensions of an ass. The hide
is so thick that spears are made out of it. In its internal organs it
resembles the horse and the ass.)
1436
8
Some animals share the properties of man and the quadrupeds,
as the ape, the monkey, and the baboon. The monkey is a tailed
ape. The baboon resembles the ape in form, only that it is bigger
and stronger, more like a dog in face, and is more savage in its
habits, and its teeth are more dog-like and more powerful.
Apes are hairy on the back in keeping with their quadrupedal
nature, and hairy on the belly in keeping with their human form
- for, as was said above, this characteristic is reversed in man
and the quadruped - only that the hair is coarse, so that the ape
is thickly coated both on the belly and on the back. Its face
resembles that of man in many respects; in other words, it has
similar nostrils and ears, and teeth like those of man, both front
teeth and molars. Further, whereas quadrupeds in general are
not furnished with lashes on one of the two eyelids, this
creature has them on both, only very thinly set, especially the
under ones; in fact they are very insignificant indeed. And we
must bear in mind that all other quadrupeds have no under
eyelash at all.
The ape has also in its chest two teats upon poorly developed
breasts. It has also arms like man, only covered with hair, and it
bends these legs like man, with the convexities of both limbs
facing one another. In addition, it has hands and fingers and
nails like man, only that all these parts are somewhat more
beast-like in appearance. Its feet are exceptional in kind. That is,
they are like large hands, and the toes are like fingers, with the
middle one the longest of all, and the under part of the foot is
like a hand except for its length, and stretches out towards the
extremities like the palm of the hand; and this palm at the after
1437
end is unusually hard, and in a clumsy obscure kind of way
resembles a heel. The creature uses its feet either as hands or
feet, and doubles them up as one doubles a fist. Its upper-arm
and thigh are short in proportion to the forearm and the shin. It
has no projecting navel, but only a hardness in the ordinary
locality of the navel. Its upper part is much larger than its lower
part, as is the case with quadrupeds; in fact, the proportion of
the former to the latter is about as five to three. Owing to this
circumstance and to the fact that its feet resemble hands and
are composed in a manner of hand and of foot: of foot in the
heel extremity, of the hand in all else - for even the toes have
what is called a 'palm': - for these reasons the animal is oftener
to be found on all fours than upright. It has neither hips,
inasmuch as it is a quadruped, nor yet a tail, inasmuch as it is a
biped, except nor yet a tal by the way that it has a tail as small
as small can be, just a sort of indication of a tail. The genitals of
the female resemble those of the female in the human species;
those of the male are more like those of a dog than are those of
a man.
The monkey, as has been observed, is furnished with a tail. In
all such creatures the internal organs are found under
dissection to correspond to those of man.
So much then for the properties of the organs of such animals
as bring forth their young into the world alive.
1438
10
Oviparous and blooded quadrupeds - and, by the way, no
terrestrial blooded animal is oviparous unless it is quadrupedal
or is devoid of feet altogether - are furnished with a head, a
neck, a back, upper and under parts, the front legs and hind
legs, and the part analogous to the chest, all as in the case of
viviparous quadrupeds, and with a tail, usually large, in
exceptional cases small. And all these creatures are many-toed,
and the several toes are cloven apart. Furthermore, they all have
the ordinary organs of sensation, including a tongue, with the
exception of the Egyptian crocodile.
This latter animal, by the way, resembles certain fishes. For, as a
general rule, fishes have a prickly tongue, not free in its
movements; though there are some fishes that present a
smooth undifferentiated surface where the tongue should be,
until you open their mouths wide and make a close inspection.
Again, oviparous blooded quadrupeds are unprovided with ears,
but possess only the passage for hearing; neither have they
breasts, nor a copulatory organ, nor external testicles, but
internal ones only; neither are they hair coated, but are in all
cases covered with scaly plates. Moreover, they are without
exception saw-toothed.
River crocodiles have pigs' eyes, large teeth and tusks, and
strong nails, and an impenetrable skin composed of scaly
plates. They see but poorly under water, but above the surface of
it with remarkable acuteness. As a rule, they pass the day-time
on land and the nighttime in the water; for the temperature of
the water is at night-time more genial than that of the open air.
1439
11
The chameleon resembles the lizard in the general
configuration of its body, but the ribs stretch downwards and
meet together under the belly as is the case with fishes, and the
spine sticks up as with the fish. Its face resembles that of the
baboon. Its tail is exceedingly long, terminates in a sharp point,
and is for the most part coiled up, like a strap of leather. It
stands higher off the ground than the lizard, but the flexure of
the legs is the same in both creatures. Each of its feet is divided
into two parts, which bear the same relation to one another that
the thumb and the rest of the hand bear to one another in man.
Each of these parts is for a short distance divided after a fashion
into toes; on the front feet the inside part is divided into three
and the outside into two, on the hind feet the inside part into
two and the outside into three; it has claws also on these parts
resembling those of birds of prey. Its body is rough all over, like
that of the crocodile. Its eyes are situated in a hollow recess, and
are very large and round, and are enveloped in a skin
resembling that which covers the entire body; and in the middle
a slight aperture is left for vision, through which the animal
sees, for it never covers up this aperture with the cutaneous
envelope. It keeps twisting its eyes round and shifting its line of
vision in every direction, and thus contrives to get a sight of any
object that it wants to see. The change in its colour takes place
when it is inflated with air; it is then black, not unlike the
crocodile, or green like the lizard but black-spotted like the pard.
This change of colour takes place over the whole body alike, for
the eyes and the tail come alike under its influence. In its
movements it is very sluggish, like the tortoise. It assumes a
greenish hue in dying, and retains this hue after death. It
resembles the lizard in the position of the oesophagus and the
windpipe. It has no flesh anywhere except a few scraps of flesh
on the head and on the jaws and near to the root of the tail. It
has blood only round about the heart, the eyes, the region above
1440
the heart, and in all the veins extending from these parts; and
in all these there is but little blood after all. The brain is situated
a little above the eyes, but connected with them. When the
outer skin is drawn aside from off the eye, a something is found
surrounding the eye, that gleams through like a thin ring of
copper. Membranes extend well nigh over its entire frame,
numerous and strong, and surpassing in respect of number and
relative strength those found in any other animal. After being
cut open along its entire length it continues to breathe for a
considerable time; a very slight motion goes on in the region of
the heart, and, while contraction is especially manifested in the
neighbourhood of the ribs, a similar motion is more or less
discernible over the whole body. It has no spleen visible. It
hibernates, like the lizard.
12
Birds also in some parts resemble the above mentioned
animals; that is to say, they have in all cases a head, a neck, a
back, a belly, and what is analogous to the chest. The bird is
remarkable among animals as having two feet, like man; only,
by the way, it bends them backwards as quadrupeds bend their
hind legs, as was noticed previously. It has neither hands nor
front feet, but wings - an exceptional structure as compared
with other animals. Its haunch-bone is long, like a thigh, and is
attached to the body as far as the middle of the belly; so like to
a thigh is it that when viewed separately it looks like a real one,
while the real thigh is a separate structure betwixt it and the
shin. Of all birds those that have crooked talons have the
biggest thighs and the strongest breasts. All birds are furnished
with many claws, and all have the toes separated more or less
asunder; that is to say, in the greater part the toes are clearly
1441
distinct from one another, for even the swimming birds,
although they are web-footed, have still their claws fully
articulated and distinctly differentiated from one another. Birds
that fly high in air are in all cases four-toed: that is, the greater
part have three toes in front and one behind in place of a heel;
some few have two in front and two behind, as the wryneck.
This latter bird is somewhat bigger than the chaffinch, and is
mottled in appearance. It is peculiar in the arrangement of its
toes, and resembles the snake in the structure of its tongue; for
the creature can protrude its tongue to the extent of four finger-
breadths, and then draw it back again. Moreover, it can twist its
head backwards while keeping all the rest of its body still, like
the serpent. It has big claws, somewhat resembling those of the
woodpecker. Its note is a shrill chirp.
Birds are furnished with a mouth, but with an exceptional one,
for they have neither lips nor teeth, but a beak. Neither have
they ears nor a nose, but only passages for the sensations
connected with these organs: that for the nostrils in the beak,
and that for hearing in the head. Like all other animals they all
have two eyes, and these are devoid of lashes. The heavy-bodied
(or gallinaceous) birds close the eye by means of the lower lid,
and all birds blink by means of a skin extending over the eye
from the inner corner; the owl and its congeners also close the
eye by means of the upper lid. The same phenomenon is
observable in the animals that are protected by horny scutes, as
in the lizard and its congeners; for they all without exception
close the eye with the lower lid, but they do not blink like birds.
Further, birds have neither scutes nor hair, but feathers; and the
feathers are invariably furnished with quills. They have no tail,
but a rump with tail-feathers, short in such as are long-legged
and web-footed, large in others. These latter kinds of birds fly
with their feet tucked up close to the belly; but the small
rumped or short-tailed birds fly with their legs stretched out at
1442
full length. All are furnished with a tongue, but the organ is
variable, being long in some birds and broad in others. Certain
species of birds above all other animals, and next after man,
possess the faculty of uttering articulate sounds; and this
faculty is chiefly developed in broad-tongued birds. No
oviparous creature has an epiglottis over the windpipe, but
these animals so manage the opening and shutting of the
windpipe as not to allow any solid substance to get down into
the lung.
Some species of birds are furnished additionally with spurs, but
no bird with crooked talons is found so provided. The birds with
talons are among those that fly well, but those that have spurs
are among the heavy-bodied.
Again, some birds have a crest. As a general rule the crest sticks
up, and is composed of feathers only; but the crest of the barn-
door cock is exceptional in kind, for, whereas it is not just
exactly flesh, at the same time it is not easy to say what else it
is.
13
Of water animals the genus of fishes constitutes a single group
apart from the rest, and including many diverse forms.
In the first place, the fish has a head, a back, a belly, in the
neighbourhood of which last are placed the stomach and
viscera; and behind it has a tail of continuous, undivided shape,
but not, by the way, in all cases alike. No fish has a neck, or any
limb, or testicles at all, within or without, or breasts. But, by the
way this absence of breasts may predicated of all non-
viviparous animals; and in point of fact viviparous animals are
1443
not in all cases provided with the organ, excepting such as are
directly viviparous without being first oviparous. Thus the
dolphin is directly viviparous, and accordingly we find it
furnished with two breasts, not situated high up, but in the
neighbourhood of the genitals. And this creature is not
provided, like quadrupeds, with visible teats, but has two vents,
one on each flank, from which the milk flows; and its young
have to follow after it to get suckled, and this phenomenon has
been actually witnessed.
Fishes, then, as has been observed, have no breasts and no
passage for the genitals visible externally. But they have an
exceptional organ in the gills, whereby, after taking the water in
the mouth, they discharge it again; and in the fins, of which the
greater part have four, and the lanky ones two, as, for instance,
the eel, and these two situated near to the gills. In like manner
the grey mullet - as, for instance, the mullet found in the lake at
Siphae - have only two fins; and the same is the case with the
fish called Ribbon-fish. Some of the lanky fishes have no fins at
all, such as the muraena, nor gills articulated like those of other
fish.
And of those fish that are provided with gills, some have
coverings for this organ, whereas all the selachians have the
organ unprotected by a cover. And those fishes that have
coverings or opercula for the gills have in all cases their gills
placed sideways; whereas, among selachians, the broad ones
have the gills down below on the belly, as the torpedo and the
ray, while the lanky ones have the organ placed sideways, as is
the case in all the dog-fish.
The fishing-frog has gills placed sideways, and covered not with
a spiny operculum, as in all but the selachian fishes, but with
one of skin.
1444
Morever, with fishes furnished with gills, the gills in some cases
are simple in others duplicate; and the last gill in the direction
of the body is always simple. And, again, some fishes have few
gills, and others have a great number; but all alike have the
same number on both sides. Those that have the least number
have one gill on either side, and this one duplicate, like the
boar-fish; others have two on either side, one simple and the
other duplicate, like the conger and the scarus; others have four
on either side, simple, as the elops, the synagris, the muraena,
and the eel; others have four, all, with the exception of the
hindmost one, in double rows, as the wrasse, the perch, the
sheat-fish, and the carp. The dog-fish have all their gills double,
five on a side; and the sword-fish has eight double gills. So
much for the number of gills as found in fishes.
Again, fishes differ from other animals in more ways than as
regards the gills. For they are not covered with hairs as are
viviparous land animals, nor, as is the case with certain
oviparous quadrupeds, with tessellated scutes, nor, like birds,
with feathers; but for the most part they are covered with
scales. Some few are rough-skinned, while the smooth-skinned
are very few indeed. Of the Selachia some are rough-skinned
and some smooth-skinned; and among the smooth-skinned
fishes are included the conger, the eel, and the tunny.
All fishes are saw-toothed excepting the scarus; and the teeth
in all cases are sharp and set in many rows, and in some cases
are placed on the tongue. The tongue is hard and spiny, and so
firmly attached that fishes in many instances seem to be devoid
of the organ altogether. The mouth in some cases is wide-
stretched, as it is with some viviparous quadrupeds....
With regard to organs of sense, all save eyes, fishes possess
none of them, neither the organs nor their passages, neither
ears nor nostrils; but all fishes are furnished with eyes, and the
1445
eyes devoid of lids, though the eyes are not hard; with regard to
the organs connected with the other senses, hearing and smell,
they are devoid alike of the organs themselves and of passages
indicative of them.
Fishes without exception are supplied with blood. Some of them
are oviparous, and some viviparous; scaly fish are invariably
oviparous, but cartilaginous fishes are all viviparous, with the
single exception of the fishing- frog.
14
Of blooded animals there now remains the serpent genus. This
genus is common to both elements, for, while most species
comprehended therein are land animals, a small minority, to
wit the aquatic species, pass their lives in fresh water. There are
also sea-serpents, in shape to a great extent resembling their
congeners of the land, with this exception that the head in their
case is somewhat like the head of the conger; and there are
several kinds of sea-serpent, and the different kinds differ in
colour; these animals are not found in very deep water.
Serpents, like fish, are devoid of feet.
There are also sea-scolopendras, resembling in shape their land
congeners, but somewhat less in regard to magnitude. These
creatures are found in the neighbourhood of rocks; as compared
with their land congeners they are redder in colour, are
furnished with feet in greater numbers and with legs of more
delicate structure. And the same remark applies to them as to
the sea-serpents, that they are not found in very deep water.
Of fishes whose habitat is in the vicinity of rocks there is a tiny
one, which some call the Echeneis, or 'ship-holder', and which
1446
is by some people used as a charm to bring luck in affairs of law
and love. The creature is unfit for eating. Some people assert
that it has feet, but this is not the case: it appears, however, to
be furnished with feet from the fact that its fins resemble those
organs.
So much, then, for the external parts of blooded animals, as
regards their numbers, their properties, and their relative
diversities.
15
As for the properties of the internal organs, these we must first
discuss in the case of the animals that are supplied with blood.
For the principal genera differ from the rest of animals, in that
the former are supplied with blood and the latter are not; and
the former include man, viviparous and oviparous quadrupeds,
birds, fishes, cetaceans, and all the others that come under no
general designation by reason of their not forming genera, but
groups of which simply the specific name is predicable, as when
we say 'the serpent,' the 'crocodile'.
All viviparous quadrupeds, then, are furnished with an
oesophagus and a windpipe, situated as in man; the same
statement is applicable to oviparous quadrupeds and to birds,
only that the latter present diversities in the shapes of these
organs. As a general rule, all animals that take up air and
breathe it in and out are furnished with a lung, a windpipe, and
an oesophagus, with the windpipe and oesophagus not
admitting of diversity in situation but admitting of diversity in
properties, and with the lung admitting of diversity in both
these respects. Further, all blooded animals have a heart and a
diaphragm or midriff; but in small animals the existence of the
1447
latter organ is not so obvious owing to its delicacy and minute
size.
In regard to the heart there is an exceptional phenomenon
observable in oxen. In other words, there is one species of ox
where, though not in all cases, a bone is found inside the heart.
And, by the way, the horse's heart also has a bone inside it.
The genera referred to above are not in all cases furnished with
a lung: for instance, the fish is devoid of the organ, as is also
every animal furnished with gills. All blooded animals are
furnished with a liver. As a general rule blooded animals are
furnished with a spleen; but with the great majority of non-
viviparous but oviparous animals the spleen is so small as all
but to escape observation; and this is the case with almost all
birds, as with the pigeon, the kite, the falcon, the owl: in point of
fact, the aegocephalus is devoid of the organ altogether. With
oviparous quadrupeds the case is much the same as with the
viviparous; that is to say, they also have the spleen exceedingly
minute, as the tortoise, the freshwater tortoise, the toad, the
lizard, the crocodile, and the frog.
Some animals have a gall-bladder close to the liver, and others
have not. Of viviparous quadrupeds the deer is without the
organ, as also the roe, the horse, the mule, the ass, the seal, and
some kinds of pigs. Of deer those that are called Achainae
appear to have gall in their tail, but what is so called does
resemble gall in colour, though it is not so completely fluid, and
the organ internally resembles a spleen.
However, without any exception, stags are found to have
maggots living inside the head, and the habitat of these
creatures is in the hollow underneath the root of the tongue
and in the neighbourhood of the vertebra to which the head is
attached. These creatures are as large as the largest grubs; they
1448
grow all together in a cluster, and they are usually about twenty
in number.
Deer then, as has been observed, are without a gall-bladder;
their gut, however, is so bitter that even hounds refuse to eat it
unless the animal is exceptionally fat. With the elephant also
the liver is unfurnished with a gall-bladder, but when the
animal is cut in the region where the organ is found in animals
furnished with it, there oozes out a fluid resembling gall, in
greater or less quantities. Of animals that take in sea-water and
are furnished with a lung, the dolphin is unprovided with a gall-
bladder. Birds and fishes all have the organ, as also oviparous
quadrupeds, all to a greater or a lesser extent. But of fishes
some have the organ close to the liver, as the dogfishes, the
sheat-fish, the rhine or angel-fish, the smooth skate, the
torpedo, and, of the lanky fishes, the eel, the pipe-fish, and the
hammer-headed shark. The callionymus, also, has the gall-
bladder close to the liver, and in no other fish does the organ
attain so great a relative size. Other fishes have the organ close
to the gut, attached to the liver by certain extremely fine ducts.
The bonito has the gall-bladder stretched alongside the gut and
equalling it in length, and often a double fold of it. others have
the organ in the region of the gut; in some cases far off, in
others near; as the fishing-frog, the elops, the synagris, the
muraena, and the sword-fish. Often animals of the same species
show this diversity of position; as, for instance, some congers
are found with the organ attached close to the liver, and others
with it detached from and below it. The case is much the same
with birds: that is, some have the gall-bladder close to the
stomach, and others close to the gut, as the pigeon, the raven,
the quail, the swallow, and the sparrow; some have it near at
once to the liver and to the stomach as the aegocephalus;
others have it near at once to the liver and the gut, as the falcon
and the kite.
1449
16
Again, all viviparous quadrupeds are furnished with kidneys
and a bladder. Of the ovipara that are not quadrupedal there is
no instance known of an animal, whether fish or bird, provided
with these organs. Of the ovipara that are quadrupedal, the
turtle alone is provided with these organs of a magnitude to
correspond with the other organs of the animal. In the turtle
the kidney resembles the same organ in the ox; that is to say, it
looks one single organ composed of a number of small ones.
(The bison also resembles the ox in all its internal parts).
17
With all animals that are furnished with these parts, the parts
are similarly situated, and with the exception of man, the heart
is in the middle; in man, however, as has been observed, the
heart is placed a little to the left-hand side. In all animals the
pointed end of the heart turns frontwards; only in fish it would
at first sight seem otherwise, for the pointed end is turned not
towards the breast, but towards the head and the mouth. And
(in fish) the apex is attached to a tube just where the right and
left gills meet together. There are other ducts extending from
the heart to each of the gills, greater in the greater fish, lesser in
the lesser; but in the large fishes the duct at the pointed end of
the heart is a tube, white-coloured and exceedingly thick. Fishes
in some few cases have an oesophagus, as the conger and the
eel; and in these the organ is small.
1450
In fishes that are furnished with an undivided liver, the organ
lies entirely on the right side; where the liver is cloven from the
root, the larger half of the organ is on the right side: for in some
fishes the two parts are detached from one another, without
any coalescence at the root, as is the case with the dogfish. And
there is also a species of hare in what is named the Fig district,
near Lake Bolbe, and elsewhere, which animal might be taken to
have two livers owing to the length of the connecting ducts,
similar to the structure in the lung of birds.
The spleen in all cases, when normally placed, is on the left-
hand side, and the kidneys also lie in the same position in all
creatures that possess them. There have been known instances
of quadrupeds under dissection, where the spleen was on the
right hand and the liver on the left; but all such cases are
regarded as supernatural.
In all animals the wind-pipe extends to the lung, and the
manner how, we shall discuss hereafter; and the oesophagus, in
all that have the organ, extends through the midriff into the
stomach. For, by the way, as has been observed, most fishes
have no oesophagus, but the stomach is united directly with the
mouth, so that in some cases when big fish are pursuing little
ones, the stomach tumbles forward into the mouth.
All the afore-mentioned animals have a stomach, and one
similarly situated, that is to say, situated directly under the
midriff; and they have a gut connected therewith and closing at
the outlet of the residuum and at what is termed the 'rectum'.
However, animals present diversities in the structure of their
stomachs. In the first place, of the viviparous quadrupeds, such
of the horned animals as are not equally furnished with teeth in
both jaws are furnished with four such chambers. These
animals, by the way, are those that are said to chew the cud. In
these animals the oesophagus extends from the mouth
1451
downwards along the lung, from the midriff to the big stomach
(or paunch); and this stomach is rough inside and semi-
partitioned. And connected with it near to the entry of the
oesophagus is what from its appearance is termed the
'reticulum' (or honeycomb bag); for outside it is like the
stomach, but inside it resembles a netted cap; and the
reticulum is a great deal smaller than the stomach. Connected
with this is the 'echinus' (or many-plies), rough inside and
laminated, and of about the same size as the reticulum. Next
after this comes what is called the 'enystrum' (or abomasum),
larger an longer than the echinus, furnished inside with
numerous folds or ridges, large and smooth. After all this comes
the gut.
Such is the stomach of those quadrupeds that are horned and
have an unsymmetrical dentition; and these animals differ one
from another in the shape and size of the parts, and in the fact
of the oesophagus reaching the stomach centralwise in some
cases and sideways in others. Animals that are furnished
equally with teeth in both jaws have one stomach; as man, the
pig, the dog, the bear, the lion, the wolf. (The Thos, by the by, has
all its internal organs similar to the wolf's.)
All these, then have a single stomach, and after that the gut; but
the stomach in some is comparatively large, as in the pig and
bear, and the stomach of the pig has a few smooth folds or
ridges; others have a much smaller stomach, not much bigger
than the gut, as the lion, the dog, and man. In the other animals
the shape of the stomach varies in the direction of one or other
of those already mentioned; that is, the stomach in some
animals resembles that of the pig; in others that of the dog,
alike with the larger animals and the smaller ones. In all these
animals diversities occur in regard to the size, the shape, the
thickness or the thinness of the stomach, and also in regard to
the place where the oesophagus opens into it.
1452
There is also a difference in structure in the gut of the two
groups of animals above mentioned (those with unsymmetrical
and those with symmetrical dentition) in size, in thickness, and
in foldings.
The intestines in those animals whose jaws are unequally
furnished with teeth are in all cases the larger, for the animals
themselves are larger than those in the other category; for very
few of them are small, and no single one of the horned animals
is very small. And some possess appendages (or caeca) to the
gut, but no animal that has not incisors in both jaws has a
straight gut.
The elephant has a gut constricted into chambers, so
constructed that the animal appears to have four stomachs; in
it the food is found, but there is no distinct and separate
receptacle. Its viscera resemble those of the pig, only that the
liver is four times the size of that of the ox, and the other
viscera in like proportion, while the spleen is comparatively
small.
Much the same may be predicated of the properties of the
stomach and the gut in oviparous quadrupeds, as in the land
tortoise, the turtle, the lizard, both crocodiles, and, in fact, in all
animals of the like kind; that is to say, their stomach is one and
simple, resembling in some cases that of the pig, and in other
cases that of the dog.
The serpent genus is similar and in almost all respects
furnished similarly to the saurians among land animals, if one
could only imagine these saurians to be increased in length and
to be devoid of legs. That is to say, the serpent is coated with
tessellated scutes, and resembles the saurian in its back and
belly; only, by the way, it has no testicles, but, like fishes, has
two ducts converging into one, and an ovary long and bifurcate.
The rest of its internal organs are identical with those of the
1453
saurians, except that, owing to the narrowness and length of
the animal, the viscera are correspondingly narrow and
elongated, so that they are apt to escape recognition from the
similarities in shape. Thus, the windpipe of the creature is
exceptionally long, and the oesophagus is longer still, and the
windpipe commences so close to the mouth that the tongue
appears to be underneath it; and the windpipe seems to project
over the tongue, owing to the fact that the tongue draws back
into a sheath and does not remain in its place as in other
animals. The tongue, moreover, is thin and long and black, and
can be protruded to a great distance. And both serpents and
saurians have this altogether exceptional property in the
tongue, that it is forked at the outer extremity, and this property
is the more marked in the serpent, for the tips of his tongue are
as thin as hairs. The seal, also, by the way, has a split tongue.
The stomach of the serpent is like a more spacious gut,
resembling the stomach of the dog; then comes the gut, long,
narrow, and single to the end. The heart is situated close to the
pharynx, small and kidney-shaped; and for this reason the
organ might in some cases appear not to have the pointed end
turned towards the breast. Then comes the lung, single, and
articulated with a membranous passage, very long, and quite
detached from the heart. The liver is long and simple; the
spleen is short and round: as is the case in both respects with
the saurians. Its gall resembles that of the fish; the water-
snakes have it beside the liver, and the other snakes have it
usually beside the gut. These creatures are all saw-toothed.
Their ribs are as numerous as the days of the month; in other
words, they are thirty in number.
Some affirm that the same phenomenon is observable with
serpents as with swallow chicks; in other words, they say that if
you prick out a serpent's eyes they will grow again. And further,
1454
the tails of saurians and of serpents, if they be cut off, will grow
again.
With fishes the properties of the gut and stomach are similar;
that is, they have a stomach single and simple, but variable in
shape according to species. For in some cases the stomach is
gut-shaped, as with the scarus, or parrot-fish; which fish, by the
way, appears to be the only fish that chews the cud. And the
whole length of the gut is simple, and if it have a reduplication
or kink it loosens out again into a simple form.
An exceptional property in fishes and in birds for the most part
is the being furnished with gut-appendages or caeca. Birds have
them low down and few in number. Fishes have them high up
about the stomach, and sometimes numerous, as in the goby,
the galeos, the perch, the scorpaena, the citharus, the red
mullet, and the sparus; the cestreus or grey mullet has several
of them on one side of the belly, and on the other side only one.
Some fish possess these appendages but only in small numbers,
as the hepatus and the glaucus; and, by the way, they are few
also in the dorado. These fishes differ also from one another
within the same species, for in the dorado one individual has
many and another few. Some fishes are entirely without the
part, as the majority of the selachians. As for all the rest, some
of them have a few and some a great many. And in all cases
where the gut-appendages are found in fish, they are found
close up to the stomach.
In regard to their internal parts birds differ from other animals
and from one another. Some birds, for instance, have a crop in
front of the stomach, as the barn-door cock, the cushat, the
pigeon, and the partridge; and the crop consists of a large
hollow skin, into which the food first enters and where it lies
ingested. Just where the crop leaves the oesophagus it is
somewhat narrow; by and by it broadens out, but where it
1455
communicates with the stomach it narrows down again. The
stomach (or gizzard) in most birds is fleshy and hard, and inside
is a strong skin which comes away from the fleshy part. Other
birds have no crop, but instead of it an oesophagus wide and
roomy, either all the way or in the part leading to the stomach,
as with the daw, the raven, and the carrion-crow. The quail also
has the oesophagus widened out at the lower extremity, and in
the aegocephalus and the owl the organ is slightly broader at
the bottom than at the top. The duck, the goose, the gull, the
catarrhactes, and the great bustard have the oesophagus wide
and roomy from one end to the other, and the same applies to a
great many other birds. In some birds there is a portion of the
stomach that resembles a crop, as in the kestrel. In the case of
small birds like the swallow and the sparrow neither the
oesophagus nor the crop is wide, but the stomach is long. Some
few have neither a crop nor a dilated oesophagus, but the latter
is exceedingly long, as in long necked birds, such as the
porphyrio, and, by the way, in the case of all these birds the
excrement is unusually moist. The quail is exceptional in regard
to these organs, as compared with other birds; in other words, it
has a crop, and at the same time its oesophagus is wide and
spacious in front of the stomach, and the crop is at some
distance, relatively to its size, from the oesophagus at that part.
Further, in most birds, the gut is thin, and simple when
loosened out. The gut-appendages or caeca in birds, as has been
observed, are few in number, and are not situated high up, as in
fishes, but low down towards the extremity of the gut. Birds,
then, have caeca - not all, but the greater part of them, such as
the barn-door cock, the partridge, the duck, the night-raven, (the
localus,) the ascalaphus, the goose, the swan, the great bustard,
and the owl. Some of the little birds also have these
appendages; but the caeca in their case are exceedingly minute,
as in the sparrow.
1456
Book III
Now that we have stated the magnitudes, the properties, and
the relative differences of the other internal organs, it remains
for us to treat of the organs that contribute to generation. These
organs in the female are in all cases internal; in the male they
present numerous diversities.
In the blooded animals some males are altogether devoid of
testicles, and some have the organ but situated internally; and
of those males that have the organ internally situated, some
have it close to the loin in the neighbourhood of the kidney and
others close to the belly. Other males have the organ situated
externally. In the case of these last, the penis is in some cases
attached to the belly, whilst in others it is loosely suspended, as
is the case also with the testicles; and, in the cases where the
penis is attached to the belly, the attachment varies accordingly
as the animal is emprosthuretic or opisthuretic.
No fish is furnished with testicles, nor any other creature that
has gills, nor any serpent whatever: nor, in short, any animal
devoid of feet, save such only as are viviparous within
themselves. Birds are furnished with testicles, but these are
internally situated, close to the loin. The case is similar with
oviparous quadrupeds, such as the lizard, the tortoise and the
crocodile; and among the viviparous animals this peculiarity is
1457
found in the hedgehog. Others among those creatures that have
the organ internally situated have it close to the belly, as is the
case with the dolphin amongst animals devoid of feet, and with
the elephant among viviparous quadrupeds. In other cases
these organs are externally conspicuous.
We have already alluded to the diversities observed in the
attachment of these organs to the belly and the adjacent region;
in other words, we have stated that in some cases the testicles
are tightly fastened back, as in the pig and its allies, and that in
others they are freely suspended, as in man.
Fishes, then, are devoid of testicles, as has been stated, and
serpents also. They are furnished, however, with two ducts
connected with the midriff and running on to either side of the
backbone, coalescing into a single duct above the outlet of the
residuum, and by 'above' the outlet I mean the region near to
the spine. These ducts in the rutting season get filled with the
genital fluid, and, if the ducts be squeezed, the sperm oozes out
white in colour. As to the differences observed in male fishes of
diverse species, the reader should consult my treatise on
Anatomy, and the subject will be hereafter more fully discussed
when we describe the specific character in each case.
The males of oviparous animals, whether biped or quadruped,
are in all cases furnished with testicles close to the loin
underneath the midriff. With some animals the organ is
whitish, in others somewhat of a sallow hue; in all cases it is
entirely enveloped with minute and delicate veins. From each of
the two testicles extends a duct, and, as in the case of fishes,
the two ducts coalesce into one above the outlet of the
residuum. This constitutes the penis, which organ in the case of
small ovipara is inconspicuous; but in the case of the larger
ovipara, as in the goose and the like, the organ becomes quite
visible just after copulation.
1458
The ducts in the case of fishes and in biped and quadruped
ovipara are attached to the loin under the stomach and the gut,
in betwixt them and the great vein, from which ducts or blood-
vessels extend, one to each of the two testicles. And just as with
fishes the male sperm is found in the seminal ducts, and the
ducts become plainly visible at the rutting season and in some
instances become invisible after the season is passed, so also is
it with the testicles of birds; before the breeding season the
organ is small in some birds and quite invisible in others, but
during the season the organ in all cases is greatly enlarged. This
phenomenon is remarkably illustrated in the ring-dove and the
partridge, so much so that some people are actually of opinion
that these birds are devoid of the organ in the winter-time.
Of male animals that have their testicles placed frontwards,
some have them inside, close to the belly, as the dolphin; some
have them outside, exposed to view, close to the lower
extremity of the belly. These animals resemble one another thus
far in respect to this organ; but they differ from one another in
this fact, that some of them have their testicles situated
separately by themselves, while others, which have the organ
situated externally, have them enveloped in what is termed the
scrotum.
Again, in all viviparous animals furnished with feet the
following properties are observed in the testicles themselves.
From the aorta there extend vein-like ducts to the head of each
of the testicles, and another two from the kidneys; these two
from the kidneys are supplied with blood, while the two from
the aorta are devoid of it. From the head of the testicle
alongside of the testicle itself is a duct, thicker and more sinewy
than the other just alluded to - a duct that bends back again at
the end of the testicle to its head; and from the head of each of
the two testicles the two ducts extend until they coalesce in
front at the penis. The duct that bends back again and that
1459
which is in contact with the testicle are enveloped in one and
the same membrane, so that, until you draw aside the
membrane, they present all the appearance of being a single
undifferentiated duct. Further, the duct in contact with the
testicle has its moist content qualified by blood, but to a
comparatively less extent than in the case of the ducts higher
up which are connected with the aorta; in the ducts that bend
back towards the tube of the penis, the liquid is white-coloured.
There also runs a duct from the bladder, opening into the upper
part of the canal, around which lies, sheathwise, what is called
the 'penis'.
All these descriptive particulars may be regarded by the light of
the accompanying diagram; wherein the letter A marks the
starting-point of the ducts that extend from the aorta; the
letters KK mark the heads of the testicles and the ducts
descending thereunto; the ducts extending from these along the
testicles are marked MM; the ducts turning back, in which is the
white fluid, are marked BB; the penis D; the bladder E; and the
testicles XX.
(By the way, when the testicles are cut off or removed, the ducts
draw upwards by contraction. Moreover, when male animals are
young, their owner sometimes destroys the organ in them by
attrition; sometimes they castrate them at a later period. And I
may here add, that a bull has been known to serve a cow
immediately after castration, and actually to impregnate her.)
So much then for the properties of testicles in male animals.
In female animals furnished with a womb, the womb is not in
all cases the same in form or endowed with the same
properties, but both in the vivipara and the ovipara great
diversities present themselves. In all creatures that have the
womb close to the genitals, the womb is two-horned, and one
horn lies to the right-hand side and the other to the left; its
1460
commencement, however, is single, and so is the orifice,
resembling in the case of the most numerous and largest
animals a tube composed of much flesh and gristle. Of these
parts one is termed the hystera or delphys, whence is derived
the word adelphos, and the other part, the tube or orifice, is
termed metra. In all biped or quadruped vivipara the womb is in
all cases below the midriff, as in man, the dog, the pig, the
horse, and the ox; the same is the case also in all horned
animals. At the extremity of the so-called ceratia, or horns, the
wombs of most animals have a twist or convolution.
In the case of those ovipara that lay eggs externally, the wombs
are not in all cases similarly situated. Thus the wombs of birds
are close to the midriff, and the wombs of fishes down below,
just like the wombs of biped and quadruped vivipara, only that,
in the case of the fish, the wombs are delicately formed,
membranous, and elongated; so much so that in extremely
small fish, each of the two bifurcated parts looks like a single
egg, and those fishes whose egg is described as crumbling
would appear to have inside them a pair of eggs, whereas in
reality each of the two sides consists not of one but of many
eggs, and this accounts for their breaking up into so many
particles.
The womb of birds has the lower and tubular portion fleshy and
firm, and the part close to the midriff membranous and
exceedingly thin and fine: so thin and fine that the eggs might
seem to be outside the womb altogether. In the larger birds the
membrane is more distinctly visible, and, if inflated through the
tube, lifts and swells out; in the smaller birds all these parts are
more indistinct.
The properties of the womb are similar in oviparous
quadrupeds, as the tortoise, the lizard, the frog and the like; for
the tube below is single and fleshy, and the cleft portion with
1461
the eggs is at the top close to the midriff. With animals devoid
of feet that are internally oviparous and viviparous externally,
as is the case with the dogfish and the other so-called
Selachians (and by this title we designate such creatures
destitute of feet and furnished with gills as are viviparous), with
these animals the womb is bifurcate, and beginning down below
it extends as far as the midriff, as in the case of birds. There is
also a narrow part between the two horns running up as far as
the midriff, and the eggs are engendered here and above at the
origin of the midriff; afterwards they pass into the wider space
and turn from eggs into young animals. However, the
differences in respect to the wombs of these fishes as compared
with others of their own species or with fishes in general, would
be more satisfactorily studied in their various forms in
specimens under dissection.
The members of the serpent genus also present divergencies
either when compared with the above-mentioned creatures or
with one another. Serpents as a rule are oviparous, the viper
being the only viviparous member of the genus. The viper is,
previously to external parturition, oviparous internally; and
owing to this perculiarity the properties of the womb in the
viper are similar to those of the womb in the selachians. The
womb of the serpent is long, in keeping with the body, and
starting below from a single duct extends continuously on both
sides of the spine, so as to give the impression of thus being a
separate duct on each side of the spine, until it reaches the
midriff, where the eggs are engendered in a row; and these eggs
are laid not one by one, but all strung together. (And all animals
that are viviparous both internally and externally have the
womb situated above the stomach, and all the ovipara
underneath, near to the loin. Animals that are viviparous
externally and internally oviparous present an intermediate
arrangement; for the underneath portion of the womb, in which
1462
the eggs are, is placed near to the loin, but the part about the
orifice is above the gut.)
Further, there is the following diversity observable in wombs as
compared with one another: namely that the females of horned
nonambidental animals are furnished with cotyledons in the
womb when they are pregnant, and such is the case, among
ambidentals, with the hare, the mouse, and the bat; whereas all
other animals that are ambidental, viviparous, and furnished
with feet, have the womb quite smooth, and in their case the
attachment of the embryo is to the womb itself and not to any
cotyledon inside it.
The parts, then, in animals that are not homogeneous with
themselves and uniform in their texture, both parts external
and parts internal, have the properties above assigned to them.
In sanguineous animals the homogeneous or uniform part most
universally found is the blood, and its habitat the vein; next in
degree of universality, their analogues, lymph and fibre, and,
that which chiefly constitutes the frame of animals, flesh and
whatsoever in the several parts is analogous to flesh; then bone,
and parts that are analogous to bone, as fish-bone and gristle;
and then, again, skin, membrane, sinew, hair, nails, and
whatever corresponds to these; and, furthermore, fat, suet, and
the excretions: and the excretions are dung, phlegm, yellow bile,
and black bile.
Now, as the nature of blood and the nature of the veins have all
the appearance of being primitive, we must discuss their
properties first of all, and all the more as some previous writers
1463
have treated them very unsatisfactorily. And the cause of the
ignorance thus manifested is the extreme difficulty experienced
in the way of observation. For in the dead bodies of animals the
nature of the chief veins is undiscoverable, owing to the fact
that they collapse at once when the blood leaves them; for the
blood pours out of them in a stream, like liquid out of a vessel,
since there is no blood separately situated by itself, except a
little in the heart, but it is all lodged in the veins. In living
animals it is impossible to inspect these parts, for of their very
nature they are situated inside the body and out of sight. For
this reason anatomists who have carried on their investigations
on dead bodies in the dissecting room have failed to discover
the chief roots of the veins, while those who have narrowly
inspected bodies of living men reduced to extreme attenuation
have arrived at conclusions regarding the origin of the veins
from the manifestations visible externally. Of these
investigators, Syennesis, the physician of Cyprus, writes as
follows:
'The big veins run thus:-from the navel across the loins, along
the back, past the lung, in under the breasts; one from right to
left, and the other from left to right; that from the left, through
the liver to the kidney and the testicle, that from the right, to
the spleen and kidney and testicle, and from thence to the
penis.' Diogenes of Apollonia writes thus:
'The veins in man are as follows: There are two veins pre-
eminent in magnitude. These extend through the belly along
the backbone, one to right, one to left; either one to the leg on
its own side, and upwards to the head, past the collar bones,
through the throat. From these, veins extend all over the body,
from that on the right hand to the right side and from that on
the left hand to the left side; the most important ones, two in
number, to the heart in the region of the backbone; other two a
little higher up through the chest in underneath the armpit,
1464
each to the hand on its side: of these two, one being termed the
vein splenitis, and the other the vein hepatitis. Each of the pair
splits at its extremity; the one branches in the direction of the
thumb and the other in the direction of the palm; and from
these run off a number of minute veins branching off to the
fingers and to all parts of the hand. Other veins, more minute,
extend from the main veins; from that on the right towards the
liver, from that on the left towards the spleen and the kidneys.
The veins that run to the legs split at the juncture of the legs
with the trunk and extend right down the thigh. The largest of
these goes down the thigh at the back of it, and can be
discerned and traced as a big one; the second one runs inside
the thigh, not quite as big as the one just mentioned. After this
they pass on along the knee to the shin and the foot (as the
upper veins were described as passing towards the hands), and
arrive at the sole of the foot, and from thence continue to the
toes. Moreover, many delicate veins separate off from the great
veins towards the stomach and towards the ribs.
'The veins that run through the throat to the head can be
discerned and traced in the neck as large ones; and from each
one of the two, where it terminates, there branch off a number
of veins to the head; some from the right side towards the left,
and some from the left side towards the right; and the two veins
terminate near to each of the two ears. There is another pair of
veins in the neck running along the big vein on either side,
slightly less in size than the pair just spoken of, and with these
the greater part of the veins in the head are connected. This
other pair runs through the throat inside; and from either one
of the two there extend veins in underneath the shoulder blade
and towards the hands; and these appear alongside the veins
splenitis and hepatitis as another pair of veins smaller in size.
When there is a pain near the surface of the body, the physician
lances these two latter veins; but when the pain is within and in
the region of the stomach he lances the veins splenitis and
1465
hepatitis. And from these, other veins depart to run below the
breasts.
'There is also another pair running on each side through the
spinal marrow to the testicles, thin and delicate. There is,
further, a pair running a little underneath the cuticle through
the flesh to the kidneys, and these with men terminate at the
testicle, and with women at the womb. These veins are termed
the spermatic veins. The veins that leave the stomach are
comparatively broad just as they leave; but they become
gradually thinner, until they change over from right to left and
from left to right.
'Blood is thickest when it is imbibed by the fleshy parts; when it
is transmitted to the organs above-mentioned, it becomes thin,
warm, and frothy.'
Such are the accounts given by Syennesis and Diogenes. Polybus
writes to the following effect:
'There are four pairs of veins. The first extends from the back of
the head, through the neck on the outside, past the backbone on
either side, until it reaches the loins and passes on to the legs,
after which it goes on through the shins to the outer side of the
ankles and on to the feet. And it is on this account that
surgeons, for pains in the back and loin, bleed in the ham and in
the outer side of the ankle. Another pair of veins runs from the
head, past ears, through the neck; which veins are termed the
jugular veins. This pair goes on inside along the backbone, past
the muscles of the loins, on to the testicles, and onwards to the
thighs, and through the inside of the hams and through the
1466
shins down to the inside of the ankles and to the feet; and for
this reason, surgeons, for pains in the muscles of the loins and
in the testicles, bleed on the hams and the inner side of the
ankles. The third pair extends from the temples, through the
neck, in underneath the shoulder-blades, into the lung; those
from right to left going in underneath the breast and on to the
spleen and the kidney; those from left to right running from the
lung in underneath the breast and into the liver and the kidney;
and both terminate in the fundament. The fourth pair extend
from the front part of the head and the eyes in underneath the
neck and the collar-bones; from thence they stretch on through
the upper part of the upper arms to the elbows and then
through the fore-arms on to the wrists and the jointings of the
fingers, and also through the lower part of the upper-arms to
the armpits, and so on, keeping above the ribs, until one of the
pair reaches the spleen and the other reaches the liver; and
after this they both pass over the stomach and terminate at the
penis.'
The above quotations sum up pretty well the statements of all
previous writers. Furthermore, there are some writers on
Natural History who have not ventured to lay down the law in
such precise terms as regards the veins, but who all alike agree
in assigning the head and the brain as the starting-point of the
veins. And in this opinion they are mistaken.
The investigation of such a subject, as has been remarked, is
one fraught with difficulties; but, if any one be keenly interested
in the matter, his best plan will be to allow his animals to starve
to emaciation, then to strangle them on a sudden, and
thereupon to prosecute his investigations.
We now proceed to give particulars regarding the properties and
functions of the veins. There are two blood-vessels in the thorax
by the backbone, and lying to its inner side; and of these two
1467
the larger one is situated to the front, and the lesser one is to
the rear of it; and the larger is situated rather to the right hand
side of the body, and the lesser one to the left; and by some this
vein is termed the 'aorta', from the fact that even in dead bodies
part of it is observed to be full of air. These blood-vessels have
their origins in the heart, for they traverse the other viscera, in
whatever direction they happen to run, without in any way
losing their distinctive characteristic as blood-vessels, whereas
the heart is as it were a part of them (and that too more in
respect to the frontward and larger one of the two), owing to the
fact that these two veins are above and below, with the heart
lying midway.
The heart in all animals has cavities inside it. In the case of the
smaller animals even the largest of the chambers is scarcely
discernible; the second larger is scarcely discernible in animals
of medium size; but in the largest animals all three chambers
are distinctly seen. In the heart then (with its pointed end
directed frontwards, as has been observed) the largest of the
three chambers is on the right-hand side and highest up; the
least one is on the left-hand side; and the medium-sized one
lies in betwixt the other two; and the largest one of the three
chambers is a great deal larger than either of the two others. All
three, however, are connected with passages leading in the
direction of the lung, but all these communications are
indistinctly discernible by reason of their minuteness, except
one.
The great blood-vessel, then, is attached to the biggest of the
three chambers, the one that lies uppermost and on the right-
hand side; it then extends right through the chamber, coming
out as blood-vessel again; just as though the cavity of the heart
were a part of the vessel, in which the blood broadens its
channel as a river that widens out in a lake. The aorta is
1468
attached to the middle chamber; only, by the way, it is
connected with it by much narrower pipe.
The great blood-vessel then passes through the heart (and runs
from the heart into the aorta). The great vessel looks as though
made of membrane or skin, while the aorta is narrower than it,
and is very sinewy; and as it stretches away to the head and to
the lower parts it becomes exceedingly narrow and sinewy.
First of all, then, upwards from the heart there stretches a part
of the great blood-vessel towards the lung and the attachment
of the aorta, a part consisting of a large undivided vessel. But
there split off from it two parts; one towards the lung and the
other towards the backbone and the last vertebra of the neck.
The vessel, then, that extends to the lung, as the lung itself is
duplicate, divides at first into two; and then extends along by
every pipe and every perforation, greater along the greater ones,
lesser along the less, so continuously that it is impossible to
discern a single part wherein there is not perforation and vein;
for the extremities are indistinguishable from their minuteness,
and in point of fact the whole lung appears to be filled with
blood.
The branches of the blood-vessels lie above the tubes that
extend from the windpipe. And that vessel which extends to the
vertebra of the neck and the backbone, stretches back again
along the backbone; as Homer represents in the lines:
(Antilochus, asThoon turned him round),
Transpierc'd his back with a dishonest wound;
The hollow vein that to the neck extends,
Along the chine, the eager javelin rends.
1469
From this vessel there extend small blood-vessels at each rib
and each vertebra; and at the vertebra above the kidneys the
vessel bifurcates. And in the above way the parts branch off
from the great blood-vessel.
But up above all these, from that part which is connected with
the heart, the entire vein branches off in two directions. For its
branches extend to the sides and to the collarbones, and then
pass on, in men through the armpits to the arms, in quadrupeds
to the forelegs, in birds to the wings, and in fishes to the upper
or pectoral fins. (See diagram.) The trunks of these veins, where
they first branch off, are called the 'jugular' veins; and, where
they branch off to the neck the great vein run alongside the
windpipe; and, occasionally, if these veins are pressed
externally, men, though not actually choked, become insensible,
shut their eyes, and fall flat on the ground. Extending in the way
described and keeping the windpipe in betwixt them, they pass
on until they reach the ears at the junction of the lower jaw
with the skull. Hence again they branch off into four veins, of
which one bends back and descends through the neck and the
shoulder, and meets the previous branching off of the vein at
the bend of the arm, while the rest of it terminates at the hand
and fingers. (See diagram.)
Each vein of the other pair stretches from the region of the ear
to the brain, and branches off in a number of fine and delicate
veins into the so-called meninx, or membrane, which surrounds
the brain. The brain itself in all animals is destitute of blood,
and no vein, great or small, holds its course therein. But of the
remaining veins that branch off from the last mentioned vein
some envelop the head, others close their courses in the organs
of sense and at the roots of the teeth in veins exceedingly fine
and minute.
1470
And in like manner the parts of the lesser one of the two chief
blood-vessels, designated the aorta, branch off, accompanying
the branches from the big vein; only that, in regard to the aorta,
the passages are less in size, and the branches very considerably
less than are those of the great vein. So much for the veins as
observed in the regions above the heart.
The part of the great vein that lies underneath the heart
extends, freely suspended, right through the midriff, and is
united both to the aorta and the backbone by slack
membranous communications. From it one vein, short and
wide, extends through the liver, and from it a number of minute
veins branch off into the liver and disappear. From the vein that
passes through the liver two branches separate off, of which
one terminates in the diaphragm or so-called midriff, and the
other runs up again through the armpit into the right arm and
unites with the other veins at the inside of the bend of the arm;
and it is in consequence of this local connexion that, when the
surgeon opens this vein in the forearm, the patient is relieved of
certain pains in the liver; and from the left-hand side of it there
extends a short but thick vein to the spleen and the little veins
branching off it disappear in that organ. Another part branches
off from the left-hand side of the great vein, and ascends, by a
course similar to the course recently described, into the left
arm; only that the ascending vein in the one case is the vein
that traverses the liver, while in this case it is distinct from the
vein that runs into the spleen. Again, other veins branch off
from the big vein; one to the omentum, and another to the
pancreas, from which vein run a number of veins through the
mesentery. All these veins coalesce in a single large vein, along
1471
the entire gut and stomach to the oesophagus; about these
parts there is a great ramification of branch veins.
As far as the kidneys, each of the two remaining undivided, the
aorta and the big vein extend; and here they get more closely
attached to the backbone, and branch off, each of the two, into a
A shape, and the big vein gets to the rear of the aorta. But the
chief attachment of the aorta to the backbone takes place in the
region of the heart; and the attachment is effected by means of
minute and sinewy vessels. The aorta, just as it draws off from
the heart, is a tube of considerable volume, but, as it advances
in its course, it gets narrower and more sinewy. And from the
aorta there extend veins to the mesentery just like the veins
that extend thither from the big vein, only that the branches in
the case of the aorta are considerably less in magnitude; they
are, indeed, narrow and fibrillar, and they end in delicate hollow
fibre-like veinlets.
There is no vessel that runs from the aorta into the liver or the
spleen.
From each of the two great blood-vessels there extend branches
to each of the two flanks, and both branches fasten on to the
bone. Vessels also extend to the kidneys from the big vein and
the aorta; only that they do not open into the cavity of the
organ, but their ramifications penetrate into its substance. From
the aorta run two other ducts to the bladder, firm and
continuous; and there are other ducts from the hollow of the
kidneys, in no way communicating with the big vein. From the
centre of each of the two kidneys springs a hollow sinewy vein,
running along the backbone right through the loins; by and by
each of the two veins first disappears in its own flank, and soon
afterwards reappears stretching in the direction of the flank.
The extremities of these attach to the bladder, and also in the
male to the penis and in the female to the womb. From the big
1472
vein no vein extends to the womb, but the organ is connected
with the aorta by veins numerous and closely packed.
Furthermore, from the aorta and the great vein at the points of
divarication there branch off other veins. Some of these run to
the groins - large hollow veins - and then pass on down
through the legs and terminate in the feet and toes. And, again,
another set run through the groins and the thighs cross-garter
fashion, from right to left and from left to right, and unite in the
hams with the other veins.
In the above description we have thrown light upon the course
of the veins and their points of departure.
In all sanguineous animals the case stands as here set forth in
regard to the points of departure and the courses of the chief
veins. But the description does not hold equally good for the
entire vein-system in all these animals. For, in point of fact, the
organs are not identically situated in them all; and, what is
more, some animals are furnished with organs of which other
animals are destitute. At the same time, while the description
so far holds good, the proof of its accuracy is not equally easy in
all cases, but is easiest in the case of animals of considerable
magnitude and supplied abundantly with blood. For in little
animals and those scantily supplied with blood, either from
natural and inherent causes or from a prevalence of fat in the
body, thorough accuracy in investigation is not equally
attainable; for in the latter of these creatures the passages get
clogged, like water-channels choked with slush; and the others
have a few minute fibres to serve instead of veins. But in all
cases the big vein is plainly discernible, even in creatures of
insignificant size.
1473
The sinews of animals have the following properties. For these
also the point of origin is the heart; for the heart has sinews
within itself in the largest of its three chambers, and the aorta is
a sinew-like vein; in fact, at its extremity it is actually a sinew,
for it is there no longer hollow, and is stretched like the sinews
where they terminate at the jointings of the bones. Be it
remembered, however, that the sinews do not proceed in
unbroken sequence from one point of origin, as do the blood-
vessels.
For the veins have the shape of the entire body, like a sketch of
a mannikin; in such a way that the whole frame seems to be
filled up with little veins in attenuated subjects - for the space
occupied by flesh in fat individuals is filled with little veins in
thin ones - whereas the sinews are distributed about the joints
and the flexures of the bones. Now, if the sinews were derived in
unbroken sequence from a common point of departure, this
continuity would be discernible in attenuated specimens.
In the ham, or the part of the frame brought into full play in the
effort of leaping, is an important system of sinews; and another
sinew, a double one, is that called 'the tendon', and others are
those brought into play when a great effort of physical strength
is required; that is to say, the epitonos or back-stay and the
shoulder-sinews. Other sinews, devoid of specific designation,
are situated in the region of the flexures of the bones; for all the
bones that are attached to one another are bound together by
sinews, and a great quantity of sinews are placed in the
neighbourhood of all the bones. Only, by the way, in the head
there is no sinew; but the head is held together by the sutures
of the bones.
Sinew is fissile lengthwise, but crosswise it is not easily broken,
but admits of a considerable amount of hard tension. In
1474
connexion with sinews a liquid mucus is developed, white and
glutinous, and the organ, in fact, is sustained by it and appears
to be substantially composed of it. Now, vein may be submitted
to the actual cautery, but sinew, when submitted to such action,
shrivels up altogether; and, if sinews be cut asunder, the
severed parts will not again cohere. A feeling of numbness is
incidental only to parts of the frame where sinew is situated.
There is a very extensive system of sinews connected severally
with the feet, the hands, the ribs, the shoulder-blades, the neck,
and the arms.
All animals supplied with blood are furnished with sinews; but
in the case of animals that have no flexures to their limbs, but
are, in fact, destitute of either feet or hands, the sinews are fine
and inconspicuous; and so, as might have been anticipated, the
sinews in the fish are chiefly discernible in connexion with the
fin.
The ines (or fibrous connective tissue) are a something
intermediate between sinew and vein. Some of them are
supplied with fluid, the lymph; and they pass from sinew to
vein and from vein to sinew. There is another kind of ines or
fibre that is found in blood, but not in the blood of all animals
alike. If this fibre be left in the blood, the blood will coagulate; if
it be removed or extracted, the blood is found to be incapable of
coagulation. While, however, this fibrous matter is found in the
blood of the great majority of animals, it is not found in all. For
instance, we fail to find it in the blood of the deer, the roe, the
antelope, and some other animals; and, owing to this deficiency
of the fibrous tissue, the blood of these animals does not
1475
coagulate to the extent observed in the blood of other animals.
The blood of the deer coagulates to about the same extent as
that of the hare: that is to the blood in either case coagulates,
but not into a stiff or jelly-like substance, like the blood of
ordinary animals, but only into a flaccid consistency like that of
milk which is not subjected to the action of rennet. The blood of
the antelope admits of a firmer consistency in coagulation; for
in this respect it resembles, or only comes a little short of, the
blood of sheep. Such are the properties of vein, sinew, and
fibrous tissue.
The bones in animals are all connected with one single bone,
and are interconnected, like the veins, in one unbroken
sequence; and there is no instance of a bone standing apart by
itself. In all animals furnished with bones, the spine or
backbone is the point of origin for the entire osseous system.
The spine is composed of vertebrae, and it extends from the
head down to the loins. The vertebrae are all perforated, and,
above, the bony portion of the head is connected with the
topmost vertebrae, and is designated the 'skull'. And the
serrated lines on the skull are termed 'sutures'.
The skull is not formed alike in all animals. In some animals the
skull consists of one single undivided bone, as in the case of the
dog; in others it is composite in structure, as in man; and in the
human species the suture is circular in the female, while in the
male it is made up of three separate sutures, uniting above in
three-corner fashion; and instances have been known of a
man's skull being devoid of suture altogether. The skull is
composed not of four bones, but of six; two of these are in the
1476
region of the ears, small in comparison with the other four.
From the skull extend the jaws, constituted of bone. (Animals in
general move the lower jaw; the river crocodile is the only
animal that moves the upper one.) In the jaws is the tooth-
system; and the teeth are constituted of bone, and are half-way
perforated; and the bone in question is the only kind of bone
which it is found impossible to grave with a graving tool.
On the upper part of the course of the backbone are the collar-
bones and the ribs. The chest rests on ribs; and these ribs meet
together, whereas the others do not; for no animal has bone in
the region of the stomach. Then come the shoulder-bones, or
blade-bones, and the arm-bones connected with these, and the
bones in the hands connected with the bones of the arms. With
animals that have forelegs, the osseous system of the foreleg
resembles that of the arm in man.
Below the level of the backbone, after the haunch-bone, comes
the hip-socket; then the leg-bones, those in the thighs and
those in the shins, which are termed colenes or limb-bones, a
part of which is the ankle, while a part of the same is the so-
called 'plectrum' in those creatures that have an ankle; and
connected with these bones are the bones in the feet.
Now, with all animals that are supplied with blood and
furnished with feet, and are at the same time viviparous, the
bones do not differ greatly one from another, but only in the
way of relative hardness, softness, or magnitude. A further
difference, by the way, is that in one and the same animal
certain bones are supplied with marrow, while others are
destitute of it. Some animals might on casual observation
appear to have no marrow whatsoever in their bones: as is the
case with the lion, owing to his having marrow only in small
amount, poor and thin, and in very few bones; for marrow is
found in his thigh and armbones. The bones of the lion are
1477
exceptionally hard; so hard, in fact, that if they are rubbed hard
against one another they emit sparks like flint-stones. The
dolphin has bones, and not fish-spine.
Of the other animals supplied with blood, some differ but little,
as is the case with birds; others have systems analogous, as
fishes; for viviparous fishes, such as the cartilaginous species,
are gristle-spined, while the ovipara have a spine which
corresponds to the backbone in quadrupeds. This exceptional
property has been observed in fishes, that in some of them
there are found delicate spines scattered here and there
throughout the fleshy parts. The serpent is similarly
constructed to the fish; in other words, his backbone is spinous.
With oviparous quadrupeds, the skeleton of the larger ones is
more or less osseous; of the smaller ones, more or less spinous.
But all sanguineous animals have a backbone of either one kind
or other: that is, composed either of bone or of spine.
The other portions of the skeleton are found in some animals
and not found in others, but the presence or the absence of this
and that part carries with it, as a matter of course, the presence
or the absence of the bones or the spines corresponding to this
or that part. For animals that are destitute of arms and legs
cannot be furnished with limb-bones: and in like manner with
animals that have the same parts, but yet have them unlike in
form; for in these animals the corresponding bones differ from
one another in the way of relative excess or relative defect, or in
the way of analogy taking the place of identity. So much for the
osseous or spinous systems in animals.
1478
8
Gristle is of the same nature as bone, but differs from it in the
way of relative excess or relative defect. And just like bone,
cartilage also, if cut, does not grow again. In terrestrial
viviparous sanguinea the gristle formations are unperforated,
and there is no marrow in them as there is in bones; in the
selachia, however - for, be it observed, they are gristle-spined -
there is found in the case of the flat space in the region of the
backbone, a gristle-like substance analogous to bone, and in this
gristle-like substance there is a liquid resembling marrow. In
viviparous animals furnished with feet, gristle formations are
found in the region of the ears, in the nostrils, and around
certain extremities of the bones.
Furthermore, there are parts of other kinds, neither identical
with, nor altogether diverse from, the parts above enumerated:
such as nails, hooves, claws, and horns; and also, by the way,
beaks, such as birds are furnished with - all in the several
animals that are furnished therewithal. All these parts are
flexible and fissile; but bone is neither flexible nor fissile, but
frangible.
And the colours of horns and nails and claw and hoof follow the
colour of the skin and the hair. For according as the skin of an
animal is black, or white, or of medium hue, so are the horns,
the claws, or the hooves, as the case may be, of hue to match.
And it is the same with nails. The teeth, however, follow after
the bones. Thus in black men, such as the Aethiopians and the
like, the teeth and bones are white, but the nails are black, like
the whole of the skin.
1479
Horns in general are hollow at their point of attachment to the
bone which juts out from the head inside the horn, but they
have a solid portion at the tip, and they are simple and
undivided in structure. In the case of the stag alone of all
animals the horns are solid throughout, and ramify into
branches (or antlers). And, whereas no other animal is known to
shed its horns, the deer sheds its horns annually, unless it has
been castrated; and with regard to the effects of castration in
animals we shall have much to say hereafter. Horns attach
rather to the skin than to the bone; which will account for the
fact that there are found in Phrygia and elsewhere cattle that
can move their horns as freely as their ears.
Of animals furnished with nails - and, by the way, all animals
have nails that have toes, and toes that have feet, except the
elephant; and the elephant has toes undivided and slightly
articulated, but has no nails whatsoever - of animals furnished
with nails, some are straight-nailed, like man; others are
crooked nailed, as the lion among animals that walk, and the
eagle among animals that fly.
10
The following are the properties of hair and of parts analogous
to hair, and of skin or hide. All viviparous animals furnished
with feet have hair; all oviparous animals furnished with feet
have horn-like tessellates; fishes, and fishes only, have scales -
that is, such oviparous fishes as have the crumbling egg or roe.
For of the lanky fishes, the conger has no such egg, nor the
muraena, and the eel has no egg at all.
The hair differs in the way of thickness and fineness, and of
length, according to the locality of the part in which it is found,
1480
and according to the quality of skin or hide on which it grows.
For, as a general rule, the thicker the hide, the harder and the
thicker is the hair; and the hair is inclined to grow in abundance
and to a great length in localities of the bodies hollow and
moist, if the localities be fitted for the growth of hair at all. The
facts are similar in the case of animals whether coated with
scales or with tessellates. With soft-haired animals the hair gets
harder with good feeding, and with hard-haired or bristly
animals it gets softer and scantier from the same cause. Hair
differs in quality also according to the relative heat or warmth
of the locality: just as the hair in man is hard in warm places
and soft in cold ones. Again, straight hair is inclined to be soft,
and curly hair to be bristly.
11
Hair is naturally fissile, and in this respect it differs in degree in
diverse animals. In some animals the hair goes on gradually
hardening into bristle until it no longer resembles hair but
spine, as in the case of the hedgehog. And in like manner with
the nails; for in some animals the nail differs as regards solidity
in no way from bone.
Of all animals man has the most delicate skin: that is, if we take
into consideration his relative size. In the skin or hide of all
animals there is a mucous liquid, scanty in some animals and
plentiful in others, as, for instance, in the hide of the ox; for
men manufacture glue out of it. (And, by the way, in some cases
glue is manufactured from fishes also.) The skin, when cut, is in
itself devoid of sensation; and this is especially the case with
the skin on the head, owing to there being no flesh between it
and the skull. And wherever the skin is quite by itself, if it be cut
1481
asunder, it does not grow together again, as is seen in the thin
part of the jaw, in the prepuce, and the eyelid. In all animals the
skin is one of the parts that extends continuous and unbroken,
and it comes to a stop only where the natural ducts pour out
their contents, and at the mouth and nails.
All sanguineous animals, then, have skin; but not all such
animals have hair, save only under the circumstances described
above. The hair changes its colour as animals grow old, and in
man it turns white or grey. With animals, in general, the change
takes place, but not very obviously, or not so obviously as in the
case of the horse. Hair turns grey from the point backwards to
the roots. But, in the majority of cases, grey hairs are white from
the beginning; and this is a proof that greyness of hair does not,
as some believe to be the case, imply withering or decrepitude,
for no part is brought into existence in a withered or decrepit
condition.
In the eruptive malady called the white-sickness all the hairs
get grey; and instances have been known where the hair
became grey while the patients were ill of the malady, whereas
the grey hairs shed off and black ones replaced them on their
recovery. (Hair is more apt to turn grey when it is kept covered
than when exposed to the action of the outer air.) In men, the
hair over the temples is the first to turn grey, and the hair in the
front grows grey sooner than the hair at the back; and the hair
on the pubes is the last to change colour.
Some hairs are congenital, others grow after the maturity of the
animal; but this occurs in man only. The congenital hairs are on
the head, the eyelids, and the eyebrows; of the later growths the
hairs on the pubes are the first to come, then those under the
armpits, and, thirdly, those on the chin; for, singularly enough,
the regions where congenital growths and the subsequent
growths are found are equal in number. The hair on the head
1482
grows scanty and sheds out to a greater extent and sooner than
all the rest. But this remark applies only to hair in front; for no
man ever gets bald at the back of his head. Smoothness on the
top of the head is termed 'baldness', but smoothness on the
eyebrows is denoted by a special term which means 'forehead-
baldness'; and neither of these conditions of baldness
supervenes in a man until he shall have come under the
influence of sexual passion. For no boy ever gets bald, no
woman, and no castrated man. In fact, if a man be castrated
before reaching puberty, the later growths of hair never come at
all; and, if the operation take place subsequently, the
aftergrowths, and these only, shed off; or, rather, two of the
growths shed off, but not that on the pubes.
Women do not grow hairs on the chin; except that a scanty
beard grows on some women after the monthly courses have
stopped; and similar phenomenon is observed at times in
priestesses in Caria, but these cases are looked upon as
portentous with regard to coming events. The other after-
growths are found in women, but more scanty and sparse. Men
and women are at times born constitutionally and congenitally
incapable of the after- growths; and individuals that are
destitute even of the growth upon the pubes are
constitutionally impotent.
Hair as a rule grows more or less in length as the wearer grows
in age; chiefly the hair on the head, then that in the beard, and
fine hair grows longest of all. With some people as they grow
old the eyebrows grow thicker, to such an extent that they have
to be cut off; and this growth is owing to the fact that the
eyebrows are situated at a conjuncture of bones, and these
bones, as age comes on, draw apart and exude a gradual
increase of moisture or rheum. The eyelashes do not grow in
size, but they shed when the wearer comes first under the
influence of sexual feelings, and shed all the quicker as this
1483
influence is the more powerful; and these are the last hairs to
grow grey.
Hairs if plucked out before maturity grow again; but they do not
grow again if plucked out afterwards. Every hair is supplied with
a mucous moisture at its root, and immediately after being
plucked out it can lift light articles if it touch them with this
mucus.
Animals that admit of diversity of colour in the hair admit of a
similar diversity to start with in the skin and in the cuticle of
the tongue.
In some cases among men the upper lip and the chin is thickly
covered with hair, and in other cases these parts are smooth
and the cheeks are hairy; and, by the way, smooth-chinned men
are less inclined than bearded men to baldness.
The hair is inclined to grow in certain diseases, especially in
consumption, and in old age, and after death; and under these
circumstances the hair hardens concomitantly with its growth,
and the same duplicate phenomenon is observable in respect of
the nails.
In the case of men of strong sexual passions the congenital
hairs shed the sooner, while the hairs of the after-growths are
the quicker to come. When men are afflicted with varicose veins
they are less inclined to take on baldness; and if they be bald
when they become thus afflicted, they have a tendency to get
their hair again.
If a hair be cut, it does not grow at the point of section; but it
gets longer by growing upward from below. In fishes the scales
grow harder and thicker with age, and when the amimal gets
emaciated or is growing old the scales grow harder. In
quadrupeds as they grow old the hair in some and the wool in
others gets deeper but scantier in amount: and the hooves or
1484
claws get larger in size; and the same is the case with the beaks
of birds. The claws also increase in size, as do also the nails.
12
With regard to winged animals, such as birds, no creature is
liable to change of colour by reason of age, excepting the crane.
The wings of this bird are ash-coloured at first, but as it grows
old the wings get black. Again, owing to special climatic
influences, as when unusual frost prevails, a change is
sometimes observed to take place in birds whose plumage is of
one uniform colour; thus, birds that have dusky or downright
black plumage turn white or grey, as the raven, the sparrow, and
the swallow; but no case has ever yet been known of a change
of colour from white to black. (Further, most birds change the
colour of their plumage at different seasons of the year, so
much so that a man ignorant of their habits might be mistaken
as to their identity.) Some animals change the colour of their
hair with a change in their drinking-water, for in some
countries the same species of animal is found white in one
district and black in another. And in regard to the commerce of
the sexes, water in many places is of such peculiar quality that
rams, if they have intercourse with the female after drinking it,
beget black lambs, as is the case with the water of the Psychrus
(so-called from its coldness), a river in the district of Assyritis in
the Chalcidic Peninsula, on the coast of Thrace; and in
Antandria there are two rivers of which one makes the lambs
white and the other black. The river Scamander also has the
reputation of making lambs yellow, and that is the reason, they
say, why Homer designates it the 'Yellow River.' Animals as a
general rule have no hair on their internal surfaces, and, in
1485
regard to their extremities, they have hair on the upper, but not
on the lower side.
The hare, or dasypod, is the only animal known to have hair
inside its mouth and underneath its feet. Further, the so-called
mousewhale instead of teeth has hairs in its mouth resembling
pigs' bristles.
Hairs after being cut grow at the bottom but not at the top; if
feathers be cut off, they grow neither at top nor bottom, but
shed and fall out. Further, the bee's wing will not grow again
after being plucked off, nor will the wing of any creature that
has undivided wings. Neither will the sting grow again if the bee
lose it, but the creature will die of the loss.
13
In all sanguineous animals membranes are found. And
membrane resembles a thin close-textured skin, but its
qualities are different, as it admits neither of cleavage nor of
extension. Membrane envelops each one of the bones and each
one of the viscera, both in the larger and the smaller animals;
though in the smaller animals the membranes are indiscernible
from their extreme tenuity and minuteness. The largest of all
the membranes are the two that surround the brain, and of
these two the one that lines the bony skull is stronger and
thicker than the one that envelops the brain; next in order of
magnitude comes the membrane that encloses the heart. If
membrane be bared and cut asunder it will not grow together
again, and the bone thus stripped of its membrane mortifies.
I486
14
The omentum or caul, by the way, is membrane. All
sanguineous animals are furnished with this organ; but in some
animals the organ is supplied with fat, and in others it is devoid
of it. The omentum has both its starting-point and its
attachment, with ambidental vivipara, in the centre of the
stomach, where the stomach has a kind of suture; in non-
ambidental vivipara it has its starting-point and attachment in
the chief of the ruminating stomachs.
15
The bladder also is of the nature of membrane, but of
membrane peculiar in kind, for it is extensile. The organ is not
common to all animals, but, while it is found in all the vivipara,
the tortoise is the only oviparous animal that is furnished
therewithal. The bladder, like ordinary membrane, if cut
asunder will not grow together again, unless the section be just
at the commencement of the urethra: except indeed in very rare
cases, for instances of healing have been known to occur. After
death, the organ passes no liquid excretion; but in life, in
addition to the normal liquid excretion, it passes at times dry
excretion also, which turns into stones in the case of sufferers
from that malady. Indeed, instances have been known of
concretions in the bladder so shaped as closely to resemble
cockleshells.
Such are the properties, then, of vein, sinew and skin, of fibre
and membrane, of hair, nail, claw and hoof, of horns, of teeth, of
1487
beak, of gristle, of bones, and of parts that are analogous to any
of the parts here enumerated.
16
Flesh, and that which is by nature akin to it in sanguineous
animals, is in all cases situated in between the skin and the
bone, or the substance analogous to bone; for just as spine is a
counterpart of bone, so is the flesh-like substance of animals
that are constructed a spinous system the counterpart of the
flesh of animals constructed on an osseous one.
Flesh can be divided asunder in any direction, not lengthwise
only as is the case with sinew and vein. When animals are
subjected to emaciation the flesh disappears, and the creatures
become a mass of veins and fibres; when they are over fed, fat
takes the place of flesh. Where the flesh is abundant in an
animal, its veins are somewhat small and the blood abnormally
red; the viscera also and the stomach are diminutive; whereas
with animals whose veins are large the blood is somewhat
black, the viscera and the stomach are large, and the flesh is
somewhat scanty. And animals with small stomachs are
disposed to take on flesh.
17
Again, fat and suet differ from one another. Suet is frangible in
all directions and congeals if subjected to extreme cold,
whereas fat can melt but cannot freeze or congeal; and soups
made of the flesh of animals supplied with fat do not congeal or
1488
coagulate, as is found with horse-flesh and pork; but soups
made from the flesh of animals supplied with suet do coagulate,
as is seen with mutton and goat's flesh. Further, fat and suet
differ as to their localities: for fat is found between the skin and
flesh, but suet is found only at the limit of the fleshy parts. Also,
in animals supplied with fat the omentum or caul is supplied
with fat, and it is supplied with suet in animals supplied with
suet. Moreover, ambidental animals are supplied with fat, and
non-ambidentals with suet.
Of the viscera the liver in some animals becomes fatty, as,
among fishes, is the case with the selachia, by the melting of
whose livers an oil is manufactured. These cartilaginous fish
themselves have no free fat at all in connexion with the flesh or
with the stomach. The suet in fish is fatty, and does not solidify
or congeal. All animals are furnished with fat, either
intermingled with their flesh, or apart. Such as have no free or
separate fat are less fat than others in stomach and omentum,
as the eel; for it has only a scanty supply of suet about the
omentum. Most animals take on fat in the belly, especially such
animals as are little in motion.
The brains of animals supplied with fat are oily, as in the pig; of
animals supplied with suet, parched and dry. But it is about the
kidneys more than any other viscera that animals are inclined
to take on fat; and the right kidney is always less supplied with
fat than the left kidney, and, be the two kidneys ever so fat,
there is always a space devoid of fat in between the two.
Animals supplied with suet are specially apt to have it about the
kidneys, and especially the sheep; for this animal is apt to die
from its kidneys being entirely enveloped. Fat or suet about the
kidney is superinduced by overfeeding, as is found at Leontini in
Sicily; and consequently in this district they defer driving out
sheep to pasture until the day is well on, with the view of
limiting their food by curtailment of the hours of pasture.
1489
18
The part around the pupil of the eye is fatty in all animals, and
this part resembles suet in all animals that possess such a part
and that are not furnished with hard eyes.
Fat animals, whether male or female, are more or less unfitted
for breeding purposes. Animals are disposed to take on fat more
when old than when young, and especially when they have
attained their full breadth and their full length and are
beginning to grow depthways.
19
And now to proceed to the consideration of the blood. In
sanguineous animals blood is the most universal and the most
indispensable part; and it is not an acquired or adventitious
part, but it is a consubstantial part of all animals that are not
corrupt or moribund. All blood is contained in a vascular
system, to wit, the veins, and is found nowhere else, excepting
in the heart. Blood is not sensitive to touch in any animal, any
more than the excretions of the stomach; and the case is
similar with the brain and the marrow. When flesh is lacerated,
blood exudes, if the animal be alive and unless the flesh be
gangrened. Blood in a healthy condition is naturally sweet to
the taste, and red in colour, blood that deteriorates from natural
decay or from disease more or less black. Blood at its best,
before it undergoes deterioration from either natural decay or
from disease, is neither very thick nor very thin. In the living
1490
animal it is always liquid and warm, but, on issuing from the
body, it coagulates in all cases except in the case of the deer, the
roe, and the like animals; for, as a general rule, blood coagulates
unless the fibres be extracted. Bull's blood is the quickest to
coagulate.
Animals that are internally and externally viviparous are more
abundantly supplied with blood than the sanguineous ovipara.
Animals that are in good condition, either from natural causes
or from their health having been attended to, have the blood
neither too abundant - as creatures just after drinking have the
liquid inside them in abundance - nor again very scanty, as is
the case with animals when exceedingly fat. For animals in this
condition have pure blood, but very little of it, and the fatter an
animal gets the less becomes its supply of blood; for whatsoever
is fat is destitute of blood.
A fat substance is incorruptible, but blood and all things
containing it corrupt rapidly, and this property characterizes
especially all parts connected with the bones. Blood is finest
and purest in man; and thickest and blackest in the bull and the
ass, of all vivipara. In the lower and the higher parts of the body
blood is thicker and blacker than in the central parts.
Blood beats or palpitates in the veins of all animals alike all over
their bodies, and blood is the only liquid that permeates the
entire frames of living animals, without exception and at all
times, as long as life lasts. Blood is developed first of all in the
heart of animals before the body is differentiated as a whole. If
blood be removed or if it escape in any considerable quantity,
animals fall into a faint or swoon; if it be removed or if it escape
in an exceedingly large quantity they die. If the blood get
exceedingly liquid, animals fall sick; for the blood then turns
into something like ichor, or a liquid so thin that it at times has
been known to exude through the pores like sweat. In some
1491
cases blood, when issuing from the veins, does not coagulate at
all, or only here and there. Whilst animals are sleeping the
blood is less abundantly supplied near the exterior surfaces, so
that, if the sleeping creature be pricked with a pin, the blood
does not issue as copiously as it would if the creature were
awake. Blood is developed out of ichor by coction, and fat in like
manner out of blood. If the blood get diseased, haemorrhoids
may ensue in the nostril or at the anus, or the veins may
become varicose. Blood, if it corrupt in the body, has a tendency
to turn into pus, and pus may turn into a solid concretion.
Blood in the female differs from that in the male, for, supposing
the male and female to be on a par as regards age and general
health, the blood in the female is thicker and blacker than in
the male; and with the female there is a comparative
superabundance of it in the interior. Of all female animals the
female in man is the most richly supplied with blood, and of all
female animals the menstruous discharges are the most
copious in woman. The blood of these discharges under disease
turns into flux. Apart from the menstrual discharges, the female
in the human species is less subject to diseases of the blood
than the male.
Women are seldom afflicted with varicose veins, with
haemorrhoids, or with bleeding at the nose, and, if any of these
maladies supervene, the menses are imperfectly discharged.
Blood differs in quantity and appearance according to age; in
very young animals it resembles ichor and is abundant, in the
old it is thick and black and scarce, and in middle-aged animals
its qualities are intermediate. In old animals the blood
coagulates rapidly, even blood at the surface of the body; but
this is not the case with young animals. Ichor is, in fact, nothing
else but unconcocted blood: either blood that has not yet been
concocted, or that has become fluid again.
1492
20
We now proceed to discuss the properties of marrow; for this is
one of the liquids found in certain sanguineous animals. All the
natural liquids of the body are contained in vessels: as blood in
veins, marrow in bones other moistures in membranous
structures of the skin
In young animals the marrow is exceedingly sanguineous, but,
as animals grow old, it becomes fatty in animals supplied with
fat, and suet-like in animals with suet. All bones, however, are
not supplied with marrow, but only the hollow ones, and not all
of these. For of the bones in the lion some contain no marrow at
all, and some are only scantily supplied therewith; and that
accounts, as was previously observed, for the statement made
by certain writers that the lion is marrowless. In the bones of
pigs it is found in small quantities; and in the bones of certain
animals of this species it is not found at all.
These liquids, then, are nearly always congenital in animals, but
milk and sperm come at a later time. Of these latter, that which,
whensoever it is present, is secreted in all cases ready-made, is
the milk; sperm, on the other hand, is not secreted out in all
cases, but in some only, as in the case of what are designated
thori in fishes.
Whatever animals have milk, have it in their breasts. All
animals have breasts that are internally and externally
viviparous, as for instance all animals that have hair, as man
and the horse; and the cetaceans, as the dolphin, the porpoise,
and the whale - for these animals have breasts and are supplied
with milk. Animals that are oviparous or only externally
1493
viviparous have neither breasts nor milk, as the fish and the
bird.
All milk is composed of a watery serum called 'whey', and a
consistent substance called curd (or cheese); and the thicker the
milk, the more abundant the curd. The milk, then, of non-
ambidentals coagulates, and that is why cheese is made of the
milk of such animals under domestication; but the milk of
ambidentals does not coagulate, nor their fat either, and the
milk is thin and sweet. Now the camel's milk is the thinnest,
and that of the human species next after it, and that of the ass
next again, but cow's milk is the thickest. Milk does not
coagulate under the influence of cold, but rather runs to whey;
but under the influence of heat it coagulates and thickens. As a
general rule milk only comes to animals in pregnancy. When
the animal is pregnant milk is found, but for a while it is unfit
for use, and then after an interval of usefulness it becomes unfit
for use again. In the case of female animals not pregnant a
small quantity of milk has been procured by the employment of
special food, and cases have been actually known where women
advanced in years on being submitted to the process of milking
have produced milk, and in some cases have produced it in
sufficient quantities to enable them to suckle an infant.
The people that live on and about Mount Oeta take such she-
goats as decline the male and rub their udders hard with nettles
to cause an irritation amounting to pain; hereupon they milk
the animals, procuring at first a liquid resembling blood, then a
liquid mixed with purulent matter, and eventually milk, as
freely as from females submitting to the male.
As a general rule, milk is not found in the male of man or of any
other animal, though from time to time it has been found in a
male; for instance, once in Lemnos a he-goat was milked by its
dugs (for it has, by the way, two dugs close to the penis), and
1494
was milked to such effect that cheese was made of the produce,
and the same phenomenon was repeated in a male of its own
begetting. Such occurrences, however, are regarded as
supernatural and fraught with omen as to futurity, and in point
of fact when the Lemnian owner of the animal inquired of the
oracle, the god informed him that the portent foreshadowed the
acquisition of a fortune. With some men, after puberty, milk can
be produced by squeezing the breasts; cases have been known
where on their being subjected to a prolonged milking process a
considerable quantity of milk has been educed.
In milk there is a fatty element, which in clotted milk gets to
resemble oil. Goat's milk is mixed with sheep's milk in Sicily,
and wherever sheep's milk is abundant. The best milk for
clotting is not only that where the cheese is most abundant, but
that also where the cheese is driest.
Now some animals produce not only enough milk to rear their
young, but a superfluous amount for general use, for cheese-
making and for storage. This is especially the case with the
sheep and the goat, and next in degree with the cow. Mare's
milk, by the way, and milk of the she-ass are mixed in with
Phrygian cheese. And there is more cheese in cow's milk than in
goat's milk; for graziers tell us that from nine gallons of goat's
milk they can get nineteen cheeses at an obol apiece, and from
the same amount of cow's milk, thirty. Other animals give only
enough of milk to rear their young withal, and no superfluous
amount and none fitted for cheese-making, as is the case with
all animals that have more than two breasts or dugs; for with
none of such animals is milk produced in superabundance or
used for the manufacture of cheese.
The juice of the fig and rennet are employed to curdle milk. The
fig-juice is first squeezed out into wool; the wool is then washed
and rinsed, and the rinsing put into a little milk, and if this be
1495
mixed with other milk it curdles Rennet is a kind of milk, for it
is found in the stomach of the animal while it is yet suckling.
21
Rennet then consists of milk with an admixture of fire, which
comes from the natural heat of the animal, as the milk is
concocted. All ruminating animals produce rennet, and, of
ambidentals, the hare. Rennet improves in quality the longer it
is kept; and cow's rennet, after being kept a good while, and also
hare's rennet, is good for diarrhoea, and the best of all rennet is
that of the young deer.
In milk-producing animals the comparative amount of the yield
varies with the size of the animal and the diversities of
pasturage. For instance, there are in Phasis small cattle that in
all cases give a copious supply of milk, and the large cows in
Epirus yield each one daily some nine gallons of milk, and half
of this from each pair of teats, and the milker has to stand erect,
stooping forward a little, as otherwise, if he were seated, he
would be unable to reach up to the teats. But, with the
exception of the ass, all the quadrupeds in Epirus are of large
size, and relatively, the cattle and the dogs are the largest. Now
large animals require abundant pasture, and this country
supplies just such pasturage, and also supplies diverse pasture
grounds to suit the diverse seasons of the year. The cattle are
particularly large, and likewise the sheep of the so-called
Pyrrhic breed, the name being given in honour of King Pyrrhus.
Some pasture quenches milk, as Median grass or lucerne, and
that especially in ruminants; other feeding renders it copious,
as cytisus and vetch; only, by the way, cytisus in flower is not
recommended, as it has burning properties, and vetch is not
1496
good for pregnant kine, as it causes increased difficulty in
parturition. However, beasts that have access to good feeding, as
they are benefited thereby in regard to pregnancy, so also being
well nourished produce milk in plenty. Some of the leguminous
plants bring milk in abundance, as for instance, a large feed of
beans with the ewe, the common she-goat, the cow, and the
small she-goat; for this feeding makes them drop their udders.
And, by the way, the pointing of the udder to the ground before
parturition is a sign of there being plenty of milk coming.
Milk remains for a long time in the female, if she be kept from
the male and be properly fed, and, of quadrupeds, this is
especially true of the ewe; for the ewe can be milked for eight
months. As a general rule, ruminating animals give milk in
abundance, and milk fitted for cheese manufacture. In the
neighbourhood of Torone cows run dry for a few days before
calving, and have milk all the rest of the time. In women, milk
of a livid colour is better than white for nursing purposes; and
swarthy women give healthier milk than fair ones. Milk that is
richest in cheese is the most nutritious, but milk with a scanty
supply of cheese is the more wholesome for children.
22
All sanguineous animals eject sperm. As to what, and how, it
contributes to generation, these questions will be discussed in
another treatise. Taking the size of his body into account, man
emits more sperm than any other animal. In hairy-coated
animals the sperm is sticky, but in other animals it is not so. It
is white in all cases, and Herodotus is under a misapprehension
when he states that the Aethiopians eject black sperm.
1497
Sperm issues from the body white and consistent, if it be
healthy, and after quitting the body becomes thin and black. In
frosty weather it does not coagulate, but gets exceedingly thin
and watery both in colour and consistency; but it coagulates
and thickens under the influence of heat. If it be long in the
womb before issuing out, it comes more than usually thick; and
sometimes it comes out dry and compact. Sperm capable of
impregnating or of fructification sinks in water; sperm
incapable Of producing that result dissolves away. But there is
no truth in what Ctesias has written about the sperm of the
elephant.
Book IV
We have now treated, in regard to blooded animals of the parts
they have in common and of the parts peculiar to this genus or
that, and of the parts both composite and simple, whether
without or within. We now proceed to treat of animals devoid of
blood. These animals are divided into several genera.
One genus consists of so-called 'molluscs'; and by the term
'mollusc' we mean an animal that, being devoid of blood, has its
flesh-like substance outside, and any hard structure it may
happen to have, inside - in this respect resembling the red -
blooded animals, such as the genus of the cuttle-fish.
1498
Another genus is that of the malacostraca. These are animals
that have their hard structure outside, and their soft or fleshlike
substance inside, and the hard substance belonging to them has
to be crushed rather than shattered; and to this genus belongs
the crawfish and the crab.
A third genus is that of the ostracoderms or 'testaceans'. These
are animals that have their hard substance outside and their
flesh-like substance within, and their hard substance can be
shattered but not crushed; and to this genus belong the snail
and the oyster.
The fourth genus is that of insects; and this genus
comprehends numerous and dissimilar species. Insects are
creatures that, as the name implies, have nicks either on the
belly or on the back, or on both belly and back, and have no one
part distinctly osseous and no one part distinctly fleshy, but are
throughout a something intermediate between bone and flesh;
that is to say, their body is hard all through, inside and outside.
Some insects are wingless, such as the iulus and the centipede;
some are winged, as the bee, the cockchafer, and the wasp; and
the same kind is in some cases both winged and wingless, as
the ant and the glow-worm.
In molluscs the external parts are as follows: in the first place,
the so-called feet; secondly, and attached to these, the head;
thirdly, the mantle-sac, containing the internal parts, and
incorrectly designated by some writers the head; and, fourthly,
fins round about the sac. (See diagram.) In all molluscs the head
is found to be between the feet and the belly. All molluscs are
furnished with eight feet, and in all cases these feet are
severally furnished with a double row of suckers, with the
exception of one single species of poulpe or octopus. The sepia,
the small calamary and the large calamary have an exceptional
organ in a pair of long arms or tentacles, having at their
1499
extremities a portion rendered rough by the presence of two
rows of suckers; and with these arms or tentacles they
apprehend their food and draw it into their mouths, and in
stormy weather they cling by them to a rock and sway about in
the rough water like ships lying at anchor. They swim by the aid
of the fins that they have about the sac. In all cases their feet
are furnished with suckers.
The octopus, by the way, uses his feelers either as feet or hands;
with the two which stand over his mouth he draws in food, and
the last of his feelers he employs in the act of copulation; and
this last one, by the way, is extremely sharp, is exceptional as
being of a whitish colour, and at its extremity is bifurcate; that
is to say, it has an additional something on the rachis, and by
rachis is meant the smooth surface or edge of the arm on the
far side from the suckers. (See diagram.)
In front of the sac and over the feelers they have a hollow tube,
by means of which they discharge any sea-water that they may
have taken into the sac of the body in the act of receiving food
by the mouth. They can shift the tube from side to side, and by
means of it they discharge the black liquid peculiar to the
animal.
Stretching out its feet, it swims obliquely in the direction of the
so-called head, and by this mode of swimming it can see in
front, for its eyes are at the top, and in this attitude it has its
mouth at the rear. The 'head', while the creature is alive, is hard,
and looks as though it were inflated. It apprehends and retains
objects by means of the under-surface of its arms, and the
membrane in between its feet is kept at full tension; if the
animal get on to the sand it can no longer retain its hold.
There is a difference between the octopus and the other
molluscs above mentioned: the body of the octopus is small,
and his feet are long, whereas in the others the body is large
1500
and the feet short; so short, in fact, that they cannot walk on
them. Compared with one another, the teuthis, or calamary, is
long-shaped, and the sepia flat-shaped; and of the calamaries
the so-called teuthus is much bigger than the teuthis; for teuthi
have been found as much as five ells long. Some sepiae attain a
length of two ells, and the feelers of the octopus are sometimes
as long, or even longer. The species teuthus is not a numerous
one; the teuthus differs from the teuthis in shape; that is, the
sharp extremity of the teuthus is broader than that of the other,
and, further, the encircling fin goes all round the trunk, whereas
it is in part lacking in the teuthis; both animals are pelagic.
In all cases the head comes after the feet, in the middle of the
feet that are called arms or feelers. There is here situated a
mouth, and two teeth in the mouth; and above these two large
eyes, and betwixt the eyes a small cartilage enclosing a small
brain; and within the mouth it has a minute organ of a fleshy
nature, and this it uses as a tongue, for no other tongue does it
possess. Next after this, on the outside, is what looks like a sac;
the flesh of which it is made is divisible, not in long straight
strips, but in annular flakes; and all molluscs have a cuticle
around this flesh. Next after or at the back of the mouth comes
a long and narrow oesophagus, and close after that a crop or
craw, large and spherical, like that of a bird; then comes the
stomach, like the fourth stomach in ruminants; and the shape
of it resembles the spiral convolution in the trumpet-shell; from
the stomach there goes back again, in the direction of the
mouth, thin gut, and the gut is thicker than the oesophagus.
(See diagram.)
Molluscs have no viscera, but they have what is called a mytis,
and on it a vessel containing a thick black juice; in the sepia or
cuttle-fish this vessel is the largest, and this juice is most
abundant. All molluscs, when frightened, discharge such a juice,
but the discharge is most copious in the cuttle-fish. The mytis,
1501
then, is situated under the mouth, and the oesophagus runs
through it; and down below at the point to which the gut
extends is the vesicle of the black juice, and the animal has the
vesicle and the gut enveloped in one and the same membrane,
and by the same membrane, same orifice discharges both the
black juice and the residuum. The animals have also certain
hair-like or furry growths in their bodies.
In the sepia, the teuthis, and the teuthus the hard parts are
within, towards the back of the body; those parts are called in
one the sepium, and in the other the 'sword'. They differ from
one another, for the sepium in the cuttle-fish and teuthus is
hard and flat, being a substance intermediate between bone and
fishbone, with (in part) a crumbling, spongy texture, but in the
teuthis the part is thin and somewhat gristly. These parts differ
from one another in shape, as do also the bodies of the animals.
The octopus has nothing hard of this kind in its interior, but it
has a gristly substance round the head, which, if the animal
grows old, becomes hard.
The females differ from the males. The males have a duct in
under the oesophagus, extending from the mantle-cavity to the
lower portion of the sac, and there is an organ to which it
attaches, resembling a breast; (see diagram) in the female there
are two of these organs, situated higher up; (see diagram) with
both sexes there are underneath these organs certain red
formations. The egg of the octopus is single, uneven on its
surface, and of large size; the fluid substance within is all
uniform in colour, smooth, and in colour white; the size of the
egg is so great as to fill a vessel larger than the creature's head.
The sepia has two sacs, and inside them a number of eggs, like
in appearance to white hailstones. For the disposition of these
parts I must refer to my anatomical diagrams.
1502
The males of all these animals differ from the females, and the
difference between the sexes is most marked in the sepia; for
the back of the trunk, which is blacker than the belly, is rougher
in the male than in the female, and in the male the back is
striped, and the rump is more sharply pointed.
There are several species of the octopus. One keeps close to the
surface, and is the largest of them all, and near the shore the
size is larger than in deep water; and there are others, small,
variegated in colour, which are not articles of food. There are
two others, one called the heledone, which differs from its
congeners in the length of its legs and in having one row of
suckers - all the rest of the molluscs having two, - the other
nicknamed variously the bolitaina or the 'onion,' and the ozolis
or the 'stinkard'.
There are two others found in shells resembling those of the
testaceans. One of them is nicknamed by some persons the
nautilus or the pontilus, or by others the 'polypus' egg'; and the
shell of this creature is something like a separate valve of a
deep scallop-shell. This polypus lives very often near to the
shore, and is apt to be thrown up high and dry on the beach;
under these circumstances it is found with its shell detached,
and dies by and by on dry land. These polypods are small, and
are shaped, as regards the form of their bodies, like the bolbidia.
There is another polypus that is placed within a shell like a
snail; it never comes out of the shell, but lives inside the shell
like the snail, and from time to time protrudes its feelers.
So much for molluscs.
1503
With regard to the Malacostraca or crustaceans, one species is
that of the crawfish, and a second, resembling the first, is that
of the lobster; the lobster differing from the crawfish in having
claws, and in a few other respects as well. Another species is
that of the carid, and another is that of the crab, and there are
many kinds both of carid and of crab.
Of carids there are the so-called cyphae, or 'hunch-backs', the
crangons, or squillae, and the little kind, or shrimps, and the
little kind do not develop into a larger kind.
Of the crab, the varieties are indefinite and incalculable. The
largest of all crabs is one nicknamed Maia, a second variety is
the pagarus and the crab of Heracleotis, and a third variety is
the fresh-water crab; the other varieties are smaller in size and
destitute of special designations. In the neighbourhood of
Phoenice there are found on the beach certain crabs that are
nicknamed the 'horsemen', from their running with such speed
that it is difficult to overtake them; these crabs, when opened,
are usually found empty, and this emptiness may be put down
to insufficiency of nutriment. (There is another variety, small
like the crab, but resembling in shape the lobster.) All these
animals, as has been stated, have their hard and shelly part
outside, where the skin is in other animals, and the fleshy part
inside; and the belly is more or less provided with lamellae, or
little flaps, and the female here deposits her spawn.
The crawfishes have five feet on either side, including the claws
at the end; and in like manner the crabs have ten feet in all,
including the claws. Of the carids, the hunch-backed, or prawns,
have five feet on either side, which are sharp-pointed - those
towards the head; and five others on either side in the region of
the belly, with their extremities flat; they are devoid of flaps on
the under side such as the crawfish has, but on the back they
1504
resemble the crawfish. (See diagram.)It is very different with the
crangon, or squilla; it has four front legs on either side, then
three thin ones close behind on either side, and the rest of the
body is for the most part devoid of feet. (See diagram.) Of all
these animals the feet bend out obliquely, as is the case with
insects; and the claws, where claws are found, turn inwards.
The crawfish has a tail, and five fins on it; and the round-
backed carid has a tail and four fins; the squilla also has fins at
the tail on either side. In the case of both the hump-backed
carid and the squilla the middle art of the tail is spinous: only
that in the squilla the part is flattened and in the carid it is
sharp-pointed. Of all animals of this genus the crab is the only
one devoid of a rump; and, while the body of the carid and the
crawfish is elongated, that of the crab is rotund.
In the crawfish the male differs from the female: in the female
the first foot is bifurcate, in the male it is undivided; the belly-
fins in the female are large and overlapping on the neck, while
in the male they are smaller and do not overlap; and, further, on
the last feet of the male there are spur-like projections, large
and sharp, which projections in the female are small and
smooth. Both male and female have two antennae in front of
the eyes, large and rough, and other antennae underneath,
small and smooth. The eyes of all these creatures are hard and
beady, and can move either to the inner or to the outer side. The
eyes of most crabs have a similar facility of movement, or
rather, in the crab this facility is developed in a higher degree.
(See diagram.)
The lobster is all over grey-coloured, with a mottling of black. Its
under or hinder feet, up to the big feet or claws, are eight in
number; then come the big feet, far larger and flatter at the tips
than the same organs in the crawfish; and these big feet or
claws are exceptional in their structure, for the right claw has
the extreme flat surface long and thin, while the left claw has
1505
the corresponding surface thick and round. Each of the two
claws, divided at the end like a pair of jaws, has both below and
above a set of teeth: only that in the right claw they are all small
and saw-shaped, while in the left claw those at the apex are
saw-shaped and those within are molar-shaped, these latter
being, in the under part of the cleft claw, four teeth close
together, and in the upper part three teeth, not close together.
Both right and left claws have the upper part mobile, and bring
it to bear against the lower one, and both are curved like bandy-
legs, being thereby adapted for apprehension and constriction.
Above the two large claws come two others, covered with hair, a
little underneath the mouth; and underneath these the gill-like
formations in the region of the mouth, hairy and numerous.
These organs the animal keeps in perpetual motion; and the
two hairy feet it bends and draws in towards its mouth. The feet
near the mouth are furnished also with delicate outgrowing
appendages. Like the crawfish, the lobster has two teeth, or
mandibles, and above these teeth are its antennae, long, but
shorter and finer by far than those of the crawfish, and then
four other antennae similar in shape, but shorter and finer than
the others. Over these antennae come the eyes, small and short,
not large like the eyes of the crawfish. Over the eyes is a peaky
rough projection like a forehead, larger than the same part in
the crawfish; in fact, the frontal part is more pointed and the
thorax is much broader in the lobster than in the crawfish, and
the body in general is smoother and more full of flesh. Of the
eight feet, four are bifurcate at the extremities, and four are
undivided. The region of the so-called neck is outwardly divided
into five divisions, and sixthly comes the flattened portion at
the end, and this portion has five flaps, or tail-fins; and the
inner or under parts, into which the female drops her spawn,
are four in number and hairy, and on each of the aforesaid parts
is a spine turned outwards, short and straight. The body in
general and the region of the thorax in particular are smooth,
1506
not rough as in the crawfish; but on the large claws the outer
portion has larger spines. There is no apparent difference
between the male and female, for they both have one claw,
whichever it may be, larger than the other, and neither male nor
female is ever found with both claws of the same size.
All crustaceans take in water close by the mouth. The crab
discharges it, closing up, as it does so, a small portion of the
same, and the crawfish discharges it by way of the gills; and, by
the way, the gill-shaped organs in the crawfish are very
numerous.
The following properties are common to all crustaceans: they
have in all cases two teeth, or mandibles (for the front teeth in
the crawfish are two in number), and in all cases there is in the
mouth a small fleshy structure serving for a tongue; and the
stomach is close to the mouth, only that the crawfish has a little
oesophagus in front of the stomach, and there is a straight gut
attached to it. This gut, in the crawfish and its congeners, and in
the carids, extends in a straight line to the tail, and terminates
where the animal discharges the residuum, and where the
female deposits her spawn; in the crab it terminates where the
flap is situated, and in the centre of the flap. (And by the way, in
all these animals the spawn is deposited outside.) Further, the
female has the place for the spawn running along the gut. And,
again, all these animals have, more or less, an organ termed the
'mytis', or 'poppyjuice'.
We must now proceed to review their several differentiae.
The crawfish then, as has been said, has two teeth, large and
hollow, in which is contained a juice resembling the mytis, and
in between the teeth is a fleshy substance, shaped like a tongue.
After the mouth comes a short oesophagus, and then a
membranous stomach attached to the oesophagus, and at the
orifice Of the stomach are three teeth, two facing one another
1507
and a third standing by itself underneath. Coming off at a bend
from the stomach is a gut, simple and of equal thickness
throughout the entire length of the body until it reaches the
anal vent.
These are all common properties of the crawfish, the carid, and
the crab; for the crab, be it remembered, has two teeth.
Again, the crawfish has a duct attached all the way from the
chest to the anal vent; and this duct is connected with the ovary
in the female, and with the seminal ducts in the male. This
passage is attached to the concave surface of the flesh in such a
way that the flesh is in betwixt the duct and the gut; for the gut
is related to the convexity and this duct to the concavity, pretty
much as is observed in quadrupeds. And the duct is identical in
both the sexes; that is to say, the duct in both is thin and white,
and charged with a sallow-coloured moisture, and is attached to
the chest.
(The following are the properties of the egg and of the
convolutes in the carid.)
The male, by the way, differs from the female in regard to its
flesh, in having in connexion with the chest two separate and
distinct white substances, resembling in colour and
conformation the tentacles of the cuttle-fish, and they are
convoluted like the 'poppy' or quasi-liver of the trumpet-shell.
These organs have their starting-point in 'cotyledons' or
papillae, which are situated under the hindmost feet; and
hereabouts the flesh is red and blood-coloured, but is slippery to
the touch and in so far unlike flesh. Off from the convolute
organ at the chest branches off another coil about as thick as
ordinary twine; and underneath there are two granular seminal
bodies in juxta-position with the gut. These are the organs of
the male. The female has red-coloured eggs, which are adjacent
1508
to the stomach and to each side of the gut all along to the fleshy
parts, being enveloped in a thin membrane.
Such are the parts, internal and external, of the carid.
The inner organs of sanguineous animals happen to have
specific designations; for these animals have in all cases the
inner viscera, but this is not the case with the bloodless
animals, but what they have in common with red-blooded
animals is the stomach, the oesophagus, and the gut.
With regard to the crab, it has already been stated that it has
claws and feet, and their position has been set forth;
furthermore, for the most part they have the right claw bigger
and stronger than the left. It has also been stated' that in
general the eyes of the crab look sideways. Further, the trunk of
the crab's body is single and undivided, including its head and
any other part it may possess. Some crabs have eyes placed
sideways on the upper part, immediately under the back, and
standing a long way apart, and some have their eyes in the
centre and close together, like the crabs of Heracleotis and the
so-called 'grannies'. The mouth lies underneath the eyes, and
inside it there are two teeth, as is the case with the crawfish,
only that in the crab the teeth are not rounded but long; and
over the teeth are two lids, and in betwixt them are structures
such as the crawfish has besides its teeth. The crab takes in
water near by the mouth, using the lids as a check to the inflow,
and discharges the water by two passages above the mouth,
closing by means of the lids the way by which it entered; and
the two passage-ways are underneath the eyes. When it has
taken in water it closes its mouth by means of both lids, and
1509
ejects the water in the way above described. Next after the teeth
comes the oesophagus, very short, so short in fact that the
stomach seems to come straightway after the mouth. Next after
the oesophagus comes the stomach, two-horned, to the centre
of which is attached a simple and delicate gut; and the gut
terminates outwards, at the operculum, as has been previously
stated. (The crab has the parts in between the lids in the
neighbourhood of the teeth similar to the same parts in the
crawfish.) Inside the trunk is a sallow juice and some few little
bodies, long and white, and others spotted red. The male differs
from the female in size and breadth, and in respect of the
ventral flap; for this is larger in the female than in the male, and
stands out further from the trunk, and is more hairy (as is the
case also with the female in the crawfish).
So much, then, for the organs of the malacostraca or Crustacea.
With the ostracoderma, or testaceans, such as the land-snails
and the sea-snails, and all the 'oysters' so-called, and also with
the sea-urchin genus, the fleshy part, in such as have flesh, is
similarly situated to the fleshy part in the crustaceans; in other
words, it is inside the animal, and the shell is outside, and there
is no hard substance in the interior. As compared with one
another the testaceans present many diversities both in regard
to their shells and to the flesh within. Some of them have no
flesh at all, as the sea-urchin; others have flesh, but it is inside
and wholly hidden, except the head, as in the land-snails, and
the so-called cocalia, and, among pelagic animals, in the purple
murex, the ceryx or trumpet-shell, the sea-snail, and the spiral-
shaped testaceans in general. Of the rest, some are bivalved and
1510
some univalved; and by 'bivalves' I mean such as are enclosed
within two shells, and by 'univalved' such as are enclosed
within a single shell, and in these last the fleshy part is
exposed, as in the case of the limpet. Of the bivalves, some can
open out, like the scallop and the mussel; for all such shells are
grown together on one side and are separate on the other, so as
to open and shut. Other bivalves are closed on both sides alike,
like the solen or razor-fish. Some testaceans there are, that are
entirely enveloped in shell and expose no portion of their flesh
outside, as the tethya or ascidians.
Again, in regard to the shells themselves, the testaceans present
differences when compared with one another. Some are
smooth-shelled, like the solen, the mussel, and some clams, viz.
those that are nicknamed 'milkshells', while others are rough-
shelled, such as the pool-oyster or edible oyster, the pinna, and
certain species of cockles, and the trumpet shells; and of these
some are ribbed, such as the scallop and a certain kind of clam
or cockle, and some are devoid of ribs, as the pinna and another
species of clam. Testaceans also differ from one another in
regard to the thickness or thinness of their shell, both as
regards the shell in its entirety and as regards specific parts of
the shell, for instance, the lips; for some have thin-lipped shells,
like the mussel, and others have thick-lipped shells, like the
oyster. A property common to the above mentioned, and, in fact,
to all testaceans, is the smoothness of their shells inside. Some
also are capable of motion, like the scallop, and indeed some
aver that scallops can actually fly, owing to the circumstance
that they often jump right out of the apparatus by means of
which they are caught; others are incapable of motion and are
attached fast to some external object, as is the case with the
pinna. All the spiral-shaped testaceans can move and creep, and
even the limpet relaxes its hold to go in quest of food. In the
case of the univalves and the bivalves, the fleshy substance
adheres to the shell so tenaciously that it can only be removed
1511
by an effort; in the case of the stromboids, it is more loosely
attached. And a peculiarity of all the stromboids is the spiral
twist of the shell in the part farthest away from the head; they
are also furnished from birth with an operculum. And, further,
all stromboid testaceans have their shells on the right hand
side, and move not in the direction of the spire, but the opposite
way. Such are the diversities observed in the external parts of
these animals.
The internal structure is almost the same in all these creatures,
and in the stromboids especially; for it is in size that these
latter differ from one another, and in accidents of the nature of
excess or defect. And there is not much difference between
most of the univalves and bivalves; but, while those that open
and shut differ from one another but slightly, they differ
considerably from such as are incapable of motion. And this will
be illustrated more satisfactorily hereafter.
The spiral-shaped testaceans are all similarly constructed, but
differ from one another, as has been said, in the way of excess
or defect (for the larger species have larger and more
conspicuous organs, and the smaller have smaller and less
conspicuous), and, furthermore, in relative hardness or softness,
and in other such accidents or properties. All the stromboids,
for instance, have the flesh that extrudes from the mouth of the
shell, hard and stiff; some more, and some less. From the
middle of this protrudes the head and two horns, and these
horns are large in the large species, but exceedingly minute in
the smaller ones. The head protrudes from them all in the same
way; and, if the animal be alarmed, the head draws in again.
Some of these creatures have a mouth and teeth, as the snail;
teeth sharp, and small, and delicate. They have also a proboscis
just like that of the fly; and the proboscis is tongue-shaped. The
ceryx and the purple murex have this organ firm and solid; and
just as the myops, or horse-fly, and the oestrus, or gadfly, can
1512
pierce the skin of a quadruped, so is that proboscis
proportionately stronger in these testaceans; for they bore right
through the shells of other shell-fish on which they prey. The
stomach follows close upon the mouth, and, by the way, this
organ in the snail resembles a bird's crop. Underneath come two
white firm formations, mastoid or papillary in form; and similar
formations are found in the cuttle-fish also, only that they are
of a firmer consistency in the cuttle-fish. After the stomach
comes an oesophagus, simple and long, extending to the poppy
or quasi-liver, which is in the innermost recess of the shell. All
these statements may be verified in the case of the purple
murex and the ceryx by observation within the whorl of the
shell. What comes next to the oesophagus is the gut; in fact, the
gut is continuous with the oesophagus, and runs its whole
length uncomplicated to the outlet of the residuum. The gut has
its point of origin in the region of the coil of the mecon, or so-
called 'poppy', and is wider hereabouts (for remember, the
mecon is for the most part a sort of excretion in all testaceans);
it then takes a bend and runs up again towards the fleshy part,
and terminates by the side of the head, where the animal
discharges its residuum; and this holds good in the case of all
stromboid testaceans, whether terrestrial or marine. From the
stomach there is drawn in a parallel direction with the
oesophagus, in the larger snails, a long white duct enveloped in
a membrane, resembling in colour the mastoid formations
higher up; and in it are nicks or interruptions, as in the egg-
mass of the crawfish, only, by the way, the duct of which we are
treating is white and the egg-mass of the crawfish is red. This
formation has no outlet nor duct, but is enveloped in a thin
membrane with a narrow cavity in its interior. And from the gut
downward extend black and rough formations, in close
connexion, something like the formations in the tortoise, only
not so black. Marine snails, also, have these formations, and the
1513
white ones, only that the formations are smaller in the smaller
species.
The non-spiral univalves and bivalves are in some respect
similar in construction, and in some respects dissimilar, to the
spiral testaceans. They all have a head and horns, and a mouth,
and the organ resembling a tongue; but these organs, in the
smaller species, are indiscernible owing to the minuteness of
these animals, and some are indiscernible even in the larger
species when dead, or when at rest and motionless. They all
have the mecon, or poppy, but not all in the same place, nor of
equal size, nor similarly open to observation; thus, the limpets
have this organ deep down in the bottom of the shell, and the
bivalves at the hinge connecting the two valves. They also have
in all cases the hairy growths or beards, in a circular form, as in
the scallops. And, with regard to the so-called 'egg', in those
that have it, when they have it, it is situated in one of the semi-
circles of the periphery, as is the case with the white formation
in the snail; for this white formation in the snail corresponds to
the so-called egg of which we are speaking. But all these organs,
as has been stated, are distinctly traceable in the larger species,
while in the small ones they are in some cases almost, and in
others altogether, indiscernible. Hence they are most plainly
visible in the large scallops; and these are the bivalves that have
one valve flat-shaped, like the lid of a pot. The outlet of the
excretion is in all these animals (save for the exception to be
afterwards related) on one side; for there is a passage whereby
the excretion passes out. (And, remember, the mecon or poppy,
as has been stated, is an excretion in all these animals - an
excretion enveloped in a membrane.) The so-called egg has no
outlet in any of these creatures, but is merely an excrescence in
the fleshy mass; and it is not situated in the same region with
the gut, but the 'egg' is situated on the right-hand side and the
gut on the left. Such are the relations of the anal vent in most of
these animals; but in the case of the wild limpet (called by some
1514
the 'sea-ear'), the residuum issues beneath the shell, for the
shell is perforated to give an outlet. In this particular limpet the
stomach is seen coming after the mouth, and the egg-shaped
formations are discernible. But for the relative positions of these
parts you are referred to my Treatise on Anatomy.
The so-called carcinium or hermit crab is in a way intermediate
between the crustaceans and the testaceans. In its nature it
resembles the crawfish kind, and it is born simple of itself, but
by its habit of introducing itself into a shell and living there it
resembles the testaceans, and so appears to partake of the
characters of both kinds. In shape, to give a simple illustration,
it resembles a spider, only that the part below the head and
thorax is larger in this creature than in the spider. It has two
thin red horns, and underneath these horns two long eyes, not
retreating inwards, nor turning sideways like the eyes of the
crab, but protruding straight out; and underneath these eyes the
mouth, and round about the mouth several hair-like growths,
and next after these two bifurcate legs or claws, whereby it
draws in objects towards itself, and two other legs on either
side, and a third small one. All below the thorax is soft, and
when opened in dissection is found to be sallow-coloured
within. From the mouth there runs a single passage right on to
the stomach, but the passage for the excretions is not
discernible. The legs and the thorax are hard, but not so hard as
the legs and the thorax of the crab. It does not adhere to its
shell like the purple murex and the ceryx, but can easily slip out
of it. It is longer when found in the shell of the stromboids than
when found in the shell of the neritae.
And, by the way, the animal found in the shell of the neritae is a
separate species, like to the other in most respects; but of its
bifurcate feet or claws, the right-hand one is small and the left-
hand one is large, and it progresses chiefly by the aid of this
latter and larger one. (In the shells of these animals, and in
1515
certain others, there is found a parasite whose mode of
attachment is similar. The particular one which we have just
described is named the cyllarus.)
The nerites has a smooth large round shell, and resembles the
ceryx in shape, only the poppy-juice is, in its case, not black but
red. It clings with great force near the middle. In calm weather,
then, they go free afield, but when the wind blows the carcinia
take shelter against the rocks: the neritae themselves cling fast
like limpets; and the same is the case with the haemorrhoid or
aporrhaid and all others of the like kind. And, by the way, they
cling to the rock, when they turn back their operculum, for this
operculum seems like a lid; in fact this structure represents the
one part, in the stromboids, of that which in the bivalves is a
duplicate shell. The interior of the animal is fleshy, and the
mouth is inside. And it is the same with the haemorrhoid, the
purple murex, and all suchlike animals.
Such of the little crabs as have the left foot or claw the bigger of
the two are found in the neritae, but not in the stromboids. are
some snail-shells which have inside them creatures resembling
those little crayfish that are also found in fresh water. These
creatures, however, differ in having the part inside the shells
But as to the characters, you are referred to my Treatise on
Anatomy.
The urchins are devoid of flesh, and this is a character peculiar
to them; and while they are in all cases empty and devoid of
any flesh within, they are in all cases furnished with the black
formations. There are several species of the urchin, and one of
these is that which is made use of for food; this is the kind in
1516
which are found the so-called eggs, large and edible, in the
larger and smaller specimens alike; for even when as yet very
small they are provided with them. There are two other species,
the spatangus, and the so-called bryssus, these animals are
pelagic and scarce. Further, there are the echinometrae, or
'mother-urchins', the largest in size of all the species. In
addition to these there is another species, small in size, but
furnished with large hard spines; it lives in the sea at a depth of
several fathoms; and is used by some people as a specific for
cases of strangury. In the neighbourhood of Torone there are
sea-urchins of a white colour, shells, spines, eggs and all, and
that are longer than the ordinary sea-urchin. The spine in this
species is not large nor strong, but rather limp; and the black
formations in connexion with the mouth are more than usually
numerous, and communicate with the external duct, but not
with one another; in point of fact, the animal is in a manner
divided up by them. The edible urchin moves with greatest
freedom and most often; and this is indicated by the fact that
these urchins have always something or other on their spines.
All urchins are supplied with eggs, but in some of the species
the eggs are exceedingly small and unfit for food. Singularly
enough, the urchin has what we may call its head and mouth
down below, and a place for the issue of the residuum up above;
(and this same property is common to all stromboids and to
limpets). For the food on which the creature lives lies down
below; consequently the mouth has a position well adapted for
getting at the food, and the excretion is above, near to the back
of the shell. The urchin has, also, five hollow teeth inside, and in
the middle of these teeth a fleshy substance serving the office
of a tongue. Next to this comes the oesophagus, and then the
stomach, divided into five parts, and filled with excretion, all
the five parts uniting at the anal vent, where the shell is
perforated for an outlet. Underneath the stomach, in another
membrane, are the so-called eggs, identical in number in all
1517
cases, and that number is always an odd number, to wit five. Up
above, the black formations are attached to the starting-point of
the teeth, and they are bitter to the taste, and unfit for food. A
similar or at least an analogous formation is found in many
animals; as, for instance, in the tortoise, the toad, the frog, the
stromboids, and, generally, in the molluscs; but the formation
varies here and there in colour, and in all cases is altogether
uneatable, or more or less unpalatable. In reality the mouth-
apparatus of the urchin is continuous from one end to the other,
but to outward appearance it is not so, but looks like a horn
lantern with the panes of horn left out. The urchin uses its
spines as feet; for it rests its weight on these, and then moving
shifts from place to place.
The so-called tethyum or ascidian has of all these animals the
most remarkable characteristics. It is the only mollusc that has
its entire body concealed within its shell, and the shell is a
substance intermediate between hide and shell, so that it cuts
like a piece of hard leather. It is attached to rocks by its shell,
and is provided with two passages placed at a distance from
one another, very minute and hard to see, whereby it admits
and discharges the sea-water; for it has no visible excretion
(whereas of shell fish in general some resemble the urchin in
this matter of excretion, and others are provided with the so-
called mecon, or poppy-juice). If the animal be opened, it is
found to have, in the first place, a tendinous membrane running
round inside the shell-like substance, and within this
membrane is the flesh-like substance of the ascidian, not
resembling that in other molluscs; but this flesh, to which I now
allude, is the same in all ascidia. And this substance is attached
1518
in two places to the membrane and the skin, obliquely; and at
the point of attachment the space is narrowed from side to side,
where the fleshy substance stretches towards the passages that
lead outwards through the shell; and here it discharges and
admits food and liquid matter, just as it would if one of the
passages were a mouth and the other an anal vent; and one of
the passages is somewhat wider than the other Inside it has a
pair of cavities, one on either side, a small partition separating
them; and one of these two cavities contains the liquid. The
creature has no other organ whether motor or sensory, nor, as
was said in the case of the others, is it furnished with any organ
connected with excretion, as other shell-fish are. The colour of
the ascidian is in some cases sallow, and in other cases red.
There is, furthermore, the genus of the sea-nettles, peculiar in
its way. The sea-nettle, or sea-anemone, clings to rocks like
certain of the testaceans, but at times relaxes its hold. It has no
shell, but its entire body is fleshy. It is sensitive to touch, and, if
you put your hand to it, it will seize and cling to it, as the
cuttlefish would do with its feelers, and in such a way as to
make the flesh of your hand swell up. Its mouth is in the centre
of its body, and it lives adhering to the rock as an oyster to its
shell. If any little fish come up against it it it clings to it; in fact,
just as I described it above as doing to your hand, so it does to
anything edible that comes in its way; and it feeds upon sea-
urchins and scallops. Another species of the sea-nettle roams
freely abroad. The sea-nettle appears to be devoid altogether of
excretion, and in this respect it resembles a plant.
Of sea-nettles there are two species, the lesser and more edible,
and the large hard ones, such as are found in the
neighbourhood of Chalcis. In winter time their flesh is firm, and
accordingly they are sought after as articles of food, but in
summer weather they are worthless, for they become thin and
watery, and if you catch at them they break at once into bits,
1519
and cannot be taken off the rocks entire; and being oppressed
by the heat they tend to slip back into the crevices of the rocks.
So much for the external and the internal organs of molluscs,
crustaceans, and testaceans.
We now proceed to treat of insects in like manner. This genus
comprises many species, and, though several kinds are clearly
related to one another, these are not classified under one
common designation, as in the case of the bee, the drone, the
wasp, and all such insects, and again as in the case of those that
have their wings in a sheath or shard, like the cockchafer, the
carabus or stag-beetle, the cantharis or blister-beetle, and the
like.
Insects have three parts common to them all; the head, the
trunk containing the stomach, and a third part in betwixt these
two, corresponding to what in other creatures embraces chest
and back. In the majority of insects this intermediate part is
single; but in the long and multipedal insects it has practically
the same number of segments as of nicks.
All insects when cut in two continue to live, excepting such as
are naturally cold by nature, or such as from their minute size
chill rapidly; though, by the way, wasps notwithstanding their
small size continue living after severance. In conjunction with
the middle portion either the head or the stomach can live, but
the head cannot live by itself. Insects that are long in shape and
many-footed can live for a long while after being cut in twain,
and the severed portions can move in either direction,
backwards or forwards; thus, the hinder portion, if cut off, can
1520
crawl either in the direction of the section or in the direction of
the tail, as is observed in the scolopendra.
All insects have eyes, but no other organ of sense discernible,
except that some insects have a kind of a tongue corresponding
to a similar organ common to all testaceans; and by this organ
such insects taste and imbibe their food. In some insects this
organ is soft; in other insects it is firm; as it is, by the way, in the
purple-fish, among testaceans. In the horsefly and the gadfly
this organ is hard, and indeed it is hard in most insects. In point
of fact, such insects as have no sting in the rear use this organ
as a weapon, (and, by the way, such insects as are provided with
this organ are unprovided with teeth, with the exception of a
few insects); the fly by a touch can draw blood with this organ,
and the gnat can prick or sting with it.
Certain insects are furnished with prickers or stings. Some
insects have the sting inside, as the bee and the wasp, others
outside, as the scorpion; and, by the way, this is the only insect
furnished with a long tail. And, further, the scorpion is
furnished with claws, as is also the creature resembling a
scorpion found within the pages of books.
In addition to their other organs, flying insects are furnished
with wings. Some insects are dipterous or double-winged, as
the fly; others are tetrapterous or furnished with four wings, as
the bee; and, by the way, no insect with only two wings has a
sting in the rear. Again, some winged insects have a sheath or
shard for their wings, as the cockchafer; whereas in others the
wings are unsheathed, as in the bee. But in the case of all alike,
flight is in no way modified by tail-steerage, and the wing is
devoid of quill-structure or division of any kind.
Again, some insects have antennae in front of their eyes, as the
butterfly and the horned beetle. Such of them as have the power
of jumping have the hinder legs the longer; and these long
1521
hind-legs whereby they jump bend backwards like the hind-legs
of quadrupeds. All insects have the belly different from the
back; as, in fact, is the case with all animals. The flesh of an
insect's body is neither shell-like nor is it like the internal
substance of shell-covered animals, nor is it like flesh in the
ordinary sense of the term; but it is a something intermediate in
quality. Wherefore they have nor spine, nor bone, nor sepia-
bone, nor enveloping shell; but their body by its hardness is its
own protection and requires no extraneous support. However,
insects have a skin; but the skin is exceedingly thin. These and
such-like are the external organs of insects.
Internally, next after the mouth, comes a gut, in the majority of
cases straight and simple down to the outlet of the residuum:
but in a few cases the gut is coiled. No insect is provided with
any viscera, or is supplied with fat; and these statements apply
to all animals devoid of blood. Some have a stomach also, and
attached to this the rest of the gut, either simple or convoluted
as in the case of the acris or grasshopper.
The tettix or cicada, alone of such creatures (and, in fact, alone
of all creatures), is unprovided with a mouth, but it is provided
with the tongue-like formation found in insects furnished with
frontward stings; and this formation in the cicada is long,
continuous, and devoid of any split; and by the aid of this the
creature feeds on dew, and on dew only, and in its stomach no
excretion is ever found. Of the cicada there are several kinds,
and they differ from one another in relative magnitude, and in
this respect that the achetes or chirper is provided with a cleft
or aperture under the hypozoma and has in it a membrane
quite discernible, whilst the membrane is indiscernible in the
tettigonia.
Furthermore, there are some strange creatures to be found in
the sea, which from their rarity we are unable to classify.
1522
Experienced fishermen affirm, some that they have at times
seen in the sea animals like sticks, black, rounded, and of the
same thickness throughout; others that they have seen
creatures resembling shields, red in colour, and furnished with
fins packed close together; and others that they have seen
creatures resembling the male organ in shape and size, with a
pair of fins in the place of the testicles, and they aver that on
one occasion a creature of this description was brought up on
the end of a nightline.
So much then for the parts, external and internal, exceptional
and common, of all animals.
8
We now proceed to treat of the senses; for there are diversities
in animals with regard to the senses, seeing that some animals
have the use of all the senses, and others the use of a limited
number of them. The total number of the senses (for we have no
experience of any special sense not here included), is five: sight,
hearing, smell, taste, and touch.
Man, then, and all vivipara that have feet, and, further, all red-
blooded ovipara, appear to have the use of all the five senses,
except where some isolated species has been subjected to
mutilation, as in the case of the mole. For this animal is
deprived of sight; it has no eyes visible, but if the skin - a thick
one, by the way - be stripped off the head, about the place in the
exterior where eyes usually are, the eyes are found inside in a
stunted condition, furnished with all the parts found in
ordinary eyes; that is to say, we find there the black rim, and the
fatty part surrounding it; but all these parts are smaller than
the same parts in ordinary visible eyes. There is no external sign
1523
of the existence of these organs in the mole, owing to the
thickness of the skin drawn over them, so that it would seem
that the natural course of development were congenitally
arrested; (for extending from the brain at its junction with the
marrow are two strong sinewy ducts running past the sockets of
the eyes, and terminating at the upper eye-teeth). All the other
animals of the kinds above mentioned have a perception of
colour and of sound, and the senses of smell and taste; the fifth
sense, that, namely, of touch, is common to all animals
whatsoever.
In some animals the organs of sense are plainly discernible; and
this is especially the case with the eyes. For animals have a
special locality for the eyes, and also a special locality for
hearing: that is to say, some animals have ears, while others
have the passage for sound discernible. It is the same with the
sense of smell; that is to say, some animals have nostrils, and
others have only the passages for smell, such as birds. It is the
same also with the organ of taste, the tongue. Of aquatic red-
blooded animals, fishes possess the organ of taste, namely the
tongue, but it is in an imperfect and amorphous form, in other
words it is osseous and undetached. In some fish the palate is
fleshy, as in the fresh-water carp, so that by an inattentive
observer it might be mistaken for a tongue.
There is no doubt but that fishes have the sense of taste, for a
great number of them delight in special flavours; and fishes
freely take the hook if it be baited with a piece of flesh from a
tunny or from any fat fish, obviously enjoying the taste and the
eating of food of this kind. Fishes have no visible organs for
hearing or for smell; for what might appear to indicate an organ
for smell in the region of the nostril has no communication
with the brain. These indications, in fact, in some cases lead
nowhere, like blind alleys, and in other cases lead only to the
gills; but for all this fishes undoubtedly hear and smell. For they
1524
are observed to run away from any loud noise, such as would be
made by the rowing of a galley, so as to become easy of capture
in their holes; for, by the way, though a sound be very slight in
the open air, it has a loud and alarming resonance to creatures
that hear under water. And this is shown in the capture of the
dolphin; for when the hunters have enclosed a shoal of these
fishes with a ring of their canoes, they set up from inside the
canoes a loud splashing in the water, and by so doing induce
the creatures to run in a shoal high and dry up on the beach,
and so capture them while stupefied with the noise. And yet, for
all this, the dolphin has no organ of hearing discernible.
Furthermore, when engaged in their craft, fishermen are
particularly careful to make no noise with oar or net; and after
they have spied a shoal, they let down their nets at a spot so far
off that they count upon no noise being likely to reach the
shoal, occasioned either by oar or by the surging of their boats
through the water; and the crews are strictly enjoined to
preserve silence until the shoal has been surrounded. And, at
times, when they want the fish to crowd together, they adopt
the stratagem of the dolphin-hunter; in other words they clatter
stones together, that the fish may, in their fright, gather close
into one spot, and so they envelop them within their nets.
(Before surrounding them, then, they preserve silence, as was
said; but, after hemming the shoal in, they call on every man to
shout out aloud and make any kind of noise; for on hearing the
noise and hubbub the fish are sure to tumble into the nets from
sheer fright.) Further, when fishermen see a shoal of fish
feeding at a distance, disporting themselves in calm bright
weather on the surface of the water, if they are anxious to
descry the size of the fish and to learn what kind of a fish it is,
they may succeed in coming upon the shoal whilst yet basking
at the surface if they sail up without the slightest noise, but if
any man make a noise previously, the shoal will be seen to
scurry away in alarm. Again, there is a small river-fish called the
1525
cottus or bullhead; this creature burrows under a rock, and
fishers catch it by clattering stones against the rock, and the
fish, bewildered at the noise, darts out of its hiding-place. From
these facts it is quite obvious that fishes can hear; and indeed
some people, from living near the sea and frequently witnessing
such phenomena, affirm that of all living creatures the fish is
the quickest of hearing. And, by the way, of all fishes the
quickest of hearing are the cestreus or mullet, the chremps, the
labrax or basse, the salpe or saupe, the chromis or sciaena, and
such like. Other fishes are less quick of hearing, and, as might
be expected, are more apt to be found living at the bottom of
the sea.
The case is similar in regard to the sense of smell. Thus, as a
rule, fishes will not touch a bait that is not fresh, neither are
they all caught by one and the same bait, but they are severally
caught by baits suited to their several likings, and these baits
they distinguish by their sense of smell; and, by the way, some
fishes are attracted by malodorous baits, as the saupe, for
instance, is attracted by excrement. Again, a number of fishes
live in caves; and accordingly fishermen, when they want to
entice them out, smear the mouth of a cave with strong-
smelling pickles, and the fish are Soon attracted to the smell.
And the eel is caught in a similar way; for the fisherman lays
down an earthen pot that has held pickles, after inserting a
'weel' in the neck thereof. As a general rule, fishes are especially
attracted by savoury smells. For this reason, fishermen roast the
fleshy parts of the cuttle-fish and use it as bait on account of its
smell, for fish are peculiarly attracted by it; they also bake the
octopus and bait their fish-baskets or weels with it, entirely, as
they say, on account of its smell. Furthermore, gregarious fishes,
if fish washings or bilge-water be thrown overboard, are
observed to scud off to a distance, from apparent dislike of the
smell. And it is asserted that they can at once detect by smell
the presence of their own blood; and this faculty is manifested
1526
by their hurrying off to a great distance whenever fish-blood is
spilt in the sea. And, as a general rule, if you bait your weel with
a stinking bait, the fish refuse to enter the weel or even to draw
near; but if you bait the weel with a fresh and savoury bait, they
come at once from long distances and swim into it. And all this
is particularly manifest in the dolphin; for, as was stated, it has
no visible organ of hearing, and yet it is captured when
stupefied with noise; and so, while it has no visible organ for
smell, it has the sense of smell remarkably keen. It is manifest,
then, that the animals above mentioned are in possession of all
the five senses.
All other animals may, with very few exceptions, be
comprehended within four genera: to wit, molluscs,
crustaceans, testaceans, and insects. Of these four genera, the
mollusc, the crustacean, and the insect have all the senses: at
all events, they have sight, smell, and taste. As for insects, both
winged and wingless, they can detect the presence of scented
objects afar off, as for instance bees and snipes detect the
presence of honey at a distance; and do so recognizing it by
smell. Many insects are killed by the smell of brimstone; ants, if
the apertures to their dwellings be smeared with powdered
origanum and brimstone, quit their nests; and most insects may
be banished with burnt hart's horn, or better still by the burning
of the gum styrax. The cuttle-fish, the octopus, and the crawfish
may be caught by bait. The octopus, in fact, clings so tightly to
the rocks that it cannot be pulled off, but remains attached even
when the knife is employed to sever it; and yet, if you apply
fleabane to the creature, it drops off at the very smell of it. The
facts are similar in regard to taste. For the food that insects go
in quest of is of diverse kinds, and they do not all delight in the
same flavours: for instance, the bee never settles on a withered
or wilted flower, but on fresh and sweet ones; and the conops or
gnat settles only on acrid substances and not on sweet. The
sense of touch, by the way, as has been remarked, is common to
1527
all animals. Testaceans have the senses of smell and taste. With
regard to their possession of the sense of smell, that is proved
by the use of baits, e.g. in the case of the purple-fish; for this
creature is enticed by baits of rancid meat, which it perceives
and is attracted to from a great distance. The proof that it
possesses a sense of taste hangs by the proof of its sense of
smell; for whenever an animal is attracted to a thing by
perceiving its smell, it is sure to like the taste of it. Further, all
animals furnished with a mouth derive pleasure or pain from
the touch of sapid juices.
With regard to sight and hearing, we cannot make statements
with thorough confidence or on irrefutable evidence. However,
the solen or razor-fish, if you make a noise, appears to burrow
in the sand, and to hide himself deeper when he hears the
approach of the iron rod (for the animal, be it observed, juts a
little out of its hole, while the greater part of the body remains
within), - and scallops, if you present your finger near their
open valves, close them tight again as though they could see
what you were doing. Furthermore, when fishermen are laying
bait for neritae, they always get to leeward of them, and never
speak a word while so engaged, under the firm impression that
the animal can smell and hear; and they assure us that, if any
one speaks aloud, the creature makes efforts to escape. With
regard to testaceans, of the walking or creeping species the
urchin appears to have the least developed sense of smell; and,
of the stationary species, the ascidian and the barnacle.
So much for the organs of sense in the general run of animals.
We now proceed to treat of voice.
1528
Voice and sound are different from one another; and language
differs from voice and sound. The fact is that no animal can give
utterance to voice except by the action of the pharynx, and
consequently such animals as are devoid of lung have no voice;
and language is the articulation of vocal sounds by the
instrumentality of the tongue. Thus, the voice and larynx can
emit vocal or vowel sounds; non-vocal or consonantal sounds
are made by the tongue and the lips; and out of these vocal and
non-vocal sounds language is composed. Consequently, animals
that have no tongue at all or that have a tongue not freely
detached, have neither voice nor language; although, by the
way, they may be enabled to make noises or sounds by other
organs than the tongue.
Insects, for instance, have no voice and no language, but they
can emit sound by internal air or wind, though not by the
emission of air or wind; for no insects are capable of respiration.
But some of them make a humming noise, like the bee and the
other winged insects; and others are said to sing, as the cicada.
And all these latter insects make their special noises by means
of the membrane that is underneath the 'hypozoma' - those
insects, that is to say, whose body is thus divided; as for
instance, one species of cicada, which makes the sound by
means of the friction of the air. Flies and bees, and the like,
produce their special noise by opening and shutting their wings
in the act of flying; for the noise made is by the friction of air
between the wings when in motion. The noise made by
grasshoppers is produced by rubbing or reverberating with their
long hind-legs.
No mollusc or crustacean can produce any natural voice or
sound. Fishes can produce no voice, for they have no lungs, nor
windpipe and pharynx; but they emit certain inarticulate
1529
sounds and squeaks, which is what is called their 'voice', as the
lyra or gurnard, and the sciaena (for these fishes make a
grunting kind of noise) and the caprus or boar-fish in the river
Achelous, and the chalcis and the cuckoo-fish; for the chalcis
makes a sort piping sound, and the cuckoo-fish makes a sound
greatly like the cry of the cuckoo, and is nicknamed from the
circumstance. The apparent voice in all these fishes is a sound
caused in some cases by a rubbing motion of their gills, which
by the way are prickly, or in other cases by internal parts about
their bellies; for they all have air or wind inside them, by
rubbing and moving which they produce the sounds. Some
cartilaginous fish seem to squeak.
But in these cases the term 'voice' is inappropriate; the more
correct expression would be 'sound'. For the scallop, when it
goes along supporting itself on the water, which is technically
called 'flying', makes a whizzing sound; and so does the sea-
swallow or flying-fish: for this fish flies in the air, clean out of
the water, being furnished with fins broad and long. Just then as
in the flight of birds the sound made by their wings is obviously
not voice, so is it in the case of all these other creatures.
The dolphin, when taken out of the water, gives a squeak and
moans in the air, but these noises do not resemble those above
mentioned. For this creature has a voice (and can therefore
utter vocal or vowel sounds), for it is furnished with a lung and
a windpipe; but its tongue is not loose, nor has it lips, so as to
give utterance to an articulate sound (or a sound of vowel and
consonant in combination.)
Of animals which are furnished with tongue and lung, the
oviparous quadrupeds produce a voice, but a feeble one; in
some cases, a shrill piping sound, like the serpent; in others, a
thin faint cry; in others, a low hiss, like the tortoise. The
formation of the tongue in the frog is exceptional. The front part
1530
of the tongue, which in other animals is detached, is tightly
fixed in the frog as it is in all fishes; but the part towards the
pharynx is freely detached, and may, so to speak, be spat
outwards, and it is with this that it makes its peculiar croak. The
croaking that goes on in the marsh is the call of the males to
the females at rutting time; and, by the way, all animals have a
special cry for the like end at the like season, as is observed in
the case of goats, swine, and sheep. (The bull-frog makes its
croaking noise by putting its under jaw on a level with the
surface of the water and extending its upper jaw to its utmost
capacity. The tension is so great that the upper jaw becomes
transparent, and the animal's eyes shine through the jaw like
lamps; for, by the way, the commerce of the sexes takes place
usually in the night time.) Birds can utter vocal sounds; and
such of them can articulate best as have the tongue moderately
flat, and also such as have thin delicate tongues. In some cases,
the male and the female utter the same note; in other cases,
different notes. The smaller birds are more vocal and given to
chirping than the larger ones; but in the pairing season every
species of bird becomes particularly vocal. Some of them call
when fighting, as the quail, others cry or crow when challenging
to combat, as the partridge, or when victorious, as the barn-door
cock. In some cases cock-birds and hens sing alike, as is
observed in the nightingale, only that the hen stops singing
when brooding or rearing her young; in other birds, the cocks
sing more than the hens; in fact, with barn-door fowls and
quails, the cock sings and the hen does not.
Viviparous quadrupeds utter vocal sounds of different kinds,
but they have no power of converse. In fact, this power, or
language, is peculiar to man. For while the capability of talking
implies the capability of uttering vocal sounds, the converse
does not hold good. Men that are born deaf are in all cases also
dumb; that is, they can make vocal sounds, but they cannot
speak. Children, just as they have no control over other parts, so
1531
have no control, at first, over the tongue; but it is so far
imperfect, and only frees and detaches itself by degrees, so that
in the interval children for the most part lisp and stutter.
Vocal sounds and modes of language differ according to locality.
Vocal sounds are characterized chiefly by their pitch, whether
high or low, and the kinds of sound capable of being produced
are identical within the limits of one and the same species; but
articulate sound, that one might reasonably designate
'language', differs both in various animals, and also in the same
species according to diversity of locality; as for instance, some
partridges cackle, and some make a shrill twittering noise. Of
little birds, some sing a different note from the parent birds, if
they have been removed from the nest and have heard other
birds singing; and a mother-nightingale has been observed to
give lessons in singing to a young bird, from which spectacle we
might obviously infer that the song of the bird was not equally
congenital with mere voice, but was something capable of
modification and of improvement. Men have the same voice or
vocal sounds, but they differ from one another in speech or
language.
The elephant makes a vocal sound of a windlike sort by the
mouth alone, unaided by the trunk, just like the sound of a man
panting or sighing; but, if it employ the trunk as well, the sound
produced is like that of a hoarse trumpet.
10
With regard to the sleeping and waking of animals, all creatures
that are red-blooded and provided with legs give sensible proof
that they go to sleep and that they waken up from sleep; for, as
a matter of fact, all animals that are furnished with eyelids shut
1532
them up when they go to sleep. Furthermore, it would appear
that not only do men dream, but horses also, and dogs, and
oxen; aye, and sheep, and goats, and all viviparous quadrupeds;
and dogs show their dreaming by barking in their sleep. With
regard to oviparous animals we cannot be sure that they dream,
but most undoubtedly they sleep. And the same may be said of
water animals, such as fishes, molluscs, crustaceans, to wit
crawfish and the like. These animals sleep without doubt,
although their sleep is of very short duration. The proof of their
sleeping cannot be got from the condition of their eyes - for
none of these creatures are furnished with eyelids - but can be
obtained only from their motionless repose.
Apart from the irritation caused by lice and what are
nicknamed fleas, fish are met with in a state so motionless that
one might easily catch them by hand; and, as a matter of fact,
these little creatures, if the fish remain long in one position, will
attack them in myriads and devour them. For these parasites
are found in the depths of the sea, and are so numerous that
they devour any bait made of fish's flesh if it be left long on the
ground at the bottom; and fishermen often draw up a cluster of
them, all clinging on to the bait.
But it is from the following facts that we may more reasonably
infer that fishes sleep. Very often it is possible to take a fish off
its guard so far as to catch hold of it or to give it a blow
unawares; and all the while that you are preparing to catch or
strike it, the fish is quite still but for a slight motion of the tail.
And it is quite obvious that the animal is sleeping, from its
movements if any disturbance be made during its repose; for it
moves just as you would expect in a creature suddenly
awakened. Further, owing to their being asleep, fish may be
captured by torchlight. The watchmen in the tunny-fishery
often take advantage of the fish being asleep to envelop them in
a circle of nets; and it is quite obvious that they were thus
1533
sleeping by their lying still and allowing the glistening under-
pays of their bodies to become visible, while the capture is
taking Place. They sleep in the night-time more than during the
day; and so soundly at night that you may cast the net without
making them stir. Fish, as a general rule, sleep close to the
ground, or to the sand or to a stone at the bottom, or after
concealing themselves under a rock or the ground. Flat fish go
to sleep in the sand; and they can be distinguished by the
outlines of their shapes in the sand, and are caught in this
position by being speared with pronged instruments. The basse,
the chrysophrys or gilt-head, the mullet, and fish of the like sort
are often caught in the daytime by the prong owing to their
having been surprised when sleeping; for it is scarcely probable
that fish could be pronged while awake. Cartilaginous fish sleep
at times so soundly that they may be caught by hand. The
dolphin and the whale, and all such as are furnished with a
blow-hole, sleep with the blow-hole over the surface of the
water, and breathe through the blow-hole while they keep up a
quiet flapping of their fins; indeed, some mariners assure us
that they have actually heard the dolphin snoring.
Molluscs sleep like fishes, and crustaceans also. It is plain also
that insects sleep; for there can be no mistaking their condition
of motionless repose. In the bee the fact of its being asleep is
very obvious; for at night-time bees are at rest and cease to
hum. But the fact that insects sleep may be very well seen in
the case of common every-day creatures; for not only do they
rest at night-time from dimness of vision (and, by the way, all
hard-eyed creatures see but indistinctly), but even if a lighted
candle be presented they continue sleeping quite as soundly.
Of all animals man is most given to dreaming. Children and
infants do not dream, but in most cases dreaming comes on at
the age of four or five years. Instances have been known of full-
grown men and women that have never dreamed at all; in
1534
exceptional cases of this kind, it has been observed that when a
dream occurs in advanced life it prognosticates either actual
dissolution or a general break-up of the system.
So much then for sensation and for the phenomena of sleeping
and of awakening.
11
With regard to sex, some animals are divided into male and
female, but others are not so divided but can only be said in a
comparative way to bring forth young and to be pregnant. In
animals that live confined to one spot there is no duality of sex;
nor is there such, in fact, in any testaceans. In molluscs and in
crustaceans we find male and female: and, indeed, in all
animals furnished with feet, biped or quadruped; in short, in all
such as by copulation engender either live young or egg or grub.
In the several genera, with however certain exceptions, there
either absolutely is or absolutely is not a duality of sex. Thus, in
quadrupeds the duality is universal, while the absence of such
duality is universal in testaceans, and of these creatures, as
with plants, some individuals are fruitful and some are not their
lying still
But among insects and fishes, some cases are found wholly
devoid of this duality of sex. For instance, the eel is neither male
nor female, and can engender nothing. In fact, those who assert
that eels are at times found with hair-like or worm-like progeny
attached, make only random assertions from not having
carefully noticed the locality of such attachments. For no eel
nor animal of this kind is ever viviparous unless previously
oviparous; and no eel was ever yet seen with an egg. And
animals that are viviparous have their young in the womb and
1535
closely attached, and not in the belly; for, if the embryo were
kept in the belly, it would be subjected to the process of
digestion like ordinary food. When people rest duality of sex in
the eel on the assertion that the head of the male is bigger and
longer, and the head of the female smaller and more snubbed,
they are taking diversity of species for diversity of sex.
There are certain fish that are nicknamed the epitragiae, or
capon-fish, and, by the way, fish of this description are found in
fresh water, as the carp and the balagrus. This sort of fish never
has either roe or milt; but they are hard and fat all over, and are
furnished with a small gut; and these fish are regarded as of
super-excellent quality.
Again, just as in testaceans and in plants there is what bears
and engenders, but not what impregnates, so is it, among fishes,
with the psetta, the erythrinus, and the channe; for these fish
are in all cases found furnished with eggs.
As a general rule, in red-blooded animals furnished with feet
and not oviparous, the male is larger and longer-lived than the
female (except with the mule, where the female is longer-lived
and bigger than the male); whereas in oviparous and
vermiparous creatures, as in fishes and in insects, the female is
larger than the male; as, for instance, with the serpent, the
phalangium or venom-spider, the gecko, and the frog. The same
difference in size of the sexes is found in fishes, as, for instance,
in the smaller cartilaginous fishes, in the greater part of the
gregarious species, and in all that live in and about rocks. The
fact that the female is longer-lived than the male is inferred
from the fact that female fishes are caught older than males.
Furthermore, in all animals the upper and front parts are better,
stronger, and more thoroughly equipped in the male than in the
female, whereas in the female those parts are the better that
may be termed hinder-parts or underparts. And this statement
1536
is applicable to man and to all vivipara that have feet. Again, the
female is less muscular and less compactly jointed, and more
thin and delicate in the hair - that is, where hair is found; and,
where there is no hair, less strongly furnished in some
analogous substance. And the female is more flaccid in texture
of flesh, and more knock-kneed, and the shin-bones are
thinner; and the feet are more arched and hollow in such
animals as are furnished with feet. And with regard to voice, the
female in all animals that are vocal has a thinner and sharper
voice than the male; except, by the way, with kine, for the
lowing and bellowing of the cow has a deeper note than that of
the bull. With regard to organs of defence and offence, such as
teeth, tusks, horns, spurs, and the like, these in some species
the male possesses and the female does not; as, for instance,
the hind has no horns, and where the cock-bird has a spur the
hen is entirely destitute of the organ; and in like manner the
sow is devoid of tusks. In other species such organs are found in
both sexes, but are more perfectly developed in the male; as, for
instance, the horn of the bull is more powerful than the horn of
the cow.
BookV
As to the parts internal and external that all animals are
furnished withal, and further as to the senses, to voice, and
1537
sleep, and the duality sex, all these topics have now been
touched upon. It now remains for us to discuss, duly and in
order, their several modes of propagation.
These modes are many and diverse, and in some respects are
like, and in other respects are unlike to one another. As we
carried on our previous discussion genus by genus, so we must
attempt to follow the same divisions in our present argument;
only that whereas in the former case we started with a
consideration of the parts of man, in the present case it behoves
us to treat of man last of all because he involves most
discussion. We shall commence, then, with testaceans, and then
proceed to crustaceans, and then to the other genera in due
order; and these other genera are, severally, molluscs, and
insects, then fishes viviparous and fishes oviparous, and next
birds; and afterwards we shall treat of animals provided with
feet, both such as are oviparous and such as are viviparous, and
we may observe that some quadrupeds are viviparous, but that
the only viviparous biped is man.
Now there is one property that animals are found to have in
common with plants. For some plants are generated from the
seed of plants, whilst other plants are self-generated through
the formation of some elemental principle similar to a seed;
and of these latter plants some derive their nutriment from the
ground, whilst others grow inside other plants, as is mentioned,
by the way, in my treatise on Botany. So with animals, some
spring from parent animals according to their kind, whilst
others grow spontaneously and not from kindred stock; and of
these instances of spontaneous generation some come from
putrefying earth or vegetable matter, as is the case with a
number of insects, while others are spontaneously generated in
the inside of animals out of the secretions of their several
organs.
1538
In animals where generation goes by heredity, wherever there is
duality of sex generation is due to copulation. In the group of
fishes, however, there are some that are neither male nor
female, and these, while they are identical generically with
other fish, differ from them specifically; but there are others
that stand altogether isolated and apart by themselves. Other
fishes there are that are always female and never male, and
from them are conceived what correspond to the wind-eggs in
birds. Such eggs, by the way, in birds are all unfruitful; but it is
their nature to be independently capable of generation up to the
egg-stage, unless indeed there be some other mode than the
one familiar to us of intercourse with the male; but concerning
these topics we shall treat more precisely later on. In the case of
certain fishes, however, after they have spontaneously
generated eggs, these eggs develop into living animals; only that
in certain of these cases development is spontaneous, and in
others is not independent of the male; and the method of
proceeding in regard to these matters will set forth by and by,
for the method is somewhat like to the method followed in the
case of birds. But whensoever creatures are spontaneously
generated, either in other animals, in the soil, or on plants, or in
the parts of these, and when such are generated male and
female, then from the copulation of such spontaneously
generated males and females there is generated a something- a
something never identical in shape with the parents, but a
something imperfect. For instance, the issue of copulation in
lice is nits; in flies, grubs; in fleas, grubs egg-like in shape; and
from these issues the parent-species is never reproduced, nor is
any animal produced at all, but the like nondescripts only.
First, then, we must proceed to treat of 'covering' in regard to
such animals as cover and are covered; and then after this to
treat in due order of other matters, both the exceptional and
those of general occurrence.
1539
Those animals, then, cover and are covered in which there is a
duality of sex, and the modes of covering in such animals are
not in all cases similar nor analogous. For the red-blooded
animals that are viviparous and furnished with feet have in all
cases organs adapted for procreation, but the sexes do not in all
cases come together in like manner. Thus, opisthuretic animals
copulate with a rearward presentment, as is the case with the
lion, the hare, and the lynx; though, by the way, in the case of
the hare, the female is often observed to cover the male.
The case is similar in most other such animals; that is to say,
the majority of quadrupeds copulate as best they can, the male
mounting the female; and this is the only method of copulating
adopted by birds, though there are certain diversities of method
observed even in birds. For in some cases the female squats on
the ground and the male mounts on top of her, as is the case
with the cock and hen bustard, and the barn-door cock and hen;
in other cases, the male mounts without the female squatting,
as with the male and female crane; for, with these birds, the
male mounts on to the back of the female and covers her, and
like the cock-sparrow consumes but very little time in the
operation. Of quadrupeds, bears perform the operation lying
prone on one another, in the same way as other quadrupeds do
while standing up; that is to say, with the belly of the male
pressed to the back of the female. Hedgehogs copulate erect,
belly to belly.
With regard to large-sized vivipara, the hind only very rarely
sustains the mounting of the stag to the full conclusion of the
operation, and the same is the case with the cow as regards the
1540
bull, owing to the rigidity of the penis of the bull. In point of
fact, the females of these animals elicit the sperm of the male
in the act of withdrawing from underneath him; and, by the
way, this phenomenon has been observed in the case of the stag
and hind, domesticated, of course. Covering with the wolf is the
same as with the dog. Cats do not copulate with a rearward
presentment on the part of the female, but the male stands
erect and the female puts herself underneath him; and, by the
way, the female cat is peculiarly lecherous, and wheedles the
male on to sexual commerce, and caterwauls during the
operation. Camels copulate with the female in a sitting posture,
and the male straddles over and covers her, not with the hinder
presentment on the female's part but like the other quadrupeds
mentioned above, and they pass the whole day long in the
operation; when thus engaged they retire to lonely spots, and
none but their keeper dare approach them. And, be it observed,
the penis of the camel is so sinewy that bow-strings are
manufactured out of it. Elephants, also, copulate in lonely
places, and especially by river-sides in their usual haunts; the
female squats down, and straddles with her legs, and the male
mounts and covers her. The seal covers like all opisthuretic
animals, and in this species the copulation extends over a
lengthened time, as is the case with the dog and bitch; and the
penis in the male seal is exceptionally large.
Oviparous quadrupeds cover one another in the same way. That
is to say, in some cases the male mounts the female precisely as
in the viviparous animals, as is observed in both the land and
the sea tortoise.... And these creatures have an organ in which
the ducts converge, and with which they perform the act of
1541
copulation, as is also observed in the toad, the frog, and all
other animals of the same group.
Long animals devoid of feet, like serpents and muraenae,
intertwine in coition, belly to belly. And, in fact, serpents coil
round one another so tightly as to present the appearance of a
single serpent with a pair of heads. The same mode is followed
by the saurians; that is to say, they coil round one another in the
act of coition.
All fishes, with the exception of the flat selachians, lie down
side by side, and copulate belly to belly. Fishes, however, that are
flat and furnished with tails - as the ray, the trygon, and the like
- copulate not only in this way, but also, where the tail from its
thinness is no impediment, by mounting of the male upon the
female, belly to back. But the rhina or angel-fish, and other like
fishes where the tail is large, copulate only by rubbing against
one another sideways, belly to belly. Some men assure us that
they have seen some of the selachia copulating hindways, dog
and bitch. In the cartilaginous species the female is larger than
the male; and the same is the case with other fishes for the
most part. And among cartilaginous fishes are included, besides
those already named, the bos, the lamia, the aetos, the narce or
torpedo, the fishing-frog, and all the galeodes or sharks and
dogfish. Cartilaginous fishes, then, of all kinds, have in many
1542
instances been observed copulating in the way above
mentioned; for, by the way, in viviparous animals the process of
copulation is of longer duration than in the ovipara.
It is the same with the dolphin and with all cetaceans; that is to
say, they come side by side, male and female, and copulate, and
the act extends over a time which is neither short nor very long.
Again, in cartilaginous fishes the male, in some species, differs
from the female in the fact that he is furnished with two
appendages hanging down from about the exit of the residuum,
and that the female is not so furnished; and this distinction
between the sexes is observed in all the species of the sharks
and dog-fish.
Now neither fishes nor any animals devoid of feet are furnished
with testicles, but male serpents and male fishes have a pair of
ducts which fill with milt or sperm at the rutting season, and
discharge, in all cases, a milk-like juice. These ducts unite, as in
birds; for birds, by the way, have their testicles in their interior,
and so have all ovipara that are furnished with feet. And this
union of the ducts is so far continued and of such extension as
to enter the receptive organ in the female.
In viviparous animals furnished with feet there is outwardly
one and the same duct for the sperm and the liquid residuum;
but there are separate ducts internally, as has been observed in
the differentiation of the organs. And with such animals as are
not viviparous the same passage serves for the discharge also of
the solid residuum; although, internally, there are two passages,
separate but near to one another. And these remarks apply to
both male and female; for these animals are unprovided with a
bladder except in the case of the tortoise; and the she-tortoise,
though furnished with a bladder, has only one passage; and
tortoises, by the way, belong to the ovipara.
1543
In the case of oviparous fishes the process of coition is less
open to observation. In point of fact, some are led by the want
of actual observation to surmise that the female becomes
impregnated by swallowing the seminal fluid of the male. And
there can be no doubt that this proceeding on the part of the
female is often witnessed; for at the rutting season the females
follow the males and perform this operation, and strike the
males with their mouths under the belly, and the males are
thereby induced to part with the sperm sooner and more
plentifully. And, further, at the spawning season the males go in
pursuit of the females, and, as the female spawns, the males
swallow the eggs; and the species is continued in existence by
the spawn that survives this process. On the coast of Phoenicia
they take advantage of these instinctive propensities of the two
sexes to catch both one and the other: that is to say, by using
the male of the grey mullet as a decoy they collect and net the
female, and by using the female, the male.
The repeated observation of this phenomenon has led to the
notion that the process was equivalent to coition, but the fact is
that a similar phenomenon is observable in quadrupeds. For at
the rutting seasons both the males and the females take to
running at their genitals, and the two sexes take to smelling
each other at those parts. (With partridges, by the way, if the
female gets to leeward of the male, she becomes thereby
impregnated. And often when they happen to be in heat she is
affected in this wise by the voice of the male, or by his
breathing down on her as he flies overhead; and, by the way,
both the male and the female partridge keep the mouth wide
open and protrude the tongue in the process of coition.)
The actual process of copulation on the part of oviparous fishes
is seldom accurately observed, owing to the fact that they very
soon fall aside and slip asunder. But, for all that, the process has
been observed to take place in the manner above described.
1544
Molluscs, such as the octopus, the sepia, and the calamary, have
sexual intercourse all in the same way; that is to say, they unite
at the mouth, by an interlacing of their tentacles. When, then,
the octopus rests its so-called head against the ground and
spreads abroad its tentacles, the other sex fits into the
outspreading of these tentacles, and the two sexes then bring
their suckers into mutual connexion.
Some assert that the male has a kind of penis in one of his
tentacles, the one in which are the largest suckers; and they
further assert that the organ is tendinous in character, growing
attached right up to the middle of the tentacle, and that the
latter enables it to enter the nostril or funnel of the female.
Now cuttle-fish and calamaries swim about closely intertwined,
with mouths and tentacles facing one another and fitting
closely together, and swim thus in opposite directions; and they
fit their so-called nostrils into one another, and the one sex
swims backwards and the other frontwards during the
operation. And the female lays its spawn by the so-called 'blow-
hole'; and, by the way, some declare that it is at this organ that
the coition really takes place.
Crustaceans copulate, as the crawfish, the lobster, the carid and
the like, just like the opisthuretic quadrupeds, when the one
animal turns up its tail and the other puts his tail on the other's
1545
tail. Copulation takes place in the early spring, near to the
shore; and, in fact, the process has often been observed in the
case of all these animals. Sometimes it takes place about the
time when the figs begin to ripen. Lobsters and carids copulate
in like manner.
Crabs copulate at the front parts of one another, belly to belly,
throwing their overlapping opercula to meet one another: first
the smaller crab mounts the larger at the rear; after he has
mounted, the larger one turns on one side. Now, the female
differs in no respect from the male except in the circumstance
that its operculum is larger, more elevated, and more hairy, and
into this operculum it spawns its eggs and in the same
neighbourhood is the outlet of the residuum. In the copulative
process of these animals there is no protrusion of a member
from one animal into the other.
8
Insects copulate at the hinder end, and the smaller individuals
mount the larger; and the smaller individual is the male. The
female pushes from underneath her sexual organ into the body
of the male above, this being the reverse of the operation
observed in other creatures; and this organ in the case of some
insects appears to be disproportionately large when compared
to the size of the body, and that too in very minute creatures; in
some insects the disproportion is not so striking. This
phenomenon may be witnessed if any one will pull asunder
flies that are copulating; and, by the way, these creatures are,
under the circumstances, averse to separation; for the
intercourse of the sexes in their case is of long duration, as may
be observed with common everyday insects, such as the fly and
1546
the cantharis. They all copulate in the manner above described,
the fly, the cantharis, the sphondyle, (the phalangium spider)
any others of the kind that copulate at all. The phalangia - that
is to say, such of the species as spin webs - perform the
operation in the following way: the female takes hold of the
suspended web at the middle and gives a pull, and the male
gives a counter pull; this operation they repeat until they are
drawn in together and interlaced at the hinder ends; for, by the
way, this mode of copulation suits them in consequence of the
rotundity of their stomachs.
So much for the modes of sexual intercourse in all animals; but,
with regard to the same phenomenon, there are definite laws
followed as regards the season of the year and the age of the
animal.
Animals in general seem naturally disposed to this intercourse
at about the same period of the year, and that is when winter is
changing into summer. And this is the season of spring, in
which almost all things that fly or walk or swim take to pairing.
Some animals pair and breed in autumn also and in winter, as
is the case with certain aquatic animals and certain birds. Man
pairs and breeds at all seasons, as is the case also with
domesticated animals, owing to the shelter and good feeding
they enjoy: that is to say, with those whose period of gestation
is also comparatively brief, as the sow and the bitch, and with
those birds that breed frequently. Many animals time the
season of intercourse with a view to the right nurture
subsequently of their young. In the human species, the male is
more under sexual excitement in winter, and the female in
summer.
With birds the far greater part, as has been said, pair and breed
during the spring and early summer, with the exception of the
halcyon.
1547
The halcyon breeds at the season of the winter solstice.
Accordingly, when this season is marked with calm weather, the
name of 'halcyon days' is given to the seven days preceding, and
to as many following, the solstice; as Simonides the poet says:
God lulls for fourteen days the winds to sleep
In winter; and this temperate interlude
Men call the Holy Season, when the deep
Cradles the mother Halcyon and her brood.
And these days are calm, when southerly winds prevail at the
solstice, northerly ones having been the accompaniment of the
Pleiads. The halcyon is said to take seven days for building her
nest, and the other seven for laying and hatching her eggs. In
our country there are not always halcyon days about the time of
the winter solstice, but in the Sicilian seas this season of calm is
almost periodical. The bird lays about five eggs.
(The aithyia, or diver, and the larus, or gull, lay their eggs on
rocks bordering on the sea, two or three at a time; but the gull
lays in the summer, and the diver at the beginning of spring,
just after the winter solstice, and it broods over its eggs as birds
do in general. And neither of these birds resorts to a hiding-
place.)
The halcyon is the most rarely seen of all birds. It is seen only
about the time of the setting of the Pleiads and the winter
solstice. When ships are lying at anchor in the roads, it will
hover about a vessel and then disappear in a moment, and
1548
Stesichorus in one of his poems alludes to this peculiarity. The
nightingale also breeds at the beginning of summer, and lays
five or six eggs; from autumn until spring it retires to a hiding-
place.
Insects copulate and breed in winter also, that is when the
weather is fine and south winds prevail; such, I mean, as do not
hibernate, as the fly and the ant. The greater part of wild
animals bring forth once and once only in the year, except in
the case of animals like the hare, where the female can become
superfoetally impregnated.
In like manner the great majority of fishes breed only once a
year, like the shoal-fishes (or, in other words, such as are caught
in nets), the tunny, the pelamys, the grey mullet, the chalcis, the
mackerel, the sciaena, the psetta and the like, with the
exception of the labrax or basse; for this fish (alone amongst
those mentioned) breeds twice a year, and the second brood is
the weaker of the two. The trichias and the rock-fishes breed
twice a year; the red mullet breeds thrice a year, and is
exceptional in this respect. This conclusion in regard to the red
mullet is inferred from the spawn; for the spawn of the fish may
be seen in certain places at three different times of the year. The
scorpaena breeds twice a year. The sargue breeds twice, in the
spring and in the autumn. The saupe breeds once a year only, in
the autumn. The female tunny breeds only once a year, but
owing to the fact that the fish in some cases spawn early and in
others late, it looks as though the fish bred twice over. The first
spawning takes place in December before the solstice, and the
latter spawning in the spring. The male tunny differs from the
female in being unprovided with the fin beneath the belly
which is called aphareus.
1549
10
Of cartilaginous fishes, the rhina or angelfish is the only one
that breeds twice; for it breeds at the beginning of autumn, and
at the setting of the Pleiads: and, of the two seasons, it is in
better condition in the autumn. It engenders at a birth seven or
eight young. Certain of the dog-fishes, for example the spotted
dog, seem to breed twice a month, and this results from the
circumstance that the eggs do not all reach maturity at the
same time.
Some fishes breed at all seasons, as the muraena. This animal
lays a great number of eggs at a time; and the young when
hatched are very small but grow with great rapidity, like the
young of the hippurus, for these fishes from being diminutive at
the outset grow with exceptional rapidity to an exceptional size.
(Be it observed that the muraena breeds at all seasons, but the
hippurus only in the spring. The smyrus differs from the
smyraena; for the muraena is mottled and weakly, whereas the
smyrus is strong and of one uniform colour, and the colour
resembles that of the pine-tree, and the animal has teeth inside
and out. They say that in this case, as in other similar ones, the
one is the male, and the other the female, of a single species.
They come out on to the land, and are frequently caught.)
Fishes, then, as a general rule, attain their full growth with great
rapidity, but this is especially the case, among small fishes, with
the coracine or crow-fish: it spawns, by the way, near the shore,
in weedy and tangled spots. The orphus also, or sea-perch, is
small at first, and rapidly attains a great size. The pelamys and
the tunny breed in the Euxine, and nowhere else. The cestreus
or mullet, the chrysophrys or gilt-head, and the labrax or basse,
breed best where rivers run into the sea. The orcys or large-
sized tunny, the scorpis, and many other species spawn in the
open sea.
1550
11
Fish for the most part breed some time or other during the
three months between the middle of March and the middle of
June. Some few breed in autumn: as, for instance, the saupe and
the sargus, and such others of this sort as breed shortly before
the autumn equinox; likewise the electric ray and the angel-
fish. Other fishes breed both in winter and in summer, as was
previously observed: as, for instance, in winter-time the basse,
the grey mullet, and the belone or pipe-fish; and in summer-
time, from the middle of June to the middle of July, the female
tunny, about the time of the summer solstice; and the tunny
lays a sac-like enclosure in which are contained a number of
small eggs. The ryades or shoal-fishes breed in summer.
Of the grey mullets, the chelon begins to be in roe between the
middle of November and the middle of December; as also the
sargue, and the smyxon or myxon, and the cephalus; and their
period of gestation is thirty days. And, by the way, some of the
grey mullet species are not produced from copulation, but grow
spontaneously from mud and sand.
As a general rule, then, fishes are in roe in the spring-time;
while some, as has been said, are so in summer, in autumn, or
in winter. But whereas the impregnation in the spring-time
follows a general law, impregnation in the other seasons does
not follow the same rule either throughout or within the limits
of one genus; and, further, conception in these variant seasons
is not so prolific. And, indeed, we must bear this in mind, that
just as with plants and quadrupeds diversity of locality has
much to do not only with general physical health but also with
the comparative frequency of sexual intercourse and
1551
generation, so also with regard to fishes locality of itself has
much to do not only in regard to the size and vigour of the
creature, but also in regard to its parturition and its copulations,
causing the same species to breed oftener in one place and
seldomer in another.
12
The molluscs also breed in spring. Of the marine molluscs one
of the first to breed is the sepia. It spawns at all times of the day
and its period of gestation is fifteen days. After the female has
laid her eggs, the male comes and discharges the milt over the
eggs, and the eggs thereupon harden. And the two sexes of this
animal go about in pairs, side by side; and the male is more
mottled and more black on the back than the female.
The octopus pairs in winter and breeds in spring, lying hidden
for about two months. Its spawn is shaped like a vine-tendril,
and resembles the fruit of the white poplar; the creature is
extraordinarily prolific, for the number of individuals that come
from the spawn is something incalculable. The male differs
from the female in the fact that its head is longer, and that the
organ called by the fishermen its penis, in the tentacle, is white.
The female, after laying her eggs, broods over them, and in
consequence gets out of condition, by reason of not going in
quest of food during the hatching period.
The purple murex breeds about springtime, and the ceryx at the
close of the winter. And, as a general rule, the testaceans are
found to be furnished with their so-called eggs in spring-time
and in autumn, with the exception of the edible urchin; for this
animal has the so-called eggs in most abundance in these
seasons, but at no season is unfurnished with them; and it is
1552
furnished with them in especial abundance in warm weather or
when a full moon is in the sky. Only, by the way, these remarks
do not apply to the sea-urchin found in the Pyrrhaean Straits,
for this urchin is at its best for table purposes in the winter; and
these urchins are small but full of eggs.
Snails are found by observations to become in all cases
impregnated about the same season.
13
(Of birds the wild species, as has been stated, as a general rule
pair and breed only once a year. The swallow, however, and the
blackbird breed twice. With regard to the blackbird, however, its
first brood is killed by inclemency of weather (for it is the
earliest of all birds to breed), but the second brood it usually
succeeds in rearing.
Birds that are domesticated or that are capable of domestication
breed frequently, just as the common pigeon breeds all through
the summer, and as is seen in the barn-door hen; for the barn-
door cock and hen have intercourse, and the hen breeds, at all
seasons alike: excepting by the way, during the days about the
winter solstice.
Of the pigeon family there are many diversities; for the peristera
or common pigeon is not identical with the peleias or rock-
pigeon. In other words, the rock-pigeon is smaller than the
common pigeon, and is less easily domesticated; it is also black,
and small, red-footed and rough-footed; and in consequence of
these peculiarities it is neglected by the pigeon-fancier. The
largest of all the pigeon species is the phatta or ring-dove; and
the next in size is the oenas or stock-dove; and the stock-dove is
1553
a little larger than the common pigeon. The smallest of all the
species is the turtle-dove. Pigeons breed and hatch at all
seasons, if they are furnished with a sunny place and all
requisites; unless they are so furnished, they breed only in the
summer. The spring brood is the best, or the autumn brood. At
all events, without doubt, the produce of the hot season, the
summer brood, is the poorest of the three.)
14
Further, animals differ from one another in regard to the time of
life that is best adapted for sexual intercourse.
To begin with, in most animals the secretion of the seminal
fluid and its generative capacity are not phenomena
simultaneously manifested, but manifested successively. Thus,
in all animals, the earliest secretion of sperm is unfruitful, or if
it be fruitful the issue is comparatively poor and small. And this
phenomenon is especially observable in man, in viviparous
quadrupeds, and in birds; for in the case of man and the
quadruped the offspring is smaller, and in the case of the bird,
the egg.
For animals that copulate, of one and the same species, the age
for maturity is in most species tolerably uniform, unless it
occurs prematurely by reason of abnormality, or is postponed by
physical injury.
In man, then, maturity is indicated by a change of the tone of
voice, by an increase in size and an alteration in appearance of
the sexual organs, as also in an increase of size and alteration in
appearance of the breasts; and above all, in the hair-growth at
the pubes. Man begins to possess seminal fluid about the age of
1554
fourteen, and becomes generatively capable at about the age of
twenty-one years.
In other animals there is no hair-growth at the pubes (for some
animals have no hair at all, and others have none on the belly,
or less on the belly than on the back), but still, in some animals
the change of voice is quite obvious; and in some animals other
organs give indication of the commencing secretion of the
sperm and the onset of generative capacity. As a general rule
the female is sharper-toned in voice than the male, and the
young animal than the elder; for, by the way, the stag has a
much deeper-toned bay than the hind. Moreover, the male cries
chiefly at rutting time, and the female under terror and alarm;
and the cry of the female is short, and that of the male
prolonged. With dogs also, as they grow old, the tone of the bark
gets deeper.
There is a difference observable also in the neighings of horses.
That is to say, the female foal has a thin small neigh, and the
male foal a small neigh, yet bigger and deeper-toned than that
of the female, and a louder one as time goes on. And when the
young male and female are two years old and take to breeding,
the neighing of the stallion becomes loud and deep, and that of
the mare louder and shriller than heretofore; and this change
goes on until they reach the age of about twenty years; and after
this time the neighing in both sexes becomes weaker and
weaker.
As a rule, then, as was stated, the voice of the male differs from
the voice of the female, in animals where the voice admits of a
continuous and prolonged sound, in the fact that the note in
the male voice is more deep and bass; not, however, in all
animals, for the contrary holds good in the case of some, as for
instance in kine: for here the cow has a deeper note than the
bull, and the calves a deeper note than the cattle. And we can
1555
thus understand the change of voice in animals that undergo
gelding; for male animals that undergo this process assume the
characters of the female.
The following are the ages at which various animals become
capacitated for sexual commerce. The ewe and the she-goat are
sexually mature when one year old, and this statement is made
more confidently in respect to the she-goat than to the ewe; the
ram and the he-goat are sexually mature at the same age. The
progeny of very young individuals among these animals differs
from that of other males: for the males improve in the course of
the second year, when they become fully mature. The boar and
the sow are capable of intercourse when eight months old, and
the female brings forth when one year old, the difference
corresponding to her period of gestation. The boar is capable of
generation when eight months old, but, with a sire under a year
in age, the litter is apt to be a poor one. The ages, however, are
not invariable; now and then the boar and the sow are capable
of intercourse when four months old, and are capable of
producing a litter which can be reared when six months old; but
at times the boar begins to be capable of intercourse when ten
months. He continues sexually mature until he is three years
old. The dog and the bitch are, as a rule, sexually capable and
sexually receptive when a year old, and sometimes when eight
months old; but the priority in date is more common with the
dog than with the bitch. The period of gestation with the bitch is
sixty days, or sixty-one, or sixty-two, or sixty-three at the
utmost; the period is never under sixty days, or, if it is, the litter
comes to no good. The bitch, after delivering a litter, submits to
the male in six months, but not before. The horse and the mare
are, at the earliest, sexually capable and sexually mature when
two years old; the issue, however, of parents of this age is small
and poor. As a general rule these animals are sexually capable
when three years old, and they grow better for breeding
purposes until they reach twenty years. The stallion is sexually
1556
capable up to the age of thirty-three years, and the mare up to
forty, so that, in point of fact, the animals are sexually capable
all their lives long; for the stallion, as a rule, lives for about
thirty-five years, and the mare for a little over forty; although,
by the way, a horse has known to live to the age of seventy-five.
The ass and the she-ass are sexually capable when thirty
months old; but, as a rule, they are not generatively mature
until they are three years old, or three years and a half. An
instance has been known of a she-ass bearing and bringing
forth a foal when only a year old. A cow has been known to
calve when only a year old, and the calf grew as big as might be
expected, but no more. So much for the dates in time at which
these animals attain to generative capacity.
In the human species, the male is generative, at the longest, up
to seventy years, and the female up to fifty; but such extended
periods are rare. As a rule, the male is generative up to the age
of sixty-five, and to the age of forty-five the female is capable of
conception.
The ewe bears up to eight years, and, if she be carefully tended,
up to eleven years; in fact, the ram and the ewe are sexually
capable pretty well all their lives long. He-goats, if they be fat,
are more or less unserviceable for breeding; and this, by the
way, is the reason why country folk say of a vine when it stops
bearing that it is 'running the goat'. However, if an over-fat he-
goat be thinned down, he becomes sexually capable and
generative.
Rams single out the oldest ewes for copulation, and show no
regard for the young ones. And, as has been stated, the issue of
the younger ewes is poorer than that of the older ones.
The boar is good for breeding purposes until he is three years of
age; but after that age his issue deteriorates, for after that age
his vigour is on the decline. The boar is most capable after a
1557
good feed, and with the first sow it mounts; if poorly fed or put
to many females, the copulation is abbreviated, and the litter is
comparatively poor. The first litter of the sow is the fewest in
number; at the second litter she is at her prime. The animal, as
it grows old, continues to breed, but the sexual desire abates.
When they reach fifteen years, they become unproductive, and
are getting old. If a sow be highly fed, it is all the more eager for
sexual commerce, whether old or young; but, if it be over-
fattened in pregnancy, it gives the less milk after parturition.
With regard to the age of the parents, the litter is the best when
they are in their prime; but with regard to the seasons of the
year, the litter is the best that comes at the beginning of winter;
and the summer litter the poorest, consisting as it usually does
of animals small and thin and flaccid. The boar, if it be well fed,
is sexually capable at all hours, night and day; but otherwise is
peculiarly salacious early in the morning. As it grows old the
sexual passion dies away, as we have already remarked. Very
often a boar, when more or less impotent from age or debility,
finding itself unable to accomplish the sexual commerce with
due speed, and growing fatigued with the standing posture, will
roll the sow over on the ground, and the pair will conclude the
operation side by side of one another. The sow is sure of
conception if it drops its lugs in rutting time; if the ears do not
thus drop, it may have to rut a second time before impregnation
takes place.
Bitches do not submit to the male throughout their lives, but
only until they reach a certain maturity of years. As a general
rule, they are sexually receptive and conceptive until they are
twelve years old; although, by the way, cases have been known
where dogs and bitches have been respectively procreative and
conceptive to the ages of eighteen and even of twenty years.
But, as a rule, age diminishes the capability of generation and of
conception with these animals as with all others.
1558
The female of the camel is opisthuretic, and submits to the
male in the way above described; and the season for copulation
in Arabia is about the month of October. Its period of gestation
is twelve months; and it is never delivered of more than one
foal at a time. The female becomes sexually receptive and the
male sexually capable at the age of three years. After
parturition, an interval of a year elapses before the female is
again receptive to the male.
The female elephant becomes sexually receptive when ten
years old at the youngest, and when fifteen at the oldest; and
the male is sexually capable when five years old, or six. The
season for intercourse is spring. The male allows an interval of
three years to elapse after commerce with a female: and, after it
has once impregnated a female, it has no intercourse with her
again. The period of gestation with the female is two years; and
only one young animal is produced at a time, in other words it
is uniparous. And the embryo is the size of a calf two or three
months old.
15
So much for the copulations of such animals as copulate.
We now proceed to treat of generation both with respect to
copulating and non-copulating animals, and we shall
commence with discussing the subject of generation in the case
of the testaceans.
The testacean is almost the only genus that throughout all its
species is non-copulative.
1559
The porphyrae, or purple murices, gather together to some one
place in the spring-time, and deposit the so-called 'honeycomb'.
This substance resembles the comb, only that it is not so neat
and delicate; and looks as though a number of husks of white
chick-peas were all stuck together. But none of these structures
has any open passage, and the porphyra does not grow out of
them, but these and all other testaceans grow out of mud and
decaying matter. The substance, is, in fact, an excretion of the
porphyra and the ceryx; for it is deposited by the ceryx as well.
Such, then, of the testaceans as deposit the honeycomb are
generated spontaneously like all other testaceans, but they
certainly come in greater abundance in places where their
congeners have been living previously. At the commencement
of the process of depositing the honeycomb, they throw off a
slippery mucus, and of this the husklike formations are
composed. These formations, then, all melt and deposit their
contents on the ground, and at this spot there are found on the
ground a number of minute porphyrae, and porphyrae are
caught at times with these animalculae upon them, some of
which are too small to be differentiated in form. If the
porphyrae are caught before producing this honey-comb, they
sometimes go through the process in fishing-creels, not here
and there in the baskets, but gathering to some one spot all
together, just as they do in the sea; and owing to the
narrowness of their new quarters they cluster together like a
bunch of grapes.
There are many species of the purple murex; and some are
large, as those found off Sigeum and Lectum; others are small,
as those found in the Euripus, and on the coast of Caria. And
those that are found in bays are large and rough; in most of
them the peculiar bloom from which their name is derived is
dark to blackness, in others it is reddish and small in size; some
of the large ones weigh upwards of a mina apiece. But the
specimens that are found along the coast and on the rocks are
1560
small-sized, and the bloom in their case is of a reddish hue.
Further, as a general rule, in northern waters the bloom is
blackish, and in southern waters of a reddish hue. The murex is
caught in the spring-time when engaged in the construction of
the honeycomb; but it is not caught at any time about the rising
of the dog-star, for at that period it does not feed, but conceals
itself and burrows. The bloom of the animal is situated between
the mecon (or quasi-liver) and the neck, and the co-attachment
of these is an intimate one. In colour it looks like a white
membrane, and this is what people extract; and if it be removed
and squeezed it stains your hand with the colour of the bloom.
There is a kind of vein that runs through it, and this quasi-vein
would appear to be in itself the bloom. And the qualities, by the
way, of this organ are astringent. It is after the murex has
constructed the honeycomb that the bloom is at its worst. Small
specimens they break in pieces, shells and all, for it is no easy
matter to extract the organ; but in dealing with the larger ones
they first strip off the shell and then abstract the bloom. For this
purpose the neck and mecon are separated, for the bloom lies in
between them, above the so-called stomach; hence the
necessity of separating them in abstracting the bloom.
Fishermen are anxious always to break the animal in pieces
while it is yet alive, for, if it die before the process is completed,
it vomits out the bloom; and for this reason the fishermen keep
the animals in creels, until they have collected a sufficient
number and can attend to them at their leisure. Fishermen in
past times used not to lower creels or attach them to the bait, so
that very often the animal got dropped off in the pulling up; at
present, however, they always attach a basket, so that if the
animal fall off it is not lost. The animal is more inclined to slip
off the bait if it be full inside; if it be empty it is difficult to
shake it off. Such are the phenomena connected with the
porphyra or murex.
1561
The same phenomena are manifested by the ceryx or trumpet-
shell; and the seasons are the same in which the phenomena
are observable. Both animals, also, the murex and the ceryx,
have their opercula similarly situated - and, in fact, all the
stromboids, and this is congenital with them all; and they feed
by protruding the so-called tongue underneath the operculum.
The tongue of the murex is bigger than one's finger, and by
means of it, it feeds, and perforates conchylia and the shells of
its own kind. Both the murex and the ceryx are long lived. The
murex lives for about six years; and the yearly increase is
indicated by a distinct interval in the spiral convolution of the
shell.
The mussel also constructs a honeycomb.
With regard to the limnostreae, or lagoon oysters, wherever you
have slimy mud there you are sure to find them beginning to
grow. Cockles and clams and razor-fishes and scallops row
spontaneously in sandy places. The pinna grows straight up
from its tuft of anchoring fibres in sandy and slimy places;
these creatures have inside them a parasite nicknamed the
pinna-guard, in some cases a small carid and in other cases a
little crab; if the pinna be deprived of this pinna-guard it soon
dies.
As a general rule, then, all testaceans grow by spontaneous
generation in mud, differing from one another according to the
differences of the material; oysters growing in slime, and
cockles and the other testaceans above mentioned on sandy
bottoms; and in the hollows of the rocks the ascidian and the
barnacle, and common sorts, such as the limpet and the nerites.
All these animals grow with great rapidity, especially the murex
and the scallop; for the murex and the scallop attain their full
growth in a year. In some of the testaceans white crabs are
found, very diminutive in size; they are most numerous in the
1562
trough shaped mussel. In the pinna also is found the so-called
pinna-guard. They are found also in the scallop and in the
oyster; these parasites never appear to grow in size. Fishermen
declare that the parasite is congenital with the larger animal.
(Scallops burrow for a time in the sand, like the murex.)
(Shell-fish, then, grow in the way above mentioned; and some of
them grow in shallow water, some on the sea-shore, some in
rocky places, some on hard and stony ground, and some in
sandy places.) Some shift about from place to place, others
remain permanent on one spot. Of those that keep to one spot
the pinnae are rooted to the ground; the razor-fish and the clam
keep to the same locality, but are not so rooted; but still, if
forcibly removed they die.
(The star-fish is naturally so warm that whatever it lays hold of
is found, when suddenly taken away from the animal, to have
undergone a process like boiling. Fishermen say that the star-
fish is a great pest in the Strait of Pyrrha. In shape it resembles
a star as seen in an ordinary drawing. The so-called 'lungs' are
generated spontaneously. The shells that painters use are a
good deal thicker, and the bloom is outside the shell on the
surface. These creatures are mostly found on the coast of Caria.)
The hermit-crab grows spontaneously out of soil and slime, and
finds its way into untenanted shells. As it grows it shifts to a
larger shell, as for instance into the shell of the nerites, or of the
strombus or the like, and very often into the shell of the small
ceryx. After entering new shell, it carries it about, and begins
again to feed, and, by and by, as it grows, it shifts again into
another larger one.
1563
16
Moreover, the animals that are unfurnished with shells grow
spontaneously, like the testaceans, as, for instance, the sea-
nettles and the sponges in rocky caves.
Of the sea-nettle, or sea-anemone, there are two species; and of
these one species lives in hollows and never loosens its hold
upon the rocks, and the other lives on smooth flat reefs, free
and detached, and shifts its position from time to time.
(Limpets also detach themselves, and shift from place to place.)
In the chambered cavities of sponges pinna-guards or parasites
are found. And over the chambers there is a kind of spider's
web, by the opening and closing of which they catch mute
fishes; that is to say, they open the web to let the fish get in, and
close it again to entrap them.
Of sponges there are three species; the first is of loose porous
texture, the second is close textured, the third, which is
nicknamed 'the sponge of Achilles', is exceptionally fine and
close-textured and strong. This sponge is used as a lining to
helmets and greaves, for the purpose of deadening the sound of
the blow; and this is a very scarce species. Of the close textured
sponges such as are particularly hard and rough are nicknamed
'goats'.
Sponges grow spontaneously either attached to a rock or on
sea-beaches, and they get their nutriment in slime: a proof of
this statement is the fact that when they are first secured they
are found to be full of slime. This is characteristic of all living
creatures that get their nutriment by close local attachment.
And, by the way, the close-textured sponges are weaker than
the more openly porous ones because their attachment extends
over a smaller area.
1564
It is said that the sponge is sensitive; and as a proof of this
statement they say that if the sponge is made aware of an
attempt being made to pluck it from its place of attachment it
draws itself together, and it becomes a difficult task to detach it.
It makes a similar contractile movement in windy and
boisterous weather, obviously with the object of tightening its
hold. Some persons express doubts as to the truth of this
assertion; as, for instance, the people of Torone.
The sponge breeds parasites, worms, and other creatures, on
which, if they be detached, the rock-fishes prey, as they prey
also on the remaining stumps of the sponge; but, if the sponge
be broken off, it grows again from the remaining stump and the
place is soon as well covered as before.
The largest of all sponges are the loose-textured ones, and these
are peculiarly abundant on the coast of Lycia. The softest are
the close-textured sponges; for, by the way, the so-called
sponges of Achilles are harder than these. As a general rule,
sponges that are found in deep calm waters are the softest; for
usually windy and stormy weather has a tendency to harden
them (as it has to harden all similar growing things), and to
arrest their growth. And this accounts for the fact that the
sponges found in the Hellespont are rough and close-textured;
and, as a general rule, sponges found beyond or inside Cape
Malea are, respectively, comparatively soft or comparatively
hard. But, by the way, the habitat of the sponge should not be
too sheltered and warm, for it has a tendency to decay, like all
similar vegetable-like growths. And this accounts for the fact
that the sponge is at its best when found in deep water close to
shore; for owing to the depth of the water they enjoy shelter
alike from stormy winds and from excessive heat.
Whilst they are still alive and before they are washed and
cleaned, they are blackish in colour. Their attachment is not
1565
made at one particular spot, nor is it made all over their bodies;
for vacant pore-spaces intervene. There is a kind of membrane
stretched over the under parts; and in the under parts the
points of attachment are the more numerous. On the top most
of the pores are closed, but four or five are open and visible; and
we are told by some that it is through these pores that the
animal takes its food.
There is a particular species that is named the 'aplysia' or the
'unwashable', from the circumstance that it cannot be cleaned.
This species has the large open and visible pores, but all the rest
of the body is close-textured; and, if it be dissected, it is found
to be closer and more glutinous than the ordinary sponge, and,
in a word, something lung like in consistency. And, on all hands,
it is allowed that this species is sensitive and long-lived. They
are distinguished in the sea from ordinary sponges from the
circumstance that the ordinary sponges are white while the
slime is in them, but that these sponges are under any
circumstances black.
And so much with regard to sponges and to generation in the
testaceans.
17
Of crustaceans, the female crawfish after copulation conceives
and retains its eggs for about three months, from about the
middle of May to about the middle of August; they then lay the
eggs into the folds underneath the belly, and their eggs grow
like grubs. This same phenomenon is observable in molluscs
also, and in such fishes as are oviparous; for in all these cases
the egg continues to grow.
1566
The spawn of the crawfish is of a loose or granular consistency,
and is divided into eight parts; for corresponding to each of the
flaps on the side there is a gristly formation to which the spawn
is attached, and the entire structure resembles a cluster of
grapes; for each gristly formation is split into several parts. This
is obvious enough if you draw the parts asunder; but at first
sight the whole appears to be one and indivisible. And the
largest are not those nearest to the outlet but those in the
middle, and the farthest off are the smallest. The size of the
small eggs is that of a small seed in a fig; and they are not quite
close to the outlet, but placed middleways; for at both ends,
tailwards and trunkwards, there are two intervals devoid of
eggs; for it is thus that the flaps also grow. The side flaps, then,
cannot close, but by placing the end flap on them the animal
can close up all, and this end-flap serves them for a lid. And in
the act of laying its eggs it seems to bring them towards the
gristly formations by curving the flap of its tail, and then,
squeezing the eggs towards the said gristly formations and
maintaining a bent posture, it performs the act of laying. The
gristly formations at these seasons increase in size and become
receptive of the eggs; for the animal lays its eggs into these
formations, just as the sepia lays its eggs among twigs and
driftwood.
It lays its eggs, then, in this manner, and after hatching them for
about twenty days it rids itself of them all in one solid lump, as
is quite plain from outside. And out of these eggs crawfish form
in about fifteen days, and these crawfish are caught at times
less then a finger's breadth, or seven-tenths of an inch, in
length. The animal, then, lays its eggs before the middle of
September, and after the middle of that month throws off its
eggs in a lump. With the humped carids or prawns the time for
gestation is four months or thereabouts.
1567
Crawfish are found in rough and rocky places, lobsters in
smooth places, and neither crawfish nor lobsters are found in
muddy ones; and this accounts for the fact that lobsters are
found in the Hellespont and on the coast of Thasos, and
crawfish in the neighbourhood of Sigeum and Mount Athos.
Fishermen, accordingly, when they want to catch these various
creatures out at sea, take bearings on the beach and elsewhere
that tell them where the ground at the bottom is stony and
where soft with slime. In winter and spring these animals keep
in near to land, in summer they keep in deep water; thus at
various times seeking respectively for warmth or coolness.
The so-called arctus or bear-crab lays its eggs at about the same
time as the crawfish; and consequently in winter and in the
spring-time, before laying their eggs, they are at their best, and
after laying at their worst.
They cast their shell in the spring-time (just as serpents shed
their so-called 'old-age' or slough), both directly after birth and
in later life; this is true both of crabs and crawfish. And, by the
way, all crawfish are long lived.
18
Molluscs, after pairing and copulation, lay a white spawn; and
this spawn, as in the case of the testacean, gets granular in
time. The octopus discharges into its hole, or into a potsherd or
into any similar cavity, a structure resembling the tendrils of a
young vine or the fruit of the white poplar, as has been
previously observed. The eggs, when the female has laid them,
are clustered round the sides of the hole. They are so numerous
that, if they be removed they suffice to fill a vessel much larger
than the animal's body in which they were contained. Some
1568
fifty days later, the eggs burst and the little polypuses creep out,
like little spiders, in great numbers; the characteristic form of
their limbs is not yet to be discerned in detail, but their general
outline is clear enough. And, by the way, they are so small and
helpless that the greater number perish; it is a fact that they
have been seen so extremely minute as to be absolutely without
organization, but nevertheless when touched they moved. The
eggs of the sepia look like big black myrtle-berries, and they are
linked all together like a bunch of grapes, clustered round a
centre, and are not easily sundered from one another: for the
male exudes over them some moist glairy stuff, which
constitutes the sticky gum. These eggs increase in size; and they
are white at the outset, but black and larger after the sprinkling
of the male seminal fluid.
When it has come into being the young sepia is first distinctly
formed inside out of the white substance, and when the egg
bursts it comes out. The inner part is formed as soon as the
female lays the egg, something like a hail-stone; and out of this
substance the young sepia grows by a head-attachment, just as
young birds grow by a belly-attachment. What is the exact
nature of the navel-attachment has not yet been observed,
except that as the young sepia grows the white substance grows
less and less in size, and at length, as happens with the yolk in
the case of birds, the white substance in the case of the young
sepia disappears. In the case of the young sepia, as in the case
of the young of most animals, the eyes at first seem very large.
To illustrate this by way of a figure, let A represent the ovum, B
and C the eyes, and D the sepidium, or body of the little sepia.
(See diagram.)
The female sepia goes pregnant in the spring-time, and lays its
eggs after fifteen days of gestation; after the eggs are laid there
comes in another fifteen days something like a bunch of grapes,
and at the bursting of these the young sepiae issue forth. But if,
1569
when the young ones are fully formed, you sever the outer
covering a moment too soon, the young creatures eject
excrement, and their colour changes from white to red in their
alarm.
Crustaceans, then, hatch their eggs by brooding over them as
they carry them about beneath their bodies; but the octopus,
the sepia, and the like hatch their eggs without stirring from the
spot where they may have laid them, and this statement is
particularly applicable to the sepia; in fact, the nest of the
female sepia is often seen exposed to view close in to shore. The
female octopus at times sits brooding over her eggs, and at
other times squats in front of her hole, stretching out her
tentacles on guard.
The sepia lays her spawn near to land in the neighbourhood of
sea-weed or reeds or any off-sweepings such as brushwood,
twigs, or stones; and fishermen place heaps of faggots here and
there on purpose, and on to such heaps the female deposits a
long continuous roe in shape like a vine tendril. It lays or spirts
out the spawn with an effort, as though there were difficulty in
the process. The female calamary spawns at sea; and it emits
the spawn, as does the sepia, in the mass.
The calamary and the cuttle-fish are short-lived, as, with few
exceptions, they never see the year out; and the same
statement is applicable to the octopus.
From one single egg comes one single sepia; and this is likewise
true of the young calamary.
The male calamary differs from the female; for if its gill-region
be dilated and examined there are found two red formations
resembling breasts, with which the male is unprovided. In the
sepia, apart from this distinction in the sexes, the male, as has
been stated, is more mottled than the female.
1570
19
With regard to insects, that the male is less than the female and
that he mounts upon her back, and how he performs the act of
copulation and the circumstance that he gives over reluctantly,
all this has already been set forth, most cases of insect
copulation this process is speedily followed up by parturition.
All insects engender grubs, with the exception of a species of
butterfly; and the female of this species lays a hard egg,
resembling the seed of the cnecus, with a juice inside it. But
from the grub, the young animal does not grow out of a mere
portion of it, as a young animal grows from a portion only of an
egg, but the grub entire grows and the animal becomes
differentiated out of it.
And of insects some are derived from insect congeners, as the
venom-spider and the common-spider from the venom-spider
and the common-spider, and so with the attelabus or locust, the
acris or grasshopper, and the tettix or cicada. Other insects are
not derived from living parentage, but are generated
spontaneously: some out of dew falling on leaves, ordinarily in
spring-time, but not seldom in winter when there has been a
stretch of fair weather and southerly winds; others grow in
decaying mud or dung; others in timber, green or dry; some in
the hair of animals; some in the flesh of animals; some in
excrements: and some from excrement after it has been voided,
and some from excrement yet within the living animal, like the
helminthes or intestinal worms. And of these intestinal worms
there are three species: one named the flat-worm, another the
round worm, and the third the ascarid. These intestinal worms
do not in any case propagate their kind. The flat-worm,
1571
however, in an exceptional way, clings fast to the gut, and lays a
thing like a melon-seed, by observing which indication the
physician concludes that his patient is troubled with the worm.
The so-called psyche or butterfly is generated from caterpillars
which grow on green leaves, chiefly leaves of the raphanus,
which some call crambe or cabbage. At first it is less than a
grain of millet; it then grows into a small grub; and in three
days it is a tiny caterpillar. After this it grows on and on, and
becomes quiescent and changes its shape, and is now called a
chrysalis. The outer shell is hard, and the chrysalis moves if you
touch it. It attaches itself by cobweb-like filaments, and is
unfurnished with mouth or any other apparent organ. After a
little while the outer covering bursts asunder, and out flies the
winged creature that we call the psyche or butterfly. At first,
when it is a caterpillar, it feeds and ejects excrement; but when
it turns into the chrysalis it neither feeds nor ejects excrement.
The same remarks are applicable to all such insects as are
developed out of the grub, both such grubs as are derived from
the copulation of living animals and such as are generated
without copulation on the part of parents. For the grub of the
bee, the anthrena, and the wasp, whilst it is young, takes food
and voids excrement; but when it has passed from the grub
shape to its defined form and become what is termed a
'nympha', it ceases to take food and to void excrement, and
remains tightly wrapped up and motionless until it has reached
its full size, when it breaks the formation with which the cell is
closed, and issues forth. The insects named the hypera and the
penia are derived from similar caterpillars, which move in an
undulatory way, progressing with one part and then pulling up
the hinder parts by a bend of the body. The developed insect in
each case takes its peculiar colour from the parent caterpillar.
1572
From one particular large grub, which has as it were horns, and
in other respects differs from grubs in general, there comes, by
a metamorphosis of the grub, first a caterpillar, then the cocoon,
then the necydalus; and the creature passes through all these
transformations within six months. A class of women unwind
and reel off the cocoons of these creatures, and afterwards
weave a fabric with the threads thus unwound; a Coan woman
of the name of Pamphila, daughter of Plateus, being credited
with the first invention of the fabric. After the same fashion the
carabus or stag-beetle comes from grubs that live in dry wood:
at first the grub is motionless, but after a while the shell bursts
and the stag-beetle issues forth.
From the cabbage is engendered the cabbageworm, and from
the leek the prasocuris or leekbane; this creature is also winged.
From the flat animalcule that skims over the surface of rivers
comes the oestrus or gadfly; and this accounts for the fact that
gadflies most abound in the neighbourhood of waters on whose
surface these animalcules are observed. From a certain small,
black and hairy caterpillar comes first a wingless glow-worm;
and this creature again suffers a metamorphosis, and
transforms into a winged insect named the bostrychus (or hair-
curl).
Gnats grow from ascarids; and ascarids are engendered in the
slime of wells, or in places where there is a deposit left by the
draining off of water. This slime decays, and first turns white,
then black, and finally blood-red; and at this stage there
originate in it, as it were, little tiny bits of red weed, which at
first wriggle about all clinging together, and finally break loose
and swim in the water, and are hereupon known as ascarids.
After a few days they stand straight up on the water motionless
and hard, and by and by the husk breaks off and the gnats are
seen sitting upon it, until the sun's heat or a puff of wind sets
them in motion, when they fly away.
1573
With all grubs and all animals that break out from the grub
state, generation is due primarily to the heat of the sun or to
wind.
Ascarids are more likely to be found, and grow with unusual
rapidity, in places where there is a deposit of a mixed and
heterogeneous kind, as in kitchens and in ploughed fields, for
the contents of such places are disposed to rapid putrefaction.
In autumn, also, owing to the drying up of moisture, they grow
in unusual numbers.
The tick is generated from couch-grass. The cockchafer comes
from a grub that is generated in the dung of the cow or the ass.
The cantharus or scarabeus rolls a piece of dung into a ball, lies
hidden within it during the winter, and gives birth therein to
small grubs, from which grubs come new canthari. Certain
winged insects also come from the grubs that are found in
pulse, in the same fashion as in the cases described.
Flies grow from grubs in the dung that farmers have gathered
up into heaps: for those who are engaged in this work
assiduously gather up the compost, and this they technically
term 'working-up' the manure. The grub is exceedingly minute
to begin with; first even at this stage - it assumes a reddish
colour, and then from a quiescent state it takes on the power of
motion, as though born to it; it then becomes a small
motionless grub; it then moves again, and again relapses into
immobility; it then comes out a perfect fly, and moves away
under the influence of the sun's heat or of a puff of air. The
myops or horse-fly is engendered in timber. The orsodacna or
budbane is a transformed grub; and this grub is engendered in
cabbage-stalks. The cantharis comes from the caterpillars that
are found on fig-trees or pear-trees or fir-trees - for on all these
grubs are engendered - and also from caterpillars found on the
dog-rose; and the cantharis takes eagerly to ill-scented
1574
substances, from the fact of its having been engendered in ill-
scented woods. The conops comes from a grub that is
engendered in the slime of vinegar.
And, by the way, living animals are found in substances that are
usually supposed to be incapable of putrefaction; for instance,
worms are found in long-lying snow; and snow of this
description gets reddish in colour, and the grub that is
engendered in it is red, as might have been expected, and it is
also hairy. The grubs found in the snows of Media are large and
white; and all such grubs are little disposed to motion. In
Cyprus, in places where copper-ore is smelted, with heaps of
the ore piled on day after day, an animal is engendered in the
fire, somewhat larger than a blue bottle fly, furnished with
wings, which can hop or crawl through the fire. And the grubs
and these latter animals perish when you keep the one away
from the fire and the other from the snow. Now the salamander
is a clear case in point, to show us that animals do actually exist
that fire cannot destroy; for this creature, so the story goes, not
only walks through the fire but puts it out in doing so.
On the river Hypanis in the Cimmerian Bosphorus, about the
time of the summer solstice, there are brought down towards
the sea by the stream what look like little sacks rather bigger
than grapes, out of which at their bursting issues a winged
quadruped. The insect lives and flies about until the evening,
but as the sun goes down it pines away, and dies at sunset
having lived just one day, from which circumstance it is called
the ephemeron.
As a rule, insects that come from caterpillars and grubs are held
at first by filaments resembling the threads of a spider's web.
Such is the mode of generation of the insects above
enumerated, but if the latter impregnation takes placeduring
the change of the yellow
1575
20
The wasps that are nicknamed 'the ichneumons' (or hunters),
less in size, by the way, than the ordinary wasp, kill spiders and
carry off the dead bodies to a wall or some such place with a
hole in it; this hole they smear over with mud and lay their
grubs inside it, and from the grubs come the hunter-wasps.
Some of the coleoptera and of the small and nameless insects
make small holes or cells of mud on a wall or on a grave-stone,
and there deposit their grubs.
With insects, as a general rule, the time of generation from its
commencement to its completion comprises three or four
weeks. With grubs and grub-like creatures the time is usually
three weeks, and in the oviparous insects as a rule four. But, in
the case of oviparous insects, the egg-formation comes at the
close of seven days from copulation, and during the remaining
three weeks the parent broods over and hatches its young; i.e.
where this is the result of copulation, as in the case of the
spider and its congeners. As a rule, the transformations take
place in intervals of three or four days, corresponding to the
lengths of interval at which the crises recur in intermittent
fevers.
So much for the generation of insects. Their death is due to the
shrivelling of their organs, just as the larger animals die of old
age.
Winged insects die in autumn from the shrinking of their wings.
The myops dies from dropsy in the eyes.
1576
21
With regard to the generation of bees different hypotheses are
in vogue. Some affirm that bees neither copulate nor give birth
to young, but that they fetch their young. And some say that
they fetch their young from the flower of the callyntrum; others
assert that they bring them from the flower of the reed, others,
from the flower of the olive. And in respect to the olive theory, it
is stated as a proof that, when the olive harvest is most
abundant, the swarms are most numerous. Others declare that
they fetch the brood of the drones from such things as above
mentioned, but that the working bees are engendered by the
rulers of the hive.
Now of these rulers there are two kinds: the better kind is red in
colour, the inferior kind is black and variegated; the ruler is
double the size of the working bee. These rulers have the
abdomen or part below the waist half as large again, and they
are called by some the 'mothers', from an idea that they bear or
generate the bees; and, as a proof of this theory of their
motherhood, they declare that the brood of the drones appears
even when there is no ruler-bee in the hive, but that the bees do
not appear in his absence. Others, again, assert that these
insects copulate, and that the drones are male and the bees
female.
The ordinary bee is generated in the cells of the comb, but the
ruler-bees in cells down below attached to the comb, suspended
from it, apart from the rest, six or seven in number, and growing
in a way quite different from the mode of growth of the
ordinary brood.
Bees are provided with a sting, but the drones are not so
provided. The rulers are provided with stings, but they never use
1577
them; and this latter circumstance will account for the belief of
some people that they have no stings at all.
22
Of bees there are various species. The best kind is a little round
mottled insect; another is long, and resembles the anthrena; a
third is a black and flat-bellied, and is nick-named the 'robber';
a fourth kind is the drone, the largest of all, but stingless and
inactive. And this proportionate size of the drone explains why
some bee-masters place a net-work in front of the hives; for the
network is put to keep the big drones out while it lets the little
bees go in.
Of the king bees there are, as has been stated, two kinds. In
every hive there are more kings than one; and a hive goes to
ruin if there be too few kings, not because of anarchy thereby
ensuing, but, as we are told, because these creatures contribute
in some way to the generation of the common bees. A hive will
go also to ruin if there be too large a number of kings in it; for
the members of the hives are thereby subdivided into too many
separate factions.
Whenever the spring-time is late a-coming, and when there is
drought and mildew, then the progeny of the hive is small in
number. But when the weather is dry they attend to the honey,
and in rainy weather their attention is concentrated on the
brood; and this will account for the coincidence of rich olive-
harvests and abundant swarms.
The bees first work at the honeycomb, and then put the pupae
in it: by the mouth, say those who hold the theory of their
bringing them from elsewhere. After putting in the pupae they
1578
put in the honey for subsistence, and this they do in the
summer and autumn; and, by the way, the autumn honey is the
better of the two.
The honeycomb is made from flowers, and the materials for the
wax they gather from the resinous gum of trees, while honey is
distilled from dew, and is deposited chiefly at the risings of the
constellations or when a rainbow is in the sky: and as a general
rule there is no honey before the rising of the Pleiads. (The bee,
then, makes the wax from flowers. The honey, however, it does
not make, but merely gathers what is deposited out of the
atmosphere; and as a proof of this statement we have the
known fact that occasionally bee-keepers find the hives filled
with honey within the space of two or three days. Furthermore,
in autumn flowers are found, but honey, if it be withdrawn, is
not replaced; now, after the withdrawal of the original honey,
when no food or very little is in the hives, there would be a
fresh stock of honey, if the bees made it from flowers.) Honey, if
allowed to ripen and mature, gathers consistency; for at first it
is like water and remains liquid for several days. If it be drawn
off during these days it has no consistency; but it attains
consistency in about twenty days. The taste of thyme-honey is
discernible at once, from its peculiar sweetness and consistency.
The bee gathers from every flower that is furnished with a calyx
or cup, and from all other flowers that are sweet-tasted, without
doing injury to any fruit; and the juices of the flowers it takes
up with the organ that resembles a tongue and carries off to the
hive.
Swarms are robbed of their honey on the appearance of the wild
fig. They produce the best larvae at the time the honey is a-
making. The bee carries wax and bees' bread round its legs, but
vomits the honey into the cell. After depositing its young, it
broods over it like a bird. The grub when it is small lies
1579
slantwise in the comb, but by and by rises up straight by an
effort of its own and takes food, and holds on so tightly to the
honeycomb as actually to cling to it.
The young of bees and of drones is white, and from the young
come the grubs; and the grubs grow into bees and drones. The
egg of the king bee is reddish in colour, and its substance is
about as consistent as thick honey; and from the first it is about
as big as the bee that is produced from it. From the young of the
king bee there is no intermediate stage, it is said, of the grub,
but the bee comes at once.
Whenever the bee lays an egg in the comb there is always a
drop of honey set against it. The larva of the bee gets feet and
wings as soon as the cell has been stopped up with wax, and
when it arrives at its completed form it breaks its membrane
and flies away. It ejects excrement in the grub state, but not
afterwards; that is, not until it has got out of the encasing
membrane, as we have already described. If you remove the
heads from off the larvae before the coming of the wings, the
bees will eat them up; and if you nip off the wings from a drone
and let it go, the bees will spontaneously bite off the wings from
off all the remaining drones.
The bee lives for six years as a rule, as an exception for seven
years. If a swarm lasts for nine years, or ten, great credit is
considered due to its management.
In Pontus are found bees exceedingly white in colour, and these
bees produce their honey twice a month. (The bees in
Themiscyra, on the banks of the river Thermodon, build
honeycombs in the ground and in hives, and these honeycombs
are furnished with very little wax but with honey of great
consistency; and the honeycomb, by the way, is smooth and
level.) But this is not always the case with these bees, but only
in the winter season; for in Pontus the ivy is abundant, and it
1580
flowers at this time of the year, and it is from the ivy-flower that
they derive their honey. A white and very consistent honey is
brought down from the upper country to Amisus, which is
deposited by bees on trees without the employment of
honeycombs: and this kind of honey is produced in other
districts in Pontus.
There are bees also that construct triple honeycombs in the
ground; and these honeycombs supply honey but never contain
grubs. But the honeycombs in these places are not all of this
sort, nor do all the bees construct them.
23
Anthrenae and wasps construct combs for their young. When
they have no king, but are wandering about in search of one, the
anthrene constructs its comb on some high place, and the wasp
inside a hole. When the anthrene and the wasp have a king,
they construct their combs underground. Their combs are in all
cases hexagonal like the comb of the bee. They are composed,
however, not of wax, but of a bark-like filamented fibre, and the
comb of the anthrene is much neater than the comb of the
wasp. Like the bee, they put their young just like a drop of liquid
on to the side of the cell, and the egg clings to the wall of the
cell. But the eggs are not deposited in the cells simultaneously;
on the contrary, in some cells are creatures big enough to fly, in
others are nymphae, and in others are mere grubs. As in the
case of bees, excrement is observed only in the cells where the
grubs are found. As long as the creatures are in the nymph
condition they are motionless, and the cell is cemented over. In
the comb of the anthrene there is found in the cell of the young
a drop of honey in front of it. The larvae of the anthrene and the
1581
wasp make their appearance not in the spring but in the
autumn; and their growth is especially discernible in times of
full moon. And, by the way, the eggs and the grubs never rest at
the bottom of the cells, but always cling on to the side wall.
24
There is a kind of humble-bee that builds a cone-shaped nest of
clay against a stone or in some similar situation, besmearing
the clay with something like spittle. And this nest or hive is
exceedingly thick and hard; in point of fact, one can hardly
break it open with a spike. Here the insects lay their eggs, and
white grubs are produced wrapped in a black membrane. Apart
from the membrane there is found some wax in the
honeycomb; and this a wax is much sallower in hue than the
wax in the honeycomb of the bee.
25
Ants copulate and engender grubs; and these grubs attach
themselves to nothing in particular, but grow on and on from
small and rounded shapes until they become elongated and
defined in shape: and they are engendered in spring-time.
1582
26
The land-scorpion also lays a number of egg shaped grubs, and
broods over them. When the hatching is completed, the parent
animal, as happens with the parent spider, is ejected and put to
death by the young ones; for very often the young ones are
about eleven in number.
27
Spiders in all cases copulate in the way above mentioned, and
generate at first small grubs. And these grubs metamorphose in
their entirety, and not partially, into spiders; for, by the way, the
grubs are round-shaped at the outset. And the spider, when it
lays its eggs, broods over them, and in three days the eggs or
grubs take definite shape.
All spiders lay their eggs in a web; but some spiders lay in a
small and fine web, and others in a thick one; and some, as a
rule, lay in a round-shaped case or capsule, and some are only
partially enveloped in the web. The young grubs are not all
developed at one and the same time into young spiders; but the
moment the development takes place, the young spider makes
a leap and begins to spin his web. The juice of the grub, if you
squeeze it, is the same as the juice found in the spider when
young; that is to say, it is thick and white.
The meadow spider lays its eggs into a web, one half of which is
attached to itself and the other half is free; and on this the
parent broods until the eggs are hatched. The phalangia lay
their eggs in a sort of strong basket which they have woven, and
brood over it until the eggs are hatched. The smooth spider is
much less prolific than the phalangium or hairy spider. These
1583
phalangia, when they grow to full size, very often envelop the
mother phalangium and eject and kill her; and not seldom they
kill the father-phalangium as well, if they catch him: for, by the
way, he has the habit of co-operating with the mother in the
hatching. The brood of a single phalangium is sometimes three
hundred in number. The spider attains its full growth in about
four weeks.
28
Grasshoppers (or locusts) copulate in the same way as other
insects; that is to say, with the lesser covering the larger, for the
male is smaller than the female. The females first insert the
hollow tube, which they have at their tails, in the ground, and
then lay their eggs: and the male, by the way, is not furnished
with this tube. The females lay their eggs all in a lump together,
and in one spot, so that the entire lump of eggs resembles a
honeycomb. After they have laid their eggs, the eggs assume the
shape of oval grubs that are enveloped by a sort of thin clay, like
a membrane; in this membrane-like formation they grow on to
maturity. The larva is so soft that it collapses at a touch. The
larva is not placed on the surface of the ground, but a little
beneath the surface; and, when it reaches maturity, it comes out
of its clayey investiture in the shape of a little black
grasshopper; by and by, the skin integument strips off, and it
grows larger and larger.
The grasshopper lays its eggs at the close of summer, and dies
after laying them. The fact is that, at the time of laying the eggs,
grubs are engendered in the region of the mother grasshopper's
neck; and the male grasshoppers die about the same time. In
spring-time they come out of the ground; and, by the way, no
1584
grasshoppers are found in mountainous land or in poor land,
but only in flat and loamy land, for the fact is they lay their eggs
in cracks of the soil. During the winter their eggs remain in the
ground; and with the coming of summer the last year's larva
develops into the perfect grasshopper.
29
The attelabi or locusts lay their eggs and die in like manner
after laying them. Their eggs are subject to destruction by the
autumn rains, when the rains are unusually heavy; but in
seasons of drought the locusts are exceedingly numerous, from
the absence of any destructive cause, since their destruction
seems then to be a matter of accident and to depend on luck.
30
Of the cicada there are two kinds; one, small in size, the first to
come and the last to disappear; the other, large, the singing one
that comes last and first disappears. Both in the small and the
large species some are divided at the waist, to wit, the singing
ones, and some are undivided; and these latter have no song.
The large and singing cicada is by some designated the 'chirper',
and the small cicada the 'tettigonium' or cicadelle. And, by the
way, such of the tettigonia as are divided at the waist can sing
just a little.
The cicada is not found where there are no trees; and this
accounts for the fact that in the district surrounding the city of
Cyrene it is not found at all in the plain country, but is found in
1585
great numbers in the neighbourhood of the city, and especially
where olive-trees are growing: for an olive grove is not thickly
shaded. And the cicada is not found in cold places, and
consequently is not found in any grove that keeps out the
sunlight.
The large and the small cicada copulate alike, belly to belly. The
male discharges sperm into the female, as is the case with
insects in general, and the female cicada has a cleft generative
organ; and it is the female into which the male discharges the
sperm.
They lay their eggs in fallow lands, boring a hole with the
pointed organ they carry in the rear, as do the locusts likewise;
for the locust lays its eggs in unfilled lands, and this fact may
account for their numbers in the territory adjacent to the city of
Cyrene. The cicadae also lay their eggs in the canes on which
husbandmen prop vines, perforating the canes; and also in the
stalks of the squill. This brood runs into the ground. And they
are most numerous in rainy weather. The grub, on attaining full
size in the ground, becomes a tettigometra (or nymph), and the
creature is sweetest to the taste at this stage before the husk is
broken. When the summer solstice comes, the creature issues
from the husk at night-time, and in a moment, as the husk
breaks, the larva becomes the perfect cicada, creature, also, at
once turns black in colour and harder and larger, and takes to
singing. In both species, the larger and the smaller, it is the
male that sings, and the female that is unvocal. At first, the
males are the sweeter eating; but, after copulation, the females,
as they are full then of white eggs.
If you make a sudden noise as they are flying overhead they let
drop something like water. Country people, in regard to this, say
that they are voiding urine, ie. that they have an excrement, and
that they feed upon dew.
1586
If you present your finger to a cicada and bend back the tip of it
and then extend it again, it will endure the presentation more
quietly than if you were to keep your finger outstretched
altogether; and it will set to climbing your finger: for the
creature is so weak-sighted that it will take to climbing your
finger as though that were a moving leaf.
31
Of insects that are not carnivorous but that live on the juices of
living flesh, such as lice and fleas and bugs, all, without
exception, generate what are called 'nits', and these nits
generate nothing.
Of these insects the flea is generated out of the slightest
amount of putrefying matter; for wherever there is any dry
excrement, a flea is sure to be found. Bugs are generated from
the moisture of living animals, as it dries up outside their
bodies. Lice are generated out of the flesh of animals.
When lice are coming there is a kind of small eruption visible,
unaccompanied by any discharge of purulent matter; and, if you
prick an animal when in this condition at the spot of eruption,
the lice jump out. In some men the appearance of lice is a
disease, in cases where the body is surcharged with moisture;
and, indeed, men have been known to succumb to this louse-
disease, as Alcmeon the poet and the Syrian Pherecydes are said
to have done. Moreover, in certain diseases lice appear in great
abundance.
There is also a species of louse called the 'wild louse', and this is
harder than the ordinary louse, and there is exceptional
difficulty in getting the skin rid of it. Boys' heads are apt to be
1587
lousy, but men's in less degree; and women are more subject to
lice than men. But, whenever people are troubled with lousy
heads, they are less than ordinarily troubled with headache.
And lice are generated in other animals than man. For birds are
infested with them; and pheasants, unless they clean
themselves in the dust, are actually destroyed by them. All
other winged animals that are furnished with feathers are
similarly infested, and all hair-coated creatures also, with the
single exception of the ass, which is infested neither with lice
nor with ticks.
Cattle suffer both from lice and from ticks. Sheep and goats
breed ticks, but do not breed lice. Pigs breed lice large and hard.
In dogs are found the flea peculiar to the animal, the
Cynoroestes. In all animals that are subject to lice, the latter
originate from the animals themselves. Moreover, in animals
that bathe at all, lice are more than usually abundant when
they change the water in which they bathe.
In the sea, lice are found on fishes, but they are generated not
out of the fish but out of slime; and they resemble multipedal
wood-lice, only that their tail is flat. Sea-lice are uniform in
shape and universal in locality, and are particularly numerous
on the body of the red mullet. And all these insects are
multipedal and devoid of blood.
The parasite that feeds on the tunny is found in the region of
the fins; it resembles a scorpion, and is about the size of a
spider. In the seas between Cyrene and Egypt there is a fish that
attends on the dolphin, which is called the 'dolphin's louse'.
This fish gets exceedingly fat from enjoying an abundance of
food while the dolphin is out in pursuit of its prey.
1588
32
Other animalcules besides these are generated, as we have
already remarked, some in wool or in articles made of wool, as
the ses or clothes-moth. And these animalcules come in greater
numbers if the woollen substances are dusty; and they come in
especially large numbers if a spider be shut up in the cloth or
wool, for the creature drinks up any moisture that may be there,
and dries up the woollen substance. This grub is found also in
men's clothes.
A creature is also found in wax long laid by, just as in wood, and
it is the smallest of animalcules and is white in colour, and is
designated the acari or mite. In books also other animalcules
are found, some resembling the grubs found in garments, and
some resembling tailless scorpions, but very small. As a general
rule we may state that such animalcules are found in practically
anything, both in dry things that are becoming moist and in
moist things that are drying, provided they contain the
conditions of life.
There is a grub entitled the 'faggot-bearer', as strange a creature
as is known. Its head projects outside its shell, mottled in
colour, and its feet are near the end or apex, as is the case with
grubs in general; but the rest of its body is cased in a tunic as it
were of spider's web, and there are little dry twigs about it, that
look as though they had stuck by accident to the creature as it
went walking about. But these twig-like formations are
naturally connected with the tunic, for just as the shell is with
the body of the snail so is the whole superstructure with our
grub; and they do not drop off, but can only be torn off, as
though they were all of a piece with him, and the removal of the
tunic is as fatal to this grub as the removal of the shell would be
to the snail. In course of time this grub becomes a chrysalis, as
is the case with the silkworm, and lives in a motionless
1589
condition. But as yet it is not known into what winged condition
it is transformed.
The fruit of the wild fig contains the psen, or fig-wasp. This
creature is a grub at first; but in due time the husk peels off and
the psen leaves the husk behind it and flies away, and enters
into the fruit of the fig-tree through its orifice, and causes the
fruit not to drop off; and with a view to this phenomenon,
country folk are in the habit of tying wild figs on to fig-trees,
and of planting wild fig-trees near domesticated ones.
33
In the case of animals that are quadrupeds and red-blooded and
oviparous, generation takes place in the spring, but copulation
does not take place in an uniform season. In some cases it takes
place in the spring, in others in summer time, and in others in
the autumn, according as the subsequent season may be
favourable for the young.
The tortoise lays eggs with a hard shell and of two colours
within, like birds' eggs, and after laying them buries them in the
ground and treads the ground hard over them; it then broods
over the eggs on the surface of the ground, and hatches the eggs
the next year. The hemys, or fresh-water tortoise, leaves the
water and lays its eggs. It digs a hole of a casklike shape, and
deposits therein the eggs; after rather less than thirty days it
digs the eggs up again and hatches them with great rapidity,
and leads its young at once off to the water. The sea-turtle lays
on the ground eggs just like the eggs of domesticated birds,
buries the eggs in the ground, and broods over them in the
night-time. It lays a very great number of eggs, amounting at
times to one hundred.
1590
Lizards and crocodiles, terrestrial and fluvial, lay eggs on land.
The eggs of lizards hatch spontaneously on land, for the lizard
does not live on into the next year; in fact, the life of the animal
is said not to exceed six months. The river-crocodile lays a
number of eggs, sixty at the most, white in colour, and broods
over them for sixty days: for, by the way, the creature is very
long-lived. And the disproportion is more marked in this animal
than in any other between the smallness of the original egg and
the huge size of the full-grown animal. For the egg is not larger
than that of the goose, and the young crocodile is small,
answering to the egg in size, but the full-grown animal attains
the length of twenty-six feet; in fact, it is actually stated that
the animal goes on growing to the end of its days.
34
With regard to serpents or snakes, the viper is externally
viviparous, having been previously oviparous internally. The egg,
as with the egg of fishes, is uniform in colour and soft-skinned.
The young serpent grows on the surface of the egg, and, like the
young of fishes, has no shell-like envelopment. The young of the
viper is born inside a membrane that bursts from off the young
creature in three days; and at times the young viper eats its way
out from the inside of the egg. The mother viper brings forth all
its young in one day, twenty in number, and one at a time. The
other serpents are externally oviparous, and their eggs are
strung on to one another like a lady's necklace; after the dam
has laid her eggs in the ground she broods over them, and
hatches the eggs in the following year.
1591
Book VI
So much for the generative processes in snakes and insects, and
also in oviparous quadrupeds. Birds without exception lay eggs,
but the pairing season and the times of parturition are not alike
for all. Some birds couple and lay at almost any time in the year,
as for instance the barn-door hen and the pigeon: the former of
these coupling and laying during the entire year, with the
exception of the month before and the month after the winter
solstice. Some hens, even in the high breeds, lay a large quantity
of eggs before brooding, amounting to as many as sixty; and, by
the way, the higher breeds are less prolific than the inferior
ones. The Adrian hens are small-sized, but they lay every day;
they are cross-tempered, and often kill their chickens; they are
of all colours. Some domesticated hens lay twice a day; indeed,
instances have been known where hens, after exhibiting
extreme fecundity, have died suddenly. Hens, then, lay eggs, as
has been stated, at all times indiscriminately; the pigeon, the
ring-dove, the turtle-dove, and the stock-dove lay twice a year,
and the pigeon actually lays ten times a year. The great majority
of birds lay during the spring-time. Some birds are prolific, and
prolific in either of two ways - either by laying often, as the
pigeon, or by laying many eggs at a sitting, as the barn-door
hen. All birds of prey, or birds with crooked talons, are
unprolific, except the kestrel: this bird is the most prolific of
birds of prey; as many as four eggs have been observed in the
nest, and occasionally it lays even more.
1592
Birds in general lay their eggs in nests, but such as are
disqualified for flight, as the partridge and the quail, do not lay
them in nests but on the ground, and cover them over with
loose material. The same is the case with the lark and the tetrix.
These birds hatch in sheltered places; but the bird called
merops in Boeotia, alone of all birds, burrows into holes in the
ground and hatches there.
Thrushes, like swallows, build nests of clay, on high trees, and
build them in rows all close together, so that from their
continuity the structure resembles a necklace of nests. Of all
birds that hatch for themselves the hoopoe is the only one that
builds no nest whatever; it gets into the hollow of the trunk of a
tree, and lays its eggs there without making any sort of nest.
The circus builds either under a dwelling-roof or on cliffs. The
tetrix, called ourax in Athens, builds neither on the ground nor
on trees, but on low-lying shrubs.
The egg in the case of all birds alike is hard-shelled, if it be the
produce of copulation and be laid by a healthy hen - for some
hens lay soft eggs. The interior of the egg is of two colours, and
the white part is outside and the yellow part within.
The eggs of birds that frequent rivers and marshes differ from
those of birds that live on dry land; that is to say, the eggs of
waterbirds have comparatively more of the yellow or yolk and
less of the white. Eggs vary in colour according to their kind.
Some eggs are white, as those of the pigeon and of the
partridge; others are yellowish, as the eggs of marsh birds; in
some cases the eggs are mottled, as the eggs of the guinea-fowl
1593
and the pheasant; while the eggs of the kestrel are red, like
vermilion.
Eggs are not symmetrically shaped at both ends: in other words,
one end is comparatively sharp, and the other end is
comparatively blunt; and it is the latter end that protrudes first
at the time of laying. Long and pointed eggs are female; those
that are round, or more rounded at the narrow end, are male.
Eggs are hatched by the incubation of the mother-bird. In some
cases, as in Egypt, they are hatched spontaneously in the
ground, by being buried in dung heaps. A story is told of a toper
in Syracuse, how he used to put eggs into the ground under his
rush-mat and to keep on drinking until he hatched them.
Instances have occurred of eggs being deposited in warm
vessels and getting hatched spontaneously.
The sperm of birds, as of animals in general, is white. After the
female has submitted to the male, she draws up the sperm to
underneath her midriff. At first it is little in size and white in
colour; by and by it is red, the colour of blood; as it grows, it
becomes pale and yellow all over. When at length it is getting
ripe for hatching, it is subject to differentiation of substance,
and the yolk gathers together within and the white settles
round it on the outside. When the full time is come, the egg
detaches itself and protrudes, changing from soft to hard with
such temporal exactitude that, whereas it is not hard during the
process of protrusion, it hardens immediately after the process
is completed: that is if there be no concomitant pathological
circumstances. Cases have occurred where substances
resembling the egg at a critical point of its growth - that is,
when it is yellow all over, as the yolk is subsequently - have
been found in the cock when cut open, underneath his midriff,
just where the hen has her eggs; and these are entirely yellow
in appearance and of the same size as ordinary eggs. Such
phenomena are regarded as unnatural and portentous.
1594
Such as affirm that wind-eggs are the residua of eggs previously
begotten from copulation are mistaken in this assertion, for we
have cases well authenticated where chickens of the common
hen and goose have laid wind-eggs without ever having been
subjected to copulation. Wind-eggs are smaller, less palatable,
and more liquid than true eggs, and are produced in greater
numbers. When they are put under the mother bird, the liquid
contents never coagulate, but both the yellow and the white
remain as they were. Wind-eggs are laid by a number of birds: as
for instance by the common hen, the hen partridge, the hen
pigeon, the peahen, the goose, and the vulpanser. Eggs are
hatched under brooding hens more rapidly in summer than in
winter; that is to say, hens hatch in eighteen days in summer,
but occasionally in winter take as many as twenty-five. And by
the way for brooding purposes some birds make better mothers
than others. If it thunders while a hen-bird is brooding, the eggs
get addled. Wind-eggs that are called by some cynosura and uria
are produced chiefly in summer. Wind-eggs are called by some
zephyr-eggs, because at spring-time hen-birds are observed to
inhale the breezes; they do the same if they be stroked in a
peculiar way by hand. Wind-eggs can turn into fertile eggs, and
eggs due to previous copulation can change breed, if before the
change of the yellow to the white the hen that contains wind-
eggs, or eggs begotten of copulation be trodden by another cock-
bird. Under these circumstances the wind-eggs turn into fertile
eggs, and the previously impregnated eggs follow the breed of
the impregnator; but if the latter impregnation takes place
during the change of the yellow to the white, then no change in
the egg takes place: the wind-egg does not become a true egg,
and the true egg does not take on the breed of the latter
impregnator. If when the egg-substance is small copulation be
intermitted, the previously existing egg-substance exhibits no
increase; but if the hen be again submitted to the male the
increase in size proceeds with rapidity.
1595
The yolk and the white are diverse not only in colour but also in
properties. Thus, the yolk congeals under the influence of cold,
whereas the white instead of congealing is inclined rather to
liquefy. Again, the white stiffens under the influence of fire,
whereas the yolk does not stiffen; but, unless it be burnt
through and through, it remains soft, and in point of fact is
inclined to set or to harden more from the boiling than from the
roasting of the egg. The yolk and the white are separated by a
membrane from one another. The so-called 'hail-stones', or
treadles, that are found at the extremity of the yellow in no way
contribute towards generation, as some erroneously suppose:
they are two in number, one below and the other above. If you
take out of the shells a number of yolks and a number of whites
and pour them into a sauce pan and boil them slowly over a low
fire, the yolks will gather into the centre and the whites will set
all around them.
Young hens are the first to lay, and they do so at the beginning
of spring and lay more eggs than the older hens, but the eggs of
the younger hens are comparatively small. As a general rule, if
hens get no brooding they pine and sicken. After copulation
hens shiver and shake themselves, and often kick rubbish about
all round them - and this, by the way, they do sometimes after
laying - whereas pigeons trail their rumps on the ground, and
geese dive under the water. Conception of the true egg and
conformation of the wind-egg take place rapidly with most
birds; as for instance with the hen-partridge when in heat. The
fact is that, when she stands to windward and within scent of
the male, she conceives, and becomes useless for decoy
purposes: for, by the way, the partridge appears to have a very
acute sense of smell.
The generation of the egg after copulation and the generation of
the chick from the subsequent hatching of the egg are not
brought about within equal periods for all birds, but differ as to
1596
time according to the size of the parent-birds. The egg of the
common hen after copulation sets and matures in ten days a
general rule; the egg of the pigeon in a somewhat lesser period.
Pigeons have the faculty of holding back the egg at the very
moment of parturition; if a hen pigeon be put about by any one,
for instance if it be disturbed on its nest, or have a feather
plucked out, or sustain any other annoyance or disturbance,
then even though she had made up her mind to lay she can
keep the egg back in abeyance. A singular phenomenon is
observed in pigeons with regard to pairing: that is, they kiss one
another just when the male is on the point of mounting the
female, and without this preliminary the male would decline to
perform his function. With the older males the preliminary kiss
is only given to begin with, and subsequently sequently he
mounts without previously kissing; with younger males the
preliminary is never omitted. Another singularity in these birds
is that the hens tread one another when a cock is not
forthcoming, after kissing one another just as takes place in the
normal pairing. Though they do not impregnate one another
they lay more eggs under these than under ordinary
circumstances; no chicks, however, result therefrom, but all
such eggs are wind-eggs.
Generation from the egg proceeds in an identical manner with
all birds, but the full periods from conception to birth differ, as
has been said. With the common hen after three days and three
nights there is the first indication of the embryo; with larger
birds the interval being longer, with smaller birds shorter.
Meanwhile the yolk comes into being, rising towards the sharp
end, where the primal element of the egg is situated, and where
1597
the egg gets hatched; and the heart appears, like a speck of
blood, in the white of the egg. This point beats and moves as
though endowed with life, and from it two vein-ducts with
blood in them trend in a convoluted course (as the egg
substance goes on growing, towards each of the two
circumjacent integuments); and a membrane carrying bloody
fibres now envelops the yolk, leading off from the vein-ducts. A
little afterwards the body is differentiated, at first very small
and white. The head is clearly distinguished, and in it the eyes,
swollen out to a great extent. This condition of the eyes lat on
for a good while, as it is only by degrees that they diminish in
size and collapse. At the outset the under portion of the body
appears insignificant in comparison with the upper portion. Of
the two ducts that lead from the heart, the one proceeds
towards the circumjacent integument, and the other, like a
navel-string, towards the yolk. The life-element of the chick is in
the white of the egg, and the nutriment comes through the
navel-string out of the yolk.
When the egg is now ten days old the chick and all its parts are
distinctly visible. The head is still larger than the rest of its body,
and the eyes larger than the head, but still devoid of vision. The
eyes, if removed about this time, are found to be larger than
beans, and black; if the cuticle be peeled off them there is a
white and cold liquid inside, quite glittering in the sunlight, but
there is no hard substance whatsoever. Such is the condition of
the head and eyes. At this time also the larger internal organs
are visible, as also the stomach and the arrangement of the
viscera; and veins that seem to proceed from the heart are now
close to the navel. From the navel there stretch a pair of veins;
one towards the membrane that envelops the yolk (and, by the
way, the yolk is now liquid, or more so than is normal), and the
other towards that membrane which envelops collectively the
membrane wherein the chick lies, the membrane of the yolk,
and the intervening liquid. (For, as the chick grows, little by little
1598
one part of the yolk goes upward, and another part downward,
and the white liquid is between them; and the white of the egg
is underneath the lower part of the yolk, as it was at the outset.)
On the tenth day the white is at the extreme outer surface,
reduced in amount, glutinous, firm in substance, and sallow in
colour.
The disposition of the several constituent parts is as follows.
First and outermost comes the membrane of the egg, not that of
the shell, but underneath it. Inside this membrane is a white
liquid; then comes the chick, and a membrane round about it,
separating it off so as to keep the chick free from the liquid;
next after the chick comes the yolk, into which one of the two
veins was described as leading, the other one leading into the
enveloping white substance. (A membrane with a liquid
resembling serum envelops the entire structure. Then comes
another membrane right round the embryo, as has been
described, separating it off against the liquid. Underneath this
comes the yolk, enveloped in another membrane (into which
yolk proceeds the navel-string that leads from the heart and the
big vein), so as to keep the embryo free of both liquids.)
About the twentieth day, if you open the egg and touch the
chick, it moves inside and chirps; and it is already coming to be
covered with down, when, after the twentieth day is ast, the
chick begins to break the shell. The head is situated over the
right leg close to the flank, and the wing is placed over the head;
and about this time is plain to be seen the membrane
resembling an after-birth that comes next after the outermost
membrane of the shell, into which membrane the one of the
navel-strings was described as leading (and, by the way, the
chick in its entirety is now within it), and so also is the other
membrane resembling an after-birth, namely that surrounding
the yolk, into which the second navel-string was described as
leading; and both of them were described as being connected
1599
with the heart and the big vein. At this conjuncture the navel-
string that leads to the outer afterbirth collapses and becomes
detached from the chick, and the membrane that leads into the
yolk is fastened on to the thin gut of the creature, and by this
time a considerable amount of the yolk is inside the chick and a
yellow sediment is in its stomach. About this time it discharges
residuum in the direction of the outer after-birth, and has
residuum inside its stomach; and the outer residuum is white
(and there comes a white substance inside). By and by the yolk,
diminishing gradually in size, at length becomes entirely used
up and comprehended within the chick (so that, ten days after
hatching, if you cut open the chick, a small remnant of the yolk
is still left in connexion with the gut), but it is detached from
the navel, and there is nothing in the interval between, but it
has been used up entirely. During the period above referred to
the chick sleeps, wakes up, makes a move and looks up and
Chirps; and the heart and the navel together palpitate as
though the creature were respiring. So much as to generation
from the egg in the case of birds.
Birds lay some eggs that are unfruitful, even eggs that are the
result of copulation, and no life comes from such eggs by
incubation; and this phenomenon is observed especially with
pigeons.
Twin eggs have two yolks. In some twin eggs a thin partition of
white intervenes to prevent the yolks mixing with each other,
but some twin eggs are unprovided with such partition, and the
yokes run into one another. There are some hens that lay
nothing but twin eggs, and in their case the phenomenon
regarding the yolks has been observed. For instance, a hen has
been known to lay eighteen eggs, and to hatch twins out of
them all, except those that were wind-eggs; the rest were fertile
(though, by the way, one of the twins is always bigger than the
other), but the eighteenth was abnormal or monstrous.
1600
Birds of the pigeon kind, such as the ringdove and the turtle-
dove, lay two eggs at a time; that is to say, they do so as a
general rule, and they never lay more than three. The pigeon, as
has been said, lays at all seasons; the ring-dove and the turtle-
dove lay in the springtime, and they never lay more than twice
in the same season. The hen-bird lays the second pair of eggs
when the first pair happens to have been destroyed, for many of
the hen-pigeons destroy the first brood. The hen-pigeon, as has
been said, occasionally lays three eggs, but it never rears more
than two chicks, and sometimes rears only one; and the odd
one is always a wind-egg.
Very few birds propagate within their first year. All birds, after
once they have begun laying, keep on having eggs, though in the
case of some birds it is difficult to detect the fact from the
minute size of the creature.
The pigeon, as a rule, lays a male and a female egg, and
generally lays the male egg first; after laying it allows a day's
interval to ensue and then lays the second egg. The male takes
its turn of sitting during the daytime; the female sits during the
night. The first-laid egg is hatched and brought to birth within
twenty days; and the mother bird pecks a hole in the egg the
day before she hatches it out. The two parent birds brood for
some time over the chicks in the way in which they brooded
previously over the eggs. In all connected with the rearing of the
young the female parent is more cross-tempered than the male,
as is the case with most animals after parturition. The hens lay
as many as ten times in the year; occasional instances have
been known of their laying eleven times, and in Egypt they
1601
actually lay twelve times. The pigeon, male and female, couples
within the year; in fact, it couples when only six months old.
Some assert that ringdoves and turtle-doves pair and procreate
when only three months old, and instance their superabundant
numbers by way of proof of the assertion. The hen-pigeon
carries her eggs fourteen days; for as many more days the
parent birds hatch the eggs; by the end of another fourteen days
the chicks are so far capable of flight as to be overtaken with
difficulty. (The ring-dove, according to all accounts, lives up to
forty years. The partridge lives over sixteen.) (After one brood
the pigeon is ready for another within thirty days.)
The vulture builds its nest on inaccessible cliffs; for which
reason its nest and young are rarely seen. And therefore
Herodorus, father of Bryson the Sophist, declares that vultures
belong to some foreign country unknown to us, stating as a
proof of the assertion that no one has ever seen a vulture's nest,
and also that vultures in great numbers make a sudden
appearance in the rear of armies. However, difficult as it is to
get a sight of it, a vulture's nest has been seen. The vulture lays
two eggs.
(Carnivorous birds in general are observed to lay but once a
year. The swallow is the only carnivorous bird that builds a nest
twice. If you prick out the eyes of swallow chicks while they are
yet young, the birds will get well again and will see by and by.)
1602
The eagle lays three eggs and hatches two of them, as it is said
in the verses ascribed to Musaeus:
That lays three, hatches two, and cares for one.
This is the case in most instances, though occasionally a brood
of three has been observed. As the young ones grow, the mother
becomes wearied with feeding them and extrudes one of the
pair from the nest. At the same time the bird is said to abstain
from food, to avoid harrying the young of wild animals. That is
to say, its wings blanch, and for some days its talons get turned
awry. It is in consequence about this time cross-tempered to its
own young. The phene is said to rear the young one that has
been expelled the nest. The eagle broods for about thirty days.
The hatching period is about the same for the larger birds, such
as the goose and the great bustard; for the middle-sized birds it
extends over about twenty days, as in the case of the kite and
the hawk. The kite in general lays two eggs, but occasionally
rears three young ones. The so-called aegolius at times rears
four. It is not true that, as some aver, the raven lays only two
eggs; it lays a larger number. It broods for about twenty days
and then extrudes its young. Other birds perform the same
operation; at all events mother birds that lay several eggs often
extrude one of their young.
Birds of the eagle species are not alike in the treatment of their
young. The white-tailed eagle is cross, the black eagle is
affectionate in the feeding of the young; though, by the way, all
birds of prey, when their brood is rather forward in being able to
fly, beat and extrude them from the nest. The majority of birds
other than birds of prey, as has been said, also act in this
manner, and after feeding their young take no further care of
them; but the crow is an exception. This bird for a considerable
1603
time takes charge of her young; for, even when her young can
fly, she flies alongside of them and supplies them with food.
The cuckoo is said by some to be a hawk transformed, because
at the time of the cuckoo's coming, the hawk, which it
resembles, is never seen; and indeed it is only for a few days
that you will see hawks about when the cuckoo's note sounds
early in the season. The cuckoo appears only for a short time in
summer, and in winter disappears. The hawk has crooked
talons, which the cuckoo has not; neither with regard to the
head does the cuckoo resemble the hawk. In point of fact, both
as regards the head and the claws it more resembles the pigeon.
However, in colour and in colour alone it does resemble the
hawk, only that the markings of the hawk are striped, and of the
cuckoo mottled. And, by the way, in size and flight it resembles
the smallest of the hawk tribe, which bird disappears as a rule
about the time of the appearance of the cuckoo, though the two
have been seen simultaneously. The cuckoo has been seen to be
preyed on by the hawk; and this never happens between birds
of the same species. They say no one has ever seen the young of
the cuckoo. The bird eggs, but does not build a nest. Sometimes
it lays its eggs in the nest of a smaller bird after first devouring
the eggs of this bird; it lays by preference in the nest of the
ringdove, after first devouring the eggs of the pigeon. (It
occasionally lays two, but usually one.) It lays also in the nest of
the hypolais, and the hypolais hatches and rears the brood. It is
about this time that the bird becomes fat and palatable. (The
young of hawks also get palatable and fat. One species builds a
nest in the wilderness and on sheer and inaccessible cliffs.)
1604
8
With most birds, as has been said of the pigeon, the hatching is
carried on by the male and the female in turns: with some birds,
however, the male only sits long enough to allow the female to
provide herself with food. In the goose tribe the female alone
incubates, and after once sitting on the eggs she continues
brooding until they are hatched.
The nests of all marsh-birds are built in districts fenny and well
supplied with grass; consequently, the mother-bird while sitting
quiet on her eggs can provide herself with food without having
to submit to absolute fasting.
With the crow also the female alone broods, and broods
throughout the whole period; the male bird supports the
female, bringing her food and feeding her. The female of the
ring-dove begins to brood in the afternoon and broods through
the entire night until breakfast-time of the following day; the
male broods during the rest of the time. Partridges build a nest
in two compartments; the male broods on the one and the
female on the other. After hatching, each of the parent birds
rears its brood. But the male, when he first takes his young out
of the nest, treads them.
Peafowl live for about twenty-five years, breed about the third
year, and at the same time take on their spangled plumage.
They hatch their eggs within thirty days or rather more. The
1605
peahen lays but once a year, and lays twelve eggs, or may be a
slightly lesser number: she does not lay all the eggs there and
then one after the other, but at intervals of two or three days.
Such as lay for the first time lay about eight eggs. The peahen
lays wind-eggs. They pair in the spring; and laying begins
immediately after pairing. The bird moults when the earliest
trees are shedding their leaves, and recovers its plumage when
the same trees are recovering their foliage. People that rear
peafowl put the eggs under the barn-door hen, owing to the fact
that when the peahen is brooding over them the peacock
attacks her and tries to trample on them; owing to this
circumstance some birds of wild varieties run away from the
males and lay their eggs and brood in solitude. Only two eggs
are put under a barn-door hen, for she could not brood over and
hatch a large number. They take every precaution, by supplying
her with food, to prevent her going off the eggs and
discontinuing the brooding.
With male birds about pairing time the testicles are obviously
larger than at other times, and this is conspicuously the case
with the more salacious birds, such as the barn-door cock and
the cock partridge; the peculiarity is less conspicuous in such
birds as are intermittent in regard to pairing.
10
So much for the conception and generation of birds.
It has been previously stated that fishes are not all oviparous.
Fishes of the cartilaginous genus are viviparous; the rest are
oviparous. And cartilaginous fishes are first oviparous internally
and subsequently viviparous; they rear the embryos internally,
the batrachus or fishing- frog being an exception.
1606
Fishes also, as was above stated, are provided with wombs, and
wombs of diverse kinds. The oviparous genera have wombs
bifurcate in shape and low down in position; the cartilaginous
genus have wombs shaped like those of birds. The womb,
however, in the cartilaginous fishes differs in this respect from
the womb of birds, that with some cartilaginous fishes the eggs
do not settle close to the diaphragm but middle-ways along the
backbone, and as they grow they shift their position.
The egg with all fishes is not of two colours within but is of
even hue; and the colour is nearer to white than to yellow, and
that both when the young is inside it and previously as well.
Development from the egg in fishes differs from that in birds in
this respect, that it does not exhibit that one of the two navel-
strings that leads off to the membrane that lies close under the
shell, while it does exhibit that one of the two that in the case
of birds leads off to the yolk. In a general way the rest of the
development from the egg onwards is identical in birds and
fishes. That is to say, development takes place at the upper part
of the egg, and the veins extend in like manner, at first from the
heart; and at first the head, the eyes, and the upper parts are
largest; and as the creature grows the egg-substance decreases
and eventually disappears, and becomes absorbed within the
embryo, just as takes place with the yolk in birds.
The navel-string is attached a little way below the aperture of
the belly. When the creatures are young the navel-string is long,
but as they grow it diminishes in size; at length it gets small
and becomes incorporated, as was described in the case of
birds. The embryo and the egg are enveloped by a common
membrane, and just under this is another membrane that
envelops the embryo by itself; and in between the two
membranes is a liquid. The food inside the stomach of the little
1607
fishes resembles that inside the stomach of young chicks, and is
partly white and partly yellow.
As regards the shape of the womb, the reader is referred to my
treatise on Anatomy. The womb, however, is diverse in diverse
fishes, as for instance in the sharks as compared one with
another or as compared with the skate. That is to say, in some
sharks the eggs adhere in the middle of the womb round about
the backbone, as has been stated, and this is the case with the
dog-fish; as the eggs grow they shift their place; and since the
womb is bifurcate and adheres to the midriff, as in the rest of
similar creatures, the eggs pass into one or other of the two
compartments. This womb and the womb of the other sharks
exhibit, as you go a little way off from the midriff, something
resembling white breasts, which never make their appearance
unless there be conception.
Dog-fish and skate have a kind of egg-shell, in the which is
found an egg-like liquid. The shape of the egg-shell resembles
the tongue of a bagpipe, and hair-like ducts are attached to the
shell. With the dog-fish which is called by some the 'dappled
shark', the young are born when the shell-formation breaks in
pieces and falls out; with the ray, after it has laid the egg the
shell-formation breaks up and the young move out. The spiny
dog-fish has its close to the midriff above the breast like
formations; when the egg descends, as soon as it gets detached
the young is born. The mode of generation is the same in the
case of the fox-shark.
The so-called smooth shark has its eggs in betwixt the wombs
like the dog-fish; these eggs shift into each of the two horns of
the womb and descend, and the young develop with the navel-
string attached to the womb, so that, as the egg-substance gets
used up, the embryo is sustained to all appearance just as in the
case of quadrupeds. The navel-string is long and adheres to the
1608
under part of the womb (each navel-string being attached as it
were by a sucker), and also to the centre of the embryo in the
place where the liver is situated. If the embryo be cut open, even
though it has the egg-substance no longer, the food inside is
egg-like in appearance. Each embryo, as in the case of
quadrupeds, is provided with a chorion and separate
membranes. When young the embryo has its head upwards, but
downwards when it gets strong and is completed in form. Males
are generated on the left-hand side of the womb, and females
on the right-hand side, and males and females on the same side
together. If the embryo be cut open, then, as with quadrupeds,
such internal organs as it is furnished with, as for instance the
liver, are found to be large and supplied with blood.
All cartilaginous fishes have at one and the same time eggs
above close to the midriff (some larger, some smaller), in
considerable numbers, and also embryos lower down. And this
circumstance leads many to suppose that fishes of this species
pair and bear young every month, inasmuch as they do not
produce all their young at once, but now and again and over a
lengthened period. But such eggs as have come down below
within the womb are simultaneously ripened and completed in
growth.
Dog-fish in general can extrude and take in again their young,
as can also the angel-fish and the electric ray - and, by the way,
a large electric ray has been seen with about eighty embryos
inside it - but the spiny dogfish is an exception to the rule,
being prevented by the spine of the young fish from so doing. Of
the flat cartilaginous fish, the trygon and the ray cannot extrude
and take in again in consequence of the roughness of the tails
of the young. The batrachus or fishing- frog also is unable to take
in its young owing to the size of the head and the prickles; and,
by the way, as was previously remarked, it is the only one of
these fishes that is not viviparous.
1609
So much for the varieties of the cartilaginous species and for
their modes of generation from the egg.
11
At the breeding season the sperm-ducts of the male are filled
with sperm, so much so that if they be squeezed the sperm
flows out spontaneously as a white fluid; the ducts are
bifurcate, and start from the midriff and the great vein. About
this period the sperm-ducts of the male are quite distinct (from
the womb of the female) but at any other than the actual
breeding time their distinctness is not obvious to a non-expert.
The fact is that in certain fishes at certain times these organs
are imperceptible, as was stated regarding the testicles of birds.
Among other distinctions observed between the thoric ducts
and the womb-ducts is the circumstance that the thoric ducts
are attached to the loins, while the womb-ducts move about
freely and are attached by a thin membrane. The particulars
regarding the thoric ducts may be studied by a reference to the
diagrams in my treatise on Anatomy.
Cartilaginous fishes are capable of superfoetation, and their
period of gestation is six months at the longest. The so-called
starry dogfish bears young the most frequently; in other words
it bears twice a month. The breeding season is in the month of
Maemacterion. The dog-fish as a general rule bear twice in the
year, with the exception of the little dog-fish, which bears only
once a year. Some of them bring forth in the springtime. The
rhine, or angel-fish, bears its first brood in the springtime, and
its second in the autumn, about the winter setting of the
Pleiads; the second brood is the stronger of the two. The electric
ray brings forth in the late autumn.
1610
Cartilaginous fishes come out from the main seas and deep
waters towards the shore and there bring forth their young, and
they do so for the sake of warmth and by way of protection for
their young.
Observations would lead to the general rule that no one variety
of fish pairs with another variety. The angel-fish, however, and
the batus or skate appear to pair with one another; for there is a
fish called the rhinobatus, with the head and front parts of the
skate and the after parts of the rhine or angel-fish, just as
though it were made up of both fishes together.
Sharks then and their congeners, as the fox-shark and the dog-
fish, and the flat fishes, such as the electric ray, the ray, the
smooth skate, and the trygon, are first oviparous and then
viviparous in the way above mentioned, (as are also the saw-
fish and the ox-ray.)
12
The dolphin, the whale, and all the rest of the Cetacea, all, that
is to say, that are provided with a blow-hole instead of gills, are
viviparous. That is to say, no one of all these fishes is ever seen
to be supplied with eggs, but directly with an embryo from
whose differentiation comes the fish, just as in the case of
mankind and the viviparous quadrupeds.
The dolphin bears one at a time generally, but occasionally two.
The whale bears one or at the most two, generally two. The
porpoise in this respect resembles the dolphin, and, by the way,
it is in form like a little dolphin, and is found in the Euxine; it
differs, however, from the dolphin as being less in size and
1611
broader in the back; its colour is leaden-black. Many people are
of opinion that the porpoise is a variety of the dolphin.
All creatures that have a blow-hole respire and inspire, for they
are provided with lungs. The dolphin has been seen asleep with
his nose above water, and when asleep he snores.
The dolphin and the porpoise are provided with milk, and
suckle their young. They also take their young, when small,
inside them. The young of the dolphin grow rapidly, being full
grown at ten years of age. Its period of gestation is ten months.
It brings forth its young summer, and never at any other season;
(and, singularly enough, under the Dogstar it disappears for
about thirty days). Its young accompany it for a considerable
period; and, in fact, the creature is remarkable for the strength
of its parental affection. It lives for many years; some are known
to have lived for more than twenty-five, and some for thirty
years; the fact is fishermen nick their tails sometimes and set
them adrift again, and by this expedient their ages are
ascertained.
The seal is an amphibious animal: that is to say, it cannot take
in water, but breathes and sleeps and brings forth on dry land -
only close to the shore - as being an animal furnished with feet;
it spends, however, the greater part of its time in the sea and
derives its food from it, so that it must be classed in the
category of marine animals. It is viviparous by immediate
conception and brings forth its young alive, and exhibits an
after-birth and all else just like a ewe. It bears one or two at a
time, and three at the most. It has two teats, and suckles its
young like a quadruped. Like the human species it brings forth
at all seasons of the year, but especially at the time when the
earliest kids are forthcoming. It conducts its young ones, when
they are about twelve days old, over and over again during the
day down to the sea, accustoming them by slow degrees to the
1612
water. It slips down steep places instead of walking, from the
fact that it cannot steady itself by its feet. It can contract and
draw itself in, for it is fleshy and soft and its bones are gristly.
Owing to the flabbiness of its body it is difficult to kill a seal by a
blow, unless you strike it on the temple. It looks like a cow. The
female in regard to its genital organs resembles the female of
the ray; in all other respects it resembles the female of the
human species.
So much for the phenomena of generation and of parturition in
animals that live in water and are viviparous either internally or
externally.
13
Oviparous fishes have their womb bifurcate and placed low
down, as was said previously - and, by the way, all scaly fish are
oviparous, as the basse, the mullet, the grey mullet, and the
etelis, and all the so-called white-fish, and all the smooth or
slippery fish except the eel - and their roe is of a crumbling or
granular substance. This appearance is due to the fact that the
whole womb of such fishes is full of eggs, so that in little fishes
there seem to be only a couple of eggs there; for in small fishes
the womb is indistinguishable, from its diminutive size and thin
contexture. The pairing of fishes has been discussed previously.
Fishes for the most part are divided into males and females, but
one is puzzled to account for the erythrinus and the channa, for
specimens of these species are never caught except in a
condition of pregnancy.
With such fish as pair, eggs are the result of copulation, but
such fish have them also without copulation; and this is shown
1613
in the case of some river-fish, for the minnow has eggs when
quite small, - almost, one may say, as soon as it is born. These
fishes shed their eggs little by little, and, as is stated, the males
swallow the greater part of them, and some portion of them
goes to waste in the water; but such of the eggs as the female
deposits on the spawning beds are saved. If all the eggs were
preserved, each species would be infinite in number. The greater
number of these eggs so deposited are not productive, but only
those over which the male sheds the milt or sperm; for when
the female has laid her eggs, the male follows and sheds its
sperm over them, and from all the eggs so besprinkled young
fishes proceed, while the rest are left to their fate.
The same phenomenon is observed in the case of molluscs also;
for in the case of the cuttlefish or sepia, after the female has
deposited her eggs, the male besprinkles them. It is highly
probable that a similar phenomenon takes place in regard to
molluscs in general, though up to the present time the
phenomenon has been observed only in the case of the
cuttlefish.
Fishes deposit their eggs close in to shore, the goby close to
stones; and, by the way, the spawn of the goby is flat and
crumbly. Fish in general so deposit their eggs; for the water
close in to shore is warm and is better supplied with food than
the outer sea, and serves as a protection to the spawn against
the voracity of the larger fish. And it is for this reason that in
the Euxine most fishes spawn near the mouth of the river
Thermodon, because the locality is sheltered, genial, and
supplied with fresh water.
Oviparous fish as a rule spawn only once a year. The little
phycis or black goby is an exception, as it spawns twice; the
male of the black goby differs from the female as being blacker
and having larger scales.
1614
Fishes then in general produce their young by copulation, and
lay their eggs; but the pipefish, as some call it, when the time of
parturition arrives, bursts in two, and the eggs escape out. For
the fish has a diaphysis or cloven growth under the belly and
abdomen (like the blind snakes), and, after it has spawned by
the splitting of this diaphysis, the sides of the split grow
together again.
Development from the egg takes place similarly with fishes that
are oviparous internally and with fishes that are oviparous
externally; that is to say, the embryo comes at the upper end of
the egg and is enveloped in a membrane, and the eyes, large
and spherical, are the first organs visible. From this
circumstance it is plain that the assertion is untenable which is
made by some writers, to wit, that the young of oviparous fishes
are generated like the grubs of worms; for the opposite
phenomena are observed in the case of these grubs, in that
their lower extremities are the larger at the outset, and that the
eyes and the head appear later on. After the egg has been used
up, the young fishes are like tadpoles in shape, and at first,
without taking any nutriment, they grow by sustenance derived
from the juice oozing from the egg; by and by, they are
nourished up to full growth by the river-waters.
When the Euxine is 'purged' a substance called phycus is
carried into the Hellespont, and this substance is of a pale
yellow colour. Some writers aver that it is the flower of the
phycus, from which rouge is made; it comes at the beginning of
summer. Oysters and the small fish of these localities feed on
this substance, and some of the inhabitants of these maritime
districts say that the purple murex derives its peculiar colour
from it.
1615
14
Marsh-fishes and river-fishes conceive at the age of five months
as a general rule, and deposit their spawn towards the close of
the year without exception. And with these fishes, like as with
the marine fishes, the female does not void all her eggs at one
time, nor the male his sperm; but they are at all times more or
less provided, the female with eggs, and the male with sperm.
The carp spawns as the seasons come round, five or six times,
and follows in spawning the rising of the greater constellations.
The chalcis spawns three times, and the other fishes once only
in the year. They all spawn in pools left by the overflowing of
rivers, and near to reedy places in marshes; as for instance the
phoxinus or minnow and the perch.
The glanis or sheat-fish and the perch deposit their spawn in
one continuous string, like the frog; so continuous, in fact, is the
convoluted spawn of the perch that, by reason of its
smoothness, the fishermen in the marshes can unwind it off
the reeds like threads off a reel. The larger individuals of the
sheat-fish spawn in deep waters, some in water of a fathom's
depth, the smaller in shallower water, generally close to the
roots of the willow or of some other tree, or close to reeds or to
moss. At times these fishes intertwine with one another, a big
with a little one, and bring into juxtaposition the ducts - which
some writers designate as navels - at the point where they emit
the generative products and discharge the egg in the case of the
female and the milt in the case of the male. Such eggs as are
besprinkled with the milt grow, in a day or thereabouts, whiter
and larger, and in a little while afterwards the fish's eyes
become visible for these organs in all fishes, as for that matter
in all other animals, are early conspicuous and seem
disproportionately big. But such eggs as the milt fails to touch
remain, as with marine fishes, useless and infertile. From the
fertile eggs, as the little fish grow, a kind of sheath detaches
1616
itself; this is a membrane that envelops the egg and the young
fish. When the milt has mingled with the eggs, the resulting
product becomes very sticky or viscous, and adheres to the
roots of trees or wherever it may have been laid. The male keeps
on guard at the principal spawning-place, and the female after
spawning goes away.
In the case of the sheat-fish the growth from the egg is
exceptionally slow, and, in consequence, the male has to keep
watch for forty or fifty days to prevent the spawn being
devoured by such little fishes as chance to come by. Next in
point of slowness is the generation of the carp. As with fishes in
general, so even with these, the spawn thus protected
disappears and gets lost rapidly.
In the case of some of the smaller fishes when they are only
three days old young fishes are generated. Eggs touched by the
male sperm take on increase both the same day and also later.
The egg of the sheat-fish is as big as a vetch-seed; the egg of the
carp and of the carp-species as big as a millet-seed.
These fishes then spawn and generate in the way here
described. The chalcis, however, spawns in deep water in dense
shoals of fish; and the so-called tilon spawns near to beaches in
sheltered spots in shoals likewise. The carp, the baleros, and
fishes in general push eagerly into the shallows for the purpose
of spawning, and very often thirteen or fourteen males are seen
following a single female. When the female deposits her spawn
and departs, the males follow on and shed the milt. The greater
portion of the spawn gets wasted; because, owing to the fact
that the female moves about while spawning, the spawn
scatters, or so much of it as is caught in the stream and does
not get entangled with some rubbish. For, with the exception of
the sheatfish, no fish keeps on guard; unless, by the way, it be
1617
the carp, which is said to remain on guard, if it so happen that
its spawn lies in a solid mass.
All male fishes are supplied with milt, excepting the eel: with
the eel, the male is devoid of milt, and the female of spawn. The
mullet goes up from the sea to marshes and rivers; the eels, on
the contrary, make their way down from the marshes and rivers
to the sea.
15
The great majority of fish, then, as has been stated, proceed
from eggs. However, there are some fish that proceed from mud
and sand, even of those kinds that proceed also from pairing
and the egg. This occurs in ponds here and there, and especially
in a pond in the neighbourhood of Cnidos. This pond, it is said,
at one time ran dry about the rising of the Dogstar, and the mud
had all dried up; at the first fall of the rains there was a show of
water in the pond, and on the first appearance of the water
shoals of tiny fish were found in the pond. The fish in question
was a kind of mullet, one which does not proceed from normal
pairing, about the size of a small sprat, and not one of these
fishes was provided with either spawn or milt. There are found
also in Asia Minor, in rivers not communicating with the sea,
little fishes like whitebait, differing from the small fry found
near Cnidos but found under similar circumstances. Some
writers actually aver that mullet all grow spontaneously. In this
assertion they are mistaken, for the female of the fish is found
provided with spawn, and the male with milt. However, there is
a species of mullet that grows spontaneously out of mud and
sand.
1618
From the facts above enumerated it is quite proved that certain
fishes come spontaneously into existence, not being derived
from eggs or from copulation. Such fish as are neither oviparous
nor viviparous arise all from one of two sources, from mud, or
from sand and from decayed matter that rises thence as a
scum; for instance, the so-called froth of the small fry comes
out of sandy ground. This fry is incapable of growth and of
propagating its kind; after living for a while it dies away and
another creature takes its place, and so, with short intervals
excepted, it may be said to last the whole year through. At all
events, it lasts from the autumn rising of Arcturus up to the
spring-time. As a proof that these fish occasionally come out of
the ground we have the fact that in cold weather they are not
caught, and that they are caught in warm weather, obviously
coming up out of the ground to catch the heat; also, when the
fishermen use dredges and the ground is scraped up fairly
often, the fishes appear in larger numbers and of superior
quality. All other small fry are inferior in quality owing to
rapidity of growth. The fry are found in sheltered and marshy
districts, when after a spell of fine weather the ground is getting
warmer, as, for instance, in the neighbourhood of Athens, at
Salamis and near the tomb of Themistocles and at Marathon;
for in these districts the froth is found. It appears, then, in such
districts and during such weather, and occasionally appears
after a heavy fall of rain in the froth that is thrown up by the
falling rain, from which circumstance the substance derives its
specific name. Foam is occasionally brought in on the surface of
the sea in fair weather. (And in this, where it has formed on the
surface, the so-called froth collects, as grubs swarm in manure;
for which reason this fry is often brought in from the open sea.
The fish is at its best in quality and quantity in moist warm
weather.)
The ordinary fry is the normal issue of parent fishes: the so-
called gudgeon-fry of small insignificant gudgeon-like fish that
1619
burrow under the ground. From the Phaleric fry comes the
membras, from the membras the trichis, from the trichis the
trichias, and from one particular sort of fry, to wit from that
found in the harbour of Athens, comes what is called the
encrasicholus, or anchovy. There is another fry, derived from the
maenis and the mullet.
The unfertile fry is watery and keeps only a short time, as has
been stated, for at last only head and eyes are left. However, the
fishermen of late have hit upon a method of transporting it to a
distance, as when salted it keeps for a considerable time.
16
Eels are not the issue of pairing, neither are they oviparous; nor
was an eel ever found supplied with either milt or spawn, nor
are they when cut open found to have within them passages for
spawn or for eggs. In point of fact, this entire species of blooded
animals proceeds neither from pair nor from the egg.
There can be no doubt that the case is so. For in some standing
pools, after the water has been drained off and the mud has
been dredged away, the eels appear again after a fall of rain. In
time of drought they do not appear even in stagnant ponds, for
the simple reason that their existence and sustenance is
derived from rain-water.
There is no doubt, then, that they proceed neither from pairing
nor from an egg. Some writers, however, are of opinion that they
generate their kind, because in some eels little worms are
found, from which they suppose that eels are derived. But this
opinion is not founded on fact. Eels are derived from the so-
called 'earth's guts' that grow spontaneously in mud and in
1620
humid ground; in fact, eels have at times been seen to emerge
out of such earthworms, and on other occasions have been
rendered visible when the earthworms were laid open by either
scraping or cutting. Such earthworms are found both in the sea
and in rivers, especially where there is decayed matter: in the
sea in places where sea-weed abounds, and in rivers and
marshes near to the edge; for it is near to the water's edge that
sun-heat has its chief power and produces putrefaction. So
much for the generation of the eel.
17
Fish do not all bring forth their young at the same season nor all
in like manner, neither is the period of gestation for all of the
same duration.
Before pairing the males and females gather together in shoals;
at the time for copulation and parturition they pair off. With
some fishes the time of gestation is not longer than thirty days,
with others it is a lesser period; but with all it extends over a
number of days divisible by seven. The longest period of
gestation is that of the species which some call a marinus.
The sargue conceives during the month of Poseideon (or
December), and carries its spawn for thirty days; and the
species of mullet named by some the chelon, and the myxon, go
with spawn at the same period and over the same length of
time.
All fish suffer greatly during the period of gestation, and are in
consequence very apt to be thrown up on shore at this time. In
some cases they are driven frantic with pain and throw
themselves on land. At all events they are throughout this time
1621
continually in motion until parturition is over (this being
especially true of the mullet), and after parturition they are in
repose. With many fish the time for parturition terminates on
the appearance of grubs within the belly; for small living grubs
get generated there and eat up the spawn.
With shoal fishes parturition takes place in the spring, and
indeed, with most fishes, about the time of the spring equinox;
with others it is at different times, in summer with some, and
with others about the autumn equinox.
The first of shoal fishes to spawn is the atherine, and it spawns
close to land; the last is the cephalus: and this is inferred from
the fact that the brood of the atherine appears first of all and
the brood of the cephalus last. The mullet also spawns early.
The saupe spawns usually at the beginning of summer, but
occasionally in the autumn. The aulopias, which some call the
anthias, spawns in the summer. Next in order of spawning
comes the chrysophrys or gilthead, the basse, the mormyrus,
and in general such fish as are nicknamed 'runners'. Latest in
order of the shoal fish come the red mullet and the coracine;
these spawn in autumn. The red mullet spawns on mud, and
consequently, as the mud continues cold for a long while,
spawns late in the year. The coracine carries its spawn for a long
time; but, as it lives usually on rocky ground, it goes to a
distance and spawns in places abounding in seaweed, at a
period later than the red mullet. The maenis spawns about the
winter solstice. Of the others, such as are pelagic spawn for the
most part in summer; which fact is proved by their not being
caught by fishermen during this period.
Of ordinary fishes the most prolific is the sprat; of cartilaginous
fishes, the fishing-frog. Specimens, however, of the fishing-frog
are rare from the facility with which the young are destroyed, as
the female lays her spawn all in a lump close in to shore. As a
1622
rule, cartilaginous fish are less prolific than other fish owing to
their being viviparous; and their young by reason of their size
have a better chance of escaping destruction.
The so-called needle-fish (or pipe-fish) is late in spawning, and
the greater portion of them are burst asunder by the eggs before
spawning; and the eggs are not so many in number as large in
size. The young fish cluster round the parent like so many
young spiders, for the fish spawns on to herself; and, if any one
touch the young, they swim away. The atherine spawns by
rubbing its belly against the sand.
Tunny fish also burst asunder by reason of their fat. They live
for two years; and the fishermen infer this age from the
circumstance that once when there was a failure of the young
tunny fish for a year there was a failure of the full-grown tunny
the next summer. They are of opinion that the tunny is a fish a
year older than the pelamyd. The tunny and the mackerel pair
about the close of the month of Elaphebolion, and spawn about
the commencement of the month of Hecatombaeon; they
deposit their spawn in a sort of bag. The growth of the young
tunny is rapid. After the females have spawned in the Euxine,
there comes from the egg what some call scordylae, but what
the Byzantines nickname the 'auxids' or 'growers', from their
growing to a considerable size in a few days; these fish go out of
the Pontus in autumn along with the young tunnies, and enter
Pontus in the spring as pelamyds. Fishes as a rule take on
growth with rapidity, but this is peculiarly the case with all
species of fish found in the Pontus; the growth, for instance, of
the amia-tunny is quite visible from day to day.
To resume, we must bear in mind that the same fish in the
same localities have not the same season for pairing, for
conception, for parturition, or for favouring weather. The
coracine, for instance, in some places spawns about wheat-
1623
harvest. The statements here given pretend only to give the
results of general observation.
The conger also spawns, but the fact is not equally obvious in
all localities, nor is the spawn plainly visible owing to the fat of
the fish; for the spawn is lanky in shape as it is with serpents.
However, if it be put on the fire it shows its nature; for the fat
evaporates and melts, while the eggs dance about and explode
with a crack. Further, if you touch the substances and rub them
with your fingers, the fat feels smooth and the egg rough. Some
congers are provided with fat but not with any spawn, others
are unprovided with fat but have egg-spawn as here described.
18
We have, then, treated pretty fully of the animals that fly in the
air or swim in the water, and of such of those that walk on dry
land as are oviparous, to wit of their pairing, conception, and
the like phenomena; it now remains to treat of the same
phenomena in connexion with viviparous land animals and
with man.
The statements made in regard to the pairing of the sexes apply
partly to the particular kinds of animal and partly to all in
general. It is common to all animals to be most excited by the
desire of one sex for the other and by the pleasure derived from
copulation. The female is most cross-tempered just after
parturition, the male during the time of pairing; for instance,
stallions at this period bite one another, throw their riders, and
chase them. Wild boars, though usually enfeebled at this time
as the result of copulation, are now unusually fierce, and fight
with one another in an extraordinary way, clothing themselves
with defensive armour, or in other words deliberately
1624
thickening their hide by rubbing against trees or by coating
themselves repeatedly all over with mud and then drying
themselves in the sun. They drive one another away from the
swine pastures, and fight with such fury that very often both
combatants succumb. The case is similar with bulls, rams, and
he-goats; for, though at ordinary times they herd together, at
breeding time they hold aloof from and quarrel with one
another. The male camel also is cross-tempered at pairing time
if either a man or a camel comes near him; as for a horse, a
camel is ready to fight him at any time. It is the same with wild
animals. The bear, the wolf, and the lion are all at this time
ferocious towards such as come in their way, but the males of
these animals are less given to fight with one another from the
fact that they are at no time gregarious. The she-bear is fierce
after cubbing, and the bitch after pupping.
Male elephants get savage about pairing time, and for this
reason it is stated that men who have charge of elephants in
India never allow the males to have intercourse with the
females; on the ground that the males go wild at this time and
turn topsy-turvy the dwellings of their keepers, lightly
constructed as they are, and commit all kinds of havoc. They
also state that abundancy of food has a tendency to tame the
males. They further introduce other elephants amongst the wild
ones, and punish and break them in by setting on the new-
comers to chastise the others.
Animals that pair frequently and not at a single specific season,
as for instance animals domesticated by man, such as swine
and dogs, are found to indulge in such freaks to a lesser degree
owing to the frequency of their sexual intercourse.
Of female animals the mare is the most sexually wanton, and
next in order comes the cow. In fact, the mare is said to go a-
horsing; and the term derived from the habits of this one
1625
animal serves as a term of abuse applicable to such females of
the human species as are unbridled in the way of sexual
appetite. This is the common phenomenon as observed in the
sow when she is said to go a-boaring. The mare is said also
about this time to get wind-impregnated if not impregnated by
the stallion, and for this reason in Crete they never remove the
stallion from the mares; for when the mare gets into this
condition she runs away from all other horses. The mares under
these circumstances fly invariably either northwards or
southwards, and never towards either east or west. When this
complaint is on them they allow no one to approach, until
either they are exhausted with fatigue or have reached the sea.
Under either of these circumstances they discharge a certain
substance 'hippomanes', the title given to a growth on a new-
born foal; this resembles the sow-virus, and is in great request
amongst women who deal in drugs and potions. About horsing
time the mares huddle closer together, are continually
switching their tails, their neigh is abnormal in sound, and from
the sexual organ there flows a liquid resembling genital sperm,
but much thinner than the sperm of the male. It is this
substance that some call hippomanes, instead of the growth
found on the foal; they say it is extremely difficult to get as it
oozes out only in small drops at a time. Mares also, when in
heat, discharge urine frequently, and frisk with one another.
Such are the phenomena connected with the horse.
Cows go a-bulling; and so completely are they under the
influence of the sexual excitement that the herdsmen have no
control over them and cannot catch hold of them in the fields.
Mares and kine alike, when in heat, indicate the fact by the
upraising of their genital organs, and by continually voiding
urine. Further, kine mount the bulls, follow them about; and
keep standing beside them. The younger females both with
horses and oxen are the first to get in heat; and their sexual
appetites are all the keener if the weather warm and their
1626
bodily condition be healthy. Mares, when dipt of their coat,
have the sexual feeling checked, and assume a downcast
drooping appearance. The stallion recognizes by the scent the
mares that form his company, even though they have been
together only a few days before breeding time: if they get mixed
up with other mares, the stallion bites and drives away the
interlopers. He feeds apart, accompanied by his own troop of
mares. Each stallion has assigned to him about thirty mares or
even somewhat more; when a strange stallion approaches, he
huddles his mares into a close ring, runs round them, then
advances to the encounter of the newcomer; if one of the mares
make a movement, he bites her and drives her back. The bull in
breeding time begins to graze with the cows, and fights with
other bulls (having hitherto grazed with them), which is termed
by graziers 'herd-spurning'. Often in Epirus a bull disappears for
three months together. In a general way one may state that of
male animals either none or few herd with their respective
females before breeding time; but they keep separate after
reaching maturity, and the two sexes feed apart. Sows, when
they are moved by sexual desire, or are, as it is called, a-boaring,
will attack even human beings.
With bitches the same sexual condition is termed 'getting into
heat'. The sexual organ rises at this time, and there is a
moisture about the parts. Mares drip with a white liquid at this
season.
Female animals are subject to menstrual discharges, but never
in such-abundance as is the female of the human species. With
ewes and she-goats there are signs of menstruation in breeding
time, just before the for submitting to the male; after copulation
also the signs are manifest, and then cease for an interval until
the period of parturition arrives; the process then supervenes,
and it is by this supervention that the shepherd knows that
such and such an ewe is about to bring forth. After parturition
1627
comes copious menstruation, not at first much tinged with
blood, but deeply dyed with it by and by. With the cow, the she
ass, and the mare, the discharge is more copious actually, owing
to their greater bulk, but proportionally to the greater bulk it is
far less copious. The cow, for instance, when in heat, exhibits a
small discharge to the extent of a quarter of a pint of liquid or a
little less; and the time when this discharge takes place is the
best time for her to be covered by the bull. Of all quadrupeds the
mare is the most easily delivered of its young, exhibits the least
amount of discharge after parturition, and emits the least
amount of blood; that is to say, of all animals in proportion to
size. With kine and mares menstruation usually manifests itself
at intervals of two, four, and six months; but, unless one be
constantly attending to and thoroughly acquainted with such
animals, it is difficult to verify the circumstance, and the result
is that many people are under the belief that the process never
takes place with these animals at all.
With mules menstruation never takes place, but the urine of the
female is thicker than the urine of the male. As a general rule
the discharge from the bladder in the case of quadrupeds is
thicker than it is in the human species, and this discharge with
ewes and she-goats is thicker than with rams and he-goats; but
the urine of the jackass is thicker than the urine of the she-ass,
and the urine of the bull is more pungent than the urine of the
cow. After parturition the urine of all quadrupeds becomes
thicker, especially with such animals as exhibit comparatively
slight discharges. At breeding time the milk become purulent,
but after parturition it becomes wholesome. During pregnancy
ewes and she-goats get fatter and eat more; as is also the case
with cows, and, indeed, with the females of all quadrupeds.
In general the sexual appetites of animals are keenest in spring-
time; the time of pairing, however, is not the same for all, but is
1628
adapted so as to ensure the rearing of the young at a convenient
season.
Domesticated swine carry their young for four months, and
bring forth a litter of twenty at the utmost; and, by the way, if
the litter be exceedingly numerous they cannot rear all the
young. As the sow grows old she continues to bear, but grows
indifferent to the boar; she conceives after a single copulation,
but they have to put the boar to her repeatedly owing to her
dropping after intercourse what is called the sow-virus. This
incident befalls all sows, but some of them discharge the genital
sperm as well. During conception any one of the litter that gets
injured or dwarfed is called an afterpig or scut: such injury may
occur at any part of the womb. After littering the mother offers
the foremost teat to the first-born. When the sow is in heat, she
must not at once be put to the boar, but only after she lets her
lugs drop, for otherwise she is apt to get into heat again; if she
be put to the boar when in full condition of heat, one
copulation, as has been said, is sufficient. It is as well to supply
the boar at the period of copulation with barley, and the sow at
the time of parturition with boiled barley. Some swine give fine
litters only at the beginning, with others the litters improve as
the mothers grow in age and size. It is said that a sow, if she
have one of her eyes knocked out, is almost sure to die soon
afterwards. Swine for the most part live for fifteen years, but
some fall little short of the twenty.
19
Ewes conceive after three or four copulations with the ram. If
rain falls after intercourse, the ram impregnates the ewe again;
and it is the same with the she-goat. The ewe bears usually two
1629
lambs, sometimes three or four. Both ewe and she-goat carry
their young for five months; consequently wherever a district is
sunny and the animals are used to comfort and well fed, they
bear twice in the year. The goat lives for eight years and the
sheep for ten, but in most cases not so long; the bell-wether,
however, lives to fifteen years. In every flock they train one of
the rams for bell-wether. When he is called on by name by the
shepherd, he takes the lead of the flock: and to this duty the
creature is trained from its earliest years. Sheep in Ethiopia live
for twelve or thirteen years, goats for ten or eleven. In the case
of the sheep and the goat the two sexes have intercourse all
their lives long.
Twins with sheep and goats may be due to richness of
pasturage, or to the fact that either the ram or the he-goat is a
twin-begetter or that the ewe or the she-goat is a twin-bearer.
Of these animals some give birth to males and others to
females; and the difference in this respect depends on the
waters they drink and also on the sires. And if they submit to
the male when north winds are blowing, they are apt to bear
males; if when south winds are blowing, females. Such as bear
females may get to bear males, due regard being paid to their
looking northwards when put to the male. Ewes accustomed to
be put to the ram early will refuse him if he attempt to mount
them late. Lambs are born white and black according as white
or black veins are under the ram's tongue; the lambs are white
if the veins are white, and black if the veins are black, and white
and black if the veins are white and black; and red if the veins
are red. The females that drink salted waters are the first to take
the male; the water should be salted before and after
parturition, and again in the springtime. With goats the
shepherds appoint no bell-wether, as the animal is not capable
of repose but frisky and apt to ramble. If at the appointed
season the elders of the flock are eager for intercourse, the
1630
shepherds say that it bodes well for the flock; if the younger
ones, that the flock is going to be bad.
20
Of dogs there are several breeds. Of these the Laconian hound of
either sex is fit for breeding purposes when eight months old: at
about the same age some dogs lift the leg when voiding urine.
The bitch conceives with one lining; this is clearly seen in the
case where a dog contrives to line a bitch by stealth, as they
impregnate after mounting only once. The Laconian bitch
carries her young the sixth part of a year or sixty days: or more
by one, two, or three, or less by one; the pups are blind for
twelve days after birth. After pupping, the bitch gets in heat
again in six months, but not before. Some bitches carry their
young for the fifth part of the year or for seventy-two days; and
their pups are blind for fourteen days. Other bitches carry their
young for a quarter of a year or for three whole months; and the
whelps of these are blind for seventeen days. The bitch appears
go in heat for the same length of time. Menstruation continues
for seven days, and a swelling of the genital organ occurs
simultaneously; it is not during this period that the bitch is
disposed to submit to the dog, but in the seven days that follow.
The bitch as a rule goes in heat for fourteen days, but
occasionally for sixteen. The birth-discharge occurs
simultaneously with the delivery of the whelps, and the
substance of it is thick and mucous. (The falling-off in bulk on
the part of the mother is not so great as might have been
inferred from the size of her frame.) The bitch is usually
supplied with milk five days before parturition; some seven
days previously, some four; and the milk is serviceable
immediately after birth. The Laconian bitch is supplied with
1631
milk thirty days after lining. The milk at first is thickish, but
gets thinner by degrees; with the bitch the milk is thicker than
with the female of any other animal excepting the sow and the
hare. When the bitch arrives at full growth an indication is given
of her capacity for the male; that is to say, just as occurs in the
female of the human species, a swelling takes place in the teats
of the breasts, and the breasts take on gristle. This incident,
however, it is difficult for any but an expert to detect, as the part
that gives the indication is inconsiderable. The preceding
statements relate to the female, and not one of them to the
male. The male as a rule lifts his leg to void urine when six
months old; some at a later period, when eight months old,
some before they reach six months. In a general way one may
put it that they do so when they are out of puppyhood. The
bitch squats down when she voids urine; it is a rare exception
that she lifts the leg to do so. The bitch bears twelve pups at the
most, but usually five or six; occasionally a bitch will bear one
only. The bitch of the Laconian breed generally bears eight. The
two sexes have intercourse with each other at all periods of life.
A very remarkable phenomenon is observed in the case of the
Laconian hound: in other words, he is found to be more
vigorous in commerce with the female after being hard-worked
than when allowed to live idle.
The dog of the Laconian breed lives ten years, and the bitch
twelve. The bitch of other breeds usually lives for fourteen or
fifteen years, but some live to twenty; and for this reason
certain critics consider that Homer did well in representing the
dog of Ulysses as having died in his twentieth year. With the
Laconian hound, owing to the hardships to which the male is
put, he is less long-lived than the female; with other breeds the
distinction as to longevity is not very apparent, though as a
general rule the male is the longer-lived.
1632
The dog sheds no teeth except the so-called 'canines'; these a
dog of either sex sheds when four months old. As they shed
these only, many people are in doubt as to the fact, and some
people, owing to their shedding but two and its being hard to hit
upon the time when they do so, fancy that the animal sheds no
teeth at all; others, after observing the shedding of two, come to
the conclusion that the creature sheds the rest in due turn. Men
discern the age of a dog by inspection of its teeth; with young
dogs the teeth are white and sharp pointed, with old dogs black
and blunted.
21
The bull impregnates the cow at a single mount, and mounts
with such vigour as to weigh down the cow; if his effort be
unsuccessful, the cow must be allowed an interval of twenty
days before being again submitted. Bulls of mature age decline
to mount the same cow several times on one day, except, by the
way, at considerable intervals. Young bulls by reason of their
vigour are enabled to mount the same cow several times in one
day, and a good many cows besides. The bull is the least
salacious of male animals.... The victor among the bulls is the
one that mounts the females; when he gets exhausted by his
amorous efforts, his beaten antagonist sets on him and very
often gets the better of the conflict. The bull and the cow are
about a year old when it is possible for them to have commerce
with chance of offspring: as a rule, however, they are about
twenty months old, but it is universally allowed that they are
capable in this respect at the age of two years. The cow goes
with calf for nine months, and she calves in the tenth month;
some maintain that they go in calf for ten months, to the very
day. A calf delivered before the times here specified is an
1633
abortion and never lives, however little premature its birth may
have been, as its hooves are weak and imperfect. The cow as a
rule bears but one calf, very seldom two; she submits to the bull
and bears as long as she lives.
Cows live for about fifteen years, and the bulls too, if they have
been castrated; but some live for twenty years or even more, if
their bodily constitutions be sound. The herdsmen tame the
castrated bulls, and give them an office in the herd analogous to
the office of the bell-wether in a flock; and these bulls live to an
exceptionally advanced age, owing to their exemption from
hardship and to their browsing on pasture of good quality. The
bull is in fullest vigour when five years old, which leads the
critics to commend Homer for applying to the bull the epithets
of 'five-year-old', or 'of nine seasons', which epithets are alike in
meaning. The ox sheds his teeth at the age of two years, not all
together but just as the horse sheds his. When the animal
suffers from podagra it does not shed the hoof, but is subject to
a painful swelling in the feet. The milk of the cow is serviceable
after parturition, and before parturition there is no milk at all.
The milk that first presents itself becomes as hard as stone
when it clots; this result ensues unless it be previously diluted
with water. Oxen younger than a year old do not copulate
unless under circumstances of an unnatural and portentous
kind: instances have been recorded of copulation in both sexes
at the age of four months. Kine in general begin to submit to the
male about the month of Thargelion or of Scirophorion; some,
however, are capable of conception right on to the autumn.
When kine in large numbers receive the bull and conceive, it is
looked upon as prognostic of rain and stormy weather. Kine
herd together like mares, but in lesser degree.
1634
22
In the case of horses, the stallion and the mare are first fitted
for breeding purposes when two years old. Instances, however,
of such early maturity are rare, and their young are
exceptionally small and weak; the ordinary age for sexual
maturity is three years, and from that age to twenty the two
sexes go on improving in the quality of their offspring. The mare
carries her foal for eleven months, and casts it in the twelfth. It
is not a fixed number of days that the stallion takes to
impregnate the mare; it may be one, two, three, or more. An ass
in covering will impregnate more expeditiously than a stallion.
The act of intercourse with horses is not laborious as it is with
oxen. In both sexes the horse is the most salacious of animals
next after the human species. The breeding faculties of the
younger horses may be stimulated beyond their years if they be
supplied with good feeding in abundance. The mare as a rule
bears only one foal; occasionally she has two, but never more. A
mare has been known to cast two mules; but such a
circumstance was regarded as unnatural and portentous.
The horse then is first fitted for breeding purposes at the age of
two and a half years, but achieves full sexual maturity when it
has ceased to shed teeth, except it be naturally infertile; it must
be added, however, that some horses have been known to
impregnate the mare while the teeth were in process of
shedding.
The horse has forty teeth. It sheds its first set of four, two from
the upper jaw and two from the lower, when two and a half
years old. After a year's interval, it sheds another set of four in
like manner, and another set of four after yet another year's
interval; after arriving at the age of four years and six months it
sheds no more. An instance has occurred where a horse shed all
his teeth at once, and another instance of a horse shedding all
1635
his teeth with his last set of four; but such instances are very
rare. It consequently happens that a horse when four and a half
years old is in excellent condition for breeding purposes.
The older horses, whether of the male or female, are the more
generatively productive. Horses will cover mares from which
they have been foaled and mares which they have begotten;
and, indeed, a troop of horses is only considered perfect when
such promiscuity of intercourse occurs. Scythians use pregnant
mares for riding when the embryo has turned rather soon in the
womb, and they assert that thereby the mothers have all the
easier delivery. Quadrupeds as a rule lie down for parturition,
and in consequence the young of them all come out of the
womb sideways. The mare, however, when the time for
parturition arrives, stands erect and in that posture casts its
foal.
The horse in general lives for eighteen or twenty years; some
horses live for twenty-five or even thirty, and if a horse be
treated with extreme care, it may last on to the age of fifty
years; a horse, however, when it reaches thirty years is regarded
as exceptionally old. The mare lives usually for twenty-five
years, though instances have occurred of their attaining the age
of forty. The male is less long-lived than the female by reason of
the sexual service he is called on to render; and horses that are
reared in a private stable live longer than such as are reared in
troops. The mare attains her full length and height at five years
old, the stallion at six; in another six years the animal reaches
its full bulk, and goes on improving until it is twenty years old.
The female, then, reaches maturity more rapidly than the male,
but in the womb the case is reversed, just as is observed in
regard to the sexes of the human species; and the same
phenomenon is observed in the case of all animals that bear
several young.
1636
The mare is said to suckle a mule-foal for six months, but not to
allow its approach for any longer on account of the pain it is put
to by the hard tugging of the young; an ordinary foal it allows to
suck for a longer period.
Horse and mule are at their best after the shedding of the teeth.
After they have shed them all, it is not easy to distinguish their
age; hence they are said to carry their mark before the
shedding, but not after. However, even after the shedding their
age is pretty well recognized by the aid of the canines; for in the
case of horses much ridden these teeth are worn away by
attrition caused by the insertion of the bit; in the case of horses
not ridden the teeth are large and detached, and in young
horses they are sharp and small.
The male of the horse will breed at all seasons and during its
whole life; the mare can take the horse all its life long, but is not
thus ready to pair at all seasons unless it be held in check by a
halter or some other compulsion be brought to bear. There is no
fixed time at which intercourse of the two sexes cannot take
place; and accordingly intercourse may chance to take place at
a time that may render difficult the rearing of the future
progeny. In a stable in Opus there was a stallion that used to
serve mares when forty years old: his fore legs had to be lifted
up for the operation.
Mares first take the horse in the spring-time. After a mare has
foaled she does not get impregnated at once again, but only
after a considerable interval; in fact, the foals will be all the
better if the interval extend over four or five years. It is, at all
events, absolutely necessary to allow an interval of one year,
and for that period to let her lie fallow. A mare, then, breeds at
intervals; a she-ass breeds on and on without intermission. Of
mares some are absolutely sterile, others are capable of
conception but incapable of bringing the foal to full term; it is
1637
said to be an indication of this condition in a mare, that her foal
if dissected is found to have other kidney-shaped substances
round about its kidneys, presenting the appearance of having
four kidneys.
After parturition the mare at once swallows the after-birth, and
bites off the growth, called the 'hippomanes', that is found on
the forehead of the foal. This growth is somewhat smaller than
a dried fig; and in shape is broad and round, and in colour black.
If any bystander gets possession of it before the mare, and the
mare gets a smell of it, she goes wild and frantic at the smell.
And it is for this reason that venders of drugs and simples hold
the substance in high request and include it among their stores.
If an ass cover a mare after the mare has been covered by a
horse, the ass will destroy the previously formed embryo.
(Horse-trainers do not appoint a horse as leader to a troop, as
herdsmen appoint a bull as leader to a herd, and for this reason
that the horse is not steady but quick-tempered and skittish.)
23
The ass of both sexes is capable of breeding, and sheds its first
teeth at the age of two and a half years; it sheds its second teeth
within six months, its third within another six months, and the
fourth after the like interval. These fourth teeth are termed the
gnomons or age-indicators.
A she-ass has been known to conceive when a year old, and the
foal to be reared. After intercourse with the male it will
discharge the genital sperm unless it be hindered, and for this
reason it is usually beaten after such intercourse and chased
1638
about. It casts its young in the twelfth month. It usually bears
but one foal, and that is its natural number, occasionally
however it bears twins. The ass if it cover a mare destroys, as
has been said, the embryo previously begotten by the horse; but,
after the mare has been covered by the ass, the horse
supervening will not spoil the embryo. The she-ass has milk in
the tenth month of pregnancy. Seven days after casting a foal
the she-ass submits to the male, and is almost sure to conceive
if put to the male on this particular day; the same result,
however, is quite possible later on. The she-ass will refuse to
cast her foal with any one looking on or in the daylight and just
before foaling she has to be led away into a dark place. If the
she-ass has had young before the shedding of the index-teeth,
she will bear all her life through; but if not, then she will neither
conceive nor bear for the rest of her days. The ass lives for more
than thirty years, and the she-ass lives longer than the male.
When there is a cross between a horse and a she-ass or a
jackass and a mare, there is much greater chance of a
miscarriage than where the commerce is normal. The period for
gestation in the case of a cross depends on the male, and is just
what it would have been if the male had had commerce with a
female of his own kind. In regard to size, looks, and vigour, the
foal is more apt to resemble the mother than the sire. If such
hybrid connexions be continued without intermittence, the
female will soon go sterile; and for this reason trainers always
allow of intervals between breeding times. A mare will not take
the ass, nor a she ass the horse, unless the ass or she-ass shall
have been suckled by a mare; and for this reason trainers put
foals of the she-ass under mares, which foals are technically
spoken of as 'mare-suckled'. These asses, thus reared, mount
the mares in the open pastures, mastering them by force as the
stallions do.
1639
24
A mule is fitted for commerce with the female after the first
shedding of its teeth, and at the age of seven will impregnate
effectually; and where connexion has taken place with a mare,
a 'hinny' has been known to be produced. After the seventh year
it has no further intercourse with the female. A female mule
has been known to be impregnated, but without the
impregnation being followed up by parturition. In Syrophoenicia
she-mules submit to the mule and bear young; but the breed,
though it resembles the ordinary one, is different and specific.
The hinny or stunted mule is foaled by a mare when she has
gone sick during gestation, and corresponds to the dwarf in the
human species and to the after-pig or scut in swine; and as is
the case with dwarfs, the sexual organ of the hinny is
abnormally large.
The mule lives for a number of years. There are on record cases
of mules living to the age of eighty, as did one in Athens at the
time of the building of the temple; this mule on account of its
age was let go free, but continued to assist in dragging burdens,
and would go side by side with the other draught-beasts and
stimulate them to their work; and in consequence a public
decree was passed forbidding any baker driving the creature
away from his bread-tray. The she-mule grows old more slowly
than the mule. Some assert that the she-mule menstruates by
the act of voiding her urine, and that the mule owes the
prematurity of his decay to his habit of smelling at the urine. So
much for the modes of generation in connexion with these
animals.
1640
25
Breeders and trainers can distinguish between young and old
quadrupeds. If, when drawn back from the jaw, the skin at once
goes back to its place, the animal is young; if it remains long
wrinkled up, the animal is old.
26
The camel carries its young for ten months, and bears but one
at a time and never more; the young camel is removed from the
mother when a year old. The animal lives for a long period,
more than fifty years. It bears in spring-time, and gives milk
until the time of the next conception. Its flesh and milk are
exceptionally palatable. The milk is drunk mixed with water in
the proportion of either two to one or three to one.
27
The elephant of either sex is fitted for breeding before reaching
the age of twenty. The female carries her young, according to
some accounts, for two and a half years; according to others, for
three years; and the discrepancy in the assigned periods is due
to the fact that there are never human eyewitnesses to the
commerce between the sexes. The female settles down on its
rear to cast its young, and obviously suffers greatly during the
process. The young one, immediately after birth, sucks the
mother, not with its trunk but with the mouth; and can walk
about and see distinctly the moment it is born.
1641
28
The wild sow submits to the boar at the beginning of winter,
and in the spring-time retreats for parturition to a lair in some
district inaccessible to intrusion, hemmed in with sheer cliffs
and chasms and overshadowed by trees. The boar usually
remains by the sow for thirty days. The number of the litter and
the period gestation is the same as in the case of the
domesticated congener. The sound of the grunt also is similar;
only that the sow grunts continually, and the boar but seldom.
Of the wild boars such as are castrated grow to the largest size
and become fiercest: to which circumstance Homer alludes
when he says:
'He reared against him a wild castrated boar: it was not like a
food-devouring brute, but like a forest-clad promontory.'
Wild boars become castrated owing to an itch befalling them in
early life in the region of the testicles, and the castration is
superinduced by their rubbing themselves against the trunks of
trees.
29
The hind, as has been stated, submits to the stag as a rule only
under compulsion, as she is unable to endure the male often
owing to the rigidity of the penis. However, they do occasionally
submit to the stag as the ewe submits ram; and when they are
in heat the hinds avoid one another. The stag is not constant to
one particular hind, but after a while quits one and mates with
1642
others. The breeding time is after the rising of Arcturus, during
the months of Boedromion and Maimacterion. The period of
gestation lasts for eight months. Conception comes on a few
days after intercourse; and a number of hinds can be
impregnated by a single male. The hind, as a rule, bears but one
fawn, although instances have been known of her casting two.
Out of dread of wild beasts she casts her young by the side of
the high-road. The young fawn grows with rapidity.
Menstruation occurs at no other time with the hind; it takes
place only after parturition, and the substance is phlegm-like.
The hind leads the fawn to her lair; this is her place of refuge, a
cave with a single inlet, inside which she shelters herself
against attack.
Fabulous stories are told concerning the longevity of the animal,
but the stories have never been verified, and the brevity of the
period of gestation and the rapidity of growth in the fawn would
not lead one to attribute extreme longevity to this creature.
In the mountain called Elaphoeis or Deer Mountain, which is in
Arginussa in Asia Minor - the place, by the way, where
Alcibiades was assassinated - all the hinds have the ear split, so
that, if they stray to a distance, they can be recognized by this
mark; and the embryo actually has the mark while yet in the
womb of the mother.
The hind has four teats like the cow. After the hinds have
become pregnant, the males all segregate one by one, and in
consequence of the violence of their sexual passions they keep
each one to himself, dig a hole in the ground, and bellow from
time to time; in all these particulars they resemble the goat, and
their foreheads from getting wetted become black, as is also the
case with the goat. In this way they pass the time until the rain
falls, after which time they turn to pasture. The animal acts in
this way owing to its sexual wantonness and also to its obesity;
1643
for in summer-time it becomes so exceptionally fat as to be
unable to run: in fact at this period they can be overtaken by the
hunters that pursue them on foot in the second or third run;
and, by the way, in consequence of the heat of the weather and
their getting out of breath they always make for water in their
runs. In the rutting season, the flesh of the deer is unsavoury
and rank, like the flesh of the he-goat. In winter-time the deer
becomes thin and weak, but towards the approach of the spring
he is at his best for running. When on the run the deer keeps
pausing from time to time, and waits until his pursuer draws
upon him, whereupon he starts off again. This habit appears
due to some internal pain: at all events, the gut is so slender
and weak that, if you strike the animal ever so softly, it is apt to
break asunder, though the hide of the animal remains sound
and uninjured.
30
Bears, as has been previously stated, do not copulate with the
male mounting the back of the female, but with the female
lying down under the male. The she-bear goes with young for
thirty days. She brings forth sometimes one cub, sometimes two
cubs, and at most five. Of all animals the newly born cub of the
she bear is the smallest in proportion to the size of the mother;
that is to say, it is larger than a mouse but smaller than a
weasel. It is also smooth and blind, and its legs and most of its
organs are as yet inarticulate. Pairing takes Place in the month
of Elaphebolion, and parturition about the time for retiring into
winter quarters; about this time the bear and the she-bear are
at the fattest. After the she-bear has reared her young, she
comes out of her winter lair in the third month, when it is
already spring. The female porcupine, by the way, hibernates
1644
and goes with young the same number of days as the she-bear,
and in all respects as to parturition resembles this animal.
When a she-bear is with young, it is a very hard task to catch
her.
31
It has already been stated that the lion and lioness copulate
rearwards, and that these animals are opisthuretic. They do not
copulate nor bring forth at all seasons indiscriminately, but
once in the year only. The lioness brings forth in the spring,
generally two cubs at a time, and six at the very most; but
sometimes only one. The story about the lioness discharging her
womb in the act of parturition is a pure fable, and was merely
invented to account for the scarcity of the animal; for the
animal is, as is well known, a rare animal, and is not found in
many countries. In fact, in the whole of Europe it is only found
in the strip between the rivers Achelous and Nessus. The cubs of
the lioness when newly born are exceedingly small, and can
scarcely walk when two months old. The Syrian lion bears cubs
five times: five cubs at the first litter, then four, then three, then
two, and lastly one; after this the lioness ceases to bear for the
rest of her days. The lioness has no mane, but this appendage is
peculiar to the lion. The lion sheds only the four so-called
canines, two in the upper jaw and two in the lower; and it sheds
them when it is six months old.
1645
32
The hyena in colour resembles the wolf, but is more shaggy, and
is furnished with a mane running all along the spine. What is
recounted concerning its genital organs, to the effect that every
hyena is furnished with the organ both of the male and the
female, is untrue. The fact is that the sexual organ of the male
hyena resembles the same organ in the wolf and in the dog; the
part resembling the female genital organ lies underneath the
tail, and does to some extent resemble the female organ, but it
is unprovided with duct or passage, and the passage for the
residuum comes underneath it. The female hyena has the part
that resembles the organ of the male, and, as in the case of the
male, has it underneath her tail, unprovided with duct or
passage; and after it the passage for the residuum, and
underneath this the true female genital organ. The female
hyena has a womb, like all other female animals of the same
kind. It is an exceedingly rare circumstance to meet with a
female hyena. At least a hunter said that out of eleven hyenas
he had caught, only one was a female.
33
Hares copulate in a rearward posture, as has been stated, for the
animal is opisthuretic. They breed and bear at all seasons,
superfoetate during pregnancy, and bear young every month.
They do not give birth to their young ones all together at one
time, but bring them forth at intervals over as many days as the
circumstances of each case may require. The female is supplied
with milk before parturition; and after bearing submits
immediately to the male, and is capable of conception while
suckling her young. The milk in consistency resembles sow's
1646
milk. The young are born blind, as is the case with the greater
part Of the fissipeds or toed animals.
34
The fox mounts the vixen in copulation, and the vixen bears
young like the she-bear; in fact, her young ones are even more
inarticulately formed. Before parturition she retires to
sequestered places, so that it is a great rarity for a vixen to be
caught while pregnant. After parturition she warms her young
and gets them into shape by licking them. She bears four at
most at a birth.
35
The wolf resembles the dog in regard to the time of conception
and parturition, the number of the litter, and the blindness of
the newborn young. The sexes couple at one special period, and
the female brings forth at the beginning of the summer. There is
an account given of the parturition of the she-wolf that borders
on the fabulous, to the effect that she confines her lying-in to
within twelve particular days of the year. And they give the
reason for this in the form of a myth, viz. that when they
transported Leto in so many days from the land of the
Hyperboreans to the island of Delos, she assumed the form of a
she-wolf to escape the anger of Here. Whether the account be
correct or not has not yet been verified; I give it merely as it is
currently told. There is no more of truth in the current
1647
statement that the she-wolf bears once and only once in her
lifetime.
The cat and the ichneumon bear as many young as the dog, and
live on the same food; they live about six years. The cubs of the
panther are born blind like those of the wolf, and the female
bears four at the most at one birth. The particulars of
conception are the same for the thos, or civet, as for the dog; the
cubs of the animal are born blind, and the female bears two, or
three, or four at a birth. It is long in the body and low in stature;
but not withstanding the shortness of its legs it is exceptionally
fleet of foot, owing to the suppleness of its frame and its
capacity for leaping.
36
There is found in Syria a so-called mule. It is not the same as
the cross between the horse and ass, but resembles it just as a
wild ass resembles the domesticated congener, and derives its
name from the resemblance. Like the wild ass, this wild mule is
remarkable for its speed. The animals of this species interbreed
with one another; and a proof of this statement may be
gathered from the fact that a certain number of them were
brought into Phrygia in the time of Pharnaces, the father of
Pharnabazus, and the animal is there still. The number
originally introduced was nine, and there are three there at the
present day.
1648
37
The phenomena of generation in regard to the mouse are the
most astonishing both for the number of the young and for the
rapidity of recurrence in the births. On one occasion a she-
mouse in a state of pregnancy was shut up by accident in a jar
containing millet-seed, and after a little while the lid of the jar
was removed and upwards of one hundred and twenty mice
were found inside it.
The rate of propagation of field mice in country places, and the
destruction that they cause, are beyond all telling. In many
places their number is so incalculable that but very little of the
corn-crop is left to the farmer; and so rapid is their mode of
proceeding that sometimes a small farmer will one day observe
that it is time for reaping, and on the following morning, when
he takes his reapers afield, he finds his entire crop devoured.
Their disappearance is unaccountable: in a few days not a
mouse will there be to be seen. And yet in the time before these
few days men fail to keep down their numbers by fumigating
and unearthing them, or by regularly hunting them and turning
in swine upon them; for pigs, by the way, turn up the mouse-
holes by rooting with their snouts. Foxes also hunt them, and
the wild ferrets in particular destroy them, but they make no
way against the prolific qualities of the animal and the rapidity
of its breeding. When they are super-abundant, nothing
succeeds in thinning them down except the rain; but after
heavy rains they disappear rapidly.
In a certain district of Persia when a female mouse is dissected
the female embryos appear to be pregnant. Some people assert,
and positively assert, that a female mouse by licking salt can
become pregnant without the intervention of the male.
Mice in Egypt are covered with bristles like the hedgehog. There
is also a different breed of mice that walk on their two hind-
1649
legs; their front legs are small and their hind-legs long; the
breed is exceedingly numerous. There are many other breeds of
mice than are here referred to.
Book VII
As to Man's growth, first within his mother's womb and
afterward to old age, the course of nature, in so far as man is
specially concerned, is after the following manner. And, by the
way, the difference of male and female and of their respective
organs has been dealt with heretofore. When twice seven years
old, in the most of cases, the male begins to engender seed; and
at the same time hair appears upon the pubes, in like manner,
so Alcmaeon of Croton remarks, as plants first blossom and
then seed. About the same time, the voice begins to alter,
getting harsher and more uneven, neither shrill as formerly nor
deep as afterward, nor yet of any even tone, but like an
instrument whose strings are frayed and out of tune; and it is
called, by way of by-word, the bleat of the billy-goat. Now this
breaking of the voice is the more apparent in those who are
making trial of their sexual powers; for in those who are prone
to lustfulness the voice turns into the voice of a man, but not so
in the continent. For if a lad strive diligently to hinder his voice
from breaking, as some do of those who devote themselves to
music, the voice lasts a long while unbroken and may even
1650
persist with little change. And the breasts swell and likewise the
private parts, altering in size and shape. (And by the way, at this
time of life those who try by friction to provoke emission of
seed are apt to experience pain as well as voluptuous
sensations.) At the same age in the female, the breasts swell
and the so-called catamenia commence to flow; and this fluid
resembles fresh blood. There is another discharge, a white one,
by the way, which occurs in girls even at a very early age, more
especially if their diet be largely of a fluid nature; and this
malady causes arrest of growth and loss of flesh. In the majority
of cases the catamenia are noticed by the time the breasts have
grown to the height of two fingers' breadth. In girls, too, about
this time the voice changes to a deeper note; for while in
general the woman's voice is higher than the man's, so also the
voices of girls are pitched in a higher key than the elder
women's, just as the boy's are higher than the men's; and the
girls' voices are shriller than the boys', and a maid's flute is
tuned sharper than a lad's.
Girls of this age have much need of surveillance. For then in
particular they feel a natural impulse to make usage of the
sexual faculties that are developing in them; so that unless they
guard against any further impulse beyond that inevitable one
which their bodily development of itself supplies, even in the
case of those who abstain altogether from passionate
indulgence, they contract habits which are apt to continue into
later life. For girls who give way to wantonness grow more and
more wanton; and the same is true of boys, unless they be
safeguarded from one temptation and another; for the passages
become dilated and set up a local flux or running, and besides
this the recollection of pleasure associated with former
indulgence creates a longing for its repetition.
Some men are congenitally impotent owing to structural defect;
and in like manner women also may suffer from congenital
1651
incapacity. Both men and women are liable to constitutional
change, growing healthier or more sickly, or altering in the way
of leanness, stoutness, and vigour; thus, after puberty some lads
who were thin before grow stout and healthy, and the converse
also happens; and the same is equally true of girls. For when in
boy or girl the body is loaded with superfluous matter, then,
when such superfluities are got rid of in the spermatic or
catamenial discharge, their bodies improve in health and
condition owing to the removal of what had acted as an
impediment to health and proper nutrition; but in such as are of
opposite habit their bodies become emaciated and out of
health, for then the spermatic discharge in the one case and the
catamenial flow in the other take place at the cost of natural
healthy conditions.
Furthermore, in the case of maidens the condition of the
breasts is diverse in different individuals, for they are
sometimes quite big and sometimes little; and as a general rule
their size depends on whether or not the body was burthened in
childhood with superfluous material. For when the signs of
womanhood are nigh but not come, the more there be of
moisture the more will it cause the breasts to swell, even to the
bursting point; and the result is that the breasts remain during
after-life of the bulk that they then acquired. And among men,
the breasts grow more conspicuous and more like to those of
women, both in young men and old, when the individual
temperament is moist and sleek and the reverse of sinewy, and
all the more among the dark-complexioned than the fair.
At the outset and till the age of one and twenty the spermatic
discharge is devoid of fecundity; afterwards it becomes fertile,
but young men and women produce undersized and imperfect
progeny, as is the case also with the common run of animals.
Young women conceive readily, but, having conceived, their
labour in childbed is apt to be difficult.
1652
The frame fails of reaching its full development and ages
quickly in men of intemperate lusts and in women who become
mothers of many children; for it appears to be the case that
growth ceases when the woman has given birth to three
children. Women of a lascivious disposition grow more sedate
and virtuous after they have borne several children.
After the age of twenty-one women are fully ripe for child-
bearing, but men go on increasing in vigour. When the
spermatic fluid is of a thin consistency it is infertile; when
granular it is fertile and likely to produce male children, but
when thin and unclotted it is apt to produce female offspring.
And it is about this time of life that in men the beard makes its
appearance.
The onset of the catamenia in women takes place towards the
end of the month; and on this account the wiseacres assert that
the moon is feminine, because the discharge in women and the
waning of the moon happen at one and the same time, and
after the wane and the discharge both one and the other grow
whole again. (In some women the catamenia occur regularly but
sparsely every month, and more abundantly every third month.)
With those in whom the ailment lasts but a little while, two
days or three, recovery is easy; but where the duration is longer,
the ailment is more troublesome. For women are ailing during
these days; and sometimes the discharge is sudden and
sometimes gradual, but in all cases alike there is bodily distress
until the attack be over. In many cases at the commencement of
the attack, when the discharge is about to appear, there occur
1653
spasms and rumbling noises within the womb until such time
as the discharge manifests itself.
Under natural conditions it is after recovery from these
symptoms that conception takes place in women, and women
in whom the signs do not manifest themselves for the most
part remain childless. But the rule is not without exception, for
some conceive in spite of the absence of these symptoms; and
these are cases in which a secretion accumulates, not in such a
way as actually to issue forth, but in amount equal to the
residuum left in the case of child-bearing women after the
normal discharge has taken place. And some conceive while the
signs are on but not afterwards, those namely in whom the
womb closes up immediately after the discharge. In some cases
the menses persist during pregnancy up to the very last; but the
result in these cases is that the offspring are poor, and either
fail to survive or grow up weakly.
In many cases, owing to excessive desire, arising either from
youthful impetuosity or from lengthened abstinence, prolapsion
of the womb takes place and the catamenia appear repeatedly,
thrice in the month, until conception occurs; and then the
womb withdraws upwards again to its proper place...
As we have remarked above, the discharge is wont to be more
abundant in women than in the females of any other animals.
In creatures that do not bring forth their young alive nothing of
the sort manifests itself, this particular superfluity being
converted into bodily substance; and by the way, in such
animals the females are sometimes larger than the males; and
moreover, the material is used up sometimes for scutes and
sometimes for scales, and sometimes for the abundant covering
of feathers, whereas in the vivipara possessed of limbs it is
turned into hair and into bodily substance (for man alone
among them is smooth-skinned), and into urine, for this
1654
excretion is in the majority of such animals thick and copious.
Only in the case of women is the superfluity turned into a
discharge instead of being utilized in these other ways.
There is something similar to be remarked of men: for in
proportion to his size man emits more seminal fluid than any
other animal (for which reason man is the smoothest of
animals), especially such men as are of a moist habit and not
over corpulent, and fair men in greater degree than dark. It is
likewise with women; for in the stout, great part of the
excretion goes to nourish the body. In the act of intercourse,
women of a fair complexion discharge a more plentiful
secretion than the dark; and furthermore, a watery and pungent
diet conduces to this phenomenon.
It is a sign of conception in women when the place is dry
immediately after intercourse. If the lips of the orifice be
smooth conception is difficult, for the matter slips off; and if
they be thick it is also difficult. But if on digital examination the
lips feel somewhat rough and adherent, and if they be likewise
thin, then the chances are in favour of conception. Accordingly,
if conception be desired, we must bring the parts into such a
condition as we have just described; but if on the contrary we
want to avoid conception then we must bring about a contrary
disposition. Wherefore, since if the parts be smooth conception
is prevented, some anoint that part of the womb on which the
seed falls with oil of cedar, or with ointment of lead or with
frankincense, commingled with olive oil. If the seed remain
within for seven days then it is certain that conception has
1655
taken place; for it is during that period that what is known as
effluxion takes place.
In most cases the menstrual discharge recurs for some time
after conception has taken place, its duration being mostly
thirty days in the case of a female and about forty days in the
case of a male child. After parturition also it is common for the
discharge to be withheld for an equal number of days, but not in
all cases with equal exactitude. After conception, and when the
above-mentioned days are past, the discharge no longer takes
its natural course but finds its way to the breasts and turns to
milk. The first appearance of milk in the breasts is scant in
quantity and so to speak cobwebby or interspersed with little
threads. And when conception has taken place, there is apt to
be a sort of feeling in the region of the flanks, which in some
cases quickly swell up a little, especially in thin persons, and
also in the groin.
In the case of male children the first movement usually occurs
on the right-hand side of the womb and about the fortieth day,
but if the child be a female then on the left-hand side and about
the ninetieth day. However, we must by no means assume this
to be an accurate statement of fact, for there are many
exceptions, in which the movement is manifested on the right-
hand side though a female child be coming, and on the left-
hand side though the infant be a male. And in short, these and
all suchlike phenomena are usually subject to differences that
may be summed up as differences of degree.
About this period the embryo begins to resolve into distinct
parts, it having hitherto consisted of a fleshlike substance
without distinction of parts.
What is called effluxion is a destruction of the embryo within
the first week, while abortion occurs up to the fortieth day; and
1656
the greater number of such embryos as perish do so within the
space of these forty days.
In the case of a male embryo aborted at the fortieth day, if it be
placed in cold water it holds together in a sort of membrane,
but if it be placed in any other fluid it dissolves and disappears.
If the membrane be pulled to bits the embryo is revealed, as big
as one of the large kind of ants; and all the limbs are plain to
see, including the penis, and the eyes also, which as in other
animals are of great size. But the female embryo, if it suffer
abortion during the first three months, is as a rule found to be
undifferentiated; if however it reach the fourth month it comes
to be subdivided and quickly attains further differentiation. In
short, while within the womb, the female infant accomplishes
the whole development of its parts more slowly than the male,
and more frequently than the man-child takes ten months to
come to perfection. But after birth, the females pass more
quickly than the males through youth and maturity and age;
and this is especially true of those that bear many children, as
indeed I have already said.
When the womb has conceived the seed, straightway in the
majority of cases it closes up until seven months are fulfilled;
but in the eighth month it opens, and the embryo, if it be fertile,
descends in the eighth month. But such embryos as are not
fertile but are devoid of breath at eight months old, their
mothers do not bring into the world by parturition at eight
months, neither does the embryo descend within the womb at
that period nor does the womb open. And it is a sign that the
1657
embryo is not capable of life if it be formed without the above-
named circumstances taking place.
After conception women are prone to a feeling of heaviness in
all parts of their bodies, and for instance they experience a
sensation of darkness in front of the eyes and suffer also from
headache. These symptoms appear sooner or later, sometimes
as early as the tenth day, according as the patient be more or
less burthened with superfluous humours. Nausea also and
sickness affect the most of women, and especially such as those
that we have just now mentioned, after the menstrual discharge
has ceased and before it is yet turned in the direction of the
breasts.
Moreover, some women suffer most at the beginning of their
pregnancy and some at a later period when the embryo has had
time to grow; and in some women it is a common occurrence to
suffer from strangury towards the end of their time. As a
general rule women who are pregnant of a male child escape
comparatively easily and retain a comparatively healthy look,
but it is otherwise with those whose infant is a female; for these
latter look as a rule paler and suffer more pain, and in many
cases they are subject to swellings of the legs and eruptions on
the body. Nevertheless the rule is subject to exceptions.
Women in pregnancy are a prey to all sorts of longings and to
rapid changes of mood, and some folks call this the 'ivy-
sickness'; and with the mothers of female infants the longings
are more acute, and they are less contented when they have got
what they desired.
In a certain few cases the patient feels unusually well during
pregnancy. The worst time of all is just when the child's hair is
beginning to grow.
1658
In pregnant women their own natural hair is inclined to grow
thin and fall out, but on the other hand hair tends to grow on
parts of the body where it was not wont to be. As a general rule,
a man-child is more prone to movement within its mother's
womb than a female child, and it is usually born sooner. And
labour in the case of female children is apt to be protracted and
sluggish, while in the case of male children it is acute and by a
long way more difficult. Women who have connexion with their
husbands shortly before childbirth are delivered all the more
quickly. Occasionally women seem to be in the pains of labour
though labour has not in fact commenced, what seemed like
the commencement of labour being really the result of the
foetus turning its head.
Now all other animals bring the time of pregnancy to an end in
a uniform way; in other words, one single term of pregnancy is
defined for each of them. But in the case of mankind alone of all
animals the times are diverse; for pregnancy may be of seven
months' duration, or of eight months or of nine, and still more
commonly of ten months, while some few women go even into
the eleventh month.
Children that come into the world before seven months can
under no circumstances survive. The seven-months' children
are the earliest that are capable of life, and most of them are
weakly - for which reason, by the way, it is customary to
swaddle them in wool, - and many of them are born with some
of the orifices of the body imperforate, for instance the ears or
the nostrils. But as they get bigger they become more perfectly
developed, and many of them grow up.
In Egypt, and in some other places where the women are
fruitful and are wont to bear and bring forth many children
without difficulty, and where the children when born are
capable of living even if they be born subject to deformity, in
1659
these places the eight-months' children live and are brought up,
but in Greece it is only a few of them that survive while most
perish. And this being the general experience, when such a child
does happen to survive the mother is apt to think that it was
not an eight months' child after all, but that she had conceived
at an earlier period without being aware of it.
Women suffer most pain about the fourth and the eighth
months, and if the foetus perishes in the fourth or in the eighth
month the mother also succumbs as a general rule; so that not
only do the eight-months' children not live, but when they die
their mothers are in great danger of their own lives. In like
manner children that are apparently born at a later term than
eleven months are held to be in doubtful case; inasmuch as
with them also the beginning of conception may have escaped
the notice of the mother. What I mean to say is that often the
womb gets filled with wind, and then when at a later period
connexion and conception take place, they think that the
former circumstance was the beginning of conception from the
similarity of the symptoms that they experienced.
Such then are the differences between mankind and other
animals in regard to the many various modes of completion of
the term of pregnancy. Furthermore, some animals produce one
and some produce many at a birth, but the human species does
sometimes the one and sometimes the other. As a general rule
and among most nations the women bear one child a birth; but
frequently and in many lands they bear twins, as for instance in
Egypt especially. Sometimes women bring forth three and even
four children, and especially in certain parts of the world, as has
already been stated. The largest number ever brought forth is
five, and such an occurrence has been witnessed on several
occasions. There was once upon a time a certain women who
had twenty children at four births; each time she had five, and
most of them grew up.
1660
Now among other animals, if a pair of twins happen to be male
and female they have as good a chance of surviving as though
both had been males or both females; but among mankind very
few twins survive if one happen to be a boy and the other a girl.
Of all animals the woman and the mare are most inclined to
receive the commerce of the male during pregnancy; while all
other animals when they are pregnant avoid the male, save
those in which the phenomenon of superfoetation occurs, such
as the hare. Unlike that animal, the mare after once conceiving
cannot be rendered pregnant again, but brings forth one foal
only, at least as a general rule; in the human species cases of
superfoetation are rare, but they do happen now and then.
An embryo conceived some considerable time after a previous
conception does not come to perfection, but gives rise to pain
and causes the destruction of the earlier embryo; and, by the
way, a case has been known to occur where owing to this
destructive influence no less than twelve embryos conceived by
superfoetation have been discharged. But if the second
conception take place at a short interval, then the mother bears
that which was later conceived, and brings forth the two
children like actual twins, as happened, according to the legend,
in the case of Iphicles and Hercules. The following also is a
striking example: a certain woman, having committed adultery,
brought forth the one child resembling her husband and the
other resembling the adulterous lover.
The case has also occurred where a woman, being pregnant of
twins, has subsequently conceived a third child; and in course
of time she brought forth the twins perfect and at full term, but
the third a five-months' child; and this last died there and then.
And in another case it happened that the woman was first
delivered of a seven-months' child, and then of two which were
1661
of full term; and of these the first died and the other two
survived.
Some also have been known to conceive while about to
miscarry, and they have lost the one child and been delivered of
the other.
If women while going with child cohabit after the eighth month
the child is in most cases born covered over with a slimy fluid.
Often also the child is found to be replete with food of which
the mother had partaken.
When women have partaken of salt in overabundance their
children are apt to be born destitute of nails.
Milk that is produced earlier than the seventh month is unfit for
use; but as soon as the child is fit to live the milk is fit to use.
The first of the milk is saltish, as it is likewise with sheep. Most
women are sensibly affected by wine during pregnancy, for if
they partake of it they grow relaxed and debilitated.
The beginning of child-bearing in women and of the capacity to
procreate in men, and the cessation of these functions in both
cases, coincide in the one case with the emission of seed and in
the other with the discharge of the catamenia: with this
qualification that there is a lack of fertility at the
commencement of these symptoms, and again towards their
close when the emissions become scanty and weak. The age at
which the sexual powers begin has been related already. As for
their end, the menstrual discharges ceases in most women
about their fortieth year; but with those in whom it goes on
1662
longer it lasts even to the fiftieth year, and women of that age
have been known to bear children. But beyond that age there is
no case on record.
Men in most cases continue to be sexually competent until they
are sixty years old, and if that limit be overpassed then until
seventy years; and men have been actually known to procreate
children at seventy years of age. With many men and many
women it so happens that they are unable to produce children
to one another, while they are able to do so in union with other
individuals. The same thing happens with regard to the
production of male and female offspring; for sometimes men
and women in union with one another produce male children
or female, as the case may be, but children of the opposite sex
when otherwise mated. And they are apt to change in this
respect with advancing age: for sometimes a husband and wife
while they are young produce female children and in later life
male children; and in other cases the very contrary occurs. And
just the same thing is true in regard to the generative faculty:
for some while young are childless, but have children when
they grow older; and some have children to begin with, and
later on no more.
There are certain women who conceive with difficulty, but if
they do conceive, bring the child to maturity; while others again
conceive readily, but are unable to bring the child to birth.
Furthermore, some men and some women produce female
offspring and some male, as for instance in the story of
Hercules, who among all his two and seventy children is said to
have begotten but one girl. Those women who are unable to
1663
conceive, save with the help of medical treatment or some other
adventitious circumstance, are as a general rule apt to bear
female children rather than male.
It is a common thing with men to be at first sexually competent
and afterwards impotent, and then again to revert to their
former powers.
From deformed parents come deformed children, lame from
lame and blind from blind, and, speaking generally, children
often inherit anything that is peculiar in their parents and are
born with similar marks, such as pimples or scars. Such things
have been known to be handed down through three
generations; for instance, a certain man had a mark on his arm
which his son did not possess, but his grandson had it in the
same spot though not very distinct.
Such cases, however, are few; for the children of cripples are
mostly sound, and there is no hard and fast rule regarding
them. While children mostly resemble their parents or their
ancestors, it sometimes happens that no such resemblance is to
be traced. But parents may pass on resemblance after several
generations, as in the case of the woman in Elis, who
committed adultery with a negro; in this case it was not the
woman's own daughter but the daughter's child that was a
blackamoor.
As a rule the daughters have a tendency to take after the
mother, and the boys after the father; but sometimes it is the
other way, the boys taking after the mother and the girls after
the father. And they may resemble both parents in particular
features.
There have been known cases of twins that had no resemblance
to one another, but they are alike as a general rule. There was
once upon a time a woman who had intercourse with her
1664
husband a week after giving birth to a child and she conceived
and bore a second child as like the first as any twin. Some
women have a tendency to produce children that take after
themselves, and others children that take after the husband;
and this latter case is like that of the celebrated mare in
Pharsalus, that got the name of the Honest Wife.
In the emission of sperm there is a preliminary discharge of air,
and the outflow is manifestly caused by a blast of air; for
nothing is cast to a distance save by pneumatic pressure. After
the seed reaches the womb and remains there for a while, a
membrane forms around it; for when it happens to escape
before it is distinctly formed, it looks like an egg enveloped in its
membrane after removal of the eggshell; and the membrane is
full of veins.
All animals whatsoever, whether they fly or swim or walk upon
dry land, whether they bring forth their young alive or in the
egg, develop in the same way: save only that some have the
navel attached to the womb, namely the viviparous animals,
and some have it attached to the egg, and some to both parts
alike, as in a certain sort of fishes. And in some cases
membranous envelopes surround the egg, and in other cases
the chorion surrounds it. And first of all the animal develops
within the innermost envelope, and then another membrane
appears around the former one, which latter is for the most part
attached to the womb, but is in part separated from it and
contains fluid. In between is a watery or sanguineous fluid,
which the women folk call the forewaters.
1665
8
All animals, or all such as have a navel, grow by the navel. And
the navel is attached to the cotyledon in all such as possess
cotyledons, and to the womb itself by a vein in all such as have
the womb smooth. And as regards their shape within the womb,
the four-footed animals all lie stretched out, and the footless
animals lie on their sides, as for instance fishes; but two-legged
animals lie in a bent position, as for instance birds; and human
embryos lie bent, with nose between the knees and eyes upon
the knees, and the ears free at the sides.
All animals alike have the head upwards to begin with; but as
they grow and approach the term of egress from the womb they
turn downwards, and birth in the natural course of things takes
place in all animals head foremost; but in abnormal cases it
may take place in a bent position, or feet foremost.
The young of quadrupeds when they are near their full time
contain excrements, both liquid and in the form of solid lumps,
the latter in the lower part of the bowel and the urine in the
bladder.
In those animals that have cotyledons in the womb the
cotyledons grow less as the embryo grows bigger, and at length
they disappear altogether. The navel-string is a sheath wrapped
about blood-vessels which have their origin in the womb, from
the cotyledons in those animals which possess them and from
a blood-vessel in those which do not. In the larger animals, such
as the embryos of oxen, the vessels are four in number, and in
smaller animals two; in the very little ones, such as fowls, one
vessel only.
Of the four vessels that run into the embryo, two pass through
the liver where the so-called gates or 'portae' are, running in the
1666
direction of the great vein, and the other two run in the
direction of the aorta towards the point where it divides and
becomes two vessels instead of one. Around each pair of blood-
vessels are membranes, and surrounding these membranes is
the navel-string itself, after the manner of a sheath. And as the
embryo grows, the veins themselves tend more and more to
dwindle in size. And also as the embryo matures it comes down
into the hollow of the womb and is observed to move here, and
sometimes rolls over in the vicinity of the groin.
When women are in labour, their pains determine towards
many divers parts of the body, and in most cases to one or other
of the thighs. Those are the quickest to be delivered who
experience severe pains in the region of the belly; and
parturition is difficult in those who begin by suffering pain in
the loins, and speedy when the pain is abdominal. If the child
about to be born be a male, the preliminary flood is watery and
pale in colour, but if a girl it is tinged with blood, though still
watery. In some cases of labour these latter phenomena do not
occur, either one way or the other.
In other animals parturition is unaccompanied by pain, and the
dam is plainly seen to suffer but moderate inconvenience. In
women, however, the pains are more severe, and this is
especially the case in persons of sedentary habits, and in those
who are weak-chested and short of breath. Labour is apt to be
especially difficult if during the process the woman while
exerting force with her breath fails to hold it in.
First of all, when the embryo starts to move and the membranes
burst, there issues forth the watery flood; then afterwards
1667
comes the embryo, while the womb everts and the afterbirth
comes out from within.
10
The cutting of the navel-string, which is the nurse's duty, is a
matter calling for no little care and skill. For not only in cases of
difficult labour must she be able to render assistance with
skilful hand, but she must also have her wits about her in all
contingencies, and especially in the operation of tying the cord.
For if the afterbirth have come away, the navel is ligatured off
from the afterbirth with a woollen thread and is then cut above
the ligature; and at the place where it has been tied it heals up,
and the remaining portion drops off. (If the ligature come loose
the child dies from loss of blood.) But if the afterbirth has not
yet come away, but remains after the child itself is extruded, it
is cut away within after the ligaturing of the cord.
It often happens that the child appears to have been born dead
when it is merely weak, and when before the umbilical cord has
been ligatured, the blood has run out into the cord and its
surroundings. But experienced midwives have been known to
squeeze back the blood into the child's body from the cord, and
immediately the child that a moment before was bloodless
came back to life again.
It is the natural rule, as we have mentioned above, for all
animals to come into the world head foremost, and children,
moreover, have their hands stretched out by their sides. And the
child gives a cry and puts its hands up to its mouth as soon as it
issues forth.
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Moreover the child voids excrement sometimes at once,
sometimes a little later, but in all cases during the first day; and
this excrement is unduly copious in comparison with the size of
the child; it is what the midwives call the meconium or 'poppy-
juice'. In colour it resembles blood, extremely dark and pitch-
like, but later on it becomes milky, for the child takes at once to
the breast. Before birth the child makes no sound, even though
in difficult labour it put forth its head while the rest of the body
remains within.
In cases where flooding takes place rather before its time, it is
apt to be followed by difficult parturition. But if discharge take
place after birth in small quantity, and in cases where it only
takes place at the beginning and does not continue till the
fortieth day, then in such cases women make a better recovery
and are the sooner ready to conceive again.
Until the child is forty days old it neither laughs nor weeps
during waking hours, but of nights it sometimes does both; and
for the most part it does not even notice being tickled, but
passes most of its time in sleep. As it keeps on growing, it gets
more and more wakeful; and moreover it shows signs of
dreaming, though it is long afterwards before it remembers
what it dreams.
In other animals there is no contrasting difference between one
bone and another, but all are properly formed; but in children
the front part of the head is soft and late of ossifying. And by
the way, some animals are born with teeth, but children begin
to cut their teeth in the seventh month; and the front teeth are
the first to come through, sometimes the upper and sometimes
the lower ones. And the warmer the nurses' milk so much the
quicker are the children's teeth to come.
1669
11
After parturition and the cleasing flood the milk comes in
plenty, and in some women it flows not only from the nipples
but at divers parts of the breasts, and in some cases even from
the armpits. And for some time afterwards there continue to be
certain indurated parts of the breast called strangalides, or
'knots', which occur when it so happens that the moisture is
not concocted, or when it finds no outlet but accumulates
within. For the whole breast is so spongy that if a woman in
drinking happen to swallow a hair, she gets a pain in her breast,
which ailment is called 'trichia'; and the pain lasts till the hair
either find its own way out or be sucked out with the milk.
Women continue to have milk until their next conception; and
then the milk stops coming and goes dry, alike in the human
species and in the quadrupedal vivipara. So long as there is a
flow of milk the menstrual purgations do not take place, at least
as a general rule, though the discharge has been known to occur
during the period of suckling. For, speaking generally, a
determination of moisture does not take place at one and the
same time in several directions; as for instance the menstrual
purgations tend to be scanty in persons suffering from
haemorrhoids. And in some women the like happens owing to
their suffering from varices, when the fluids issue from the
pelvic region before entering into the womb. And patients who
during suppression of the menses happen to vomit blood are no
whit the worse.
1670
12
Children are very commonly subject to convulsions, more
especially such of them as are more than ordinarily well-
nourished on rich or unusually plentiful milk from a stout
nurse. Wine is bad for infants, in that it tends to excite this
malady, and red wine is worse than white, especially when
taken undiluted; and most things that tend to induce flatulency
are also bad, and constipation too is prejudicial. The majority of
deaths in infancy occur before the child is a week old, hence it
is customary to name the child at that age, from a belief that it
has now a better chance of survival. This malady is worst at the
full of the moon; and by the way, it is a dangerous symptom
when the spasms begin in the child's back.
Book VIII
We have now discussed the physical characteristics of animals
and their methods of generation. Their habits and their modes
of living vary according to their character and their food.
In the great majority of animals there are traces of psychical
qualities or attitudes, which qualities are more markedly
differentiated in the case of human beings. For just as we
pointed out resemblances in the physical organs, so in a
number of animals we observe gentleness or fierceness,
1671
mildness or cross temper, courage, or timidity, fear or
confidence, high spirit or low cunning, and, with regard to
intelligence, something equivalent to sagacity. Some of these
qualities in man, as compared with the corresponding qualities
in animals, differ only quantitatively: that is to say, a man has
more or less of this quality, and an animal has more or less of
some other; other qualities in man are represented by
analogous and not identical qualities: for instance, just as in
man we find knowledge, wisdom, and sagacity, so in certain
animals there exists some other natural potentiality akin to
these. The truth of this statement will be the more clearly
apprehended if we have regard to the phenomena of childhood:
for in children may be observed the traces and seeds of what
will one day be settled psychological habits, though
psychologically a child hardly differs for the time being from an
animal; so that one is quite justified in saying that, as regards
man and animals, certain psychical qualities are identical with
one another, whilst others resemble, and others are analogous
to, each other.
Nature proceeds little by little from things lifeless to animal life
in such a way that it is impossible to determine the exact line of
demarcation, nor on which side thereof an intermediate form
should lie. Thus, next after lifeless things in the upward scale
comes the plant, and of plants one will differ from another as to
its amount of apparent vitality; and, in a word, the whole genus
of plants, whilst it is devoid of life as compared with an animal,
is endowed with life as compared with other corporeal entities.
Indeed, as we just remarked, there is observed in plants a
continuous scale of ascent towards the animal. So, in the sea,
there are certain objects concerning which one would be at a
loss to determine whether they be animal or vegetable. For
instance, certain of these objects are fairly rooted, and in several
cases perish if detached; thus the pinna is rooted to a particular
spot, and the solen (or razor-shell) cannot survive withdrawal
1672
from its burrow. Indeed, broadly speaking, the entire genus of
testaceans have a resemblance to vegetables, if they be
contrasted with such animals as are capable of progression.
In regard to sensibility, some animals give no indication
whatsoever of it, whilst others indicate it but indistinctly.
Further, the substance of some of these intermediate creatures
is fleshlike, as is the case with the so-called tethya (or ascidians)
and the acalephae (or sea-anemones); but the sponge is in every
respect like a vegetable. And so throughout the entire animal
scale there is a graduated differentiation in amount of vitality
and in capacity for motion.
A similar statement holds good with regard to habits of life.
Thus of plants that spring from seed the one function seems to
be the reproduction of their own particular species, and the
sphere of action with certain animals is similarly limited. The
faculty of reproduction, then, is common to all alike. If
sensibility be superadded, then their lives will differ from one
another in respect to sexual intercourse through the varying
amount of pleasure derived therefrom, and also in regard to
modes of parturition and ways of rearing their young. Some
animals, like plants, simply procreate their own species at
definite seasons; other animals busy themselves also in
procuring food for their young, and after they are reared quit
them and have no further dealings with them; other animals
are more intelligent and endowed with memory, and they live
with their offspring for a longer period and on a more social
footing.
The life of animals, then, may be divided into two acts -
procreation and feeding; for on these two acts all their interests
and life concentrate. Their food depends chiefly on the
substance of which they are severally constituted; for the source
of their growth in all cases will be this substance. And
1673
whatsoever is in conformity with nature is pleasant, and all
animals pursue pleasure in keeping with their nature.
Animals are also differentiated locally: that is to say, some live
upon dry land, while others live in the water. And this
differentiation may be interpreted in two different ways. Thus,
some animals are termed terrestrial as inhaling air, and others
aquatic as taking in water; and there are others which do not
actually take in these elements, but nevertheless are
constitutionally adapted to the cooling influence, so far as is
needful to them, of one element or the other, and hence are
called terrestrial or aquatic though they neither breathe air nor
take in water. Again, other animals are so called from their
finding their food and fixing their habitat on land or in water:
for many animals, although they inhale air and breed on land,
yet derive their food from the water, and live in water for the
greater part of their lives; and these are the only animals to
which as living in and on two elements the term 'amphibious' is
applicable. There is no animal taking in water that is terrestrial
or aerial or that derives its food from the land, whereas of the
great number of land animals inhaling air many get their food
from the water; moreover some are so peculiarly organized that
if they be shut off altogether from the water they cannot
possibly live, as for instance, the so-called sea-turtle, the
crocodile, the hippopotamus, the seal, and some of the smaller
creatures, such as the fresh-water tortoise and the frog: now all
these animals choke or drown if they do not from time to time
breathe atmospheric air: they breed and rear their young on dry
land, or near the land, but they pass their lives in water.
1674
But the dolphin is equipped in the most remarkable way of all
animals: the dolphin and other similar aquatic animals,
including the other cetaceans which resemble it; that is to say,
the whale, and all the other creatures that are furnished with a
blow-hole. One can hardly allow that such an animal is
terrestrial and terrestrial only, or aquatic and aquatic only, if by
terrestrial we mean an animal that inhales air, and if by aquatic
we mean an animal that takes in water. For the fact is the
dolphin performs both these processes: he takes in water and
discharges it by his blow-hole, and he also inhales air into his
lungs; for, by the way, the creature is furnished with this organ
and respires thereby, and accordingly, when caught in the nets,
he is quickly suffocated for lack of air. He can also live for a
considerable while out of the water, but all this while he keeps
up a dull moaning sound corresponding to the noise made by
air-breathing animals in general; furthermore, when sleeping,
the animal keeps his nose above water, and he does so that he
may breathe the air. Now it would be unreasonable to assign
one and the same class of animals to both categories, terrestrial
and aquatic, seeing that these categories are more or less
exclusive of one another; we must accordingly supplement our
definition of the term 'aquatic' or 'marine'. For the fact is, some
aquatic animals take in water and discharge it again, for the
same reason that leads air-breathing animals to inhale air: in
other words, with the object of cooling the blood. Others take in
water as incidental to their mode of feeding; for as they get
their food in the water they cannot but take in water along with
their food, and if they take in water they must be provided with
some organ for discharging it. Those blooded animals, then, that
use water for a purpose analogous to respiration are provided
with gills; and such as take in water when catching their prey,
with the blow-hole. Similar remarks are applicable to molluscs
and crustaceans; for again it is by way of procuring food that
these creatures take in water.
1675
Aquatic in different ways, the differences depending on bodily
relation to external temperature and on habit of life, are such
animals on the one hand as take in air but live in water, and
such on the other hand as take in water and are furnished with
gills but go upon dry land and get their living there. At present
only one animal of the latter kind is known, the so-called
cordylus or water-newt; this creature is furnished not with
lungs but with gills, but for all that it is a quadruped and fitted
for walking on dry land.
In the case of all these animals their nature appears in some
kind of a way to have got warped, just as some male animals
get to resemble the female, and some female animals the male.
The fact is that animals, if they be subjected to a modification
in minute organs, are liable to immense modifications in their
general configuration. This phenomenon may be observed in
the case of gelded animals: only a minute organ of the animal is
mutilated, and the creature passes from the male to the female
form. We may infer, then, that if in the primary conformation of
the embryo an infinitesimally minute but absolutely essential
organ sustain a change of magnitude one way or the other, the
animal will in one case turn to male and in the other to female;
and also that, if the said organ be obliterated altogether, the
animal will be of neither one sex nor the other. And so by the
occurrence of modification in minute organs it comes to pass
that one animal is terrestrial and another aquatic, in both
senses of these terms. And, again, some animals are
amphibious whilst other animals are not amphibious, owing to
the circumstance that in their conformation while in the
embryonic condition there got intermixed into them some
portion of the matter of which their subsequent food is
constituted; for, as was said above, what is in conformity with
nature is to every single animal pleasant and agreeable.
1676
Animals then have been categorized into terrestrial and aquatic
in three ways, according to their assumption of air or of water,
the temperament of their bodies, or the character of their food;
and the mode of life of an animal corresponds to the category in
which it is found. That is to say, in some cases the animal
depends for its terrestrial or aquatic nature on temperament
and diet combined, as well as upon its method of respiration;
and sometimes on temperament and habits alone.
Of testaceans, some, that are incapable of motion, subsist on
fresh water, for, as the sea water dissolves into its constituents,
the fresh water from its greater thinness percolates through the
grosser parts; in fact, they live on fresh water just as they were
originally engendered from the same. Now that fresh water is
contained in the sea and can be strained off from it can be
proved in a thoroughly practical way. Take a thin vessel of
moulded wax, attach a cord to it, and let it down quite empty
into the sea: in twenty-four hours it will be found to contain a
quantity of water, and the water will be fresh and drinkable.
Sea-anemones feed on such small fishes as come in their way.
The mouth of this creature is in the middle of its body; and this
fact may be clearly observed in the case of the larger varieties.
Like the oyster it has a duct for the outlet of the residuum; and
this duct is at the top of the animal. In other words, the sea-
anemone corresponds to the inner fleshy part of the oyster, and
the stone to which the one creature clings corresponds to the
shell which encases the other.
The limpet detaches itself from the rock and goes about in
quest of food. Of shell-fish that are mobile, some are
carnivorous and live on little fishes, as for instance, the purple
murex - and there can be no doubt that the purple murex is
carnivorous, as it is caught by a bait of fish; others are
carnivorous, but feed also on marine vegetation.
1677
The sea-turtles feed on shell-fish - for, by the way, their mouths
are extraordinarily hard; whatever object it seizes, stone or
other, it crunches into bits, but when it leaves the water for dry
land it browses on grass). These creatures suffer greatly, and
oftentimes die when they lie on the surface of the water
exposed to a scorching sun; for, when once they have risen to
the surface, they find a difficulty in sinking again.
Crustaceans feed in like manner. They are omnivorous; that is
to say, they live on stones, slime, sea-weed, and excrement - as
for instance the rock-crab - and are also carnivorous. The
crawfish or spiny-lobster can get the better of fishes even of the
larger species, though in some of them it occasionally finds
more than its match. Thus, this animal is so overmastered and
cowed by the octopus that it dies of terror if it become aware of
an octopus in the same net with itself. The crawfish can master
the conger-eel, for owing to the rough spines of the crawfish the
eel cannot slip away and elude its hold. The conger-eel,
however, devours the octopus, for owing to the slipperiness of
its antagonist the octopus can make nothing of it. The crawfish
feeds on little fish, capturing them beside its hole or dwelling
place; for, by the way, it is found out at sea on rough and stony
bottoms, and in such places it makes its den. Whatever it
catches, it puts into its mouth with its pincer-like claws, like the
common crab. Its nature is to walk straight forward when it has
nothing to fear, with its feelers hanging sideways; if it be
frightened, it makes its escape backwards, darting off to a great
distance. These animals fight one another with their claws, just
as rams fight with their horns, raising them and striking their
opponents; they are often also seen crowded together in herds.
So much for the mode of life of the crustacean.
Molluscs are all carnivorous; and of molluscs the calamary and
the sepia are more than a match for fishes even of the large
species. The octopus for the most part gathers shellfish, extracts
1678
the flesh, and feeds on that; in fact, fishermen recognize their
holes by the number of shells lying about. Some say that the
octopus devours its own species, but this statement is incorrect;
it is doubtless founded on the fact that the creature is often
found with its tentacles removed, which tentacles have really
been eaten off by the conger.
Fishes, all without exception, feed on spawn in the spawning
season; but in other respects the food varies with the varying
species. Some fishes are exclusively carnivorous, as the
cartilaginous genus, the conger, the channa or Serranus, the
tunny, the bass, the synodon or Dentex, the amia, the sea-perch,
and the muraena. The red mullet is carnivorous, but feeds also
on sea-weed, on shell-fish, and on mud. The grey mullet feeds
on mud, the dascyllus on mud and offal, the scarus or parrot-
fish and the melanurus on sea-weed, the saupe on offal and
sea-weed; the saupe feeds also on zostera, and is the only fish
that is captured with a gourd. All fishes devour their own
species, with the single exception of the cestreus or mullet; and
the conger is especially ravenous in this respect. The cephalus
and the mullet in general are the only fish that eat no flesh; this
may be inferred from the facts that when caught they are never
found with flesh in their intestines, and that the bait used to
catch them is not flesh but barley-cake. Every fish of the mullet-
kind lives on sea-weed and sand. The cephalus, called by some
the 'chelon', keeps near in to the shore, the peraeas keeps out at
a distance from it, and feeds on a mucous substance exuding
from itself, and consequently is always in a starved condition.
The cephalus lives in mud, and is in consequence heavy and
slimy; it never feeds on any other fish. As it lives in mud, it has
every now and then to make a leap upwards out of the mud so
as to wash the slime from off its body. There is no creature
known to prey upon the spawn of the cephalus, so that the
species is exceedingly numerous; when, however, the is full-
grown it is preyed upon by a number of fishes, and especially by
1679
the acharnas or bass. Of all fishes the mullet is the most
voracious and insatiable, and in consequence its belly is kept at
full stretch; whenever it is not starving, it may be considered as
out of condition. When it is frightened, it hides its head in mud,
under the notion that it is hiding its whole body. The synodon is
carnivorous and feeds on molluscs. Very often the synodon and
the channa cast up their stomachs while chasing smaller fishes;
for, be it remembered, fishes have their stomachs close to the
mouth, and are not furnished with a gullet.
Some fishes then, as has been stated, are carnivorous, and
carnivorous only, as the dolphin, the synodon, the gilt-head, the
selachians, and the molluscs. Other fishes feed habitually on
mud or sea-weed or sea-moss or the so-called stalk-weed or
growing plants; as for instance, the phycis, the goby, and the
rock-fish; and, by the way, the only meat that the phycis will
touch is that of prawns. Very often, however, as has been stated,
they devour one another, and especially do the larger ones
devour the smaller. The proof of their being carnivorous is the
fact that they can be caught with flesh for a bait. The mackerel,
the tunny, and the bass are for the most part carnivorous, but
they do occasionally feed on sea-weed. The sargue feeds on the
leavings of the trigle or red mullet. The red mullet burrows in
the mud, when it sets the mud in motion and quits its haunt,
the sargue settles down into the place and feeds on what is left
behind, and prevents any smaller fish from settling in the
immediate vicinity.
Of all fishes the so-called scarus, or parrot, wrasse, is the only
one known to chew the cud like a quadruped.
As a general rule the larger fishes catch the smaller ones in
their mouths whilst swimming straight after them in the
ordinary position; but the selachians, the dolphin, and all the
cetacea must first turn over on their backs, as their mouths are
1680
placed down below; this allows a fair chance of escape to the
smaller fishes, and, indeed, if it were not so, there would be very
few of the little fishes left, for the speed and voracity of the
dolphin is something marvellous.
Of eels a few here and there feed on mud and on chance
morsels of food thrown to them; the greater part of them
subsist on fresh water. Eel-breeders are particularly careful to
have the water kept perfectly clear, by its perpetually flowing on
to flat slabs of stone and then flowing off again; sometimes they
coat the eel-tanks with plaster. The fact is that the eel will soon
choke if the water is not clear as his gills are peculiarly small.
On this account, when fishing for eels, they disturb the water. In
the river Strymon eel-fishing takes place at the rising of the
Pleiads, because at this period the water is troubled and the
mud raised up by contrary winds; unless the water be in this
condition, it is as well to leave the eels alone. When dead the
eel, unlike the majority of fishes, neither floats on nor rises to
the surface; and this is owing to the smallness of the stomach.
A few eels are supplied with fat, but the greater part have no fat
whatsoever. When removed from the water they can live for five
or six days; for a longer period if north winds prevail, for a
shorter if south winds. If they are removed in summer from the
pools to the tanks they will die; but not so if removed in the
winter. They are not capable of holding out against any abrupt
change; consequently they often die in large numbers when
men engaged in transporting them from one place to another
dip them into water particularly cold. They will also die of
suffocation if they be kept in a scanty supply of water. This
same remark will hold good for fishes in general; for they are
suffocated if they be long confined in a short supply of water,
with the water kept unchanged - just as animals that respire
are suffocated if they be shut up with a scanty supply of air. The
eel in some cases lives for seven or eight years. The river-eel
feeds on his own species, on grass, or on roots, or on any chance
1681
food found in the mud. Their usual feeding-time is at night, and
during the day-time they retreat into deep water. And so much
for the food of fishes.
Of birds, such as have crooked talons are carnivorous without
exception, and cannot swallow corn or bread-food even if it be
put into their bills in tit-bits; as for instance, the eagle of every
variety, the kite, the two species of hawks, to wit, the dove-hawk
and the sparrow-hawk - and, by the way, these two hawks differ
greatly in size from one another - and the buzzard. The buzzard
is of the same size as the kite, and is visible at all seasons of the
year. There is also the phene (or lammergeier) and the vulture.
The phene is larger than the common eagle and is ashen in
colour. Of the vulture there are two varieties: one small and
whitish, the other comparatively large and rather more ashen-
coloured than white. Further, of birds that fly by night, some
have crooked talons, such as the night-raven, the owl, and the
eagle-owl. The eagle-owl resembles the common owl in shape,
but it is quite as large as the eagle. Again, there is the eleus, the
Aegolian owl, and the little horned owl. Of these birds, the eleus
is somewhat larger than the barn-door cock, and the Aegolian
owl is of about the same size as the eleus, and both these birds
hunt the jay; the little horned owl is smaller than the common
owl. All these three birds are alike in appearance, and all three
are carnivorous.
Again, of birds that have not crooked talons some are
carnivorous, such as the swallow. Others feed on grubs, such as
the chaffinch, the sparrow, the 'batis', the green linnet, and the
titmouse. Of the titmouse there are three varieties. The largest
1682
is the finch-titmouse - for it is about the size of a finch; the
second has a long tail, and from its habitat is called the hill-
titmouse; the third resembles the other two in appearance, but
is less in size than either of them. Then come the becca-fico, the
black-cap, the bull-finch, the robin, the epilais, the midget-bird,
and the golden-crested wren. This wren is little larger than a
locust, has a crest of bright red gold, and is in every way a
beautiful and graceful little bird. Then the anthus, a bird about
the size of a finch; and the mountain-finch, which resembles a
finch and is of much the same size, but its neck is blue, and it is
named from its habitat; and lastly the wren and the rook. The
above-enumerated birds and the like of them feed either wholly
or for the most part on grubs, but the following and the like feed
on thistles; to wit, the linnet, the thraupis, and the goldfinch. All
these birds feed on thistles, but never on grubs or any living
thing whatever; they live and roost also on the plants from
which they derive their food.
There are other birds whose favourite food consists of insects
found beneath the bark of trees; as for instance, the great and
the small pie, which are nicknamed the woodpeckers. These
two birds resemble one another in plumage and in note, only
that the note of the larger bird is the louder of the two; they
both frequent the trunks of trees in quest of food. There is also
the greenpie, a bird about the size of a turtle-dove, green-
coloured all over, that pecks at the bark of trees with
extraordinary vigour, lives generally on the branch of a tree, has
a loud note, and is mostly found in the Peloponnese. There is
another bird called the 'grub-picker' (or tree-creeper), about as
small as the penduline titmouse, with speckled plumage of an
ashen colour, and with a poor note; it is a variety of the
woodpecker.
There are other birds that live on fruit and herbage, such as the
wild pigeon or ringdove, the common pigeon, the rock-dove, and
1683
the turtle-dove. The ring-dove and the common pigeon are
visible at all seasons; the turtledove only in the summer, for in
winter it lurks in some hole or other and is never seen. The
rock-dove is chiefly visible in the autumn, and is caught at that
season; it is larger than the common pigeon but smaller than
the wild one; it is generally caught while drinking. These
pigeons bring their young ones with them when they visit this
country. All our other birds come to us in the early summer and
build their nests here, and the greater part of them rear their
young on animal food, with the sole exception of the pigeon
and its varieties.
The whole genus of birds may be pretty well divided into such
as procure their food on dry land, such as frequent rivers and
lakes, and such as live on or by the sea.
Of water-birds such as are web-footed live actually on the water,
while such as are split-footed live by the edge of it - and, by the
way, water-birds that are not carnivorous live on water-plants,
(but most of them live on fish), like the heron and the spoonbill
that frequent the banks of lakes and rivers; and the spoonbill,
by the way, is less than the common heron, and has a long flat
bill. There are furthermore the stork and the seamew; and the
seamew, by the way, is ashen-coloured. There is also the
schoenilus, the cinclus, and the white-rump. Of these smaller
birds the last mentioned is the largest, being about the size of
the common thrush; all three may be described as 'wag-tails'.
Then there is the scalidris, with plumage ashen-grey, but
speckled. Moreover, the family of the halcyons or kingfishers
live by the waterside. Of kingfishers there are two varieties; one
that sits on reeds and sings; the other, the larger of the two, is
without a note. Both these varieties are blue on the back. There
is also the trochilus (or sandpiper). The halcyon also, including a
variety termed the cerylus, is found near the seaside. The crow
also feeds on such animal life as is cast up on the beach, for the
1684
bird is omnivorous. There are also the white gull, the cepphus,
the aethyia, and the charadrius.
Of web-footed birds, the larger species live on the banks of
rivers and lakes; as the swan, the duck, the coot, the grebe, and
the teal - a bird resembling the duck but less in size - and the
water-raven or cormorant. This bird is the size of a stork, only
that its legs are shorter; it is web-footed and is a good swimmer;
its plumage is black. It roosts on trees, and is the only one of all
such birds as these that is found to build its nest in a tree.
Further there is the large goose, the little gregarious goose, the
vulpanser, the horned grebe, and the penelops. The sea-eagle
lives in the neighbourhood of the sea and seeks its quarry in
lagoons.
A great number of birds are omnivorous. Birds of prey feed on
any animal or bird, other than a bird of prey, that they may
catch. These birds never touch one of their own genus, whereas
fishes often devour members actually of their own species.
Birds, as a rule, are very spare drinkers. In fact birds of prey
never drink at all, excepting a very few, and these drink very
rarely; and this last observation is peculiarly applicable to the
kestrel. The kite has been seen to drink, but he certainly drinks
very seldom.
Animals that are coated with tessellates - such as the lizard and
the other quadrupeds, and the serpents - are omnivorous: at all
events they are carnivorous and graminivorous; and serpents,
by the way, are of all animals the greatest gluttons.
1685
Tessellated animals are spare drinkers, as are also all such
animals as have a spongy lung, and such a lung, scantily
supplied with blood, is found in all oviparous animals. Serpents,
by the by, have an insatiate appetite for wine; consequently, at
times men hunt for snakes by pouring wine into saucers and
putting them into the interstices of walls, and the creatures are
caught when inebriated. Serpents are carnivorous, and
whenever they catch an animal they extract all its juices and
eject the creature whole. And, by the way, this is done by all
other creatures of similar habits, as for instance the spider; only
that the spider sucks out the juices of its prey outside, and the
serpent does so in its belly. The serpent takes any food
presented to him, eats birds and animals, and swallows eggs
entire. But after taking his prey he stretches himself until he
stands straight out to the very tip, and then he contracts and
squeezes himself into little compass, so that the swallowed
mass may pass down his outstretched body; and this action on
his part is due to the tenuity and length of his gullet. Spiders
and snakes can both go without food for a long time; and this
remark may be verified by observation of specimens kept alive
in the shops of the apothecaries.
Of viviparous quadrupeds such as are fierce and jag-toothed are
without exception carnivorous; though, by the way, it is stated
of the wolf, but of no other animal, that in extremity of hunger
it will eat a certain kind of earth. These carnivorous animals
never eat grass except when they are sick, just as dogs bring on
a vomit by eating grass and thereby purge themselves.
1686
The solitary wolf is more apt to attack man than the wolf that
goes with a pack.
The animal called 'glanus' by some and 'hyaena' by others is as
large as a wolf, with a mane like a horse, only that the hair is
stiffer and longer and extends over the entire length of the
chine. It will lie in wait for a man and chase him, and will
inveigle a dog within its reach by making a noise that resembles
the retching noise of a man vomiting. It is exceedingly fond of
putrefied flesh, and will burrow in a graveyard to gratify this
propensity.
The bear is omnivorous. It eats fruit, and is enabled by the
suppleness of its body to climb a tree; it also eats vegetables,
and it will break up a hive to get at the honey; it eats crabs and
ants also, and is in a general way carnivorous. It is so powerful
that it will attack not only the deer but the wild boar, if it can
take it unawares, and also the bull. After coming to close
quarters with the bull it falls on its back in front of the animal,
and, when the bull proceeds to butt, the bear seizes hold of the
bull's horns with its front paws, fastens its teeth into his
shoulder, and drags him down to the ground. For a short time
together it can walk erect on its hind legs. All the flesh it eats it
first allows to become carrion.
The lion, like all other savage and jag-toothed animals, is
carnivorous. It devours its food greedily and fiercely, and often
swallows its prey entire without rending it at all; it will then go
fasting for two or three days together, being rendered capable of
this abstinence by its previous surfeit. It is a spare drinker. It
discharges the solid residuum in small quantities, about every
other day or at irregular intervals, and the substance of it is
hard and dry like the excrement of a dog. The wind discharged
from off its stomach is pungent, and its urine emits a strong
odour, a phenomenon which, in the case of dogs, accounts for
1687
their habit of sniffing at trees; for, by the way, the lion, like the
dog, lifts its leg to void its urine. It infects the food it eats with a
strong smell by breathing on it, and when the animal is cut
open an overpowering vapour exhales from its inside.
Some wild quadrupeds feed in lakes and rivers; the seal is the
only one that gets its living on the sea. To the former class of
animals belong the so-called castor, the satyrium, the otter, and
the so-called latax, or beaver. The beaver is flatter than the otter
and has strong teeth; it often at night-time emerges from the
water and goes nibbling at the bark of the aspens that fringe the
riversides. The otter will bite a man, and it is said that whenever
it bites it will never let go until it hears a bone crack. The hair of
the beaver is rough, intermediate in appearance between the
hair of the seal and the hair of the deer.
Jag-toothed animals drink by lapping, as do also some animals
with teeth differently formed, as the mouse. Animals whose
upper and lower teeth meet evenly drink by suction, as the
horse and the ox; the bear neither laps nor sucks, but gulps
down his drink. Birds, a rule, drink by suction, but the long
necked birds stop and elevate their heads at intervals; the
purple coot is the only one (of the long-necked birds) that
swallows water by gulps.
Horned animals, domesticated or wild, and all such as are not
jag-toothed, are all frugivorous and graminivorous, save under
great stress of hunger. The pig is an exception, it cares little for
grass or fruit, but of all animals it is the fondest of roots, owing
to the fact that its snout is peculiarly adapted for digging them
out of the ground; it is also of all animals the most easily
1688
pleased in the matter of food. It takes on fat more rapidly in
proportion to its size than any other animal; in fact, a pig can be
fattened for the market in sixty days. Pig-dealers can tell the
amount of flesh taken on, by having first weighed the animal
while it was being starved. Before the fattening process begins,
the creature must be starved for three days; and, by the way,
animals in general will take on fat if subjected previously to a
course of starvation; after the three days of starvation, pig-
breeders feed the animal lavishly. Breeders in Thrace, when
fattening pigs, give them a drink on the first day; then they miss
one, and then two days, then three and four, until the interval
extends over seven days. The pigs' meat used for fattening is
composed of barley, millet, figs, acorns, wild pears, and
cucumbers. These animals - and other animals that have warm
bellies - are fattened by repose. (Pigs also fatten the better by
being allowed to wallow in mud. They like to feed in batches of
the same age. A pig will give battle even to a wolf.) If a pig be
weighed when living, you may calculate that after death its
flesh will weigh five-sixths of that weight, and the hair, the
blood, and the rest will weigh the other sixth. When suckling
their young, swine - like all other animals - get attenuated. So
much for these animals.
Cattle feed on corn and grass, and fatten on vegetables that
tend to cause flatulency, such as bitter vetch or bruised beans or
bean-stalks. The older ones also will fatten if they be fed up
after an incision has been made into their hide, and air blown
thereinto. Cattle will fatten also on barley in its natural state or
on barley finely winnowed, or on sweet food, such as figs, or
pulp from the wine-press, or on elm-leaves. But nothing is so
1689
fattening as the heat of the sun and wallowing in warm waters.
If the horns of young cattle be smeared with hot wax, you may
mold them to any shape you please, and cattle are less subject
to disease of the hoof if you smear the horny parts with wax,
pitch, or olive oil. Herded cattle suffer more when they are
forced to change their pasture ground by frost than when snow
is the cause of change. Cattle grow all the more in size when
they are kept from sexual commerce over a number of years;
and it is with a view to growth in size that in Epirus the so-
called Pyrrhic kine are not allowed intercourse with the bull
until they are nine years old; from which circumstance they are
nicknamed the 'unbulled' kine. Of these Pyrrhic cattle, by the
way, they say that there are only about four hundred in the
world, that they are the private property of the Epirote royal
family, that they cannot thrive out of Epirus, and that people
elsewhere have tried to rear them, but without success.
8
Horses, mules, and asses feed on corn and grass, but are
fattened chiefly by drink. Just in proportion as beasts of burden
drink water, so will they more or less enjoy their food, and a
place will give good or bad feeding according as the water is
good or bad. Green corn, while ripening, will give a smooth coat;
but such corn is injurious if the spikes are too stiff and sharp.
The first crop of clover is unwholesome, and so is clover over
which ill-scented water runs; for the clover is sure to get the
taint of the water. Cattle like clear water for drinking; but the
horse in this respect resembles the camel, for the camel likes
turbid and thick water, and will never drink from a stream until
he has trampled it into a turbid condition. And, by the way, the
1690
camel can go without water for as much as four days, but after
that when he drinks, he drinks in immense quantities.
The elephant at the most can eat nine Macedonian medimni of
fodder at one meal; but so large an amount is unwholesome. As
a general rule it can take six or seven medimni of fodder, five
medimni of wheat, and five mareis of wine - six cotylae going to
the maris. An elephant has been known to drink right off
fourteen Macedonian metretae of water, and another metretae
later in the day.
Camels live for about thirty years; in some exceptional cases
they live much longer, and instances have been known of their
living to the age of a hundred. The elephant is said by some to
live for about two hundred years; by others, for three hundred.
10
Sheep and goats are graminivorous, but sheep browse
assiduously and steadily, whereas goats shift their ground
rapidly, and browse only on the tips of the herbage. Sheep are
much improved in condition by drinking, and accordingly they
give the flocks salt every five days in summer, to the extent of
one medimnus to the hundred sheep, and this is found to
render a flock healthier and fatter. In fact they mix salt with the
greater part of their food; a large amount of salt is mixed into
their bran (for the reason that they drink more when thirsty),
and in autumn they get cucumbers with a sprinkling of salt on
1691
them; this admixture of salt in their food tends also to increase
the quantity of milk in the ewes. If sheep be kept on the move
at midday they will drink more copiously towards evening; and
if the ewes be fed with salted food as the lambing season draws
near they will get larger udders. Sheep are fattened by twigs of
the olive or of the oleaster, by vetch, and bran of every kind; and
these articles of food fatten all the more if they be first
sprinkled with brine. Sheep will take on flesh all the better if
they be first put for three days through a process of starving. In
autumn, water from the north is more wholesome for sheep
than water from the south. Pasture grounds are all the better if
they have a westerly aspect.
Sheep will lose flesh if they be kept overmuch on the move or
be subjected to any hardship. In winter time shepherds can
easily distinguish the vigorous sheep from the weakly, from the
fact that the vigorous sheep are covered with hoar-frost while
the weakly ones are quite free of it; the fact being that the
weakly ones feeling oppressed with the burden shake
themselves and so get rid of it. The flesh of all quadrupeds
deteriorates in marshy pastures, and is the better on high
grounds. Sheep that have flat tails can stand the winter better
than long-tailed sheep, and short-fleeced sheep than the
shaggy-fleeced; and sheep with crisp wool stand the rigour of
winter very poorly. Sheep are healthier than goats, but goats are
stronger than sheep. (The fleeces and the wool of sheep that
have been killed by wolves, as also the clothes made from them,
are exceptionally infested with lice.)
1692
11
Of insects, such as have teeth are omnivorous; such as have a
tongue feed on liquids only, extracting with that organ juices
from all quarters. And of these latter some may be called
omnivorous, inasmuch as they feed on every kind of juice, as for
instance, the common fly; others are blood-suckers, such as the
gadfly and the horse-fly, others again live on the juices of fruits
and plants. The bee is the only insect that invariably eschews
whatever is rotten; it will touch no article of food unless it have
a sweet-tasting juice, and it is particularly fond of drinking
water if it be found bubbling up clear from a spring
underground.
So much for the food of animals of the leading genera.
12
The habits of animals are all connected with either breeding
and the rearing of young, or with the procuring a due supply of
food; and these habits are modified so as to suit cold and heat
and the variations of the seasons. For all animals have an
instinctive perception of the changes of temperature, and, just
as men seek shelter in houses in winter, or as men of great
possessions spend their summer in cool places and their winter
in sunny ones, so also all animals that can do so shift their
habitat at various seasons.
Some creatures can make provision against change without
stirring from their ordinary haunts; others migrate, quitting
Pontus and the cold countries after the autumnal equinox to
avoid the approaching winter, and after the spring equinox
migrating from warm lands to cool lands to avoid the coming
1693
heat. In some cases they migrate from places near at hand, in
others they may be said to come from the ends of the world, as
in the case of the crane; for these birds migrate from the
steppes of Scythia to the marshlands south of Egypt where the
Nile has its source. And it is here, by the way, that they are said
to fight with the pygmies; and the story is not fabulous, but
there is in reality a race of dwarfish men, and the horses are
little in proportion, and the men live in caves underground.
Pelicans also migrate, and fly from the Strymon to the Ister, and
breed on the banks of this river. They depart in flocks, and the
birds in front wait for those in the rear, owing to the fact that
when the flock is passing over the intervening mountain range,
the birds in the rear lose sight of their companions in the van.
Fishes also in a similar manner shift their habitat now out of
the Euxine and now into it. In winter they move from the outer
sea in towards land in quest of heat; in summer they shift from
shallow waters to the deep sea to escape the heat.
Weakly birds in winter and in frosty weather come down to the
plains for warmth, and in summer migrate to the hills for
coolness. The more weakly an animal is the greater hurry will it
be in to migrate on account of extremes of temperature, either
hot or cold; thus the mackerel migrates in advance of the
tunnies, and the quail in advance of the cranes. The former
migrates in the month of Boedromion, and the latter in the
month of Maemacterion. All creatures are fatter in migrating
from cold to heat than in migrating from heat to cold; thus the
quail is fatter when he emigrates in autumn than when he
arrives in spring. The migration from cold countries is
contemporaneous with the close of the hot season. Animals are
in better trim for breeding purposes in spring-time, when they
change from hot to cool lands.
1694
Of birds, the crane, as has been said, migrates from one end of
the world to the other; they fly against the wind. The story told
about the stone is untrue: to wit, that the bird, so the story goes,
carries in its inside a stone by way of ballast, and that the stone
when vomited up is a touchstone for gold.
The cushat and the rock-dove migrate, and never winter in our
country, as is the case also with the turtle-dove; the common
pigeon, however, stays behind. The quail also migrates; only, by
the way, a few quails and turtle-doves may stay behind here and
there in sunny districts. Cushats and turtle-doves flock together,
both when they arrive and when the season for migration
comes round again. When quails come to land, if it be fair
weather or if a north wind is blowing, they will pair off and
manage pretty comfortably; but if a southerly wind prevail they
are greatly distressed owing to the difficulties in the way of
flight, for a southerly wind is wet and violent. For this reason
bird-catchers are never on the alert for these birds during fine
weather, but only during the prevalence of southerly winds,
when the bird from the violence of the wind is unable to fly.
And, by the way, it is owing to the distress occasioned by the
bulkiness of its body that the bird always screams while flying:
for the labour is severe. When the quails come from abroad they
have no leaders, but when they migrate hence, the glottis flits
along with them, as does also the landrail, and the eared owl,
and the corncrake. The corncrake calls them in the night, and
when the birdcatchers hear the croak of the bird in the
nighttime they know that the quails are on the move. The
landrail is like a marsh bird, and the glottis has a tongue that
can project far out of its beak. The eared owl is like an ordinary
owl, only that it has feathers about its ears; by some it is called
the night-raven. It is a great rogue of a bird, and is a capital
mimic; a bird-catcher will dance before it and, while the bird is
mimicking his gestures, the accomplice comes behind and
catches it. The common owl is caught by a similar trick.
1695
As a general rule all birds with crooked talons are short-necked,
flat-tongued, and disposed to mimicry. The Indian bird, the
parrot, which is said to have a man's tongue, answers to this
description; and, by the way, after drinking wine, the parrot
becomes more saucy than ever.
Of birds, the following are migratory - the crane, the swan, the
pelican, and the lesser goose.
13
Of fishes, some, as has been observed, migrate from the outer
seas in towards shore, and from the shore towards the outer
seas, to avoid the extremes of cold and heat.
Fish living near to the shore are better eating than deep-sea
fish. The fact is they have more abundant and better feeding, for
wherever the sun's heat can reach vegetation is more abundant,
better in quality, and more delicate, as is seen in any ordinary
garden. Further, the black shore-weed grows near to shore; the
other shore-weed is like wild weed. Besides, the parts of the sea
near to shore are subjected to a more equable temperature; and
consequently the flesh of shallow-water fishes is firm and
consistent, whereas the flesh of deep-water fishes is flaccid and
watery.
The following fishes are found near into the shore - the
synodon, the black bream, the merou, the gilthead, the mullet,
the red mullet, the wrasse, the weaver, the callionymus, the
goby, and rock-fishes of all kinds. The following are deep-sea
fishes - the trygon, the cartilaginous fishes, the white conger,
the serranus, the erythrinus, and the glaucus. The braize, the
sea-scorpion, the black conger, the muraena, and the piper or
1696
sea-cuckoo are found alike in shallow and deep waters. These
fishes, however, vary for various localities; for instance, the goby
and all rock-fish are fat off the coast of Crete. Again, the tunny
is out of season in summer, when it is being preyed on by its
own peculiar louse-parasite, but after the rising of Arcturus,
when the parasite has left it, it comes into season again. A
number of fish also are found in sea-estuaries; such as the
saupe, the gilthead, the red mullet, and, in point of fact, the
greater part of the gregarious fishes. The bonito also is found in
such waters, as, for instance, off the coast of Alopeconnesus;
and most species of fishes are found in Lake Bistonis. The coly-
mackerel as a rule does not enter the Euxine, but passes the
summer in the Propontis, where it spawns, and winters in the
Aegean. The tunny proper, the pelamys, and the bonito
penetrate into the Euxine in summer and pass the summer
there; as do also the greater part of such fish as swim in shoals
with the currents, or congregate in shoals together. And most
fish congregate in shoals, and shoal-fishes in all cases have
leaders.
Fish penetrate into the Euxine for two reasons, and firstly for
food. For the feeding is more abundant and better in quality
owing to the amount of fresh river-water that discharges into
the sea, and moreover, the large fishes of this inland sea are
smaller than the large fishes of the outer sea. In point of fact,
there is no large fish in the Euxine excepting the dolphin and
the porpoise, and the dolphin is a small variety; but as soon as
you get into the outer sea the big fishes are on the big scale.
Furthermore, fish penetrate into this sea for the purpose of
breeding; for there are recesses there favourable for spawning,
and the fresh and exceptionally sweet water has an invigorating
effect upon the spawn. After spawning, when the young fishes
have attained some size, the parent fish swim out of the Euxine
immediately after the rising of the Pleiads. If winter comes in
with a southerly wind, they swim out with more or less of
1697
deliberation; but, if a north wind be blowing, they swim out with
greater rapidity, from the fact that the breeze is favourable to
their own course. And, by the way, the young fish are caught
about this time in the neighbourhood of Byzantium very small
in size, as might have been expected from the shortness of their
sojourn in the Euxine. The shoals in general are visible both as
they quit and enter the Euxine. The trichiae, however, only can
be caught during their entry, but are never visible during their
exit; in point of fact, when a trichia is caught running outwards
in the neighbourhood of Byzantium, the fishermen are
particularly careful to cleanse their nets, as the circumstance is
so singular and exceptional. The way of accounting for this
phenomenon is that this fish, and this one only, swims
northwards into the Danube, and then at the point of its
bifurcation swims down southwards into the Adriatic. And, as a
proof that this theory is correct, the very opposite phenomenon
presents itself in the Adriatic; that is to say, they are not caught
in that sea during their entry, but are caught during their exit.
Tunny-fish swim into the Euxine keeping the shore on their
right, and swim out of it with the shore upon their left. It is
stated that they do so as being naturally weak-sighted, and
seeing better with the right eye.
During the daytime shoal-fish continue on their way, but during
the night they rest and feed. But if there be moonlight, they
continue their journey without resting at all. Some people
accustomed to sea-life assert that shoal-fish at the period of the
winter solstice never move at all, but keep perfectly still
wherever they may happen to have been overtaken by the
solstice, and this lasts until the equinox.
The coly-mackerel is caught more frequently on entering than
on quitting the Euxine. And in the Propontis the fish is at its
best before the spawning season. Shoal-fish, as a rule, are
1698
caught in greater quantities as they leave the Euxine, and at
that season they are in the best condition. At the time of their
entrance they are caught in very plump condition close to
shore, but those are in comparatively poor condition that are
caught farther out to sea. Very often, when the coly-mackerel
and the mackerel are met by a south wind in their exit, there
are better catches to the southward than in the neighbourhood
of Byzantium. So much then for the phenomenon of migration
of fishes.
Now the same phenomenon is observed in fishes as in
terrestrial animals in regard to hibernation: in other words,
during winter fishes take to concealing themselves in out of the
way places, and quit their places of concealment in the warmer
season. But, by the way, animals go into concealment by way of
refuge against extreme heat, as well as against extreme cold.
Sometimes an entire genus will thus seek concealment; in other
cases some species will do so and others will not. For instance,
the shell-fish seek concealment without exception, as is seen in
the case of those dwelling in the sea, the purple murex, the
ceryx, and all such like; but though in the case of the detached
species the phenomenon is obvious - for they hide themselves,
as is seen in the scallop, or they are provided with an
operculum on the free surface, as in the case of land snails - in
the case of the non-detached the concealment is not so clearly
observed. They do not go into hiding at one and the same
season; but the snails go in winter, the purple murex and the
ceryx for about thirty days at the rising of the Dog-star, and the
scallop at about the same period. But for the most part they go
into concealment when the weather is either extremely cold or
extremely hot.
1699
14
Insects almost all go into hiding, with the exception of such of
them as live in human habitations or perish before the
completion of the year. They hide in the winter; some of them
for several days, others for only the coldest days, as the bee. For
the bee also goes into hiding: and the proof that it does so is
that during a certain period bees never touch the food set before
them, and if a bee creeps out of the hive, it is quite transparent,
with nothing whatsoever in its stomach; and the period of its
rest and hiding lasts from the setting of the Pleiads until
springtime.
Animals take their winter-sleep or summer-sleep by concealing
themselves in warm places, or in places where they have been
used to lie concealed.
15
Several blooded animals take this sleep, such as the pholidotes
or tessellates, namely, the serpent, the lizard, the gecko, and the
river, crocodile, all of which go into hiding for four months in
the depth of winter, and during that time eat nothing. Serpents
in general burrow under ground for this purpose; the viper
conceals itself under a stone.
A great number of fishes also take this sleep, and notably, the
hippurus and coracinus in winter time; for, whereas fish in
general may be caught at all periods of the year more or less,
there is this singularity observed in these fishes, that they are
caught within a certain fixed period of the year, and never by
any chance out of it. The muraena also hides, and the orphus or
sea-perch, and the conger. Rock-fish pair off, male and female,
1700
for hiding (just as for breeding); as is observed in the case of the
species of wrasse called the thrush and the owzel, and in the
perch.
The tunny also takes a sleep in winter in deep waters, and gets
exceedingly fat after the sleep. The fishing season for the tunny
begins at the rising of the Pleiads and lasts, at the longest, down
to the setting of Arcturus; during the rest of the year they are
hid and enjoying immunity. About the time of hibernation a few
tunnies or other hibernating fishes are caught while swimming
about, in particularly warm localities and in exceptionally fine
weather, or on nights of full moon; for the fishes are induced (by
the warmth or the light) to emerge for a while from their lair in
quest of food.
Most fishes are at their best for the table during the summer or
winter sleep.
The primas-tunny conceals itself in the mud; this may be
inferred from the fact that during a particular period the fish is
never caught, and that, when it is caught after that period, it is
covered with mud and has its fins damaged. In the spring these
tunnies get in motion and proceed towards the coast, coupling
and breeding, and the females are now caught full of spawn. At
this time they are considered as in season, but in autumn and
in winter as of inferior quality; at this time also the males are
full of milt. When the spawn is small, the fish is hard to catch,
but it is easily caught when the spawn gets large, as the fish is
then infested by its parasite. Some fish burrow for sleep in the
sand and some in mud, just keeping their mouths outside.
Most fishes hide, then, during the winter only, but crustaceans,
the rock-fish, the ray, and the cartilaginous species hide only
during extremely severe weather, and this may be inferred from
the fact that these fishes are never by any chance caught when
the weather is extremely cold. Some fishes, however, hide
1701
during the summer, as the glaucus or grey-back; this fish hides
in summer for about sixty days. The hake also and the gilthead
hide; and we infer that the hake hides over a lengthened period
from the fact that it is only caught at long intervals. We are led
also to infer that fishes hide in summer from the circumstance
that the takes of certain fish are made between the rise and
setting of certain constellations: of the Dog-star in particular,
the sea at this period being upturned from the lower depths.
This phenomenon may be observed to best advantage in the
Bosporus; for the mud is there brought up to the surface and
the fish are brought up along with it. They say also that very
often, when the sea-bottom is dredged, more fish will be caught
by the second haul than by the first one. Furthermore, after very
heavy rains numerous specimens become visible of creatures
that at other times are never seen at all or seen only at
intervals.
16
A great number of birds also go into hiding; they do not all
migrate, as is generally supposed, to warmer countries. Thus,
certain birds (as the kite and the swallow) when they are not far
off from places of this kind, in which they have their permanent
abode, betake themselves thither; others, that are at a distance
from such places, decline the trouble of migration and simply
hide themselves where they are. Swallows, for instance, have
been often found in holes, quite denuded of their feathers, and
the kite on its first emergence from torpidity has been seen to
fly from out some such hiding-place. And with regard to this
phenomenon of periodic torpor there is no distinction observed,
whether the talons of a bird be crooked or straight; for instance,
the stork, the owzel, the turtle-dove, and the lark, all go into
1702
hiding. The case of the turtledove is the most notorious of all,
for we would defy any one to assert that he had anywhere seen
a turtle-dove in winter-time; at the beginning of the hiding time
it is exceedingly plump, and during this period it moults, but
retains its plumpness. Some cushats hide; others, instead of
hiding, migrate at the same time as the swallow. The thrush and
the starling hide; and of birds with crooked talons the kite and
the owl hide for a few days.
17
Of viviparous quadrupeds the porcupine and the bear retire into
concealment. The fact that the bear hides is well established,
but there are doubts as to its motive for so doing, whether it be
by reason of the cold or from some other cause. About this
period the male and the female become so fat as to be hardly
capable of motion. The female brings forth her young at this
time, and remains in concealment until it is time to bring the
cubs out; and she brings them out in spring, about three
months after the winter solstice. The bear hides for at least
forty days; during fourteen of these days it is said not to move
at all, but during most of the subsequent days it moves, and
from time to time wakes up. A she-bear in pregnancy has either
never been caught at all or has been caught very seldom. There
can be no doubt but that during this period they eat nothing; for
in the first place they never emerge from their hiding-place, and
further, when they are caught, their belly and intestines are
found to be quite empty. It is also said that from no food being
taken the gut almost closes up, and that in consequence the
animal on first emerging takes to eating arum with the view of
opening up and distending the gut.
1703
The dormouse actually hides in a tree, and gets very fat at that
period; as does also the white mouse of Pontus.
(Of animals that hide or go torpid some slough off what is called
their 'old-age'. This name is applied to the outermost skin, and
to the casing that envelops the developing organism.)
In discussing the case of terrestrial vivipara we stated that the
reason for the bear's seeking concealment is an open question.
We now proceed to treat of the tessellates. The tessellates for
the most part go into hiding, and if their skin is soft they slough
off their 'old-age', but not if the skin is shell-like, as is the shell
of the tortoise - for, by the way, the tortoise and the fresh water
tortoise belong to the tessellates. Thus, the old-age is sloughed
off by the gecko, the lizard, and above all, by serpents; and they
slough off the skin in springtime when emerging from their
torpor, and again in the autumn. Vipers also slough off their
skin both in spring and in autumn, and it is not the case, as
some aver, that this species of the serpent family is exceptional
in not sloughing. When the serpent begins to slough, the skin
peels off at first from the eyes, so that any one ignorant of the
phenomenon would suppose the animal were going blind; after
that it peels off the head, and so on, until the creature presents
to view only a white surface all over. The sloughing goes on for a
day and a night, beginning with the head and ending with the
tail. During the sloughing of the skin an inner layer comes to
the surface, for the creature emerges just as the embryo from its
afterbirth.
All insects that slough at all slough in the same way; as the
silphe, and the empis or midge, and all the coleoptera, as for
instance the cantharus-beetle. They all slough after the period
of development; for just as the afterbirth breaks from off the
young of the vivipara so the outer husk breaks off from around
the young of the vermipara, in the same way both with the bee
1704
and the grasshopper. The cicada the moment after issuing from
the husk goes and sits upon an olive tree or a reed; after the
breaking up of the husk the creature issues out, leaving a little
moisture behind, and after a short interval flies up into the air
and sets a. chirping.
Of marine animals the crawfish and the lobster slough
sometimes in the spring, and sometimes in autumn after
parturition. Lobsters have been caught occasionally with the
parts about the thorax soft, from the shell having there peeled
off, and the lower parts hard, from the shell having not yet
peeled off there; for, by the way, they do not slough in the same
manner as the serpent. The crawfish hides for about five
months. Crabs also slough off their old-age; this is generally
allowed with regard to the soft-shelled crabs, and it is said to be
the case with the testaceous kind, as for instance with the large
'granny' crab. When these animals slough their shell becomes
soft all over, and as for the crab, it can scarcely crawl. These
animals also do not cast their skins once and for all, but over
and over again.
So much for the animals that go into hiding or torpidity, for the
times at which, and the ways in which, they go; and so much
also for the animals that slough off their old-age, and for the
times at which they undergo the process.
18
Animals do not all thrive at the same seasons, nor do they
thrive alike during all extremes of weather. Further animals of
diverse species are in a diverse way healthy or sickly at certain
seasons; and, in point of fact, some animals have ailments that
are unknown to others. Birds thrive in times of drought, both in
1705
their general health and in regard to parturition, and this is
especially the case with the cushat; fishes, however, with a few
exceptions, thrive best in rainy weather; on the contrary rainy
seasons are bad for birds - and so by the way is much drinking -
and drought is bad for fishes. Birds of prey, as has been already
stated, may in a general way be said never to drink at all,
though Hesiod appears to have been ignorant of the fact, for in
his story about the siege of Ninus he represents the eagle that
presided over the auguries as in the act of drinking; all other
birds drink, but drink sparingly, as is the case also with all other
spongy-lunged oviparous animals. Sickness in birds may be
diagnosed from their plumage, which is ruffled when they are
sickly instead of lying smooth as when they are well.
19
The majority of fishes, as has been stated, thrive best in rainy
seasons. Not only have they food in greater abundance at this
time, but in a general way rain is wholesome for them just as it
is for vegetation - for, by the way, kitchen vegetables, though
artificially watered, derive benefit from rain; and the same
remark applies even to reeds that grow in marshes, as they
hardly grow at all without a rainfall. That rain is good for fishes
may be inferred from the fact that most fishes migrate to the
Euxine for the summer; for owing to the number of the rivers
that discharge into this sea its water is exceptionally fresh, and
the rivers bring down a large supply of food. Besides, a great
number of fishes, such as the bonito and the mullet, swim up
the rivers and thrive in the rivers and marshes. The sea-
gudgeon also fattens in the rivers, and, as a rule, countries
abounding in lagoons furnish unusually excellent fish. While
most fishes, then, are benefited by rain, they are chiefly
1706
benefited by summer rain; or we may state the case thus, that
rain is good for fishes in spring, summer, and autumn, and fine
dry weather in winter. As a general rule what is good for men is
good for fishes also.
Fishes do not thrive in cold places, and those fishes suffer most
in severe winters that have a stone in their head, as the
chromis, the basse, the sciaena, and the braize; for owing to the
stone they get frozen with the cold, and are thrown up on shore.
Whilst rain is wholesome for most fishes, it is, on the contrary,
unwholesome for the mullet, the cephalus, and the so-called
marinus, for rain superinduces blindness in most of these
fishes, and all the more rapidly if the rainfall be superabundant.
The cephalus is peculiarly subject to this malady in severe
winters; their eyes grow white, and when caught they are in
poor condition, and eventually the disease kills them. It would
appear that this disease is due to extreme cold even more than
to an excessive rainfall; for instance, in many places and more
especially in shallows off the coast of Nauplia, in the Argolid, a
number of fishes have been known to be caught out at sea in
seasons of severe cold. The gilthead also suffers in winter; the
acharnas suffers in summer, and loses condition. The coracine
is exceptional among fishes in deriving benefit from drought,
and this is due to the fact that heat and drought are apt to come
together.
Particular places suit particular fishes; some are naturally fishes
of the shore, and some of the deep sea, and some are at home
in one or the other of these regions, and others are common to
the two and are at home in both. Some fishes will thrive in one
particular spot, and in that spot only. As a general rule it may be
said that places abounding in weeds are wholesome; at all
events, fishes caught in such places are exceptionally fat: that
is, such fishes a a habit all sorts of localities as well. The fact is
1707
that weed-eating fishes find abundance of their special food in
such localities, and carnivorous fish find an unusually large
number of smaller fish. It matters also whether the wind be
from the north or south: the longer fish thrive better when a
north wind prevails, and in summer at one and the same spot
more long fish will be caught than flat fish with a north wind
blowing.
The tunny and the sword-fish are infested with a parasite about
the rising of the Dog-star; that is to say, about this time both
these fishes have a grub beside their fins that is nicknamed the
'gadfly'. It resembles the scorpion in shape, and is about the size
of the spider. So acute is the pain it inflicts that the sword-fish
will often leap as high out of the water as a dolphin; in fact, it
sometimes leaps over the bulwarks of a vessel and falls back on
the deck. The tunny delights more than any other fish in the
heat of the sun. It will burrow for warmth in the sand in shallow
waters near to shore, or will, because it is warm, disport itself
on the surface of the sea.
The fry of little fishes escape by being overlooked, for it is only
the larger ones of the small species that fishes of the large
species will pursue. The greater part of the spawn and the fry of
fishes is destroyed by the heat of the sun, for whatever of them
the sun reaches it spoils.
Fishes are caught in greatest abundance before sunrise and
after sunset, or, speaking generally, just about sunset and
sunrise. Fishermen haul up their nets at these times, and speak
of the hauls then made as the 'nick-of-time' hauls. The fact is,
that at these times fishes are particularly weak-sighted; at night
they are at rest, and as the light grows stronger they see
comparatively well.
We know of no pestilential malady attacking fishes, such as
those which attack man, and horses and oxen among the
1708
quadrupedal vivipara, and certain species of other genera,
domesticated and wild; but fishes do seem to suffer from
sickness; and fishermen infer this from the fact that at times
fishes in poor condition, and looking as though they were sick,
and of altered colour, are caught in a large haul of well-
conditioned fish of their own species. So much for sea-fishes.
20
River-fish and lake-fish also are exempt from diseases of a
pestilential character, but certain species are subject to special
and peculiar maladies. For instance, the sheat-fish just before
the rising of the Dog-star, owing to its swimming near the
surface of the water, is liable to sunstroke, and is paralysed by a
loud peal of thunder. The carp is subject to the same
eventualities but in a lesser degree. The sheatfish is destroyed in
great quantities in shallow waters by the serpent called the
dragon. In the balerus and tilon a worm is engendered about the
rising of the Dog-star, that sickens these fish and causes them
to rise towards the surface, where they are killed by the
excessive heat. The chalcis is subject to a very violent malady;
lice are engendered underneath their gills in great numbers,
and cause destruction among them; but no other species of fish
is subject to any such malady.
If mullein be introduced into water it will kill fish in its vicinity.
It is used extensively for catching fish in rivers and ponds; by
the Phoenicians it is made use of also in the sea.
There are two other methods employed for catch-fish. It is a
known fact that in winter fishes emerge from the deep parts of
rivers and, by the way, at all seasons fresh water is tolerably
cold. A trench accordingly is dug leading into a river, and
1709
wattled at the river end with reeds and stones, an aperture
being left in the wattling through which the river water flows
into the trench; when the frost comes on the fish can be taken
out of the trench in weels. Another method is adopted in
summer and winter alike. They run across a stream a dam
composed of brushwood and stones leaving a small open space,
and in this space they insert a weel; they then coop the fish in
towards this place, and draw them up in the weel as they swim
through the open space.
Shell-fish, as a rule, are benefited by rainy weather. The purple
murex is an exception; if it be placed on a shore near to where a
river discharges, it will die within a day after tasting the fresh
water. The murex lives for about fifty days after capture; during
this period they feed off one another, as there grows on the
shell a kind of sea-weed or sea-moss; if any food is thrown to
them during this period, it is said to be done not to keep them
alive, but to make them weigh more.
To shell-fish in general drought is unwholesome. During dry
weather they decrease in size and degenerate in quality; and it
is during such weather that the red scallop is found in more
than usual abundance. In the Pyrrhaean Strait the clam was
exterminated, partly by the dredging-machine used in their
capture, and partly by long-continued droughts. Rainy weather
is wholesome to the generality of shellfish owing to the fact
that the sea-water then becomes exceptionally sweet. In the
Euxine, owing to the coldness of the climate, shellfish are not
found: nor yet in rivers, excepting a few bivalves here and there.
Univalves, by the way, are very apt to freeze to death in
extremely cold weather. So much for animals that live in water.
1710
21
To turn to quadrupeds, the pig suffers from three diseases, one
of which is called branchos, a disease attended with swellings
about the windpipe and the jaws. It may break out in any part of
the body; very often it attacks the foot, and occasionally the ear;
the neighbouring parts also soon rot, and the decay goes on
until it reaches the lungs, when the animal succumbs. The
disease develops with great rapidity, and the moment it sets in
the animal gives up eating. The swineherds know but one way
to cure it, namely, by complete excision, when they detect the
first signs of the disease. There are two other diseases, which
are both alike termed craurus. The one is attended with pain
and heaviness in the head, and this is the commoner of the two,
the other with diarrhoea. The latter is incurable, the former is
treated by applying wine fomentations to the snout and rinsing
the nostrils with wine. Even this disease is very hard to cure; it
has been known to kill within three or four days. The animal is
chiefly subject to branchos when it gets extremely fat, and
when the heat has brought a good supply of figs. The treatment
is to feed on mashed mulberries, to give repeated warm baths,
and to lance the under part of the tongue.
Pigs with flabby flesh are subject to measles about the legs,
neck, and shoulders, for the pimples develop chiefly in these
parts. If the pimples are few in number the flesh is
comparatively sweet, but if they be numerous it gets watery and
flaccid. The symptoms of measles are obvious, for the pimples
show chiefly on the under side of the tongue, and if you pluck
the bristles off the chine the skin will appear suffused with
blood, and further the animal will be unable to keep its hind-
feet at rest. Pigs never take this disease while they are mere
sucklings. The pimples may be got rid of by feeding on this kind
of spelt called tiphe; and this spelt, by the way, is very good for
ordinary food. The best food for rearing and fattening pigs is
1711
chickpeas and figs, but the one thing essential is to vary the
food as much as possible, for this animal, like animals in
general lights in a change of diet; and it is said that one kind of
food blows the animal out, that another superinduces flesh, and
that another puts on fat, and that acorns, though liked by the
animal, render the flesh flaccid. Besides, if a sow eats acorns in
great quantities, it will miscarry, as is also the case with the
ewe; and, indeed, the miscarriage is more certain in the case of
the ewe than in the case of the sow. The pig is the only animal
known to be subject to measles.
22
Dogs suffer from three diseases; rabies, quinsy, and sore feet.
Rabies drives the animal mad, and ary animal whatever,
excepting man, will take the disease if bitten by a dog so
afflicted; the disease is fatal to the dog itself, and to any animal
it may bite, man excepted. Quinsy also is fatal to dogs; and only
a few recover from disease of the feet. The camel, like the dog, is
subject to rabies. The elephant, which is reputed to enjoy
immunity from all other illnesses, is occasionally subject to
flatulency.
23
Cattle in herds are liable to two diseases, foot, sickness and
craurus. In the former their feet suffer from eruptions, but the
animal recovers from the disease without even the loss of the
hoof. It is found of service to smear the horny parts with warm
1712
pitch. In craurus, the breath comes warm at short intervals; in
fact, craurus in cattle answers to fever in man. The symptoms of
the disease are drooping of the ears and disinclination for food.
The animal soon succumbs, and when the carcase is opened
the lungs are found to be rotten.
24
Horses out at pasture are free from all diseases excepting
disease of the feet. From this disease they sometimes lose their
hooves: but after losing them they grow them soon again, for as
one hoof is decaying it is being replaced by another. Symptoms
of the malady are a sinking in and wrinkling of the lip in the
middle under the nostrils, and in the case of the male, a
twitching of the right testicle.
Stall-reared horses are subject to very numerous forms of
disease. They are liable to disease called 'eileus'. Under this
disease the animal trails its hind-legs under its belly so far
forward as almost to fall back on its haunches; if it goes without
food for several days and turns rabid, it may be of service to
draw blood, or to castrate the male. The animal is subject also to
tetanus: the veins get rigid, as also the head and neck, and the
animal walks with its legs stretched out straight. The horse
suffers also from abscesses. Another painful illness afflicts
them called the 'barley-surfeit'. The are a softening of the palate
and heat of the breath; the animal may recover through the
strength of its own constitution, but no formal remedies are of
any avail.
There is also a disease called nymphia, in which the animal is
said to stand still and droop its head on hearing flute-music; if
during this ailment the horse be mounted, it will run off at a
1713
gallop until it is pulled. Even with this rabies in full force, it
preserves a dejected spiritless appearance; some of the
symptoms are a throwing back of the ears followed by a
projection of them, great languor, and heavy breathing. Heart-
ache also is incurable, of which the symptom is a drawing in of
the flanks; and so is displacement of the bladder, which is
accompanied by a retention of urine and a drawing up of the
hooves and haunches. Neither is there any cure if the animal
swallow the grape-beetle, which is about the size of the
sphondyle or knuckle-beetle. The bite of the shrewmouse is
dangerous to horses and other draught animals as well; it is
followed by boils. The bite is all the more dangerous if the
mouse be pregnant when she bites, for the boils then burst, but
do not burst otherwise. The cicigna-called 'chalcis' by some, and
'zignis' by others - either causes death by its bite or, at all
events, intense pain; it is like a small lizard, with the colour of
the blind snake. In point of fact, according to experts, the horse
and the sheep have pretty well as many ailments as the human
species. The drug known under the name of 'sandarace' or
realgar, is extremely injurious to a horse, and to all draught
animals; it is given to the animal as a medicine in a solution of
water, the liquid being filtered through a colander. The mare
when pregnant apt to miscarry when disturbed by the odour of
an extinguished candle; and a similar accident happens
occasionally to women in their pregnancy. So much for the
diseases of the horse.
The so-called hippomanes grows, as has stated, on the foal, and
the mare nibbles it off as she licks and cleans the foal. All the
curious stories connected with the hippomanes are due to old
wives and to the venders of charms. What is called the 'polium'
or foal's membrane, is, as all the accounts state, delivered by the
mother before the foal appears.
1714
A horse will recognize the neighing of any other horse with
which it may have fought at any previous period. The horse
delights in meadows and marshes, and likes to drink muddy
water; in fact, if water be clear, the horse will trample in it to
make it turbid, will then drink it, and afterwards will wallow in
it. The animal is fond of water in every way, whether for
drinking or for bathing purposes; and this explains the peculiar
constitution of the hippopotamus or river-horse. In regard to
water the ox is the opposite of the horse; for if the water be
impure or cold, or mixed up with alien matter, it will refuse to
drink it.
25
The ass suffers chiefly from one particular disease which they
call 'melis'. It arises first in the head, and a clammy humour
runs down the nostrils, thick and red; if it stays in the head the
animal may recover, but if it descends into the lungs the animal
will die. Of all animals on its of its kind it is the least capable of
enduring extreme cold, which circumstance will account for the
fact that the animal is not found on the shores of the Euxine,
nor in Scythia.
26
Elephants suffer from flatulence, and when thus afflicted can
void neither solid nor liquid residuum. If the elephant swallow
earth-mould it suffers from relaxation; but if it go on taking it
steadily, it will experience no harm. From time to time it takes
1715
to swallowing stones. It suffers also from diarrhoea: in this case
they administer draughts of lukewarm water or dip its fodder in
honey, and either one or the other prescription will prove a
costive. When they suffer from insomnia, they will be restored
to health if their shoulders be rubbed with salt, olive-oil, and
warm water; when they have aches in their shoulders they will
derive great benefit from the application of roast pork. Some
elephants like olive oil, and others do not. If there is a bit of iron
in the inside of an elephant it is said that it will pass out if the
animal takes a drink of olive-oil; if the animal refuses olive-oil,
they soak a root in the oil and give it the root to swallow. So
much, then, for quadrupeds.
27
Insects, as a general rule, thrive best in the time of year in
which they come into being, especially if the season be moist
and warm, as in spring.
In bee-hives are found creatures that do great damage to the
combs; for instance, the grub that spins a web and ruins the
honeycomb: it is called the 'cleros'. It engenders an insect like
itself, of a spider-shape, and brings disease into the swarm.
There is another insect resembling the moth, called by some the
'pyraustes', that flies about a lighted candle: this creature
engenders a brood full of a fine down. It is never stung by a bee,
and can only be got out of a hive by fumigation. A caterpillar
also is engendered in hives, of a species nicknamed the teredo,
or 'borer', with which creature the bee never interferes. Bees
suffer most when flowers are covered with mildew, or in
seasons of drought.
1716
All insects, without exception, die if they be smeared over with
oil; and they die all the more rapidly if you smear their head
with the oil and lay them out in the sun.
28
Variety in animal life may be produced by variety of locality:
thus in one place an animal will not be found at all, in another
it will be small, or short-lived, or will not thrive. Sometimes this
sort of difference is observed in closely adjacent districts. Thus,
in the territory of Miletus, in one district cicadas are found
while there are none in the district close adjoining; and in
Cephalenia there is a river on one side of which the cicada is
found and not on the other. In Pordoselene there is a public road
one side of which the weasel is found but not on the other. In
Boeotia the mole is found in great abundance in the
neighbourhood of Orchomenus, but there are none in Lebadia
though it is in the immediate vicinity, and if a mole be
transported from the one district to the other it will refuse to
burrow in the soil. The hare cannot live in Ithaca if introduced
there; in fact it will be found dead, turned towards the point of
the beach where it was landed. The horseman-ant is not found
in Sicily; the croaking frog has only recently appeared in the
neighbourhood of Cyrene. In the whole of Libya there is neither
wild boar, nor stag, nor wild goat; and in India, according to
Ctesias - no very good authority, by the way - there are no
swine, wild or tame, but animals that are devoid of blood and
such as go into hiding or go torpid are all of immense size there.
In the Euxine there are no small molluscs nor testaceans,
except a few here and there; but in the Red Sea all the
testaceans are exceedingly large. In Syria the sheep have tails a
cubit in breadth; the goats have ears a span and a palm long,
1717
and some have ears that flap down to the ground; and the cattle
have humps on their shoulders, like the camel. In Lycia goats
are shorn for their fleece, just as sheep are in all other
countries. In Libya the long-horned ram is born with horns, and
not the ram only, as Homer' words it, but the ewe as well; in
Pontus, on the confines of Scythia, the ram is without horns.
In Egypt animals, as a rule, are larger than their congeners in
Greece, as the cow and the sheep; but some are less, as the dog,
the wolf, the hare, the fox, the raven, and the hawk; others are
of pretty much the same size, as the crow and the goat. The
difference, where it exists, is attributed to the food, as being
abundant in one case and insufficient in another, for instance
for the wolf and the hawk; for provision is scanty for the
carnivorous animals, small birds being scarce; food is scanty
also for the hare and for all frugivorous animals, because
neither the nuts nor the fruit last long.
In many places the climate will account for peculiarities; thus in
Illyria, Thrace, and Epirus the ass is small, and in Gaul and in
Scythia the ass is not found at all owing to the coldness of the
climate of these countries. In Arabia the lizard is more than a
cubit in length, and the mouse is much larger than our field-
mouse, with its hind-legs a span long and its front legs the
length of the first finger-joint. In Libya, according to all
accounts, the length of the serpents is something appalling;
sailors spin a yarn to the effect that some crews once put
ashore and saw the bones of a number of oxen, and that they
were sure that the oxen had been devoured by serpents, for, just
as they were putting out to sea, serpents came chasing their
galleys at full speed and overturned one galley and set upon the
crew. Again, lions are more numerous in Libya, and in that
district of Europe that lies between the Achelous and the
Nessus; the leopard is more abundant in Asia Minor, and is not
found in Europe at all. As a general rule, wild animals are at
1718
their wildest in Asia, at their boldest in Europe, and most
diverse in form in Libya; in fact, there is an old saying, 'Always
something fresh in Libya.'
It would appear that in that country animals of diverse species
meet, on account of the rainless climate, at the watering-places,
and there pair together; and that such pairs will often breed if
they be nearly of the same size and have periods of gestation of
the same length. For it is said that they are tamed down in their
behaviour towards each other by extremity of thirst. And, by the
way, unlike animals elsewhere, they require to drink more in
wintertime than in summer: for they acquire the habit of not
drinking in summer, owing to the circumstance that there is
usually no water then; and the mice, if they drink, die.
Elsewhere also bastard-animals are born to heterogeneous
pairs; thus in Cyrene the wolf and the bitch will couple and
breed; and the Laconian hound is a cross between the fox and
the dog. They say that the Indian dog is a cross between the
tiger and the bitch, not the first cross, but a cross in the third
generation; for they say that the first cross is a savage creature.
They take the bitch to a lonely spot and tie her up: if the tiger be
in an amorous mood he will pair with her; if not he will eat her
up, and this casualty is of frequent occurrence.
29
Locality will differentiate habits also: for instance, rugged
highlands will not produce the same results as the soft
lowlands. The animals of the highlands look fiercer and bolder,
as is seen in the swine of Mount Athos; for a lowland boar is no
match even for a mountain sow.
1719
Again, locality is an important element in regard to the bite of
an animal. Thus, in Pharos and other places, the bite of the
scorpion is not dangerous; elsewhere - in Caria, for instances -
where scorpions are venomous as well as plentiful and of large
size, the sting is fatal to man or beast, even to the pig, and
especially to a black pig, though the pig, by the way, is in general
most singularly indifferent to the bite of any other creature. If a
pig goes into water after being struck by the scorpion of Caria, it
will surely die.
There is great variety in the effects produced by the bites of
serpents. The asp is found in Libya; the so-called 'septic' drug is
made from the body of the animal, and is the only remedy
known for the bite of the original. Among the silphium, also, a
snake is found, for the bite or which a certain stone is said to be
a cure: a stone that is brought from the grave of an ancient king,
which stone is put into water and drunk off. In certain parts of
Italy the bite of the gecko is fatal. But the deadliest of all bites of
venomous creatures is when one venomous animal has bitten
another; as, for instance, a viper's after it has bitten a scorpion.
To the great majority of such creatures man's is fatal. There is a
very little snake, by some entitled the 'holy-snake', which is
dreaded by even the largest serpents. It is about an ell long, and
hairy-looking; whenever it bites an animal, the flesh all round
the wound will at once mortify. There is in India a small snake
which is exceptional in this respect, that for its bite no specific
whatever is known.
30
Animals also vary as to their condition of health in connexion
with their pregnancy.
1720
Testaceans, such as scallops and all the oyster- family, and
crustaceans, such as the lobster family, are best when with
spawn. Even in the case of the testacean we speak of spawning
(or pregnancy); but whereas the crustaceans may be seen
coupling and laying their spawn, this is never the case with
testaceans. Molluscs are best in the breeding time, as the
calamary, the sepia, and the octopus.
Fishes, when they begin to breed, are nearly all good for the
table; but after the female has gone long with spawn they are
good in some cases, and in others are out of season. The
maenis, for instance, is good at the breeding time. The female of
this fish is round, the male longer and flatter; when the female
is beginning to breed the male turns black and mottled, and is
quite unfit for the table; at this period he is nicknamed the
'goat'.
The wrasses called the owzel and the thrush, and the smaris
have different colours at different seasons, as is the case with
the plumage of certain birds; that is to say, they become black in
the spring and after the spring get white again. The phycis also
changes its hue: in general it is white, but in spring it is mottled;
it is the only sea-fish which is said make a bed for itself, and the
female lays her spawn in this bed or nest. The maenis, as was
observed, changes its colour as does the smaris, and in
summer-time changes back from whitish to black, the change
being especially marked about the fins and gills. The coracine,
like the maenis, is in best condition at breeding time; the
mullet, the basse, and scaly fishes in general are in bad
condition at this period. A few fish are in much the same
condition at all times, whether with spawn or not, as the
glaucus. Old fishes also are bad eating; the old tunny is unfit
even for pickling, as a great part of its flesh wastes away with
age, and the same wasting is observed in all old fishes. The age
of a scaly fish may be told by the size and the hardness of its
1721
scales. An old tunny has been caught weighing fifteen talents,
with the span of its tail two cubits and a palm broad.
River-fish and lake-fish are best after they have discharged the
spawn in the case of the female and the milt in the case of the
male: that is, when they have fully recovered from the
exhaustion of such discharge. Some are good in the breeding
time, as the saperdis, and some bad, as the sheat-fish. As a
general rule, the male fish is better eating than the female; but
the reverse holds good of the sheat-fish. The eels that are called
females are the best for the table: they look as though they were
female, but they really are not so.
Book IX
Of the animals that are comparatively obscure and short-lived
the characters or dispositions are not so obvious to recognition
as are those of animals that are longer-lived. These latter
animals appear to have a natural capacity corresponding to
each of the passions: to cunning or simplicity, courage or
timidity, to good temper or to bad, and to other similar
dispositions of mind.
Some also are capable of giving or receiving instruction - of
receiving it from one another or from man: those that have the
faculty of hearing, for instance; and, not to limit the matter to
1722
audible sound, such as can differentiate the suggested
meanings of word and gesture.
In all genera in which the distinction of male and female is
found, Nature makes a similar differentiation in the mental
characteristics of the two sexes. This differentiation is the most
obvious in the case of human kind and in that of the larger
animals and the viviparous quadrupeds. In the case of these
latter the female softer in character, is the sooner tamed,
admits more readily of caressing, is more apt in the way of
learning; as, for instance, in the Laconian breed of dogs the
female is cleverer than the male. Of the Molossian breed of
dogs, such as are employed in the chase are pretty much the
same as those elsewhere; but sheep-dogs of this breed are
superior to the others in size, and in the courage with which
they face the attacks of wild animals.
Dogs that are born of a mixed breed between these two kinds
are remarkable for courage and endurance of hard labour.
In all cases, excepting those of the bear and leopard, the female
is less spirited than the male; in regard to the two exceptional
cases, the superiority in courage rests with the female. With all
other animals the female is softer in disposition than the male,
is more mischievous, less simple, more impulsive, and more
attentive to the nurture of the young: the male, on the other
hand, is more spirited than the female, more savage, more
simple and less cunning. The traces of these differentiated
characteristics are more or less visible everywhere, but they are
especially visible where character is the more developed, and
most of all in man.
The fact is, the nature of man is the most rounded off and
complete, and consequently in man the qualities or capacities
above referred to are found in their perfection. Hence woman is
more compassionate than man, more easily moved to tears, at
1723
the same time is more jealous, more querulous, more apt to
scold and to strike. She is, furthermore, more prone to
despondency and less hopeful than the man, more void of
shame or self-respect, more false of speech, more deceptive,
and of more retentive memory. She is also more wakeful, more
shrinking, more difficult to rouse to action, and requires a
smaller quantity of nutriment.
As was previously stated, the male is more courageous than the
female, and more sympathetic in the way of standing by to help.
Even in the case of molluscs, when the cuttle-fish is struck with
the trident the male stands by to help the female; but when the
male is struck the female runs away.
There is enmity between such animals as dwell in the same
localities or subsist on the food. If the means of subsistence run
short, creatures of like kind will fight together. Thus it is said
that seals which inhabit one and the same district will fight,
male with male, and female with female, until one combatant
kills the other, or one is driven away by the other; and their
young do even in like manner.
All creatures are at enmity with the carnivores, and the
carnivores with all the rest, for they all subsist on living
creatures. Soothsayers take notice of cases where animals keep
apart from one another, and cases where they congregate
together; calling those that live at war with one another
'dissociates', and those that dwell in peace with one another
'associates'. One may go so far as to say that if there were no
lack or stint of food, then those animals that are now afraid of
man or are wild by nature would be tame and familiar with
him, and in like manner with one another. This is shown by the
way animals are treated in Egypt, for owing to the fact that food
is constantly supplied to them the very fiercest creatures live
peaceably together. The fact is they are tamed by kindness, and
1724
in some places crocodiles are tame to their priestly keeper from
being fed by him. And elsewhere also the same phenomenon is
to be observed.
The eagle and the snake are enemies, for the eagle lives on
snakes; so are the ichneumon and the venom-spider, for the
ichneumon preys upon the latter. In the case of birds, there is
mutual enmity between the poecilis, the crested lark, the
woodpecker (?), and the chloreus, for they devour one another's
eggs; so also between the crow and the owl; for, owing to the
fact that the owl is dim-sighted by day, the crow at midday
preys upon the owl's eggs, and the owl at night upon the crow's,
each having the whip-hand of the other, turn and turn about,
night and day.
There is enmity also between the owl and the wren; for the
latter also devours the owl's eggs. In the daytime all other little
birds flutter round the owl - a practice which is popularly
termed 'admiring him' - buffet him, and pluck out his feathers;
in consequence of this habit, bird-catchers use the owl as a
decoy for catching little birds of all kinds.
The so-called presbys or 'old man' is at war with the weasel and
the crow, for they prey on her eggs and her brood; and so the
turtle-dove with the pyrallis, for they live in the same districts
and on the same food; and so with the green wood pecker and
the libyus; and so with kite and the raven, for, owing to his
having the advantage from stronger talons and more rapid
flight the former can steal whatever the latter is holding, so that
it is food also that makes enemies of these. In like manner there
is war between birds that get their living from the sea, as
between the brenthus, the gull, and the harpe; and so between
the buzzard on one side and the toad and snake on the other,
for the buzzard preys upon the eggs of the two others; and so
1725
between the turtle-dove and the chloreus; the chloreus kills the
dove, and the crow kills the so-called drummer-bird.
The aegolius, and birds of prey in general, prey upon the calaris,
and consequently there is war between it and them; and so is
there war between the gecko-lizard and the spider, for the
former preys upon the latter; and so between the woodpecker
and the heron, for the former preys upon the eggs and brood of
the latter. And so between the aegithus and the ass, owing to
the fact that the ass, in passing a furze-bush, rubs its sore and
itching parts against the prickles; by so doing, and all the more
if it brays, it topples the eggs and the brood out of the nest, the
young ones tumble out in fright, and the mother-bird, to avenge
this wrong, flies at the beast and pecks at his sore places.
The wolf is at war with the ass, the bull, and the fox, for as
being a carnivore, he attacks these other animals; and so for the
same reason with the fox and the circus, for the circus, being
carnivorous and furnished with crooked talons, attacks and
maims the animal. And so the raven is at war with the bull and
the ass, for it flies at them, and strikes them, and pecks at their
eyes; and so with the eagle and the heron, for the former,
having crooked talons, attacks the latter, and the latter usually
succumbs to the attack; and so the merlin with the vulture; and
the crex with the eleus-owl, the blackbird, and the oriole (of this
latter bird, by the way, the story goes that he was originally born
out of a funeral pyre): the cause of warfare is that the crex
injures both them and their young. The nuthatch and the wren
are at war with the eagle; the nuthatch breaks the eagle's eggs,
so the eagle is at war with it on special grounds, though, as a
bird of prey, it carries on a general war all round. The horse and
the anthus are enemies, and the horse will drive the bird out of
the field where he is grazing: the bird feeds on grass, and sees
too dimly to foresee an attack; it mimics the whinnying of the
horse, flies at him, and tries to frighten him away; but the horse
1726
drives the bird away, and whenever he catches it he kills it: this
bird lives beside rivers or on marsh ground; it has pretty
plumage, and finds its without trouble. The ass is at enmity
with the lizard, for the lizard sleeps in his manger, gets into his
nostril, and prevents his eating.
Of herons there are three kinds: the ash coloured, the white,
and the starry heron (or bittern). Of these the first mentioned
submits with reluctance to the duties of incubation, or to union
of the sexes; in fact, it screams during the union, and it is said
drips blood from its eyes; it lays its eggs also in an awkward
manner, not unattended with pain. It is at war with certain
creatures that do it injury: with the eagle for robbing it, with the
fox for worrying it at night, and with the lark for stealing its
eggs.
The snake is at war with the weasel and the pig; with the
weasel when they are both at home, for they live on the same
food; with the pig for preying on her kind. The merlin is at war
with the fox; it strikes and claws it, and, as it has crooked
talons, it kills the animal's young. The raven and the fox are
good friends, for the raven is at enmity with the merlin; and so
when the merlin assails the fox the raven comes and helps the
animal. The vulture and the merlin are mutual enemies, as
being both furnished with crooked talons. The vulture fights
with the eagle, and so, by the way, does does swan; and the
swan is often victorious: moreover, of all birds swans are most
prone to the killing of one another.
In regard to wild creatures, some sets are at enmity with other
sets at all times and under all circumstances; others, as in the
case of man and man, at special times and under incidental
circumstances. The ass and the acanthis are enemies; for the
bird lives on thistles, and the ass browses on thistles when they
are young and tender. The anthus, the acanthis, and the
1727
aegithus are at enmity with one another; it is said that the
blood of the anthus will not intercommingle with the blood of
the aegithus. The crow and the heron are friends, as also are the
sedge-bird and lark, the laedus and the celeus or green
woodpecker; the woodpecker lives on the banks of rivers and
beside brakes, the laedus lives on rocks and bills, and is greatly
attached to its nesting-place. The piphinx, the harpe, and the
kite are friends; as are the fox and the snake, for both burrow
underground; so also are the blackbird and the turtle-dove. The
lion and the thos or civet are enemies, for both are carnivorous
and live on the same food. Elephants fight fiercely with one
another, and stab one another with their tusks; of two
combatants the beaten one gets completely cowed, and dreads
the sound of his conqueror's voice. These animals differ from
one another an extraordinary extent in the way of courage.
Indians employ these animals for war purposes, irrespective of
sex; the females, however, are less in size and much inferior in
point of spirit. An elephant by pushing with his big tusks can
batter down a wall, and will butt with his forehead at a palm
until he brings it down, when he stamps on it and lays it in
orderly fashion on the ground. Men hunt the elephant in the
following way: they mount tame elephants of approved spirit
and proceed in quest of wild animals; when they come up with
these they bid the tame brutes to beat the wild ones until they
tire the latter completely. Hereupon the driver mounts a wild
brute and guides him with the application of his metal prong;
after this the creature soon becomes tame, and obeys guidance.
Now when the driver is on their back they are all tractable, but
after he has dismounted, some are tame and others vicious; in
the case of these latter, they tie their front-legs with ropes to
keep them quiet. The animal is hunted whether young or full
grown.
1728
Thus we see that in the case of the creatures above mentioned
their mutual friendship or the is due to the food they feed on
and the life they lead.
Of fishes, such as swim in shoals together are friendly to one
another; such as do not so swim are enemies. Some fishes
swarm during the spawning season; others after they have
spawned. To state the matter comprehensively, we may say that
the following are shoaling fish: the tunny, the maenis, the sea-
gudgeon, the bogue, the horse-mackerel, the coracine, the
synodon or dentex, the red mullet, the sphyraena, the anthias,
the eleginus, the atherine, the sarginus, the gar-fish, (the squid,)
the rainbow-wrasse, the pelamyd, the mackerel, the coly-
mackerel. Of these some not only swim in shoals, but go in pairs
inside the shoal; the rest without exception swim in pairs, and
only swim in shoals at certain periods: that is, as has been said,
when they are heavy with spawn or after they have spawned.
The basse and the grey mullet are bitter enemies, but they
swarm together at certain times; for at times not only do fishes
of the same species swarm together, but also those whose
feeding-grounds are identical or adjacent, if the food-supply be
abundant. The grey mullet is often found alive with its tail
lopped off, and the conger with all that part of its body removed
that lies to the rear of the vent; in the case of the mullet the
injury is wrought by the basse, in that of the conger-eel by the
muraena. There is war between the larger and the lesser fishes:
for the big fishes prey on the little ones. So much on the subject
of marine animals.
1729
The characters of animals, as has been observed, differ in
respect to timidity, to gentleness, to courage, to tameness, to
intelligence, and to stupidity.
The sheep is said to be naturally dull and stupid. Of all
quadrupeds it is the most foolish: it will saunter away to lonely
places with no object in view; oftentimes in stormy weather it
will stray from shelter; if it be overtaken by a snowstorm, it will
stand still unless the shepherd sets it in motion; it will stay
behind and perish unless the shepherd brings up the rams; it
will then follow home.
If you catch hold of a goat's beard at the extremity - the beard is
of a substance resembling hair - all the companion goats will
stand stock still, staring at this particular goat in a kind of
dumbfounderment.
You will have a warmer bed in amongst the goats than among
the sheep, because the goats will be quieter and will creep up
towards you; for the goat is more impatient of cold than the
sheep.
Shepherds train sheep to close in together at a clap of their
hands, for if, when a thunderstorm comes on, a ewe stays
behind without closing in, the storm will kill it if it be with
young; consequently if a sudden clap or noise is made, they
close in together within the sheepfold by reason of their
training.
Even bulls, when they are roaming by themselves apart from
the herd, are killed by wild animals.
1730
Sheep and goats lie crowded together, kin by kin. When the sun
turns early towards its setting, the goats are said to lie no longer
face to face, but back to back.
Cattle at pasture keep together in their accustomed herds, and
if one animal strays away the rest will follow; consequently if
the herdsmen lose one particular animal, they keep close watch
on all the rest.
When mares with their colts pasture together in the same field,
if one dam dies the others will take up the rearing of the colt. In
point of fact, the mare appears to be singularly prone by nature
to maternal fondness; in proof whereof a barren mare will steal
the foal from its dam, will tend it with all the solicitude of a
mother, but, as it will be unprovided with mother's milk, its
solicitude will prove fatal to its charge.
Among wild quadrupeds the hind appears to be pre-eminently
intelligent; for example, in its habit of bringing forth its young
on the sides of public roads, where the fear of man forbids the
approach of wild animals. Again, after parturition, it first
swallows the afterbirth, then goes in quest of the seseli shrub,
and after eating of it returns to its young. The mother takes its
young betimes to her lair, so leading it to know its place of
refuge in time of danger; this lair is a precipitous rock, with only
one approach, and there it is said to hold its own against all
1731
comers. The male when it gets fat, which it does in a high
degree in autumn, disappears, abandoning its usual resorts,
apparently under an idea that its fatness facilitates its capture.
They shed their horns in places difficult of access or discovery,
whence the proverbial expression of 'the place where the stag
sheds his horns'; the fact being that, as having parted with their
weapons, they take care not to be seen. The saying is that no
man has ever seen the animal's left horn; that the creature
keeps it out of sight because it possesses some medicinal
property.
In their first year stags grow no horns, but only an excrescence
indicating where horns will be, this excrescence being short and
thick. In their second year they grow their horns for the first
time, straight in shape, like pegs for hanging clothes on; and on
this account they have an appropriate nickname. In the third
year the antlers are bifurcate; in the fourth year they grow
trifurcate; and so they go on increasing in complexity until the
creature is six years old: after this they grow their horns
without any specific differentiation, so that you cannot by
observation of them tell the animal's age. But the patriarchs of
the herd may be told chiefly by two signs; in the first place they
have few teeth or none at all, and, in the second place, they
have ceased to grow the pointed tips to their antlers. The
forward-pointing tips of the growing horns (that is to say the
brow antlers), with which the animal meets attack, are
technically termed its 'defenders'; with these the patriarchs are
unprovided, and their antlers merely grow straight upwards.
Stags shed their horns annually, in or about the month of May;
after shedding, they conceal themselves, it is said, during the
daytime, and, to avoid the flies, hide in thick copses; during this
time, until they have grown their horns, they feed at night-time.
The horns at first grow in a kind of skin envelope, and get rough
by degrees; when they reach their full size the animal basks in
the sun, to mature and dry them. When they need no longer rub
1732
them against tree-trunks they quit their hiding places, from a
sense of security based upon the possession of arms defensive
and offensive. An Achaeine stag has been caught with a
quantity of green ivy grown over its horns, it having grown
apparently, as on fresh green wood, when the horns were young
and tender. When a stag is stung by a venom-spider or similar
insect, it gathers crabs and eats them; it is said to be a good
thing for man to drink the juice, but the taste is disagreeable.
The hinds after parturition at once swallow the afterbirth, and it
is impossible to secure it, for the hind catches it before it falls to
the ground: now this substance is supposed to have medicinal
properties. When hunted the creatures are caught by singing or
pipe-playing on the part of the hunters; they are so pleased
with the music that they lie down on the grass. If there be two
hunters, one before their eyes sings or plays the pipe, the other
keeps out of sight and shoots, at a signal given by the
confederate. If the animal has its ears cocked, it can hear well
and you cannot escape its ken; if its ears are down, you can.
When bears are running away from their pursuers they push
their cubs in front of them, or take them up and carry them;
when they are being overtaken they climb up a tree. When
emerging from their winter-den, they at once take to eating
cuckoo-pint, as has been said, and chew sticks of wood as
though they were cutting teeth.
Many other quadrupeds help themselves in clever ways. Wild
goats in Crete are said, when wounded by arrows, to go in
search of dittany, which is supposed to have the property of
ejecting arrows in the body. Dogs, when they are ill, eat some
1733
kind of grass and produce vomiting. The panther, after eating
panther's-bane, tries to find some human excrement, which is
said to heal its pain. This panther's-bane kills lions as well.
Hunters hang up human excrement in a vessel attached to the
boughs of a tree, to keep the animal from straying to any
distance; the animal meets its end in leaping up to the branch
and trying to get at the medicine. They say that the panther has
found out that wild animals are fond of the scent it emits; that,
when it goes a-hunting, it hides itself; that the other animals
come nearer and nearer, and that by this stratagem it can catch
even animals as swift of foot as stags.
The Egyptian ichneumon, when it sees the serpent called the
asp, does not attack it until it has called in other ichneumons to
help; to meet the blows and bites of their enemy the assailants
beplaster themselves with mud, by first soaking in the river and
then rolling on the ground.
When the crocodile yawns, the trochilus flies into his mouth
and cleans his teeth. The trochilus gets his food thereby, and the
crocodile gets ease and comfort; it makes no attempt to injure
its little friend, but, when it wants it to go, it shakes its neck in
warning, lest it should accidentally bite the bird.
The tortoise, when it has partaken of a snake, eats marjoram;
this action has been actually observed. A man saw a tortoise
perform this operation over and over again, and every time it
plucked up some marjoram go back to partake of its prey; he
thereupon pulled the marjoram up by the roots, and the
consequence was the tortoise died. The weasel, when it fights
with a snake, first eats wild rue, the smell of which is noxious to
the snake. The dragon, when it eats fruit, swallows endive-juice;
it has been seen in the act. Dogs, when they suffer from worms,
eat the standing corn. Storks, and all other birds, when they get
a wound fighting, apply marjoram to the place injured.
1734
Many have seen the locust, when fighting with the snake get a
tight hold of the snake by the neck. The weasel has a clever way
of getting the better of birds; it tears their throats open, as
wolves do with sheep. Weasels fight desperately with mice-
catching snakes, as they both prey on the same animal.
In regard to the instinct of hedgehogs, it has been observed in
many places that, when the wind is shifting from north to
south, and from south to north, they shift the outlook of their
earth-holes, and those that are kept in domestication shift over
from one wall to the other. The story goes that a man in
Byzantium got into high repute for foretelling a change of
weather, all owing to his having noticed this habit of the
hedgehog.
The polecat or marten is about as large as the smaller breed of
Maltese dogs. In the thickness of its fur, in its look, in the white
of its belly, and in its love of mischief, it resembles the weasel; it
is easily tamed; from its liking for honey it is a plague to bee-
hives; it preys on birds like the cat. Its genital organ, as has been
said, consists of bone: the organ of the male is supposed to be a
cure for strangury; doctors scrape it into powder, and
administer it in that form.
In a general way in the lives of animals many resemblances to
human life may be observed. Pre-eminent intelligence will be
seen more in small creatures than in large ones, as is
exemplified in the case of birds by the nest building of the
swallow. In the same way as men do, the bird mixes mud and
chaff together; if it runs short of mud, it souses its body in water
and rolls about in the dry dust with wet feathers; furthermore,
1735
just as man does, it makes a bed of straw, putting hard material
below for a foundation, and adapting all to suit its own size.
Both parents co-operate in the rearing of the young; each of the
parents will detect, with practised eye, the young one that has
had a helping, and will take care it is not helped twice over; at
first the parents will rid the nest of excrement, but, when the
young are grown, they will teach their young to shift their
position and let their excrement fall over the side of the nest.
Pigeons exhibit other phenomena with a similar likeness to the
ways of humankind. In pairing the same male and the same
female keep together; and the union is only broken by the death
of one of the two parties. At the time of parturition in the
female the sympathetic attentions of the male are
extraordinary; if the female is afraid on account of the
impending parturition to enter the nest, the male will beat her
and force her to come in. When the young are born, he will take
and masticate pieces of suitable food, will open the beaks of the
fledglings, and inject these pieces, thus preparing them betimes
to take food. (When the male bird is about to expel the the
young ones from the nest he cohabits with them all.) As a
general rule these birds show this conjugal fidelity, but
occasionally a female will cohabit with other than her mate.
These birds are combative, and quarrel with one another, and
enter each other's nests, though this occurs but seldom; at a
distance from their nests this quarrelsomeness is less marked,
but in the close neighbourhood of their nests they will fight
desperately. A peculiarity common to the tame pigeon, the ring-
dove and the turtle-dove is that they do not lean the head back
when they are in the act of drinking, but only when they have
fully quenched their thirst. The turtle-dove and the ring-dove
both have but one mate, and let no other come nigh; both sexes
co-operate in the process of incubation. It is difficult to
distinguish between the sexes except by an examination of
their interiors. Ring-doves are long-lived; cases have been
1736
known where such birds were twenty-five years old, thirty years
old, and in some cases forty. As they grow old their claws
increase in size, and pigeon-fanciers cut the claws; as far as one
can see, the birds suffer no other perceptible disfigurement by
their increase in age. Turtle-doves and pigeons that are blinded
by fanciers for use as decoys, live for eight years. Partridges live
for about fifteen years. Ring-doves and turtle-doves always build
their nests in the same place year after year. The male, as a
general rule, is more long-lived than the female; but in the case
of pigeons some assert that the male dies before the female,
taking their inference from the statements of persons who keep
decoy-birds in captivity. Some declare that the male sparrow
lives only a year, pointing to the fact that early in spring the
male sparrow has no black beard, but has one later on, as
though the blackbearded birds of the last year had all died out;
they also say that the females are the longer lived, on the
grounds that they are caught in amongst the young birds and
that their age is rendered manifest by the hardness about their
beaks. Turtle-doves in summer live in cold places, (and in warm
places during the winter); chaffinches affect warm habitations
in summer and cold ones in winter.
8
Birds of a heavy build, such as quails, partridges, and the like,
build no nests; indeed, where they are incapable of flight, it
would be of no use if they could do so. After scraping a hole on a
level piece of ground - and it is only in such a place that they
lay their eggs - they cover it over with thorns and sticks for
security against hawks and eagles, and there lay their eggs and
hatch them; after the hatching is over, they at once lead the
young out from the nest, as they are not able to fly afield for
1737
food for them. Quails and partridges, like barn-door hens, when
they go to rest, gather their brood under their wings. Not to be
discovered, as might be the case if they stayed long in one spot,
they do not hatch the eggs where they laid them. When a man
comes by chance upon a young brood, and tries to catch them,
the hen-bird rolls in front of the hunter, pretending to be lame:
the man every moment thinks he is on the point of catching
her, and so she draws him on and on, until every one of her
brood has had time to escape; hereupon she returns to the nest
and calls the young back. The partridge lays not less than ten
eggs, and often lays as many as sixteen. As has been observed,
the bird has mischievous and deceitful habits. In the spring-
time, a noisy scrimmage takes place, out of which the male-
birds emerge each with a hen. Owing to the lecherous nature of
the bird, and from a dislike to the hen sitting, the males, if they
find any eggs, roll them over and over until they break them in
pieces; to provide against this the female goes to a distance and
lays the eggs, and often, under the stress of parturition, lays
them in any chance spot that offers; if the male be near at hand,
then to keep the eggs intact she refrains from visiting them. If
she be seen by a man, then, just as with her fledged brood, she
entices him off by showing herself close at his feet until she has
drawn him to a distance. When the females have run away and
taken to sitting, the males in a pack take to screaming and
fighting; when thus engaged, they have the nickname of
'widowers'. The bird who is beaten follows his victor, and
submits to be covered by him only; and the beaten bird is
covered by a second one or by any other, only clandestinely
without the victor's knowledge; this is so, not at all times, but at
a particular season of the year, and with quails as well as with
partridges. A similar proceeding takes place occasionally with
barn-door cocks: for in temples, where cocks are set apart as
dedicate without hens, they all as a matter of course tread any
new-comer. Tame partridges tread wild birds, pecket their
1738
heads, and treat them with every possible outrage. The leader of
the wild birds, with a counter-note of challenge, pushes forward
to attack the decoy-bird, and after he has been netted, another
advances with a similar note. This is what is done if the decoy
be a male; but if it be a female that is the decoy and gives the
note, and the leader of the wild birds give a counter one, the
rest of the males set upon him and chase him away from the
female for making advances to her instead of to them; in
consequence of this the male often advances without uttering
any cry, so that no other may hear him and come and give him
battle; and experienced fowlers assert that sometimes the male
bird, when he approaches the female, makes her keep silence,
to avoid having to give battle to other males who might have
heard him. The partridge has not only the note here referred to,
but also a thin shrill cry and other notes. Oftentimes the hen-
bird rises from off her brood when she sees the male showing
attentions to the female decoy; she will give the counter note
and remain still, so as to be trodden by him and divert him from
the decoy. The quail and the partridge are so intent upon sexual
union that they often come right in the way of the decoy-birds,
and not seldom alight upon their heads. So much for the sexual
proclivities of the partridge, for the way in which it is hunted,
and the general nasty habits of the bird.
As has been said, quails and partridges build their nests upon
the ground, and so also do some of the birds that are capable of
sustained flight. Further, for instance, of such birds, the lark and
the woodcock, as well as the quail, do not perch on a branch,
but squat upon the ground.
1739
The woodpecker does not squat on the ground, but pecks at the
bark of trees to drive out from under it maggots and gnats;
when they emerge, it licks them up with its tongue, which is
large and flat. It can run up and down a tree in any way, even
with the head downwards, like the gecko-lizard. For secure hold
upon a tree, its claws are better adapted than those of the daw;
it makes its way by sticking these claws into the bark. One
species of woodpecker is smaller than a blackbird, and has
small reddish speckles; a second species is larger than the
blackbird, and a third is not much smaller than a barn-door hen.
It builds a nest on trees, as has been said, on olive trees
amongst others. It feeds on the maggots and ants that are under
the bark: it is so eager in the search for maggots that it is said
sometimes to hollow a tree out to its downfall. A woodpecker
once, in course of domestication, was seen to insert an almond
into a hole in a piece of timber, so that it might remain steady
under its pecking; at the third peck it split the shell of the fruit,
and then ate the kernel.
10
Many indications of high intelligence are given by cranes. They
will fly to a great distance and up in the air, to command an
extensive view; if they see clouds and signs of bad weather they
fly down again and remain still. They, furthermore, have a
leader in their flight, and patrols that scream on the confines of
the flock so as to be heard by all. When they settle down, the
main body go to sleep with their heads under their wing,
standing first on one leg and then on the other, while their
1740
leader, with his head uncovered, keeps a sharp look out, and
when he sees anything of importance signals it with a cry.
Pelicans that live beside rivers swallow the large smooth
mussel-shells: after cooking them inside the crop that precedes
the stomach, they spit them out, so that, now when their shells
are open, they may pick the flesh out and eat it.
11
Of wild birds, the nests are fashioned to meet the exigencies of
existence and ensure the security of the young. Some of these
birds are fond of their young and take great care of them, others
are quite the reverse; some are clever in procuring subsistence,
others are not so. Some of these birds build in ravines and
clefts, and on cliffs, as, for instance, the so-called charadrius, or
stone-curlew; this bird is in no way noteworthy for plumage or
voice; it makes an appearance at night, but in the daytime
keeps out of sight.
The hawk also builds in inaccessible places. Although a
ravenous bird, it will never eat the heart of any bird it catches;
this has been observed in the case of the quail, the thrush, and
other birds. They modify betimes their method of hunting, for in
summer they do not grab their prey as they do at other seasons.
Of the vulture, it is said that no one has ever seen either its
young or its nest; on this account and on the ground that all of
a sudden great numbers of them will appear without any one
being able to tell from whence they come, Herodorus, the father
of Bryson the sophist, says that it belongs to some distant and
elevated land. The reason is that the bird has its nest on
1741
inaccessible crags, and is found only in a few localities. The
female lays one egg as a rule, and two at the most.
Some birds live on mountains or in forests, as the hoopoe and
the brenthus; this latter bird finds his food with ease and has a
musical voice. The wren lives in brakes and crevices; it is
difficult of capture, keeps out of sight, is gentle of disposition,
finds its food with ease, and is something of a mechanic. It goes
by the nickname of 'old man' or 'king'; and the story goes that
for this reason the eagle is at war with him.
12
Some birds live on the sea-shore, as the wagtail; the bird is of a
mischievous nature, hard to capture, but when caught capable
of complete domestication; it is a cripple, as being weak in its
hinder quarters.
Web-footed birds without exception live near the sea or rivers or
pools, as they naturally resort to places adapted to their
structure. Several birds, however, with cloven toes live near
pools or marshes, as, for instance, the anthus lives by the side of
rivers; the plumage of this bird is pretty, and it finds its food
with ease. The catarrhactes lives near the sea; when it makes a
dive, it will keep under water for as long as it would take a man
to walk a furlong; it is less than the common hawk. Swans are
web-footed, and live near pools and marshes; they find their
food with ease, are good-tempered, are fond of their young, and
live to a green old age. If the eagle attacks them they will repel
the attack and get the better of their assailant, but they are
never the first to attack. They are musical, and sing chiefly at
the approach of death; at this time they fly out to sea, and men,
when sailing past the coast of Libya, have fallen in with many of
1742
them out at sea singing in mournful strains, and have actually
seen some of them dying.
The cymindis is seldom seen, as it lives on mountains; it is
black in colour, and about the size of the hawk called the 'dove-
killer'; it is long and slender in form. The Ionians call the bird by
this name; Homer in the Iliad mentions it in the line:
Chalcis its name with those of heavenly birth,
But called Cymindis by the sons of earth.
The hybris, said by some to be the same as the eagle-owl, is
never seen by daylight, as it is dim-sighted, but during the night
it hunts like the eagle; it will fight the eagle with such
desperation that the two combatants are often captured alive by
shepherds; it lays two eggs, and, like others we have mentioned,
it builds on rocks and in caverns. Cranes also fight so
desperately among themselves as to be caught when fighting,
for they will not leave off; the crane lays two eggs.
13
The jay has a great variety of notes: indeed, might almost say it
had a different note for every day in the year. It lays about nine
eggs; builds its nest on trees, out of hair and tags of wool; when
acorns are getting scarce, it lays up a store of them in hiding.
It is a common story of the stork that the old birds are fed by
their grateful progeny. Some tell a similar story of the bee-eater,
and declare that the parents are fed by their young not only
when growing old, but at an early period, as soon as the young
are capable of feeding them; and the parent-birds stay inside
the nest. The under part of the bird's wing is pale yellow; the
1743
upper part is dark blue, like that of the halcyon; the tips of the
wings are About autumn-time it lays six or seven eggs, in
overhanging banks where the soil is soft; there it burrows into
the ground to a depth of six feet.
The greenfinch, so called from the colour of its belly, is as large
as a lark; it lays four or five eggs, builds its nest out of the plant
called comfrey, pulling it up by the roots, and makes an under-
mattress to lie on of hair and wool. The blackbird and the jay
build their nests after the same fashion. The nest of the
penduline tit shows great mechanical skill; it has the
appearance of a ball of flax, and the hole for entry is very small.
People who live where the bird comes from say that there exists
a cinnamon bird which brings the cinnamon from some
unknown localities, and builds its nest out of it; it builds on
high trees on the slender top branches. They say that the
inhabitants attach leaden weights to the tips of their arrows
and therewith bring down the nests, and from the intertexture
collect the cinnamon sticks.
14
The halcyon is not much larger than the sparrow. Its colour is
dark blue, green, and light purple; the whole body and wings,
and especially parts about the neck, show these colours in a
mixed way, without any colour being sharply defined; the beak
is light green, long and slender: such, then, is the look of the
bird. Its nest is like sea-balls, i.e. the things that by the name of
halosachne or seafoam, only the colour is not the same. The
colour of the nest is light red, and the shape is that of the long-
necked gourd. The nests are larger than the largest sponge,
though they vary in size; they are roofed over, and great part of
1744
them is solid and great part hollow. If you use a sharp knife it is
not easy to cut the nest through; but if you cut it, and at the
same time bruise it with your hand, it will soon crumble to
pieces, like the halosachne. The opening is small, just enough
for a tiny entrance, so that even if the nest upset the sea does
not enter in; the hollow channels are like those in sponges. It is
not known for certain of what material the nest is constructed;
it is possibly made of the backbones of the gar-fish; for, by the
way, the bird lives on fish. Besides living on the shore, it ascends
fresh-water streams. It lays generally about five eggs, and lays
eggs all its life long, beginning to do so at the age of four
months.
15
The hoopoe usually constructs its nest out of human
excrement. It changes its appearance in summer and in winter,
as in fact do the great majority of wild birds. (The titmouse is
said to lay a very large quantity of eggs: next to the ostrich the
blackheaded tit is said by some to lay the largest number of
eggs; seventeen eggs have been seen; it lays, however, more
than twenty; it is said always to lay an odd number. Like others
we have mentioned, it builds in trees; it feeds on caterpillars.) A
peculiarity of this bird and of the nightingale is that the outer
extremity of the tongue is not sharp-pointed.
The aegithus finds its food with ease, has many young, and
walks with a limp. The golden oriole is apt at learning, is clever
at making a living, but is awkward in flight and has an ugly
plumage.
1745
16
The reed-warbler makes its living as easily as any other bird,
sits in summer in a shady spot facing the wind, in winter in a
sunny and sheltered place among reeds in a marsh; it is small
in size, with a pleasant note. The so-called chatterer has a
pleasant note, beautiful plumage, makes a living cleverly, and is
graceful in form; it appears to be alien to our country; at all
events it is seldom seen at a distance from its own immediate
home.
17
The crake is quarrelsome, clever at making a living, but in other
ways an unlucky bird. The bird called sitta is quarrelsome, but
clever and tidy, makes its living with ease, and for its
knowingness is regarded as uncanny; it has a numerous brood,
of which it is fond, and lives by pecking the bark of trees. The
aegolius-owl flies by night, is seldom seen by day; like others we
have mentioned, it lives on cliffs or in caverns; it feeds on two
kinds of food; it has a strong hold on life and is full of resource.
The tree-creeper is a little bird, of fearless disposition; it lives
among trees, feeds on caterpillars, makes a living with ease, and
has a loud clear note. The acanthis finds its food with difficulty;
its plumage is poor, but its note is musical.
1746
18
Of the herons, the ashen-coloured one, as has been said, unites
with the female not without pain; it is full of resource, carries
its food with it, is eager in the quest of it, and works by day; its
plumage is poor, and its excrement is always wet. Of the other
two species - for there are three in all - the white heron has
handsome plumage, unites without harm to itself with the
female, builds a nest and lays its eggs neatly in trees; it
frequents marshes and lakes and Plains and meadow land. The
speckled heron, which is nicknamed 'the skulker', is said in
folklore stories to be of servile origin, and, as its nickname
implies, it is the laziest bird of the three species. Such are the
habits of herons. The bird that is called the poynx has this
peculiarity, that it is more prone than any other bird to peck at
the eyes of an assailant or its prey; it is at war with the harpy, as
the two birds live on the same food.
19
There are two kinds of owsels; the one is black, and is found
everywhere, the other is quite white, about the same size as the
other, and with the same pipe. This latter is found on Cyllene in
Arcadia, and is found nowhere else. The laius, or blue-thrush, is
like the black owsel, only a little smaller; it lives on cliffs or on
tile roofings; it has not a red beak as the black owsel has.
1747
20
Of thrushes there are three species. One is the misselthrush; it
feeds only on mistletoe and resin; it is about the size of the jay.
A second is the song-thrush; it has a sharp pipe, and is about
the size of the owsel. There is another species called the Illas; it
is the smallest species of the three, and is less variegated in
plumage than the others.
21
There is a bird that lives on rocks, called the blue-bird from its
colour. It is comparatively common in Nisyros, and is somewhat
less than the owsel and a little bigger than the chaffinch. It has
large claws, and climbs on the face of the rocks. It is steel-blue
all over; its beak is long and slender; its legs are short, like those
of the woodpecker.
22
The oriole is yellow all over; it is not visible during winter, but
puts in an appearance about the time of the summer solstice,
and departs again at the rising of Arcturus; it is the size of the
turtle-dove. The so-called soft-head (or shrike) always settles on
one and the same branch, where it falls a prey to the
birdcatcher. Its head is big, and composed of gristle; it is a little
smaller than the thrush; its beak is strong, small, and round; it
is ashen-coloured all over; is fleet of foot, but slow of wing. The
bird-catcher usually catches it by help of the owl.
1748
23
There is also the pardalus. As a rule, it is seen in flocks and not
singly; it is ashen-coloured all over, and about the size of the
birds last described; it is fleet of foot and strong of wing, and its
pipe is loud and high-pitched. The collyrion (or fieldfare) feeds
on the same food as the owsel; is of the same size as the above
mentioned birds; and is trapped usually in the winter. All these
birds are found at all times. Further, there are the birds that live
as a rule in towns, the raven and the crow. These also are visible
at all seasons, never shift their place of abode, and never go into
winter quarters.
24
Of daws there are three species. One is the chough; it is as large
as the crow, but has a red beak. There is another, called the
'wolf; and further there is the little daw, called the 'railer'. There
is another kind of daw found in Lybia and Phrygia, which is
web-footed.
25
Of larks there are two kinds. One lives on the ground and has a
crest on its head; the other is gregarious, and not sporadic like
1749
the first; it is, however, of the same coloured plumage, but is
smaller, and has no crest; it is an article of human food.
26
The woodcock is caught with nets in gardens. It is about the
size of a barn-door hen; it has a long beak, and in plumage is
like the francolin-partridge. It runs quickly, and is pretty easily
domesticated. The starling is speckled; it is of the same size as
the owsel.
27
Of the Egyptian ibis there are two kinds, the white and the
black. The white ones are found over Egypt, excepting in
Pelusium; the black ones are found in Pelusium, and nowhere
else in Egypt.
28
Of the little horned owls there are two kinds, and one is visible
at all seasons, and for that reason has the nickname of 'all-the-
year-round owl'; it is not sufficiently palatable to come to table;
another species makes its appearance sometimes in the
autumn, is seen for a single day or at the most for two days, and
is regarded as a table delicacy; it scarcely differs from the first
species save only in being fatter; it has no note, but the other
1750
species has. With regard to their origin, nothing is known from
ocular observation; the only fact known for certain is that they
are first seen when a west wind is blowing.
29
The cuckoo, as has been said elsewhere, makes no nest, but
deposits its eggs in an alien nest, generally in the nest of the
ring-dove, or on the ground in the nest of the hypolais or lark, or
on a tree in the nest of the green linnet, it lays only one egg and
does not hatch it itself, but the mother-bird in whose nest it has
deposited it hatches and rears it; and, as they say, this mother
bird, when the young cuckoo has grown big, thrusts her own
brood out of the nest and lets them perish; others say that this
mother-bird kills her own brood and gives them to the alien to
devour, despising her own young owing to the beauty of the
cuckoo. Personal observers agree in telling most of these stories,
but are not in agreement as to the instruction of the young.
Some say that the mother-cuckoo comes and devours the brood
of the rearing mother; others say that the young cuckoo from its
superior size snaps up the food brought before the smaller
brood have a chance, and that in consequence the smaller
brood die of hunger; others say that, by its superior strength, it
actually kills the other ones whilst it is being reared up with
them. The cuckoo shows great sagacity in the disposal of its
progeny; the fact is, the mother cuckoo is quite conscious of her
own cowardice and of the fact that she could never help her
young one in an emergency, and so, for the security of the
young one, she makes of him a supposititious child in an alien
nest. The truth is, this bird is pre-eminent among birds in the
way of cowardice; it allows itself to be pecked at by little birds,
and flies away from their attacks.
1751
30
It has already been stated that the footless bird, which some
term the cypselus, resembles the swallow; indeed, it is not easy
to distinguish between the two birds, excepting in the fact that
the cypselus has feathers on the shank. These birds rear their
young in long cells made of mud, and furnished with a hole just
big enough for entry and exit; they build under cover of some
roofing - under a rock or in a cavern - for protection against
animals and men.
The so-called goat-sucker lives on mountains; it is a little larger
than the owsel, and less than the cuckoo; it lays two eggs, or
three at the most, and is of a sluggish disposition. It flies up to
the she-goat and sucks its milk, from which habit it derives its
name; it is said that, after it has sucked the teat of the animal,
the teat dries up and the animal goes blind. It is dim-sighted in
the day-time, but sees well enough by night.
31
In narrow circumscribed districts where the food would be
insufficient for more birds than two, ravens are only found in
isolated pairs; when their young are old enough to fly, the
parent couple first eject them from the nest, and by and by
chase them from the neighbourhood. The raven lays four or five
eggs. About the time when the mercenaries under Medius were
slaughtered at Pharsalus, the districts about Athens and the
Peloponnese were left destitute of ravens, from which it would
1752
appear that these birds have some means of
intercommunicating with one another.
32
Of eagles there are several species. One of them, called 'the
white-tailed eagle', is found on low lands, in groves, and in the
neighbourhood of cities; some call it the 'heron-killer'. It is bold
enough to fly to mountains and the interior of forests. The other
eagles seldom visit groves or low-lying land. There is another
species called the 'plangus'; it ranks second in point of size and
strength; it lives in mountain combes and glens, and by marshy
lakes, and goes by the name of 'duck-killer' and 'swart-eagle.' It
is mentioned by Homer in his account of the visit made by
Priam to the tent of Achilles. There is another species with black
Plumage, the smallest but boldest of all the kinds. It dwells on
mountains or in forests, and is called 'the black-eagle' or 'the
hare-killer'; it is the only eagle that rears its young and
thoroughly takes them out with it. It is swift of flight, is neat
and tidy in its habits, too proud for jealousy, fearless,
quarrelsome; it is also silent, for it neither whimpers nor
screams. There is another species, the percnopterus, very large,
with white head, very short wings, long tail-feathers, in
appearance like a vulture. It goes by the name of 'mountain-
stork' or 'half-eagle'. It lives in groves; has all the bad qualities
of the other species, and none of the good ones; for it lets itself
be chased and caught by the raven and the other birds. It is
clumsy in its movements, has difficulty in procuring its food,
preys on dead animals, is always hungry, and at all times
whining and screaming. There is another species, called the
'sea-eagle' or 'osprey'. This bird has a large thick neck, curved
wings, and broad tailfeathers; it lives near the sea, grasps its
1753
prey with its talons, and often, from inability to carry it, tumbles
down into the water. There is another species called the 'true-
bred'; people say that these are the only true-bred birds to be
found, that all other birds - eagles, hawks, and the smallest
birds - are all spoilt by the interbreeding of different species.
The true-bred eagle is the largest of all eagles; it is larger than
the phene; is half as large again as the ordinary eagle, and has
yellow plumage; it is seldom seen, as is the case with the so-
called cymindis. The time for an eagle to be on the wing in
search of prey is from midday to evening; in the morning until
the market-hour it remains on the nest. In old age the upper
beak of the eagle grows gradually longer and more crooked, and
the bird dies eventually of starvation; there is a folklore story
that the eagle is thus punished because it once was a man and
refused entertainment to a stranger. The eagle puts aside its
superfluous food for its young; for owing to the difficulty in
procuring food day by day, it at times may come back to the nest
with nothing. If it catch a man prowling about in the
neighbourhood of its nest, it will strike him with its wings and
scratch him with its talons. The nest is built not on low ground
but on an elevated spot, generally on an inaccessible ledge of a
cliff; it does, however, build upon a tree. The young are fed until
they can fly; hereupon the parent-birds topple them out of the
nest, and chase them completely out of the locality. The fact is
that a pair of eagles demands an extensive space for its
maintenance, and consequently cannot allow other birds to
quarter themselves in close neighbourhood. They do not hunt in
the vicinity of their nest, but go to a great distance to find their
prey. When the eagle has captured a beast, it puts it down
without attempting to carry it off at once; if on trial it finds the
burden too heavy, it will leave it. When it has spied a hare, it
does not swoop on it at once, but lets it go on into the open
ground; neither does it descend to the ground at one swoop, but
goes gradually down from higher flights to lower and lower:
1754
these devices it adopts by way of security against the stratagem
of the hunter. It alights on high places by reason of the difficulty
it experiences in soaring up from the level ground; it flies high
in the air to have the more extensive view; from its high flight it
is said to be the only bird that resembles the gods. Birds of prey,
as a rule, seldom alight upon rock, as the crookedness of their
talons prevents a stable footing on hard stone. The eagle hunts
hares, fawns, foxes, and in general all such animals as he can
master with ease. It is a long-lived bird, and this fact might be
inferred from the length of time during which the same nest is
maintained in its place.
33
In Scythia there is found a bird as large as the great bustard. The
female lays two eggs, but does not hatch them, but hides them
in the skin of a hare or fox and leaves them there, and, when it
is not in quest of prey, it keeps a watch on them on a high tree;
if any man tries to climb the tree, it fights and strikes him with
its wing, just as eagles do.
34
The owl and the night-raven and all the birds see poorly in the
daytime seek their prey in the night, but not all the night
through, but at evening and dawn. Their food consists of mice,
lizards, chafers and the like little creatures. The so-called phene,
or lammergeier, is fond of its young, provides its food with ease,
fetches food to its nest, and is of a kindly disposition. It rears its
1755
own young and those of the eagle as well; for when the eagle
ejects its young from the nest, this bird catches them up as they
fall and feeds them. For the eagle, by the way, ejects the young
birds prematurely, before they are able to feed themselves, or to
fly. It appears to do so from jealousy; for it is by nature jealous,
and is so ravenous as to grab furiously at its food; and when it
does grab at its food, it grabs it in large morsels. It is accordingly
jealous of the young birds as they approach maturity, since they
are getting good appetites, and so it scratches them with its
talons. The young birds fight also with one another, to secure a
morsel of food or a comfortable position, whereupon the
mother-bird beats them and ejects them from the nest; the
young ones scream at this treatment, and the phene hearing
them catches them as they fall. The phene has a film over its
eyes and sees badly, but the sea-eagle is very keen-sighted, and
before its young are fledged tries to make them stare at the sun,
and beats the one that refuses to do so, and twists him back in
the sun's direction; and if one of them gets watery eyes in the
process, it kills him, and rears the other. It lives near the sea,
and feeds, as has been said, on sea-birds; when in pursuit of
them it catches them one by one, watching the moment when
the bird rises to the surface from its dive. When a sea-bird,
emerging from the water, sees the sea-eagle, he in terror dives
under, intending to rise again elsewhere; the eagle, however,
owing to its keenness of vision, keeps flying after him until he
either drowns the bird or catches him on the surface. The eagle
never attacks these birds when they are in a swarm, for they
keep him off by raising a shower of water-drops with their
wings.
1756
35
The cepphus is caught by means of sea-foam; the bird snaps at
the foam, and consequently fishermen catch it by sluicing with
showers of sea-water. These birds grow to be plump and fat;
their flesh has a good odour, excepting the hinder quarters,
which smell of shoreweed.
36
Of hawks, the strongest is the buzzard; the next in point of
courage is the merlin; and the circus ranks third; other diverse
kinds are the asterias, the pigeon-hawk, and the pternis; the
broaded-winged hawk is called the half-buzzard; others go by
the name of hobby-hawk, or sparrow-hawk, or 'smooth-
feathered', or 'toad-catcher'. Birds of this latter species find
their food with very little difficulty, and flutter along the ground.
Some say that there are ten species of hawks, all differing from
one another. One hawk, they say, will strike and grab the pigeon
as it rests on the ground, but never touch it while it is in flight;
another hawk attacks the pigeon when it is perched upon a tree
or any elevation, but never touches it when it is on the ground
or on the wing; other hawks attack their prey only when it is on
the wing. They say that pigeons can distinguish the various
species: so that, when a hawk is an assailant, if it be one that
attacks its prey when the prey is on the wing, the pigeon will sit
still; if it be one that attacks sitting prey, the pigeon will rise up
and fly away.
In Thrace, in the district sometimes called that of Cedripolis,
men hunt for little birds in the marshes with the aid of hawks.
The men with sticks in their hands go beating at the reeds and
brushwood to frighten the birds out, and the hawks show
1757
themselves overhead and frighten them down. The men then
strike them with their sticks and capture them. They give a
portion of their booty to the hawks; that is, they throw some of
the birds up in the air, and the hawks catch them.
In the neighbourhood of Lake Maeotis, it is said, wolves act in
concert with the fishermen, and if the fishermen decline to
share with them, they tear their nets in pieces as they lie drying
on the shore of the lake.
37
So much for the habits of birds.
In marine creatures, also, one In marine creatures, also, one
may observe many ingenious devices adapted to the
circumstances of their lives. For the accounts commonly given
of the so-called fishing-frog are quite true; as are also those
given of the torpedo. The fishing- frog has a set of filaments that
project in front of its eyes; they are long and thin like hairs, and
are round at the tips; they lie on either side, and are used as
baits. Accordingly, when the animal stirs up a place full of sand
and mud and conceals itself therein, it raises the filaments, and,
when the little fish strike against them, it draws them in
underneath into its mouth. The torpedo narcotizes the
creatures that it wants to catch, overpowering them by the
power of shock that is resident in its body, and feeds upon
them; it also hides in the sand and mud, and catches all the
creatures that swim in its way and come under its narcotizing
influence. This phenomenon has been actually observed in
operation. The sting-ray also conceals itself, but not exactly in
the same way. That the creatures get their living by this means
is obvious from the fact that, whereas they are peculiarly
1758
inactive, they are often caught with mullets in their interior, the
swiftest of fishes. Furthermore, the fishing-frog is unusually
thin when he is caught after losing the tips of his filaments, and
the torpedo is known to cause a numbness even in human
beings. Again, the hake, the ray, the flat-fish, and the angelfish
burrow in the sand, and after concealing themselves angle with
the filaments on their mouths, that fishermen call their fishing-
rods, and the little creatures on which they feed swim up to the
filaments taking them for bits of sea-weed, such as they feed
upon.
Wherever an anthias-fish is seen, there will be no dangerous
creatures in the vicinity, and sponge-divers will dive in security,
and they call these signal-fishes 'holy-fish'. It is a sort of
perpetual coincidence, like the fact that wherever snails are
present you may be sure there is neither pig nor partridge in the
neighbourhood; for both pig and partridge eat up the snails.
The sea-serpent resembles the conger in colour and shape, but
is of lesser bulk and more rapid in its movements. If it be caught
and thrown away, it will bore a hole with its snout and burrow
rapidly in the sand; its snout, by the way, is sharper than that of
ordinary serpents. The so-called sea-scolopendra, after
swallowing the hook, turns itself inside out until it ejects it, and
then it again turns itself outside in. The sea-scolopendra, like
the land-scolopendra, will come to a savoury bait; the creature
does not bite with its teeth, but stings by contact with its entire
body, like the so-called sea-nettle. The so-called fox-shark,
when it finds it has swallowed the hook, tries to get rid of it as
the scolopendra does, but not in the same way; in other words,
it runs up the fishing-line, and bites it off short; it is caught in
some districts in deep and rapid waters, with night-lines.
The bonitos swarm together when they espy a dangerous
creature, and the largest of them swim round it, and if it
1759
touches one of the shoal they try to repel it; they have strong
teeth. Amongst other large fish, a lamia-shark, after falling in
amongst a shoal, has been seen to be covered with wounds.
Of river-fish, the male of the sheat-fish is remarkably attentive
to the young. The female after parturition goes away; the male
stays and keeps on guard where the spawn is most abundant,
contenting himself with keeping off all other little fishes that
might steal the spawn or fry, and this he does for forty or fifty
days, until the young are sufficiently grown to make away from
the other fishes for themselves. The fishermen can tell where
he is on guard: for, in warding off the little fishes, he makes a
rush in the water and gives utterance to a kind of muttering
noise. He is so earnest in the performance of his parental duties
that the fishermen at times, if the eggs be attached to the roots
of water-plants deep in the water, drag them into as shallow a
place as possible; the male fish will still keep by the young, and,
if it so happen, will be caught by the hook when snapping at the
little fish that come by; if, however, he be sensible by experience
of the danger of the hook, he will still keep by his charge, and
with his extremely strong teeth will bite the hook in pieces.
All fishes, both those that wander about and those that are
stationary, occupy the districts where they were born or very
similar places, for their natural food is found there. Carnivorous
fish wander most; and all fish are carnivorous with the
exception of a few, such as the mullet, the saupe, the red mullet,
and the chalcis. The so-called pholis gives out a mucous
discharge, which envelops the creature in a kind of nest. Of
shell-fish, and fish that are finless, the scallop moves with
greatest force and to the greatest distance, impelled along by
some internal energy; the murex or purple-fish, and others that
resemble it, move hardly at all. Out of the lagoon of Pyrrha all
the fishes swim in winter-time, except the sea-gudgeon; they
swim out owing to the cold, for the narrow waters are colder
1760
than the outer sea, and on the return of the early summer they
all swim back again. In the lagoon no scarus is found, nor
thritta, nor any other species of the spiny fish, no spotted
dogfish, no spiny dogfish, no sea-crawfish, no octopus either of
the common or the musky kinds, and certain other fish are also
absent; but of fish that are found in the lagoon the white
gudgeon is not a marine fish. Of fishes the oviparous are in their
prime in the early summer until the spawning time; the
viviparous in the autumn, as is also the case with the mullet,
the red mullet, and all such fish. In the neighbourhood of
Lesbos, the fishes of the outer sea, or of the lagoon, bring forth
their eggs or young in the lagoon; sexual union takes place in
the autumn, and parturition in the spring. With fishes of the
cartilaginous kind, the males and females swarm together in
the autumn for the sake of sexual union; in the early summer
they come swimming in, and keep apart until after parturition;
the two sexes are often taken linked together in sexual union.
Of molluscs the sepia is the most cunning, and is the only
species that employs its dark liquid for the sake of concealment
as well as from fear: the octopus and calamary make the
discharge solely from fear. These creatures never discharge the
pigment in its entirety; and after a discharge the pigment
accumulates again. The sepia, as has been said, often uses its
colouring pigment for concealment; it shows itself in front of
the pigment and then retreats back into it; it also hunts with its
long tentacles not only little fishes, but oftentimes even mullets.
The octopus is a stupid creature, for it will approach a man's
hand if it be lowered in the water; but it is neat and thrifty in its
habits: that is, it lays up stores in its nest, and, after eating up
all that is eatable, it ejects the shells and sheaths of crabs and
shell-fish, and the skeletons of little fishes. It seeks its prey by
so changing its colour as to render it like the colour of the
stones adjacent to it; it does so also when alarmed. By some the
sepia is said to perform the same trick; that is, they say it can
1761
change its colour so as to make it resemble the colour of its
habitat. The only fish that can do this is the angelfish, that is, it
can change its colour like the octopus. The octopus as a rule
does not live the year out. It has a natural tendency to run off
into liquid; for, if beaten and squeezed, it keeps losing
substance and at last disappears. The female after parturition is
peculiarly subject to this colliquefaction; it becomes stupid; if
tossed about by waves, it submits impassively; a man, if he
dived, could catch it with the hand; it gets covered over with
slime, and makes no effort to catch its wonted prey. The male
becomes leathery and clammy. As a proof that they do not live
into a second year there is the fact that, after the birth of the
little octopuses in the late summer or beginning of autumn, it is
seldom that a large-sized octopus is visible, whereas a little
before this time of year the creature is at its largest. After the
eggs are laid, they say that both the male and the female grow
so old and feeble that they are preyed upon by little fish, and
with ease dragged from their holes; and that this could not have
been done previously; they say also that this is not the case
with the small and young octopus, but that the young creature
is much stronger than the grown-up one. Neither does the sepia
live into a second year. The octopus is the only mollusc that
ventures on to dry land; it walks by preference on rough ground;
it is firm all over when you squeeze it, excepting in the neck. So
much for the mollusca.
It is also said that they make a thin rough shell about them like
a hard sheath, and that this is made larger and larger as the
animal grows larger, and that it comes out of the sheath as
though out of a den or dwelling place.
The nautilus (or argonaut) is a poulpe or octopus, but one
peculiar both in its nature and its habits. It rises up from deep
water and swims on the surface; it rises with its shell down-
turned in order that it may rise the more easily and swim with
1762
it empty, but after reaching the surface it shifts the position of
the shell. In between its feelers it has a certain amount of web-
growth, resembling the substance between the toes of web-
footed birds; only that with these latter the substance is thick,
while with the nautilus it is thin and like a spider's web. It uses
this structure, when a breeze is blowing, for a sail, and lets
down some of its feelers alongside as rudder-oars. If it be
frightened it fills its shell with water and sinks. With regard to
the mode of generation and the growth of the shell knowledge
from observation is not yet satisfactory; the shell, however, does
not appear to be there from the beginning, but to grow in their
cases as in that of other shell-fish; neither is it ascertained for
certain whether the animal can live when stripped of the shell.
38
Of all insects, one may also say of all living creatures, the most
industrious are the ant, the bee, the hornet, the wasp, and in
point of fact all creatures akin to these; of spiders some are
more skilful and more resourceful than others. The way in
which ants work is open to ordinary observation; how they all
march one after the other when they are engaged in putting
away and storing up their food; all this may be seen, for they
carry on their work even during bright moonlight nights.
39
Of spiders and phalangia there are many species. Of the
venomous phalangia there are two; one that resembles the so-
1763
called wolf-spider, small, speckled, and tapering to a point; it
moves with leaps, from which habit it is nicknamed 'the flea':
the other kind is large, black in colour, with long front legs; it is
heavy in its movements, walks slowly, is not very strong, and
never leaps. (Of all the other species wherewith poison-vendors
supply themselves, some give a weak bite, and others never bite
at all. There is another kind, comprising the so-called wolf-
spiders.) Of these spiders the small one weaves no web, and the
large weaves a rude and poorly built one on the ground or on
dry stone walls. It always builds its web over hollow places
inside of which it keeps a watch on the end-threads, until some
creature gets into the web and begins to struggle, when out the
spider pounces. The speckled kind makes a little shabby web
under trees.
There is a third species of this animal, preeminently clever and
artistic. It first weaves a thread stretching to all the exterior
ends of the future web; then from the centre, which it hits upon
with great accuracy, it stretches the warp; on the warp it puts
what corresponds to the woof, and then weaves the whole
together. It sleeps and stores its food away from the centre, but
it is at the centre that it keeps watch for its prey. Then, when
any creature touches the web and the centre is set in motion, it
first ties and wraps the creature round with threads until it
renders it helpless, then lifts it and carries it off, and, if it
happens to be hungry, sucks out the life-juices - for that is the
way it feeds; but, if it be not hungry, it first mends any damage
done and then hastens again to its quest of prey. If something
comes meanwhile into the net, the spider at first makes for the
centre, and then goes back to its entangled prey as from a fixed
starting point. If any one injures a portion of the web, it
recommences weaving at sunrise or at sunset, because it is
chiefly at these periods that creatures are caught in the web. It
is the female that does the weaving and the hunting, but the
male takes a share of the booty captured.
1764
Of the skilful spiders, weaving a substantial web, there are two
kinds, the larger and the smaller. The one has long legs and
keeps watch while swinging downwards from the web: from its
large size it cannot easily conceal itself, and so it keeps
underneath, so that its prey may not be frightened off, but may
strike upon the web's upper surface; the less awkwardly formed
one lies in wait on the top, using a little hole for a lurking-place.
Spiders can spin webs from the time of their birth, not from
their interior as a superfluity or excretion, as Democritus avers,
but off their body as a kind of tree-bark, like the creatures that
shoot out with their hair, as for instance the porcupine. The
creature can attack animals larger than itself, and enwrap them
with its threads: in other words, it will attack a small lizard, run
round and draw threads about its mouth until it closes the
mouth up; then it comes up and bites it.
40
So much for the spider. Of insects, there is a genus that has no
one name that comprehends all the species, though all the
species are akin to one another in form; it consists of all the
insects that construct a honeycomb: to wit, the bee, and all the
insects that resemble it in form.
There are nine varieties, of which six are gregarious - the bee,
the king-bee, the drone bee, the annual wasp, and, furthermore,
the anthrene (or hornet), and the tenthredo (or ground-wasp);
three are solitary - the smaller siren, of a dun colour, the larger
siren, black and speckled, and the third, the largest of all, that is
called the humble-bee. Now ants never go a-hunting, but gather
up what is ready to hand; the spider makes nothing, and lays up
no store, but simply goes a-hunting for its food; while the bee -
1765
for we shall by and by treat of the nine varieties - does not go a-
hunting, but constructs its food out of gathered material and
stores it away, for honey is the bee's food. This fact is shown by
the beekeepers' attempt to remove the combs; for the bees,
when they are fumigated, and are suffering great distress from
the process, then devour the honey most ravenously, whereas at
other times they are never observed to be so greedy, but
apparently are thrifty and disposed to lay by for their future
sustenance. They have also another food which is called bee-
bread; this is scarcer than honey and has a sweet figlike taste;
this they carry as they do the wax on their legs.
Very remarkable diversity is observed in their methods of
working and their general habits. When the hive has been
delivered to them clean and empty, they build their waxen cells,
bringing in the juice of all kinds of flowers and the 'tears' or
exuding sap of trees, such as willows and elms and such others
as are particularly given to the exudation of gum. With this
material they besmear the groundwork, to provide against
attacks of other creatures; the bee-keepers call this stuff 'stop-
wax'. They also with the same material narrow by side-building
the entrances to the hive if they are too wide. They first build
cells for themselves; then for the so-called kings and the
drones; for themselves they are always building, for the kings
only when the brood of young is numerous, and cells for the
drones they build if a superabundance of honey should suggest
their doing so. They build the royal cells next to their own, and
they are of small bulk; the drones' cells they build near by, and
these latter are less in bulk than the bee's cells.
They begin building the combs downwards from the top of the
hive, and go down and down building many combs connected
together until they reach the bottom. The cells, both those for
the honey and those also for the grubs, are double-doored; for
two cells are ranged about a single base, one pointing one way
1766
and one the other, after the manner of a double (or hour-glass-
shaped) goblet. The cells that lie at the commencement of the
combs and are attached to the hives, to the extent of two or
three concentric circular rows, are small and devoid of honey;
the cells that are well filled with honey are most thoroughly
luted with wax. At the entry to the hive the aperture of the
doorway is smeared with mitys; this substance is a deep black,
and is a sort of dross or residual by-product of wax; it has a
pungent odour, and is a cure for bruises and suppurating sores.
The greasy stuff that comes next is pitch-wax; it has a less
pungent odour and is less medicinal than the mitys. Some say
that the drones construct combs by themselves in the same
hive and in the same comb that they share with the bees; but
that they make no honey, but subsist, they and their grubs also,
on the honey made by the bees. The drones, as a rule, keep
inside the hive; when they go out of doors, they soar up in the
air in a stream, whirling round and round in a kind of
gymnastic exercise; when this is over, they come inside the hive
and feed to repletion ravenously. The kings never quit the hive,
except in conjunction with the entire swarm, either for food or
for any other reason. They say that, if a young swarm go astray,
it will turn back upon its route and by the aid of scent seek out
its leader. It is said that if he is unable to fly he is carried by the
swarm, and that if he dies the swarm perishes; and that, if this
swarm outlives the king for a while and constructs combs, no
honey is produced and the bees soon die out.
Bees scramble up the stalks of flowers and rapidly gather the
bees-wax with their front legs; the front legs wipe it off on to
the middle legs, and these pass it on to the hollow curves of the
hind-legs; when thus laden, they fly away home, and one may
see plainly that their load is a heavy one. On each expedition
the bee does not fly from a flower of one kind to a flower of
another, but flies from one violet, say, to another violet, and
never meddles with another flower until it has got back to the
1767
hive; on reaching the hive they throw off their load, and each
bee on his return is accompanied by three or four companions.
One cannot well tell what is the substance they gather, nor the
exact process of their work. Their mode of gathering wax has
been observed on olive-trees, as owing to the thickness of the
leaves the bees remain stationary for a considerable while. After
this work is over, they attend to the grubs. There is nothing to
prevent grubs, honey, and drones being all found in one and the
same comb. As long as the leader is alive, the drones are said to
be produced apart by themselves; if he be no longer living, they
are said to be reared by the bees in their own cells, and under
these circumstances to become more spirited: for this reason
they are called 'sting-drones', not that they really have stings,
but that they have the wish without the power, to use such
weapons. The cells for the drones are larger than the others;
sometimes the bees construct cells for the drones apart, but
usually they put them in amongst their own; and when this is
the case the bee-keepers cut the drone-cells out of the combs.
There are several species of bees, as has been said; two of
'kings', the better kind red, the other black and variegated, and
twice as big as the working-bee. The best workingbee is small,
round, and speckled: another kind is long and like an anthrene
wasp; another kind is what is called the robber-bee, black and
flat-bellied; then there is the drone, the largest of all, but devoid
of sting, and lazy. There is a difference between the progeny of
bees that inhabit cultivated land and of those from the
mountains: the forest-bees are more shaggy, smaller, more
industrious and more fierce. Working-bees make their combs all
even, with the superficial covering quite smooth. Each comb is
of one kind only: that is, it contains either bees only, or grubs
only, or drones only; if it happen, however, that they make in
one and the same comb all these kinds of cells, each separate
kind will be built in a continuous row right through. The long
bees build uneven combs, with the lids of the cells protuberant,
1768
like those of the anthrene; grubs and everything else have no
fixed places, but are put anywhere; from these bees come
inferior kings, a large quantity of drones, and the so-called
robber-bee; they produce either no honey at all, or honey in very
small quantities. Bees brood over the combs and so mature
them; if they fail to do so, the combs are said to go bad and to
get covered with a sort of spider's web. If they can keep
brooding over the part undamaged, the damaged part simply
eats itself away; if they cannot so brood, the entire comb
perishes; in the damaged combs small worms are engendered,
which take on wings and fly away. When the combs keep
settling down, the bees restore the level surface, and put props
underneath the combs to give themselves free passage-room;
for if such free passage be lacking they cannot brood, and the
cobwebs come on. When the robber-bee and the drone appear,
not only do they do no work themselves, but they actually
damage the work of the other bees; if they are caught in the act,
they are killed by the working-bees. These bees also kill without
mercy most of their kings, and especially kings of the inferior
sort; and this they do for fear a multiplicity of kings should lead
to a dismemberment of the hive. They kill them especially when
the hive is deficient in grubs, and a swarm is not intended to
take place; under these circumstances they destroy the cells of
the kings if they have been prepared, on the ground that these
kings are always ready to lead out swarms. They destroy also
the combs of the drones if a failure in the supply be threatening
and the hive runs short of provisions; under such circumstances
they fight desperately with all who try to take their honey, and
eject from the hive all the resident drones; and oftentimes the
drones are to be seen sitting apart in the hive. The little bees
fight vigorously with the long kind, and try to banish them from
the hives; if they succeed, the hive will be unusually productive,
but if the bigger bees get left mistresses of the field they pass
the time in idleness, and no good at all but die out before the
1769
autumn. Whenever the working-bees kill an enemy they try to
do so out of doors; and whenever one of their own body dies,
they carry the dead bee out of doors also. The so-called robber-
bees spoil their own combs, and, if they can do so unnoticed,
enter and spoil the combs of other bees; if they are caught in
the act they are put to death. It is no easy task for them to
escape detection, for there are sentinels on guard at every entry;
and, even if they do escape detection on entering, afterwards
from a surfeit of food they cannot fly, but go rolling about in
front of the hive, so that their chances of escape are small
indeed. The kings are never themselves seen outside the hive
except with a swarm in flight: during which time all the other
bees cluster around them. When the flight of a swarm is
imminent, a monotonous and quite peculiar sound made by all
the bees is heard for several days, and for two or three days in
advance a few bees are seen flying round the hive; it has never
as yet been ascertained, owing to the difficulty of the
observation, whether or no the king is among these. When they
have swarmed, they fly away and separate off to each of the
kings; if a small swarm happens to settle near to a large one, it
will shift to join this large one, and if the king whom they have
abandoned follows them, they put him to death. So much for
the quitting of the hive and the swarmflight. Separate
detachments of bees are told off for diverse operations; that is,
some carry flower-produce, others carry water, others smooth
and arrange the combs. A bee carries water when it is rearing
grubs. No bee ever settles on the flesh of any creature, or ever
eats animal food. They have no fixed date for commencing
work; but when their provender is forthcoming and they are in
comfortable trim, and by preference in summer, they set to
work, and when the weather is fine they work incessantly.
The bee, when quite young and in fact only three days old, after
shedding its chrysalis-case, begins to work if it be well fed.
When a swarm is settling, some bees detach themselves in
1770
search of food and return back to the swarm. In hives that are in
good condition the production of young bees is discontinued
only for the forty days that follow the winter solstice. When the
grubs are grown, the bees put food beside them and cover them
with a coating of wax; and, as soon as the grub is strong
enough, he of his own accord breaks the lid and comes out.
Creatures that make their appearance in hives and spoil the
combs the working-bees clear out, but the other bees from
sheer laziness look with indifference on damage done to their
produce. When the bee-masters take out the combs, they leave
enough food behind for winter use; if it be sufficient in quantity,
the occupants of the hive will survive; if it be insufficient, then,
if the weather be rough, they die on the spot, but if it be fair,
they fly away and desert the hive. They feed on honey summer
and winter; but they store up another article of food resembling
wax in hardness, which by some is called sandarace, or bee-
bread. Their worst enemies are wasps and the birds named
titmice, and furthermore the swallow and the bee-eater. The
frogs in the marsh also catch them if they come in their way by
the water-side, and for this reason bee-keepers chase the frogs
from the ponds from which the bees take water; they destroy
also wasps' nests, and the nests of swallows, in the
neighbourhood of the hives, and also the nests of bee-eaters.
Bees have fear only of one another. They fight with one another
and with wasps. Away from the hive they attack neither their
own species nor any other creature, but in the close proximity
of the hive they kill whatever they get hold of. Bees that sting
die from their inability to extract the sting without at the same
time extracting their intestines. True, they often recover, if the
person stung takes the trouble to press the sting out; but once it
loses its sting the bee must die. They can kill with their stings
even large animals; in fact, a horse has been known to have
been stung to death by them. The kings are the least disposed to
show anger or to inflict a sting. Bees that die are removed from
1771
the hive, and in every way the creature is remarkable for its
cleanly habits; in point of fact, they often fly away to a distance
to void their excrement because it is malodorous; and, as has
been said, they are annoyed by all bad smells and by the scent
of perfumes, so much so that they sting people that use
perfumes.
They perish from a number of accidental causes, and when
their kings become too numerous and try each to carry away a
portion of the swarm.
The toad also feeds on bees; he comes to the doorway of the
hive, puffs himself out as he sits on the watch, and devours the
creatures as they come flying out; the bees can in no way
retaliate, but the bee-keeper makes a point of killing him.
As for the class of bee that has been spoken of as inferior or
good-for-nothing, and as constructing its combs so roughly,
some bee-keepers say that it is the young bees that act so from
inexperience; and the bees of the current year are termed
young. The young bees do not sting as the others do; and it is
for this reason that swarms may be safely carried, as it is of
young bees that they are composed. When honey runs short
they expel the drones, and the bee-keepers supply the bees with
figs and sweet-tasting articles of food. The elder bees do the
indoor work, and are rough and hairy from staying indoors; the
young bees do the outer carrying, and are comparatively
smooth. They kill the drones also when in their work they are
confined for room; the drones, by the way, live in the innermost
recess of the hive. On one occasion, when a hive was in a poor
condition, some of the occupants assailed a foreign hive;
proving victorious in a combat they took to carrying off the
honey; when the bee-keeper tried to kill them, the other bees
came out and tried to beat off the enemy but made no attempt
to sting the man.
1772
The diseases that chiefly attack prosperous hives are first of all
the clerus-this consists in a growth of little worms on the floor,
from which, as they develop, a kind of cobweb grows over the
entire hive, and the combs decay; another diseased condition is
indicated in a lassitude on the part of the bees and in
malodorousness of the hive. Bees feed on thyme; and the white
thyme is better than the red. In summer the place for the hive
should be cool, and in winter warm. They are very apt to fall
sick if the plant they are at work on be mildewed. In a high wind
they carry a stone by way of ballast to steady them. If a stream
be near at hand, they drink from it and from it only, but before
they drink they first deposit their load; if there be no water near
at hand, they disgorge their honey as they drink elsewhere, and
at once make off to work. There are two seasons for making
honey, spring and autumn; the spring honey is sweeter, whiter,
and in every way better than the autumn honey. Superior honey
comes from fresh comb, and from young shoots; the red honey
is inferior, and owes its inferiority to the comb in which it is
deposited, just as wine is apt to be spoiled by its cask;
consequently, one should have it looked to and dried. When the
thyme is in flower and the comb is full, the honey does not
harden. The honey that is golden in hue is excellent. White
honey does not come from thyme pure and simple; it is good as
a salve for sore eyes and wounds. Poor honey always floats on
the surface and should be skimmed off; the fine clear honey
rests below. When the floral world is in full bloom, then they
make wax; consequently you must then take the wax out of the
hive, for they go to work on new wax at once. The flowers from
which they gather honey are as follows: the spindle-tree, the
melilot-clover, king's-spear, myrtle, flowering-reed, withy, and
broom. When they work at thyme, they mix in water before
sealing up the comb. As has been already stated, they all either
fly to a distance to discharge their excrement or make the
discharge into one single comb. The little bees, as has been said,
1773
are more industrious than the big ones; their wings are
battered; their colour is black, and they have a burnt-up aspect.
Gaudy and showy bees, like gaudy and showy women, are good-
for-nothings.
Bees seem to take a pleasure in listening to a rattling noise; and
consequently men say that they can muster them into a hive by
rattling with crockery or stones; it is uncertain, however,
whether or no they can hear the noise at all and also whether
their procedure is due to pleasure or alarm. They expel from the
hive all idlers and unthrifts. As has been said, they differentiate
their work; some make wax, some make honey, some make bee-
bread, some shape and mould combs, some bring water to the
cells and mingle it with the honey, some engage in out-of-door
work. At early dawn they make no noise, until some one
particular bee makes a buzzing noise two or three times and
thereby awakes the rest; hereupon they all fly in a body to work.
By and by they return and at first are noisy; then the noise
gradually decreases, until at last some one bee flies round
about, making a buzzing noise, and apparently calling on the
others to go to sleep; then all of a sudden there is a dead
silence.
The hive is known to be in good condition if the noise heard
within it is loud, and if the bees make a flutter as they go out
and in; for at this time they are constructing brood-cells. They
suffer most from hunger when they recommence work after
winter. They become somewhat lazy if the bee-keeper, in
robbing the hive, leave behind too much honey; still one should
leave cells numerous in proportion to the population, for the
bees work in a spiritless way if too few combs are left. They
become idle also, as being dispirited, if the hive be too big. A
hive yields to the bee-keeper six or nine pints of honey; a
prosperous hive will yield twelve or fifteen pints, exceptionally
good hives eighteen. Sheep and, as has been said, wasps are
1774
enemies to the bees. Bee-keepers entrap the latter, by putting a
flat dish on the ground with pieces of meat on it; when a
number of the wasps settle on it, they cover them with a lid and
put the dish and its contents on the fire. It is a good thing to
have a few drones in a hive, as their presence increases the
industry of the workers. Bees can tell the approach of rough
weather or of rain; and the proof is that they will not fly away,
but even while it is as yet fine they go fluttering about within a
restricted space, and the bee-keeper knows from this that they
are expecting bad weather. When the bees inside the hive hang
clustering to one another, it is a sign that the swarm is
intending to quit; consequently, occasion, when a bee-keepers,
on seeing this, besprinkle the hive with sweet wine. It is
advisable to plant about the hives pear-trees, beans, Median-
grass, Syrian-grass, yellow pulse, myrtle, poppies, creeping-
thyme, and almond-trees. Some bee-keepers sprinkle their bees
with flour, and can distinguish them from others when they are
at work out of doors. If the spring be late, or if there be drought
or blight, then grubs are all the fewer in the hives. So much for
the habits of bees.
41
Of wasps, there are two kinds. Of these kinds one is wild and
scarce, lives on the mountains, engenders grubs not
underground but on oak-trees, is larger, longer, and blacker than
the other kind, is invariably speckled and furnished with a sting,
and is remarkably courageous. The pain from its sting is more
severe than that caused by the others, for the instrument that
causes the pain is larger, in proportion to its own larger size.
These wild live over into a second year, and in winter time,
when oaks have been in course of felling, they may be seen
1775
coming out and flying away. They lie concealed during the
winter, and live in the interior of logs of wood. Some of them are
mother-wasps and some are workers, as with the tamer kind;
but it is by observation of the tame wasps that one may learn
the varied characteristics of the mothers and the workers. For in
the case of the tame wasps also there are two kinds; one
consists of leaders, who are called mothers, and the other of
workers. The leaders are far larger and milder-tempered than
the others. The workers do not live over into a second year, but
all die when winter comes on; and this can be proved, for at the
commencement of winter the workers become drowsy, and
about the time of the winter solstice they are never seen at all.
The leaders, the so-called mothers, are seen all through the
winter, and live in holes underground; for men when ploughing
or digging in winter have often come upon mother-wasps, but
never upon workers. The mode of reproduction of wasps is as
follows. At the approach of summer, when the leaders have
found a sheltered spot, they take to moulding their combs, and
construct the so-called sphecons, - little nests containing four
cells or thereabouts, and in these are produced working-wasps
but not mothers. When these are grown up, then they construct
other larger combs upon the first, and then again in like
manner others; so that by the close of autumn there are
numerous large combs in which the leader, the so-called
mother, engenders no longer working-wasps but mothers.
These develop high up in the nest as large grubs, in cells that
occur in groups of four or rather more, pretty much in the same
way as we have seen the grubs of the king-bees to be produced
in their cells. After the birth of the working-grubs in the cells,
the leaders do nothing and the workers have to supply them
with nourishment; and this is inferred from the fact that the
leaders (of the working- wasps) no longer fly out at this time, but
rest quietly indoors. Whether the leaders of last year after
engendering new leaders are killed by the new brood, and
1776
whether this occurs invariably or whether they can live for a
longer time, has not been ascertained by actual observation;
neither can we speak with certainty, as from observation, as to
the age attained by the mother-wasp or by the wild wasps, or as
to any other similar phenomenon. The mother-wasp is broad
and heavy, fatter and larger than the ordinary wasp, and from
its weight not very strong on the wing; these wasps cannot fly
far, and for this reason they always rest inside the nest, building
and managing its indoor arrangements. The so-called mother-
wasps are found in most of the nests; it is a matter of doubt
whether or no they are provided with stings; in all probability,
like the king-bees, they have stings, but never protrude them for
offence. Of the ordinary wasps some are destitute of stings, like
the drone-bees, and some are provided with them. Those
unprovided therewith are smaller and less spirited and never
fight, while the others are big and courageous; and these latter,
by some, are called males, and the stingless, females. At the
approach of winter many of the wasps that have stings appear
to lose them; but we have never met an eyewitness of this
phenomenon. Wasps are more abundant in times of drought
and in wild localities. They live underground; their combs they
mould out of chips and earth, each comb from a single origin,
like a kind of root. They feed on certain flowers and fruits, but
for the most part on animal food. Some of the tame wasps have
been observed when sexually united, but it was not determined
whether both, or neither, had stings, or whether one had a sting
and the other had not; wild wasps have been seen under similar
circumstances, when one was seen to have a sting but the case
of the other was left undetermined. The wasp-grub does not
appear to come into existence by parturition, for at the outset
the grub is too big to be the offspring of a wasp. If you take a
wasp by the feet and let him buzz with the vibration of his
wings, wasps that have no stings will fly toward it, and wasps
that have stings will not; from which fact it is inferred by some
1777
that one set are males and the other females. In holes in the
ground in winter-time wasps are found, some with stings, and
some without. Some build cells, small and few in number;
others build many and large ones. The so-called mothers are
caught at the change of season, mostly on elm-trees, while
gathering a substance sticky and gumlike. A large number of
mother-wasps are found when in the previous year wasps have
been numerous and the weather rainy; they are captured in
precipitous places, or in vertical clefts in the ground, and they
all appear to be furnished with stings.
42
So much for the habits of wasps.
Anthrenae do not subsist by culling from flowers as bees do, but
for the most part on animal food: for this reason they hover
about dung; for they chase the large flies, and after catching
them lop off their heads and fly away with the rest of the
carcases; they are furthermore fond of sweet fruits. Such is their
food. They have also kings or leaders like bees and wasps; and
their leaders are larger in proportion to themselves than are
wasp-kings to wasps or bee-kings to bees. The anthrena-king,
like the wasp-king, lives indoors. Anthrenae build their nests
underground, scraping out the soil like ants; for neither
anthrenae nor wasps go off in swarms as bees do, but
successive layers of young anthrenae keep to the same habitat,
and go on enlarging their nest by scraping out more and more
of soil. The nest accordingly attains a great size; in fact, from a
particularly prosperous nest have been removed three and even
four baskets full of combs. They do not, like bees, store up food,
but pass the winter in a torpid condition; the greater part of
1778
them die in the winter, but it is uncertain whether that can be
said of them all, In the hives of bees several kings are found and
they lead off detachments in swarms, but in the anthrena's nest
only one king is found. When individual anthrenae have strayed
from their nest, they cluster on a tree and construct combs, as
may be often seen above-ground, and in this nest they produce
a king; when the king is full-grown, he leads them away and
settles them along with himself in a hive or nest. With regard to
their sexual unions, and the method of their reproduction,
nothing is known from actual observation. Among bees both the
drones and the kings are stingless, and so are certain wasps, as
has been said; but anthrenae appear to be all furnished with
stings: though, by the way, it would well be worth while to carry
out investigation as to whether the anthrena-king has a sting or
not.
43
Humble-bees produce their young under a stone, right on the
ground, in a couple of cells or little more; in these cells is found
an attempt at honey, of a poor description. The tenthredon is
like the anthrena, but speckled, and about as broad as a bee.
Being epicures as to their food, they fly, one at a time, into
kitchens and on to slices of fish and the like dainties. The
tenthredon brings forth, like the wasp, underground, and is very
prolific; its nest is much bigger and longer than that of the
wasp. So much for the methods of working and the habits of life
of the bee, the wasp, and all the other similar insects.
1779
44
As regards the disposition or temper of animals, as has been
previously observed, one may detect great differences in respect
to courage and timidity, as also, even among wild animals, in
regard to tameness and wildness. The lion, while he is eating, is
most ferocious; but when he is not hungry and has had a good
meal, he is quite gentle. He is totally devoid of suspicion or
nervous fear, is fond of romping with animals that have been
reared along with him and to whom he is accustomed, and
manifests great affection towards them. In the chase, as long as
he is in view, he makes no attempt to run and shows no fear,
but even if he be compelled by the multitude of the hunters to
retreat, he withdraws deliberately, step by step, every now and
then turning his head to regard his pursuers. If, however, he
reach wooded cover, then he runs at full speed, until he comes
to open ground, when he resumes his leisurely retreat. When, in
the open, he is forced by the number of the hunters to run while
in full view, he does run at the top of his speed, but without
leaping and bounding. This running of his is evenly and
continuously kept up like the running of a dog; but when he is
in pursuit of his prey and is close behind, he makes a sudden
pounce upon it. The two statements made regarding him are
quite true; the one that he is especially afraid of fire, as Homer
pictures him in the line - 'and glowing torches, which, though
fierce he dreads,' - and the other, that he keeps a steady eye
upon the hunter who hits him, and flings himself upon him. If a
hunter hit him, without hurting him, then if with a bound he
gets hold of him, he will do him no harm, not even with his
claws, but after shaking him and giving him a fright will let him
go again. They invade the cattle-folds and attack human beings
when they are grown old and so by reason of old age and the
diseased condition of their teeth are unable to pursue their
wonted prey. They live to a good old age. The lion who was
captured when lame, had a number of his teeth broken; which
1780
fact was regarded by some as a proof of the longevity of lions, as
he could hardly have been reduced to this condition except at
an advanced age. There are two species of lions, the plump,
curly-maned, and the long-bodied, straight maned; the latter
kind is courageous, and the former comparatively timid;
sometimes they run away with their tail between their legs, like
a dog. A lion was once seen to be on the point of attacking a
boar, but to run away when the boar stiffened his bristles in
defence. It is susceptible of hurt from a wound in the flank, but
on any other part of its frame will endure any number of blows,
and its head is especially hard. Whenever it inflicts a wound,
either by its teeth or its claws, there flows from the wounded
parts suppurating matter, quite yellow, and not to be stanched
by bandage or sponge; the treatment for such a wound is the
same as that for the bite of a dog.
The thos, or civet, is fond of man's company; it does him no
harm and is not much afraid of him, but it is an enemy to the
dog and the lion, and consequently is not found in the same
habitat with them. The little ones are the best. Some say that
there are two species of the animal, and some say, three; there
are probably not more than three, but, as is the case with
certain of the fishes, birds, and quadrupeds, this animal
changes in appearance with the change of season. His colour in
winter is not the same as it is in summer; in summer the
animal is smooth-haired, in winter he is clothed in fur.
45
The bison is found in Paeonia on Mount Messapium, which
separates Paeonia from Maedica; and the Paeonians call it the
monapos. It is the size of a bull, but stouter in build, and not
1781
long in the body; its skin, stretched tight on a frame, would give
sitting room for seven people. In general it resembles the ox in
appearance, except that it has a mane that reaches down to the
point of the shoulder, as that of the horse reaches down to its
withers; but the hair in its mane is softer than the hair in the
horse's mane, and clings more closely. The colour of the hair is
brown-yellow; the mane reaches down to the eyes, and is deep
and thick. The colour of the body is half red, half ashen-grey,
like that of the so-called chestnut horse, but rougher. It has an
undercoat of woolly hair. The animal is not found either very
black or very red. It has the bellow of a bull. Its horns are
crooked, turned inwards towards each other and useless for
purposes of self-defence; they are a span broad, or a little more,
and in volume each horn would hold about three pints of liquid;
the black colour of the horn is beautiful and bright. The tuft of
hair on the forehead reaches down to the eyes, so that the
animal sees objects on either flank better than objects right in
front. It has no upper teeth, as is the case also with kine and all
other horned animals. Its legs are hairy; it is cloven-footed, and
the tail, which resembles that of the ox, seems not big enough
for the size of its body. It tosses up dust and scoops out the
ground with its hooves, like the bull. Its skin is impervious to
blows. Owing to the savour of its flesh it is sought for in the
chase. When it is wounded it runs away, and stops only when
thoroughly exhausted. It defends itself against an assailant by
kicking and projecting its excrement to a distance of eight
yards; this device it can easily adopt over and over again, and
the excrement is so pungent that the hair of hunting-dogs is
burnt off by it. It is only when the animal is disturbed or
alarmed that the dung has this property; when the animal is
undisturbed it has no blistering effect. So much for the shape
and habits of the animal. When the season comes for
parturition the mothers give birth to their young in troops upon
the mountains. Before dropping their young they scatter their
1782
dung in all directions, making a kind of circular rampart around
them; for the animal has the faculty of ejecting excrement in
most extraordinary quantities.
46
Of all wild animals the most easily tamed and the gentlest is
the elephant. It can be taught a number of tricks, the drift and
meaning of which it understands; as, for instance, it can taught
to kneel in presence of the king. It is very sensitive, and
possessed of an intelligence superior to that of other animals.
When the male has had sexual union with the female, and the
female has conceived, the male has no further intercourse with
her.
Some say that the elephant lives for two hundred years; others,
for one hundred and twenty; that the female lives nearly as
long as the male; that they reach their prime about the age of
sixty, and that they are sensitive to inclement weather and
frost. The elephant is found by the banks of rivers, but he is not
a river animal; he can make his way through water, as long as
the tip of his trunk can be above the surface, for he blows with
his trunk and breathes through it. The animal is a poor
swimmer owing to the heavy weight of his body.
47
The male camel declines intercourse with its mother; if his
keeper tries compulsion, he evinces disinclination. On one
occasion, when intercourse was being declined by the young
1783
male, the keeper covered over the mother and put the young
male to her; but, when after the intercourse the wrapping had
been removed, though the operation was completed and could
not be revoked, still by and by he bit his keeper to death. A story
goes that the king of Scythia had a highly-bred mare, and that
all her foals were splendid; that wishing to mate the best of the
young males with the mother, he had him brought to the stall
for the purpose; that the young horse declined; that, after the
mother's head had been concealed in a wrapper he, in
ignorance, had intercourse; and that, when immediately
afterwards the wrapper was removed and the head of the mare
was rendered visible, the young horse ran way and hurled
himself down a precipice.
48
Among the sea-fishes many stories are told about the dolphin,
indicative of his gentle and kindly nature, and of manifestations
of passionate attachment to boys, in and about Tarentum, Caria,
and other places. The story goes that, after a dolphin had been
caught and wounded off the coast of Caria, a shoal of dolphins
came into the harbour and stopped there until the fisherman
let his captive go free; whereupon the shoal departed. A shoal of
young dolphins is always, by way of protection, followed by a
large one. On one occasion a shoal of dolphins, large and small,
was seen, and two dolphins at a little distance appeared
swimming in underneath a little dead dolphin when it was
sinking, and supporting it on their backs, trying out of
compassion to prevent its being devoured by some predaceous
fish. Incredible stories are told regarding the rapidity of
movement of this creature. It appears to be the fleetest of all
animals, marine and terrestrial, and it can leap over the masts
1784
of large vessels. This speed is chiefly manifested when they are
pursuing a fish for food; then, if the fish endeavours to escape,
they pursue him in their ravenous hunger down to deep waters;
but, when the necessary return swim is getting too long, they
hold in their breath, as though calculating the length of it, and
then draw themselves together for an effort and shoot up like
arrows, trying to make the long ascent rapidly in order to
breathe, and in the effort they spring right over the a ship's
masts if a ship be in the vicinity. This same phenomenon is
observed in divers, when they have plunged into deep water;
that is, they pull themselves together and rise with a speed
proportional to their strength. Dolphins live together in pairs,
male and female. It is not known for what reason they run
themselves aground on dry land; at all events, it is said that
they do so at times, and for no obvious reason.
49
Just as with all animals a change of action follows a change of
circumstance, so also a change of character follows a change of
action, and often some portions of the physical frame undergo a
change, occurs in the case of birds. Hens, for instance, when
they have beaten the cock in a fight, will crow like the cock and
endeavour to tread him; the crest rises up on their head and the
tail-feathers on the rump, so that it becomes difficult to
recognize that they are hens; in some cases there is a growth of
small spurs. On the death of a hen a cock has been seen to
undertake the maternal duties, leading the chickens about and
providing them with food, and so intent upon these duties as to
cease crowing and indulging his sexual propensities. Some
cock-birds are congenitally so feminine that they will submit
patiently to other males who attempt to tread them.
1785
50
Some animals change their form and character, not only at
certain ages and at certain seasons, but in consequence of being
castrated; and all animals possessed of testicles may be
submitted to this operation. Birds have their testicles inside,
and oviparous quadrupeds close to the loins; and of viviparous
animals that walk some have them inside, and most have them
outside, but all have them at the lower end of the belly. Birds are
castrated at the rump at the part where the two sexes unite in
copulation. If you burn this twice or thrice with hot irons, then,
if the bird be full-grown, his crest grows sallow, he ceases to
crow, and foregoes sexual passion; but if you cauterize the bird
when young, none of these male attributes propensities will
come to him as he grows up. The case is the same with men: if
you mutilate them in boyhood, the later-growing hair never
comes, and the voice never changes but remains high-pitched;
if they be mutilated in early manhood, the late growths of hair
quit them except the growth on the groin, and that diminishes
but does not entirely depart. The congenital growths of hair
never fall out, for a eunuch never grows bald. In the case of all
castrated or mutilated male quadrupeds the voice changes to
the feminine voice. All other quadrupeds when castrated,
unless the operation be performed when they are young,
invariably die; but in the case of boars, and in their case only,
the age at which the operation is performed produces no
difference. All animals, if operated on when they are young,
become bigger and better looking than their unmutilated
fellows; if they be mutilated when full-grown, they do not take
on any increase of size. If stags be mutilated, when, by reason of
their age, they have as yet no horns, they never grow horns at
1786
all; if they be mutilated when they have horns, the horns
remain unchanged in size, and the animal does not lose them.
Calves are mutilated when a year old; otherwise, they turn out
uglier and smaller. Steers are mutilated in the following way:
they turn the animal over on its back, cut a little off the scrotum
at the lower end, and squeeze out the testicles, then push back
the roots of them as far as they can, and stop up the incision
with hair to give an outlet to suppurating matter; if
inflammation ensues, they cauterize the scrotum and put on a
plaster. If a full-grown bull be mutilated, he can still to all
appearance unite sexually with the cow. The ovaries of sows are
excised with the view of quenching in them sexual appetites
and of stimulating growth in size and fatness. The sow has first
to be kept two days without food, and, after being hung up by
the hind legs, it is operated on; they cut the lower belly, about
the place where the boars have their testicles, for it is there that
the ovary grows, adhering to the two divisions (or horns) of the
womb; they cut off a little piece and stitch up the incision.
Female camels are mutilated when they are wanted for war
purposes, and are mutilated to prevent their being got with
young. Some of the inhabitants of Upper Asia have as many as
three thousand camels: when they run, they run, in
consequence of the length of their stride, much quicker than
the horses of Nisaea. As a general rule, mutilated animals grow
to a greater length than the unmutilated.
All animals that ruminate derive profit and pleasure from the
process of rumination, as they do from the process of eating. It
is the animals that lack the upper teeth that ruminate, such as
kine, sheep, and goats. In the case of wild animals no
observation has been possible; save in the case of animals that
are occasionally domesticated, such as the stag, and it, we
know, chews the cud. All animals that ruminate generally do so
when lying down on the ground. They carry on the process to
the greatest extent in winter, and stall-fed ruminants carry it on
1787
for about seven months in the year; beasts that go in herds, as
they get their food out of doors, ruminate to a lesser degree and
over a lesser period. Some, also, of the animals that have teeth
in both jaws ruminate; as, for instance, the Pontic mice, and the
fish which from the habit is by some called 'the Ruminant', (as
well as other fish).
Long-limbed animals have loose faeces, and broad-chested
animals vomit with comparative facility, and these remarks are,
in a general way, applicable to quadrupeds, birds, and men.
49B
A considerable number of birds change according to season the
colour of their plumage and their note; as, for instance, the
owsel becomes yellow instead of black, and its note gets altered,
for in summer it has a musical note and in winter a discordant
chatter. The thrush also changes its colour; about the throat it is
marked in winter with speckles like a starling, in summer
distinctly spotted: however, it never alters its note. The
nightingale, when the hills are taking on verdure, sings
continually for fifteen days and fifteen nights; afterwards it
sings, but not continuously. As summer advances it has a
different song, not so varied as before, nor so deep, nor so
intricately modulated, but simple; it also changes its colour, and
in Italy about this season it goes by a different name. It goes
into hiding, and is consequently visible only for a brief period.
The erithacus (or redbreast) and the so-called redstart change
into one another; the former is a winter bird, the latter a
summer one, and the difference between them is practically
limited to the coloration of their plumage. In the same way with
the beccafico and the blackcap; these change into one another.
1788
The beccafico appears about autumn, and the blackcap as soon
as autumn has ended. These birds, also, differ from one another
only in colour and note; that these birds, two in name, are one
in reality is proved by the fact that at the period when the
change is in progress each one has been seen with the change
as yet incomplete. It is not so very strange that in these cases
there is a change in note and in plumage, for even the ring-dove
ceases to coo in winter, and recommences cooing when spring
comes in; in winter, however, when fine weather has succeeded
to very stormy weather, this bird has been known to give its
cooing note, to the astonishment of such as were acquainted
with its usual winter silence. As a general rule, birds sing most
loudly and most diversely in the pairing season. The cuckoo
changes its colour, and its note is not clearly heard for a short
time previous to its departure. It departs about the rising of the
Dog-star, and it reappears from springtime to the rising of the
Dog-star. At the rise of this star the bird called by some
oenanthe disappears, and reappears when it is setting: thus
keeping clear at one time of extreme cold, and at another time
of extreme heat. The hoopoe also changes its colour and
appearance, as Aeschylus has represented in the following lines:
The Hoopoe, witness to his own distress,
Is clad by Zeus in variable dress:
Now a gay mountain-bird, with knightly crest,
Now in the white hawk's silver plumage drest,
For, timely changing, on the hawk's white wing
He greets the apparition of the Spring.
Thus twofold form and colour are conferred,
In youth and age, upon the selfsame bird.
1789
The spangled raiment marks his youthful days,
The argent his maturity displays;
And when the fields are yellow with ripe corn
Again his particoloured plumes are worn.
But evermore, in sullen discontent,
He seeks the lonely hills, in self-sought banishment.
Of birds, some take a dust-bath by rolling in dust, some take a
water-bath, and some take neither the one bath nor the other.
Birds that do not fly but keep on the ground take the dust-bath,
as for instance the hen, the partridge, the francolin, the crested
lark, the pheasant; some of the straight-taloned birds, and such
as live on the banks of a river, in marshes, or by the sea, take a
water-bath; some birds take both the dust-bath and the
waterbath, as for instance the pigeon and the sparrow; of the
crooked-taloned birds the greater part take neither the one bath
nor the other. So much for the ways of the above-mentioned,
but some birds have a peculiar habit of making a noise at their
hinder quarters, as, for instance, the turtle-dove; and they make
a violent movement of their tails at the same time that they
produce this peculiar sound.
1790
Aristotle - On the Parts of Animals
[Translated by William Ogle]
Book I
Every systematic science, the humblest and the noblest alike,
seems to admit of two distinct kinds of proficiency; one of
which may be properly called scientific knowledge of the
subject, while the other is a kind of educational acquaintance
with it. For an educated man should be able to form a fair off-
hand judgement as to the goodness or badness of the method
used by a professor in his exposition. To be educated is in fact to
be able to do this; and even the man of universal education we
deem to be such in virtue of his having this ability. It will,
however, of course, be understood that we only ascribe
universal education to one who in his own individual person is
thus critical in all or nearly all branches of knowledge, and not
to one who has a like ability merely in some special subject. For
it is possible for a man to have this competence in some one
branch of knowledge without having it in all.
It is plain then that, as in other sciences, so in that which
inquires into nature, there must be certain canons, by reference
to which a hearer shall be able to criticize the method of a
professed exposition, quite independently of the question
whether the statements made be true or false. Ought we, for
instance (to give an illustration of what I mean), to begin by
discussing each separate species - man, lion, ox, and the like -
1791
taking each kind in hand independently of the rest, or ought we
rather to deal first with the attributes which they have in
common in virtue of some common element of their nature,
and proceed from this as a basis for the consideration of them
separately? For genera that are quite distinct yet oftentimes
present many identical phenomena, sleep, for instance,
respiration, growth, decay, death, and other similar affections
and conditions, which may be passed over for the present, as
we are not yet prepared to treat of them with clearness and
precision. Now it is plain that if we deal with each species
independently of the rest, we shall frequently be obliged to
repeat the same statements over and over again; for horse and
dog and man present, each and all, every one of the phenomena
just enumerated. A discussion therefore of the attributes of each
such species separately would necessarily involve frequent
repetitions as to characters, themselves identical but recurring
in animals specifically distinct. (Very possibly also there may be
other characters which, though they present specific
differences, yet come under one and the same category. For
instance, flying, swimming, walking, creeping, are plainly
specifically distinct, but yet are all forms of animal progression.)
We must, then, have some clear understanding as to the
manner in which our investigation is to be conducted; whether,
I mean, we are first to deal with the common or generic
characters, and afterwards to take into consideration special
peculiarities; or whether we are to start straight off with the
ultimate species. For as yet no definite rule has been laid down
in this matter. So also there is a like uncertainty as to another
point now to be mentioned. Ought the writer who deals with
the works of nature to follow the plan adopted by the
mathematicians in their astronomical demonstrations, and
after considering the phenomena presented by animals, and
their several parts, proceed subsequently to treat of the causes
and the reason why; or ought he to follow some other method?
1792
And when these questions are answered, there yet remains
another. The causes concerned in the generation of the works of
nature are, as we see, more than one. There is the final cause
and there is the motor cause. Now we must decide which of
these two causes comes first, which second. Plainly, however,
that cause is the first which we call the final one. For this is the
Reason, and the Reason forms the starting-point, alike in the
works of art and in works of nature. For consider how the
physician or how the builder sets about his work. He starts by
forming for himself a definite picture, in the one case
perceptible to mind, in the other to sense, of his end - the
physician of health, the builder of a house - and this he holds
forward as the reason and explanation of each subsequent step
that he takes, and of his acting in this or that way as the case
may be. Now in the works of nature the good end and the final
cause is still more dominant than in works of art such as these,
nor is necessity a factor with the same significance in them all;
though almost all writers, while they try to refer their origin to
this cause, do so without distinguishing the various senses in
which the term necessity is used. For there is absolute necessity,
manifested in eternal phenomena; and there is hypothetical
necessity, manifested in everything that is generated by nature
as in everything that is produced by art, be it a house or what it
may. For if a house or other such final object is to be realized, it
is necessary that such and such material shall exist; and it is
necessary that first this then that shall be produced, and first
this and then that set in motion, and so on in continuous
succession, until the end and final result is reached, for the sake
of which each prior thing is produced and exists. As with these
productions of art, so also is it with the productions of nature.
The mode of necessity, however, and the mode of ratiocination
are different in natural science from what they are in the
theoretical sciences; of which we have spoken elsewhere. For in
the latter the starting-point is that which is; in the former that
1793
which is to be. For it is that which is yet to be - health, let us say,
or a man - that, owing to its being of such and such characters,
necessitates the pre-existence or previous production of this
and that antecedent; and not this or that antecedent which,
because it exists or has been generated, makes it necessary that
health or a man is in, or shall come into, existence. Nor is it
possible to track back the series of necessary antecedents to a
starting-point, of which you can say that, existing itself from
eternity, it has determined their existence as its consequent.
These however again, are matters that have been dealt with in
another treatise. There too it was stated in what cases absolute
and hypothetical necessity exist; in what cases also the
proposition expressing hypothetical necessity is simply
convertible, and what cause it is that determines this
convertibility.
Another matter which must not be passed over without
consideration is, whether the proper subject of our exposition is
that with which the ancient writers concerned themselves,
namely, what is the process of formation of each animal; or
whether it is not rather, what are the characters of a given
creature when formed. For there is no small difference between
these two views. The best course appears to be that we should
follow the method already mentioned, and begin with the
phenomena presented by each group of animals, and, when this
is done, proceed afterwards to state the causes of those
phenomena, and to deal with their evolution. For elsewhere, as
for instance in house building, this is the true sequence. The
plan of the house, or the house, has this and that form; and
because it has this and that form, therefore is its construction
carried out in this or that manner. For the process of evolution
is for the sake of the thing Anally evolved, and not this for the
sake of the process. Empedocles, then, was in error when he
said that many of the characters presented by animals were
merely the results of incidental occurrences during their
1794
development; for instance, that the backbone was divided as it
is into vertebrae, because it happened to be broken owing to the
contorted position of the foetus in the womb. In so saying he
overlooked the fact that propagation implies a creative seed
endowed with certain formative properties. Secondly, he
neglected another fact, namely, that the parent animal pre-
exists, not only in idea, but actually in time. For man is
generated from man; and thus it is the possession of certain
characters by the parent that determines the development of
like characters in the child. The same statement holds good also
for the operations of art, and even for those which are
apparently spontaneous. For the same result as is produced by
art may occur spontaneously. Spontaneity, for instance, may
bring about the restoration of health. The products of art,
however, require the pre-existence of an efficient cause
homogeneous with themselves, such as the statuary's art,
which must necessarily precede the statue; for this cannot
possibly be produced spontaneously. Art indeed consists in the
conception of the result to be produced before its realization in
the material. As with spontaneity, so with chance; for this also
produces the same result as art, and by the same process.
The fittest mode, then, of treatment is to say, a man has such
and such parts, because the conception of a man includes their
presence, and because they are necessary conditions of his
existence, or, if we cannot quite say this, which would be best of
all, then the next thing to it, namely, that it is either quite
impossible for him to exist without them, or, at any rate, that it
is better for him that they should be there; and their existence
involves the existence of other antecedents. Thus we should
say, because man is an animal with such and such characters,
therefore is the process of his development necessarily such as
it is; and therefore is it accomplished in such and such an order,
this part being formed first, that next, and so on in succession;
1795
and after a like fashion should we explain the evolution of all
other works of nature.
Now that with which the ancient writers, who first
philosophized about Nature, busied themselves, was the
material principle and the material cause. They inquired what
this is, and what its character; how the universe is generated
out of it, and by what motor influence, whether, for instance, by
antagonism or friendship, whether by intelligence or
spontaneous action, the substratum of matter being assumed to
have certain inseparable properties; fire, for instance, to have a
hot nature, earth a cold one; the former to be light, the latter
heavy. For even the genesis of the universe is thus explained by
them. After a like fashion do they deal also with the
development of plants and of animals. They say, for instance,
that the water contained in the body causes by its currents the
formation of the stomach and the other receptacles of food or of
excretion; and that the breath by its passage breaks open the
outlets of the nostrils; air and water being the materials of
which bodies are made; for all represent nature as composed of
such or similar substances.
But if men and animals and their several parts are natural
phenomena, then the natural philosopher must take into
consideration not merely the ultimate substances of which they
are made, but also flesh, bone, blood, and all other
homogeneous parts; not only these, but also the heterogeneous
parts, such as face, hand, foot; and must examine how each of
these comes to be what it is, and in virtue of what force. For to
say what are the ultimate substances out of which an animal is
formed, to state, for instance, that it is made of fire or earth, is
no more sufficient than would be a similar account in the case
of a couch or the like. For we should not be content with saying
that the couch was made of bronze or wood or whatever it
might be, but should try to describe its design or mode of
1796
composition in preference to the material; or, if we did deal
with the material, it would at any rate be with the concretion of
material and form. For a couch is such and such a form
embodied in this or that matter, or such and such a matter with
this or that form; so that its shape and structure must be
included in our description. For the formal nature is of greater
importance than the material nature.
Does, then, configuration and colour constitute the essence of
the various animals and of their several parts? For if so, what
Democritus says will be strictly correct. For such appears to
have been his notion. At any rate he says that it is evident to
every one what form it is that makes the man, seeing that he is
recognizable by his shape and colour. And yet a dead body has
exactly the same configuration as a living one; but for all that is
not a man. So also no hand of bronze or wood or constituted in
any but the appropriate way can possibly be a hand in more
than name. For like a physician in a painting, or like a flute in a
sculpture, in spite of its name it will be unable to do the office
which that name implies. Precisely in the same way no part of a
dead body, such I mean as its eye or its hand, is really an eye or
a hand. To say, then, that shape and colour constitute the
animal is an inadequate statement, and is much the same as if
a woodcarver were to insist that the hand he had cut out was
really a hand. Yet the physiologists, when they give an account
of the development and causes of the animal form, speak very
much like such a craftsman. What, however, I would ask, are the
forces by which the hand or the body was fashioned into its
shape? The woodcarver will perhaps say, by the axe or the
auger; the physiologist, by air and by earth. Of these two
answers the artificer's is the better, but it is nevertheless
insufficient. For it is not enough for him to say that by the
stroke of his tool this part was formed into a concavity, that into
a flat surface; but he must state the reasons why he struck his
blow in such a way as to effect this, and what his final object
1797
was; namely, that the piece of wood should develop eventually
into this or that shape. It is plain, then, that the teaching of the
old physiologists is inadequate, and that the true method is to
state what the definitive characters are that distinguish the
animal as a whole; to explain what it is both in substance and
in form, and to deal after the same fashion with its several
organs; in fact, to proceed in exactly the same way as we should
do, were we giving a complete description of a couch.
If now this something that constitutes the form of the living
being be the soul, or part of the soul, or something that without
the soul cannot exist; as would seem to be the case, seeing at
any rate that when the soul departs, what is left is no longer a
living animal, and that none of the parts remain what they were
before, excepting in mere configuration, like the animals that in
the fable are turned into stone; if, I say, this be so, then it will
come within the province of the natural philosopher to inform
himself concerning the soul, and to treat of it, either in its
entirety, or, at any rate, of that part of it which constitutes the
essential character of an animal; and it will be his duty to say
what this soul or this part of a soul is; and to discuss the
attributes that attach to this essential character, especially as
nature is spoken of in two senses, and the nature of a thing is
either its matter or its essence; nature as essence including
both the motor cause and the final cause. Now it is in the latter
of these two senses that either the whole soul or some part of it
constitutes the nature of an animal; and inasmuch as it is the
presence of the soul that enables matter to constitute the
animal nature, much more than it is the presence of matter
which so enables the soul, the inquirer into nature is bound on
every ground to treat of the soul rather than of the matter. For
though the wood of which they are made constitutes the couch
and the tripod, it only does so because it is capable of receiving
such and such a form.
1798
What has been said suggests the question, whether it is the
whole soul or only some part of it, the consideration of which
comes within the province of natural science. Now if it be of the
whole soul that this should treat, then there is no place for any
other philosophy beside it. For as it belongs in all cases to one
and the same science to deal with correlated subjects - one and
the same science, for instance, deals with sensation and with
the objects of sense - and as therefore the intelligent soul and
the objects of intellect, being correlated, must belong to one and
the same science, it follows that natural science will have to
include the whole universe in its province. But perhaps it is not
the whole soul, nor all its parts collectively, that constitutes the
source of motion; but there may be one part, identical with that
in plants, which is the source of growth, another, namely the
sensory part, which is the source of change of quality, while still
another, and this not the intellectual part, is the source of
locomotion. I say not the intellectual part; for other animals
than man have the power of locomotion, but in none but him is
there intellect. Thus then it is plain that it is not of the whole
soul that we have to treat. For it is not the whole soul that
constitutes the animal nature, but only some part or parts of it.
Moreover, it is impossible that any abstraction can form a
subject of natural science, seeing that everything that Nature
makes is means to an end. For just as human creations are the
products of art, so living objects are manifest in the products of
an analogous cause or principle, not external but internal,
derived like the hot and the cold from the environing universe.
And that the heaven, if it had an origin, was evolved and is
maintained by such a cause, there is therefore even more
reason to believe, than that mortal animals so originated. For
order and definiteness are much more plainly manifest in the
celestial bodies than in our own frame; while change and
chance are characteristic of the perishable things of earth. Yet
there are some who, while they allow that every animal exists
1799
and was generated by nature, nevertheless hold that the heaven
was constructed to be what it is by chance and spontaneity; the
heaven, in which not the faintest sign of haphazard or of
disorder is discernible! Again, whenever there is plainly some
final end, to which a motion tends should nothing stand in the
way, we always say that such final end is the aim or purpose of
the motion; and from this it is evident that there must be a
something or other really existing, corresponding to what we
call by the name of Nature. For a given germ does not give rise
to any chance living being, nor spring from any chance one; but
each germ springs from a definite parent and gives rise to a
definite progeny. And thus it is the germ that is the ruling
influence and fabricator of the offspring. For these it is by
nature, the offspring being at any rate that which in nature will
spring from it. At the same time the offspring is anterior to the
germ; for germ and perfected progeny are related as the
developmental process and the result. Anterior, however, to
both germ and product is the organism from which the germ
was derived. For every germ implies two organisms, the parent
and the progeny. For germ or seed is both the seed of the
organism from which it came, of the horse, for instance, from
which it was derived, and the seed of the organism that will
eventually arise from it, of the mule, for example, which is
developed from the seed of the horse. The same seed then is the
seed both of the horse and of the mule, though in different ways
as here set forth. Moreover, the seed is potentially that which
will spring from it, and the relation of potentiality to actuality
we know.
There are then two causes, namely, necessity and the final end.
For many things are produced, simply as the results of
necessity. It may, however, be asked, of what mode of necessity
are we speaking when we say this. For it can be of neither of
those two modes which are set forth in the philosophical
treatises. There is, however, the third mode, in such things at
1800
any rate as are generated. For instance, we say that food is
necessary; because an animal cannot possibly do without it.
This third mode is what may be called hypothetical necessity.
Here is another example of it. If a piece of wood is to be split
with an axe, the axe must of necessity be hard; and, if hard,
must of necessity be made of bronze or iron. Now exactly in the
same way the body, which like the axe is an instrument - for
both the body as a whole and its several parts individually have
definite operations for which they are made - just in the same
way, I say, the body, if it is to do its work, must of necessity be of
such and such a character, and made of such and such
materials.
It is plain then that there are two modes of causation, and that
both of these must, so far as possible, be taken into account in
explaining the works of nature, or that at any rate an attempt
must be made to include them both; and that those who fail in
this tell us in reality nothing about nature. For primary cause
constitutes the nature of an animal much more than does its
matter. There are indeed passages in which even Empedocles
hits upon this, and following the guidance of fact, finds himself
constrained to speak of the ratio (olugos) as constituting the
essence and real nature of things. Such, for instance, is the case
when he explains what is a bone. For he does not merely
describe its material, and say it is this one element, or those two
or three elements, or a compound of all the elements, but states
the ratio (olugos) of their combination. As with a bone, so
manifestly is it with the flesh and all other similar parts.
The reason why our predecessors failed in hitting upon this
method of treatment was, that they were not in possession of
the notion of essence, nor of any definition of substance. The
first who came near it was Democritus, and he was far from
adopting it as a necessary method in natural science, but was
merely brought to it, spite of himself, by constraint of facts. In
1801
the time of Socrates a nearer approach was made to the
method. But at this period men gave up inquiring into the works
of nature, and philosophers diverted their attention to political
science and to the virtues which benefit mankind.
Of the method itself the following is an example. In dealing
with respiration we must show that it takes place for such or
such a final object; and we must also show that this and that
part of the process is necessitated by this and that other stage
of it. By necessity we shall sometimes mean hypothetical
necessity, the necessity, that is, that the requisite antecedants
shall be there, if the final end is to be reached; and sometimes
absolute necessity, such necessity as that which connects
substances and their inherent properties and characters. For the
alternate discharge and re-entrance of heat and the inflow of air
are necessary if we are to live. Here we have at once a necessity
in the former of the two senses. But the alternation of heat and
refrigeration produces of necessity an alternate admission and
discharge of the outer air, and this is a necessity of the second
kind.
In the foregoing we have an example of the method which we
must adopt, and also an example of the kind of phenomena, the
causes of which we have to investigate.
Some writers propose to reach the definitions of the ultimate
forms of animal life by bipartite division. But this method is
often difficult, and often impracticable.
Sometimes the final differentia of the subdivision is sufficient
by itself, and the antecedent differentiae are mere surplusage.
1802
Thus in the series Footed, Two-footed, Cleft-footed, the last term
is all-expressive by itself, and to append the higher terms is
only an idle iteration. Again it is not permissible to break up a
natural group, Birds for instance, by putting its members under
different bifurcations, as is done in the published dichotomies,
where some birds are ranked with animals of the water, and
others placed in a different class. The group Birds and the group
Fishes happen to be named, while other natural groups have no
popular names; for instance, the groups that we may call
Sanguineous and Bloodless are not known popularly by any
designations. If such natural groups are not to be broken up, the
method of Dichotomy cannot be employed, for it necessarily
involves such breaking up and dislocation. The group of the
Many-footed, for instance, would, under this method, have to be
dismembered, and some of its kinds distributed among land
animals, others among water animals.
Again, privative terms inevitably form one branch of
dichotomous division, as we see in the proposed dichotomies.
But privative terms in their character of privatives admit of no
subdivision. For there can be no specific forms of a negation, of
Featherless for instance or of Footless, as there are of Feathered
and of Footed. Yet a generic differentia must be subdivisible; for
otherwise what is there that makes it generic rather than
specific? There are to be found generic, that is specifically
subdivisible, differentiae; Feathered for instance and Footed. For
feathers are divisible into Barbed and Unbarbed, and feet into
Manycleft, and Twocleft, like those of animals with bifid hoofs,
and Uncleft or Undivided, like those of animals with solid hoofs.
Now even with differentiae capable of this specific subdivision
1803
it is difficult enough so to make the classification, as that each
animal shall be comprehended in some one subdivision and in
not more than one; but far more difficult, nay impossible, is it to
do this, if we start with a dichotomy into two contradictories.
(Suppose for instance we start with the two contradictories,
Feathered and Unfeathered; we shall find that the ant, the glow-
worm, and some other animals fall under both divisions.) For
each differentia must be presented by some species. There must
be some species, therefore, under the privative heading. Now
specifically distinct animals cannot present in their essence a
common undifferentiated element, but any apparently common
element must really be differentiated. (Bird and Man for
instance are both Two-footed, but their two-footedness is
diverse and differentiated. So any two sanguineous groups must
have some difference in their blood, if their blood is part of their
essence.) From this it follows that a privative term, being
insusceptible of differentiation, cannot be a generic differentia;
for, if it were, there would be a common undifferentiated
element in two different groups.
Again, if the species are ultimate indivisible groups, that is, are
groups with indivisible differentiae, and if no differentia be
common to several groups, the number of differentiae must be
equal to the number of species. If a differentia though not
divisible could yet be common to several groups, then it is plain
that in virtue of that common differentia specifically distinct
animals would fall into the same division. It is necessary then, if
the differentiae, under which are ranged all the ultimate and
indivisible groups, are specific characters, that none of them
shall be common; for otherwise, as already said, specifically
distinct animals will come into one and the same division. But
this would violate one of the requisite conditions, which are as
follows. No ultimate group must be included in more than a
single division; different groups must not be included in the
same division; and every group must be found in some division.
1804
It is plain then that we cannot get at the ultimate specific forms
of the animal, or any other, kingdom by bifurcate division. If we
could, the number of ultimate differentiae would equal the
number of ultimate animal forms. For assume an order of
beings whose prime differentiae are White and Black. Each of
these branches will bifurcate, and their branches again, and so
on till we reach the ultimate differentiae, whose number will be
four or some other power of two, and will also be the number of
the ultimate species comprehended in the order.
(A species is constituted by the combination differentia and
matter. For no part of an animal is purely material or purely
immaterial; nor can a body, independently of its condition,
constitute an animal or any of its parts, as has repeatedly been
observed.)
Further, the differentiae must be elements of the essence, and
not merely essential attributes. Thus if Figure is the term to be
divided, it must not be divided into figures whose angles are
equal to two right angles, and figures whose angles are together
greater than two right angles. For it is only an attribute of a
triangle and not part of its essence that its angles are equal to
two right angles.
Again, the bifurcations must be opposites, like White and Black,
Straight and Bent; and if we characterize one branch by either
term, we must characterize the other by its opposite, and not,
for example, characterize one branch by a colour, the other by a
mode of progression, swimming for instance.
Furthermore, living beings cannot be divided by the functions
common to body and soul, by Flying, for instance, and Walking,
as we see them divided in the dichotomies already referred to.
For some groups, Ants for instance, fall under both divisions,
some ants flying while others do not. Similarly as regards the
division into Wild and Tame; for it also would involve the
1805
disruption of a species into different groups. For in almost all
species in which some members are tame, there are other
members that are wild. Such, for example, is the case with Men,
Horses, Oxen, Dogs in India, Pigs, Goats, Sheep; groups which, if
double, ought to have what they have not, namely, different
appellations; and which, if single, prove that Wildness and
Tameness do not amount to specific differences. And whatever
single element we take as a basis of division the same difficulty
will occur.
The method then that we must adopt is to attempt to recognize
the natural groups, following the indications afforded by the
instincts of mankind, which led them for instance to form the
class of Birds and the class of Fishes, each of which groups
combines a multitude of differentiae, and is not defined by a
single one as in dichotomy. The method of dichotomy is either
impossible (for it would put a single group under different
divisions or contrary groups under the same division), or it only
furnishes a single ultimate differentia for each species, which
either alone or with its series of antecedents has to constitute
the ultimate species.
If, again, a new differential character be introduced at any stage
into the division, the necessary result is that the continuity of
the division becomes merely a unity and continuity of
agglomeration, like the unity and continuity of a series of
sentences coupled together by conjunctive particles. For
instance, suppose we have the bifurcation Feathered and
Featherless, and then divide Feathered into Wild and Tame, or
into White and Black. Tame and White are not a differentiation
of Feathered, but are the commencement of an independent
bifurcation, and are foreign to the series at the end of which
they are introduced.
1806
As we said then, we must define at the outset by multiplicity of
differentiae. If we do so, privative terms will be available, which
are unavailable to the dichotomist.
The impossibility of reaching the definition of any of the
ultimate forms by dichotomy of the larger group, as some
propose, is manifest also from the following considerations. It is
impossible that a single differentia, either by itself or with its
antecedents, shall express the whole essence of a species. (In
saying a single differentia by itself I mean such an isolated
differentia as Cleft-footed; in saying a single differentia with
antecedent I mean, to give an instance, Manycleft-footed
preceded by Cleft-footed. The very continuity of a series of
successive differentiae in a division is intended to show that it
is their combination that expresses the character of the
resulting unit, or ultimate group. But one is misled by the
usages of language into imagining that it is merely the final
term of the series, Manycleft-footed for instance, that
constitutes the whole differentia, and that the antecedent
terms, Footed, Cleft-footed, are superfluous. Now it is evident
that such a series cannot consist of many terms. For if one
divides and subdivides, one soon reaches the final differential
term, but for all that will not have got to the ultimate division,
that is, to the species.) No single differentia, I repeat, either by
itself or with its antecedents, can possibly express the essence
of a species. Suppose, for example, Man to be the animal to be
defined; the single differentia will be Cleft-footed, either by
itself or with its antecedents, Footed and Two-footed. Now if
man was nothing more than a Cleft-footed animal, this single
differentia would duly represent his essence. But seeing that
this is not the case, more differentiae than this one will
necessarily be required to define him; and these cannot come
under one division; for each single branch of a dichotomy ends
in a single differentia, and cannot possibly include several
differentiae belonging to one and the same animal.
1807
It is impossible then to reach any of the ultimate animal forms
by dichotomous division.
It deserves inquiry why a single name denoting a higher group
was not invented by mankind, as an appellation to comprehend
the two groups of Water animals and Winged animals. For even
these have certain attributes in common. However, the present
nomenclature is just. Groups that only differ in degree, and in
the more or less of an identical element that they possess, are
aggregated under a single class; groups whose attributes are not
identical but analogous are separated. For instance, bird differs
from bird by gradation, or by excess and defect; some birds have
long feathers, others short ones, but all are feathered. Bird and
Fish are more remote and only agree in having analogous
organs; for what in the bird is feather, in the fish is scale. Such
analogies can scarcely, however, serve universally as indications
for the formation of groups, for almost all animals present
analogies in their corresponding parts.
The individuals comprised within a species, such as Socrates
and Coriscus, are the real existences; but inasmuch as these
individuals possess one common specific form, it will suffice to
state the universal attributes of the species, that is, the
attributes common to all its individuals, once for all, as
otherwise there will be endless reiteration, as has already been
pointed out.
But as regards the larger groups - such as Birds - which
comprehend many species, there may be a question. For on the
one hand it may be urged that as the ultimate species represent
the real existences, it will be well, if practicable, to examine
1808
these ultimate species separately, just as we examine the
species Man separately; to examine, that is, not the whole class
Birds collectively, but the Ostrich, the Crane, and the other
indivisible groups or species belonging to the class.
On the other hand, however, this course would involve repeated
mention of the same attribute, as the same attribute is common
to many species, and so far would be somewhat irrational and
tedious. Perhaps, then, it will be best to treat generically the
universal attributes of the groups that have a common nature
and contain closely allied subordinate forms, whether they are
groups recognized by a true instinct of mankind, such as Birds
and Fishes, or groups not popularly known by a common
appellation, but withal composed of closely allied subordinate
groups; and only to deal individually with the attributes of a
single species, when such species, man, for instance, and any
other such, if such there be - stands apart from others, and does
not constitute with them a larger natural group.
It is generally similarity in the shape of particular organs, or of
the whole body, that has determined the formation of the larger
groups. It is in virtue of such a similarity that Birds, Fishes,
Cephalopoda, and Testacea have been made to form each a
separate class. For within the limits of each such class, the parts
do not differ in that they have no nearer resemblance than that
of analogy - such as exists between the bone of man and the
spine of fish - but differ merely in respect of such corporeal
conditions as largeness smallness, softness hardness,
smoothness roughness, and other similar oppositions, or, in one
word, in respect of degree.
We have now touched upon the canons for criticizing the
method of natural science, and have considered what is the
most systematic and easy course of investigation; we have also
dealt with division, and the mode of conducting it so as best to
1809
attain the ends of science, and have shown why dichotomy is
either impracticable or inefficacious for its professed purposes.
Having laid this foundation, let us pass on to our next topic.
Of things constituted by nature some are ungenerated,
imperishable, and eternal, while others are subject to
generation and decay. The former are excellent beyond compare
and divine, but less accessible to knowledge. The evidence that
might throw light on them, and on the problems which we long
to solve respecting them, is furnished but scantily by sensation;
whereas respecting perishable plants and animals we have
abundant information, living as we do in their midst, and ample
data may be collected concerning all their various kinds, if only
we are willing to take sufficient pains. Both departments,
however, have their special charm. The scanty conceptions to
which we can attain of celestial things give us, from their
excellence, more pleasure than all our knowledge of the world
in which we live; just as a half glimpse of persons that we love
is more delightful than a leisurely view of other things,
whatever their number and dimensions. On the other hand, in
certitude and in completeness our knowledge of terrestrial
things has the advantage. Moreover, their greater nearness and
affinity to us balances somewhat the loftier interest of the
heavenly things that are the objects of the higher philosophy.
Having already treated of the celestial world, as far as our
conjectures could reach, we proceed to treat of animals, without
omitting, to the best of our ability, any member of the kingdom,
however ignoble. For if some have no graces to charm the sense,
yet even these, by disclosing to intellectual perception the
1810
artistic spirit that designed them, give immense pleasure to all
who can trace links of causation, and are inclined to philosophy.
Indeed, it would be strange if mimic representations of them
were attractive, because they disclose the mimetic skill of the
painter or sculptor, and the original realities themselves were
not more interesting, to all at any rate who have eyes to discern
the reasons that determined their formation. We therefore must
not recoil with childish aversion from the examination of the
humbler animals. Every realm of nature is marvellous: and as
Heraclitus, when the strangers who came to visit him found
him warming himself at the furnace in the kitchen and
hesitated to go in, reported to have bidden them not to be afraid
to enter, as even in that kitchen divinities were present, so we
should venture on the study of every kind of animal without
distaste; for each and all will reveal to us something natural and
something beautiful. Absence of haphazard and conduciveness
of everything to an end are to be found in Nature's works in the
highest degree, and the resultant end of her generations and
combinations is a form of the beautiful.
If any person thinks the examination of the rest of the animal
kingdom an unworthy task, he must hold in like disesteem the
study of man. For no one can look at the primordia of the
human frame - blood, flesh, bones, vessels, and the like -
without much repugnance. Moreover, when any one of the parts
or structures, be it which it may, is under discussion, it must not
be supposed that it is its material composition to which
attention is being directed or which is the object of the
discussion, but the relation of such part to the total form.
Similarly, the true object of architecture is not bricks, mortar, or
timber, but the house; and so the principal object of natural
philosophy is not the material elements, but their composition,
and the totality of the form, independently of which they have
no existence.
1811
The course of exposition must be first to state the attributes
common to whole groups of animals, and then to attempt to
give their explanation. Many groups, as already noticed, present
common attributes, that is to say, in some cases absolutely
identical affections, and absolutely identical organs, - feet,
feathers, scales, and the like - while in other groups the
affections and organs are only so far identical as that they are
analogous. For instance, some groups have lungs, others have
no lung, but an organ analogous to a lung in its place; some
have blood, others have no blood, but a fluid analogous to blood,
and with the same office. To treat of the common attributes in
connexion with each individual group would involve, as already
suggested, useless iteration. For many groups have common
attributes. So much for this topic.
As every instrument and every bodily member subserves some
partial end, that is to say, some special action, so the whole
body must be destined to minister to some Plenary sphere of
action. Thus the saw is made for sawing, for sawing is a
function, and not sawing for the saw. Similarly, the body too
must somehow or other be made for the soul, and each part of
it for some subordinate function, to which it is adapted.
We have, then, first to describe the common functions,
common, that is, to the whole animal kingdom, or to certain
large groups, or to the members of a species. In other words, we
have to describe the attributes common to all animals, or to
assemblages, like the class of Birds, of closely allied groups
differentiated by gradation, or to groups like Man not
differentiated into subordinate groups. In the first case the
common attributes may be called analogous, in the second
generic, in the third specific.
When a function is ancillary to another, a like relation
manifestly obtains between the organs which discharge these
1812
functions; and similarly, if one function is prior to and the end
of another, their respective organs will stand to each other in
the same relation. Thirdly, the existence of these parts involves
that of other things as their necessary consequents.
Instances of what I mean by functions and affections are
Reproduction, Growth, Copulation, Waking, Sleep, Locomotion,
and other similar vital actions. Instances of what I mean by
parts are Nose, Eye, Face, and other so-called members or limbs,
and also the more elementary parts of which these are made.
So much for the method to be pursued. Let us now try to set
forth the causes of all vital phenomena, whether universal or
particular, and in so doing let us follow that order of exposition
which conforms, as we have indicated, to the order of nature.
Book II
The nature and the number of the parts of which animals are
severally composed are matters which have already been set
forth in detail in the book of Researches about Animals. We
have now to inquire what are the causes that in each case have
determined this composition, a subject quite distinct from that
dealt with in the Researches.
Now there are three degrees of composition; and of these the
first in order, as all will allow, is composition out of what some
1813
call the elements, such as earth, air, water, fire. Perhaps,
however, it would be more accurate to say composition out of
the elementary forces; nor indeed out of all of these, but out of a
limited number of them, as defined in previous treatises. For
fluid and solid, hot and cold, form the material of all composite
bodies; and all other differences are secondary to these, such
differences, that is, as heaviness or lightness, density or rarity,
roughness or smoothness, and any other such properties of
matter as there may be. second degree of composition is that by
which the homogeneous parts of animals, such as bone, flesh,
and the like, are constituted out of the primary substances. The
third and last stage is the composition which forms the
heterogeneous parts, such as face, hand, and the rest.
Now the order of actual development and the order of logical
existence are always the inverse of each other. For that which is
posterior in the order of development is antecedent in the order
of nature, and that is genetically last which in nature is first.
(That this is so is manifest by induction; for a house does not
exist for the sake of bricks and stones, but these materials for
the sake of the house; and the same is the case with the
materials of other bodies. Nor is induction required to show
this, it is included in our conception of generation. For
generation is a process from a something to a something; that
which is generated having a cause in which it originates and a
cause in which it ends. The originating cause is the primary
efficient cause, which is something already endowed with
tangible existence, while the final cause is some definite form
or similar end; for man generates man, and plant generates
plant, in each case out of the underlying material.)
In order of time, then, the material and the generative process
must necessarily be anterior to the being that is generated; but
in logical order the definitive character and form of each being
1814
precedes the material. This is evident if one only tries to define
the process of formation. For the definition of house-building
includes and presupposes that of the house; but the definition
of the house does not include nor presuppose that of house-
building; and the same is true of all other productions. So that it
must necessarily be that the elementary material exists for the
sake of the homogeneous parts, seeing that these are
genetically posterior to it, just as the heterogeneous parts are
posterior genetically to them. For these heterogeneous parts
have reached the end and goal, having the third degree of
composition, in which degree generation or development often
attains its final term.
Animals, then, are composed of homogeneous parts, and are
also composed of heterogeneous parts. The former, however,
exist for the sake of the latter. For the active functions and
operations of the body are carried on by these; that is, by the
heterogeneous parts, such as the eye, the nostril, the whole face,
the fingers, the hand, and the whole arm. But inasmuch as
there is a great variety in the functions and motions not only of
aggregate animals but also of the individual organs, it is
necessary that the substances out of which these are composed
shall present a diversity of properties. For some purposes
softness is advantageous, for others hardness; some parts must
be capable of extension, others of flexion. Such properties, then,
are distributed separately to the different homogeneous parts,
one being soft another hard, one fluid another solid, one viscous
another brittle; whereas each of the heterogeneous parts
presents a combination of multifarious properties. For the hand,
to take an example, requires one property to enable it to effect
pressure, and another and different property for simple
prehension. For this reason the active or executive parts of the
body are compounded out of bones, sinews, flesh, and the like,
but not these latter out of the former.
1815
So far, then, as has yet been stated, the relations between these
two orders of parts are determined by a final cause. We have,
however, to inquire whether necessity may not also have a
share in the matter; and it must be admitted that these mutual
relations could not from the very beginning have possibly been
other than they are. For heterogeneous parts can be made up
out of homogeneous parts, either from a plurality of them, or
from a single one, as is the case with some of the viscera which,
varying in configuration, are yet, to speak broadly, formed from
a single homogeneous substance; but that homogeneous
substances should be formed out of a combination of
heterogeneous parts is clearly an impossibility. For these
causes, then, some parts of animals are simple and
homogeneous, while others are composite and heterogeneous;
and dividing the parts into the active or executive and the
sensitive, each one of the former is, as before said,
heterogeneous, and each one of the latter homogeneous. For it
is in homogeneous parts alone that sensation can occur, as the
following considerations show.
Each sense is confined to a single order of sensibles, and its
organ must be such as to admit the action of that kind or order.
But it is only that which is endowed with a property in posse
that is acted on by that which has the like property in esse, so
that the two are the same in kind, and if the latter is single so
also is the former. Thus it is that while no physiologists ever
dream of saying of the hand or face or other such part that one
is earth, another water, another fire, they couple each separate
sense-organ with a separate element, asserting this one to be
air and that other to be fire.
Sensation, then, is confined to the simple or homogeneous
parts. But, as might reasonably be expected, the organ of touch,
though still homogeneous, is yet the least simple of all the
sense-organs. For touch more than any other sense appears to
1816
be correlated to several distinct kinds of objects, and to
recognize more than one category of contrasts, heat and cold,
for instance, solidity and fluidity, and other similar oppositions.
Accordingly, the organ which deals with these varied objects is
of all the sense-organs the most corporeal, being either the
flesh, or the substance which in some animals takes the place
of flesh.
Now as there cannot possibly be an animal without sensation, it
follows as a necessary consequence that every animal must
have some homogeneous parts; for these alone are capable of
sensation, the heterogeneous parts serving for the active
functions. Again, as the sensory faculty, the motor faculty, and
the nutritive faculty are all lodged in one and the same part of
the body, as was stated in a former treatise, it is necessary that
the part which is the primary seat of these principles shall on
the one hand, in its character of general sensory recipient, be
one of the simple parts; and on the other hand shall, in its
motor and active character, be one of the heterogeneous parts.
For this reason it is the heart which in sanguineous animals
constitutes this central part, and in bloodless animals it is that
which takes the place of a heart. For the heart, like the other
viscera, is one of the homogeneous parts; for, if cut up, its pieces
are homogeneous in substance with each other. But it is at the
same time heterogeneous in virtue of its definite configuration.
And the same is true of the other so-called viscera, which are
indeed formed from the same material as the heart. For all
these viscera have a sanguineous character owing to their being
situated upon vascular ducts and branches. For just as a stream
of water deposits mud, so the various viscera, the heart
excepted, are, as it were, deposits from the stream of blood in
the vessels. And as to the heart, the very starting-point of the
vessels, and the actual seat of the force by which the blood is
first fabricated, it is but what one would naturally expect, that
out of the selfsame nutriment of which it is the recipient its
1817
own proper substance shall be formed. Such, then, are the
reasons why the viscera are of sanguineous aspect; and why in
one point of view they are homogeneous, in another
heterogeneous.
Of the homogeneous parts of animals, some are soft and fluid,
others hard and solid; and of the former some are fluid
permanently, others only so long as they are in the living body.
Such are blood, serum, lard, suet, marrow, semen, bile, milk
when present, flesh, and their various analogues. For the parts
enumerated are not to be found in all animals, some animals
only having parts analogous to them. Of the hard and solid
homogeneous parts bone, fish-spine, sinew, blood-vessel, are
examples. The last of these points to a sub-division that may be
made in the class of homogeneous parts. For in some of them
the whole and a portion of the whole in one sense are
designated by the same term - as, for example, is the case with
blood-vessel and bit of blood-vessel - while in another sense
they are not; but a portion of a heterogeneous part, such as face,
in no sense has the same designation as the whole.
The first question to be asked is what are the causes to which
these homogeneous parts owe their existence? The causes are
various; and this whether the parts be solid or fluid. Thus one
set of homogeneous parts represent the material out of which
the heterogeneous parts are formed; for each separate organ is
constructed of bones, sinews, flesh, and the like; which are
either essential elements in its formation, or contribute to the
proper discharge of its function. A second set are the nutriment
of the first, and are invariably fluid, for all growth occurs at the
1818
expense of fluid matter; while a third set are the residue of the
second. Such, for instance, are the faeces and, in animals that
have a bladder, the urine; the former being the dregs of the solid
nutriment, the latter of the fluid.
Even the individual homogeneous parts present variations,
which are intended in each case to render them more
serviceable for their purpose. The variations of the blood may be
selected to illustrate this. For different bloods differ in their
degrees of thinness or thickness, of clearness or turbidity, of
coldness or heat; and this whether we compare the bloods from
different parts of the same individual or the bloods of different
animals. For, in the individual, all the differences just
enumerated distinguish the blood of the upper and of the lower
halves of the body; and, dealing with classes, one section of
animals is sanguineous, while the other has no blood, but only
something resembling it in its place. As regards the results of
such differences, the thicker and the hotter blood is, the more
conducive is it to strength, while in proportion to its thinness
and its coldness is its suitability for sensation and intelligence.
A like distinction exists also in the fluid which is analogous to
blood. This explains how it is that bees and other similar
creatures are of a more intelligent nature than many
sanguineous animals; and that, of sanguineous animals, those
are the most intelligent whose blood is thin and cold. Noblest of
all are those whose blood is hot, and at the same time thin and
clear. For such are suited alike for the development of courage
and of intelligence. Accordingly, the upper parts are superior in
these respects to the lower, the male superior to the female, and
the right side to the left. As with the blood so also with the
other parts, homogeneous and heterogeneous alike. For here
also such variations as occur must be held either to be related
to the essential constitution and mode of life of the several
animals, or, in other cases, to be merely matters of slightly
better or slightly worse. Two animals, for instance, may have
1819
eyes. But in one these eyes may be of fluid consistency, while in
the other they are hard; and in one there may be eyelids, in the
other no such appendages. In such a case, the fluid consistency
and the presence of eyelids, which are intended to add to the
accuracy of vision, are differences of degree. As to why all
animals must of necessity have blood or something of a similar
character, and what the nature of blood may be, these are
matters which can only be considered when we have first
discussed hot and cold. For the natural properties of many
substances are referable to these two elementary principles;
and it is a matter of frequent dispute what animals or what
parts of animals are hot and what cold. For some maintain that
water animals are hotter than such as live on land, asserting
that their natural heat counterbalances the coldness of their
medium; and again, that bloodless animals are hotter than
those with blood, and females than males. Parmenides, for
instance, and some others declare that women are hotter than
men, and that it is the warmth and abundance of their blood
which causes their menstrual flow, while Empedocles maintains
the opposite opinion. Again, comparing the blood and the bile,
some speak of the former as hot and of the latter as cold, while
others invert the description. If there be this endless disputing
about hot and cold, which of all things that affect our senses are
the most distinct, what are we to think as to our other sensory
impressions?
The explanation of the difficulty appears to be that the term
'hotter' is used in several senses; so that different statements,
though in verbal contradiction with each other, may yet all be
more or less true. There ought, then, to be some clear
understanding as to the sense in which natural substances are
to be termed hot or cold, solid or fluid. For it appears manifest
that these are properties on which even life and death are
largely dependent, and that they are moreover the causes of
sleep and waking, of maturity and old age, of health and
1820
disease; while no similar influence belongs to roughness and
smoothness, to heaviness and lightness, nor, in short, to any
other such properties of matter. That this should be so is but in
accordance with rational expectation. For hot and cold, solid
and fluid, as was stated in a former treatise, are the foundations
of the physical elements.
Is then the term hot used in one sense or in many? To answer
this we must ascertain what special effect is attributed to a
hotter substance, and if there be several such, how many these
may be. A body then is in one sense said to be hotter than
another, if it impart a greater amount of heat to an object in
contact with it. In a second sense, that is said to be hotter which
causes the keener sensation when touched, and especially if the
sensation be attended with pain. This criterion, however, would
seem sometimes to be a false one; for occasionally it is the
idiosyncrasy of the individual that causes the sensation to be
painful. Again, of two things, that is the hotter which the more
readily melts a fusible substance, or sets on fire an inflammable
one. Again, of two masses of one and the same substance, the
larger is said to have more heat than the smaller. Again, of two
bodies, that is said to be the hotter which takes the longer time
in cooling, as also we call that which is rapidly heated hotter
than that which is long about it; as though the rapidity implied
proximity and this again similarity of nature, while the want of
rapidity implied distance and this again dissimilarity of nature.
The term hotter is used then in all the various senses that have
been mentioned, and perhaps in still more. Now it is impossible
for one body to be hotter than another in all these different
fashions. Boiling water for instance, though it is more scalding
than flame, yet has no power of burning or melting combustible
or fusible matter, while flame has. So again this boiling water is
hotter than a small fire, and yet gets cold more rapidly and
completely. For in fact fire never becomes cold; whereas water
invariably does so. Boiling water, again, is hotter to the touch
1821
than oil; yet it gets cold and solid more rapidly than this other
fluid. Blood, again, is hotter to the touch than either water or oil,
and yet coagulates before them. Iron, again, and stones and
other similar bodies are longer in getting heated than water, but
when once heated burn other substances with a much greater
intensity. Another distinction is this. In some of the bodies
which are called hot the heat is derived from without, while in
others it belongs to the bodies themselves; and it makes a most
important difference whether the heat has the former or the
latter origin. For to call that one of two bodies the hotter, which
is possessed of heat, we may almost say, accidentally and not of
its own essence, is very much the same thing as if, finding that
some man in a fever was a musician, one were to say that
musicians are hotter than healthy men. Of that which is hot per
se and that which is hot per accidens, the former is the slower
to cool, while not rarely the latter is the hotter to the touch. The
former again is the more burning of the two - flame, for
instance, as compared with boiling water - while the latter, as
the boiling water, which is hot per accidens, is the more heating
to the touch. From all this it is clear that it is no simple matter
to decide which of two bodies is the hotter. For the first may be
the hotter in one sense, the second the hotter in another.
Indeed in some of these cases it is impossible to say simply
even whether a thing is hot or not. For the actual substratum
may not itself be hot, but may be hot when coupled witb heat as
an attribute, as would be the case if one attached a single name
to hot water or hot iron. It is after this manner that blood is hot.
In such cases, in those, that is, in which the substratum owes its
heat to an external influence, it is plain that cold is not a mere
privation, but an actual existence.
There is no knowing but that even fire may be another of these
cases. For the substratum of fire may be smoke or charcoal, and
though the former of these is always hot, smoke being an
uprising vapour, yet the latter becomes cold when its flame is
1822
extinguished, as also would oil and pinewood under similar
circumstances. But even substances that have been burnt nearly
all possess some heat, cinders, for example, and ashes, the
dejections also of animals, and, among the excretions, bile;
because some residue of heat has been left in them after their
combustion. It is in another sense that pinewood and fat
substances are hot; namely, because they rapidly assume the
actuality of fire.
Heat appears to cause both coagulation and melting. Now such
things as are formed merely of water are solidified by cold,
while such as are formed of nothing but earth are solidified by
fire. Hot substances again are solidified by cold, and, when they
consist chiefly of earth, the process of solidification is rapid, and
the resulting substance is insoluble; but, when their main
constituent is water, the solid matter is again soluble. What
kinds of substances, however, admit of being solidified, and
what are the causes of solidification, are questions that have
already been dealt with more precisely in another treatise.
In conclusion, then, seeing that the terms hot and hotter are
used in many different senses, and that no one substance can
be hotter than others in all these senses, we must, when we
attribute this character to an object, add such further
statements as that this substance is hotter per se, though that
other is often hotter per accidens; or again, that this substance
is potentially hot, that other actually so; or again, that this
substance is hotter in the sense of causing a greater feeling of
heat when touched, while that other is hotter in the sense of
producing flame and burning. The term hot being used in all
these various senses, it plainly follows that the term cold will
also be used with like ambiguity.
So much then as to the signification of the terms hot and cold,
hotter and colder.
1823
In natural sequence we have next to treat of solid and fluid.
These terms are used in various senses. Sometimes, for
instance, they denote things that are potentially, at other times
things that are actually, solid or fluid. Ice for example, or any
other solidified fluid, is spoken of as being actually and
accidentally solid, while potentially and essentially it is fluid.
Similarly earth and ashes and the like, when mixed with water,
are actually and accidentally fluid, but potentially and
essentially are solid. Now separate the constituents in such a
mixture and you have on the one hand the watery components
to which its fluidity was due, and these are both actually and
potentially fluid, and on the other hand the earthy components,
and these are in every way solid; and it is to bodies that are
solid in this complete manner that the term 'solid' is most
properly and absolutely applicable. So also the opposite term
'fluid' is strictly and absolutely applicable to that only which is
both potentially and actually fluid. The same remark applies
also to hot bodies and to cold.
These distinctions, then, being laid down, it is plain that blood
is essentially hot in so far as that heat is connoted in its name;
just as if boiling water were denoted by a single term, boiling
would be connoted in that term. But the substratum of blood,
that which it is in substance while it is blood in form, is not hot.
Blood then in a certain sense is essentially hot, and in another
sense is not so. For heat is included in the definition of blood,
just as whiteness is included in the definition of a white man,
and so far therefore blood is essentially hot. But so far as blood
becomes hot from some external influence, it is not hot
essentially.
1824
As with hot and cold, so also is it with solid and fluid. We can
therefore understand how some substances are hot and fluid so
long as they remain in the living body, but become perceptibly
cold and coagulate so soon as they are separated from it; while
others are hot and consistent while in the body, but when
withdrawn under a change to the opposite condition, and
become cold and fluid. Of the former blood is an example, of the
latter bile; for while blood solidifies when thus separated,
yellow bile under the same circumstances becomes more fluid.
We must attribute to such substances the possession of
opposite properties in a greater or less degree.
In what sense, then, the blood is hot and in what sense fluid,
and how far it partakes of the opposite properties, has now
been fairly explained. Now since everything that grows must
take nourishment, and nutriment in all cases consists of fluid
and solid substances, and since it is by the force of heat that
these are concocted and changed, it follows that all living
things, animals and plants alike, must on this account, if on no
other, have a natural source of heat. This natural heat,
moreover, must belong to many parts, seeing that the organs by
which the various elaborations of the food are effected are
many in number. For first of all there is the mouth and the parts
inside the mouth, on which the first share in the duty clearly
devolves, in such animals at least as live on food which requires
disintegration. The mouth, however, does not actually concoct
the food, but merely facilitates concoction; for the subdivision
of the food into small bits facilitates the action of heat upon it.
After the mouth come the upper and the lower abdominal
cavities, and here it is that concoction is effected by the aid of
natural heat. Again, just as there is a channel for the admission
of the unconcocted food into the stomach, namely the mouth,
and in some animals the so-called oesophagus, which is
continuous with the mouth and reaches to the stomach, so
must there also be other and more numerous channels by
1825
which the concocted food or nutriment shall pass out of the
stomach and intestines into the body at large, and to which
these cavities shall serve as a kind of manger. For plants get
their food from the earth by means of their roots; and this food
is already elaborated when taken in, which is the reason why
plants produce no excrement, the earth and its heat serving
them in the stead of a stomach. But animals, with scarcely an
exception, and conspicuously all such as are capable of
locomotion, are provided with a stomachal sac, which is as it
were an internal substitute for the earth. They must therefore
have some instrument which shall correspond to the roots of
plants, with which they may absorb their food from this sac, so
that the proper end of the successive stages of concoction may
at last be attained. The mouth then, its duty done, passes over
the food to the stomach, and there must necessarily be
something to receive it in turn from this. This something is
furnished by the bloodvessels, which run throughout the whole
extent of the mesentery from its lowest part right up to the
stomach. A description of these will be found in the treatises on
Anatomy and Natural History. Now as there is a receptacle for
the entire matter taken as food, and also a receptacle for its
excremental residue, and again a third receptacle, namely the
vessels, which serve as such for the blood, it is plain that this
blood must be the final nutritive material in such animals as
have it; while in bloodless animals the same is the case with the
fluid which represents the blood. This explains why the blood
diminishes in quantity when no food is taken, and increases
when much is consumed, and also why it becomes healthy and
unhealthy according as the food is of the one or the other
character. These facts, then, and others of a like kind, make it
plain that the purpose of the blood in sanguineous animals is to
subserve the nutrition of the body. They also explain why no
more sensation is produced by touching the blood than by
touching one of the excretions or the food, whereas when the
1826
flesh is touched sensation is produced. For the blood is not
continuous nor united by growth with the flesh, but simply lies
loose in its receptacle, that is in the heart and vessels. The
manner in which the parts grow at the expense of the blood,
and indeed the whole question of nutrition, will find a more
suitable place for exposition in the treatise on Generation, and
in other writings. For our present purpose all that need be said
is that the blood exists for the sake of nutrition, that is the
nutrition of the parts; and with this much let us therefore
content ourselves.
What are called fibres are found in the blood of some animals
but not of all. There are none, for instance, in the blood of deer
and of roes; and for this reason the blood of such animals as
these never coagulates. For one part of the blood consists
mainly of water and therefore does not coagulate, this process
occurring only in the other and earthy constituent, that is to say
in the fibres, while the fluid part is evaporating.
Some at any rate of the animals with watery blood have a
keener intellect than those whose blood is of an earthier nature.
This is due not to the coldness of their blood, but rather to its
thinness and purity; neither of which qualities belongs to the
earthy matter. For the thinner and purer its fluid is, the more
easily affected is an animal's sensibility. Thus it is that some
bloodless animals, notwithstanding their want of blood, are yet
more intelligent than some among the sanguineous kinds. Such
for instance, as already said, is the case with the bee and the
tribe of ants, and whatever other animals there may be of a like
nature. At the same time too great an excess of water makes
1827
animals timorous. For fear chills the body; so that in animals
whose heart contains so watery a mixture the way is prepared
for the operation of this emotion. For water is congealed by cold.
This also explains why bloodless animals are, as a general rule,
more timorous than such as have blood, so that they remain
motionless, when frightened, and discharge their excretions,
and in some instances change colour. Such animals, on the
other hand, as have thick and abundant fibres in their blood are
of a more earthy nature, and of a choleric temperament, and
liable to bursts of passion. For anger is productive of heat; and
solids, when they have been made hot, give off more heat than
fluids. The fibres therefore, being earthy and solid, are turned
into so many hot embers in the blood, like the embers in a
vapour-bath, and cause ebullition in the fits of passion.
This explains why bulls and boars are so choleric and so
passionate. For their blood is exceedingly rich in fibres, and the
bull's at any rate coagulates more rapidly than that of any other
animal. If these fibres, that is to say if the earthy constituents of
which we are speaking, are taken out of the blood, the fluid that
remains behind will no longer coagulate; just as the watery
residue of mud will not coagulate after removal of the earth. But
if the fibres are left the fluid coagulates, as also does mud,
under the influence of cold. For when the heat is expelled by the
cold, the fluid, as has been already stated, passes off with it by
evaporation, and the residue is dried up and solidified, not by
heat but by cold. So long, however, as the blood is in the body, it
is kept fluid by animal heat.
The character of the blood affects both the temperament and
the sensory faculties of animals in many ways. This is indeed
what might reasonably be expected, seeing that the blood is the
material of which the whole body is made. For nutriment
supplies the material, and the blood is the ultimate nutriment.
1828
It makes then a considerable difference whether the blood be
hot or cold, thin or thick, turbid or clear.
The watery part of the blood is serum; and it is watery, either
owing to its not being yet concocted, or owing to its having
become corrupted; so that one part of the serum is the resultant
of a necessary process, while another part is material intended
to serve for the formation of the blood.
The differences between lard and suet correspond to
differences of blood. For both are blood concocted into these
forms as a result of abundant nutrition, being that surplus blood
that is not expended on the fleshy part of the body, and is of an
easily concocted and fatty character. This is shown by the
unctuous aspect of these substances; for such unctuous aspect
in fluids is due to a combination of air and fire. It follows from
what has been said that no non-sanguineous animals have
either lard or suet; for they have no blood. Among sanguineous
animals those whose blood is dense have suet rather than lard.
For suet is of an earthy nature, that is to say, it contains but a
small proportion of water and is chiefly composed of earth; and
this it is that makes it coagulate, just as the fibrous matter of
blood coagulates, or broths which contain such fibrous matter.
Thus it is that in those horned animals that have no front teeth
in the upper jaw the fat consists of suet. For the very fact that
they have horns and huckle-bones shows that their
composition is rich in this earthy element; for all such
appurtenances are solid and earthy in character. On the other
hand in those hornless animals that have front teeth in both
jaws, and whose feet are divided into toes, there is no suet, but
1829
in its place lard; and this, not being of an earthy character,
neither coagulates nor dries up into a friable mass.
Both lard and suet when present in moderate amount are
beneficial; for they contribute to health and strength, while they
are no hindrance to sensation. But when they are present in
great excess, they are injurious and destructive. For were the
whole body formed of them it would perish. For an animal is an
animal in virtue of its sensory part, that is in virtue of its flesh,
or of the substance analogous to flesh. But the blood, as before
stated, is not sensitive; as therefore is neither lard nor suet,
seeing that they are nothing but concocted blood. Were then the
whole body composed of these substances, it would be utterly
without sensation. Such animals, again, as are excessively fat
age rapidly. For so much of their blood is used in forming fat,
that they have but little left; and when there is but little blood
the way is already open for decay. For decay may be said to be
deficiency of blood, the scantiness of which renders it liable, like
all bodies of small bulk, to be injuriously affected by any chance
excess of heat or cold. For the same reason fat animals are less
prolific than others. For that part of the blood which should go
to form semen and seed is used up in the production of lard and
suet, which are nothing but concocted blood; so that in these
animals there is either no reproductive excretion at all, or only a
scanty amount.
So much then of blood and serum, and of lard and suet. Each of
these has been described, and the purposes told for which they
severally exist. The marrow also is of the nature of blood, and
not, as some think, the germinal force of the semen. That this is
1830
the case is quite evident in very young animals. For in the
embryo the marrow of the bones has a blood-like appearance,
which is but natural, seeing that the parts are all constructed
out of blood, and that it is on blood that the embryo is
nourished. But, as the young animal grows up and ripens into
maturity, the marrow changes its colour, just as do the external
parts and the viscera. For the viscera also in animals, so long as
they are young, have each and all a blood-like look, owing to the
large amount of this fluid which they contain.
The consistency of the marrow agrees with that of the fat. For
when the fat consists of lard, then the marrow also is unctuous
and lard-like; but when the blood is converted by concoction
into suet, and does not assume the form of lard, then the
marrow also has a suety character. In those animals, therefore,
that have horns and are without upper front teeth, the marrow
has the character of suet; while it takes the form of lard in those
that have front teeth in both jaws, and that also have the foot
divided into toes. What has ben said hardly applies to the spinal
marrow. For it is necessary that this shall be continuous and
extend without break through the whole backbone, inasmuch
as this bone consists of separate vertebrae. But were the spinal
marrow either of unctuous fat or of suet, it could not hold
together in such a continuous mass as it does, but would either
be too fluid or too frangible.
There are some animals that can hardly be said to have any
marrow. These are those whose bones are strong and solid, as is
the case with the lion. For in this animal the marrow is so
utterly insignificant that the bones look as though they had
none at all. However, as it is necessary that animals shall have
bones or something analogous to them, such as the fish-spines
of water-animals, it is also a matter of necessity that some of
these bones shall contain marrow; for the substance contained
within the bones is the nutriment out of which these are
1831
formed. Now the universal nutriment, as already stated, is
blood; and the blood within the bone, owing to the heat which
is developed in it from its being thus surrounded, undergoes
concoction, and self-concocted blood is suet or lard; so that it is
perfectly intelligible how the marrow within the bone comes to
have the character of these substances. So also it is easy to
understand why, in those animals that have strong and
compact bones, some of these should be entirely void of
marrow, while the rest contain but little of it; for here the
nutriment is spent in forming the bones.
Those animals that have fish-spines in place of bones have no
other marrow than that of the chine. For in the first place they
have naturally but a small amount of blood; and secondly the
only hollow fish-spine is that of the chine. In this then marrow
is formed; this being the only spine in which there is space for
it, and, moreover, being the only one which owing to its division
into parts requires a connecting bond. This too is the reason
why the marrow of the chine, as already mentioned, is
somewhat different from that of other bones. For, having to act
the part of a clasp, it must be of glutinous character, and at the
same time sinewy so as to admit of stretching.
Such then are the reasons for the existence of marrow, in those
animals that have any, and such its nature. It is evidently the
surplus of the sanguineous nutriment apportioned to the bones
and fish-spines, which has undergone concoction owing to its
being enclosed within them.
From the marrow we pass on in natural sequence to the brain.
For there are many who think that the brain itself consists of
1832
marrow, and that it forms the commencement of that
substance, because they see that the spinal marrow is
continuous with it. In reality the two may be said to be utterly
opposite to each other in character. For of all the parts of the
body there is none so cold as the brain; whereas the marrow is
of a hot nature, as is plainly shown by its fat and unctuous
character. Indeed this is the very reason why the brain and
spinal marrow are continuous with each other. For, wherever
the action of any part is in excess, nature so contrives as to set
by it another part with an excess of contrary action, so that the
excesses of the two may counterbalance each other. Now that
the marrow is hot is clearly shown by many indications. The
coldness of the brain is also manifest enough. For in the first
place it is cold even to the touch; and, secondly, of all the fluid
parts of the body it is the driest and the one that has the least
blood; for in fact it has no blood at all in its proper substance.
This brain is not residual matter, nor yet is it one of the parts
which are anatomically continuous with each other; but it has a
character peculiar to itself, as might indeed be expected. That it
has no continuity with the organs of sense is plain from simple
inspection, and is still more clearly shown by the fact, that,
when it is touched, no sensation is produced; in which respect it
resembles the blood of animals and their excrement. The
purpose of its presence in animals is no less than the
preservation of the whole body. For some writers assert that the
soul is fire or some such force. This, however, is but a rough and
inaccurate assertion; and it would perhaps be better to say that
the soul is incorporate in some substance of a fiery character.
The reason for this being so is that of all substances there is
none so suitable for ministering to the operations of the soul as
that which is possessed of heat. For nutrition and the imparting
of motion are offices of the soul, and it is by heat that these are
most readily effected. To say then that the soul is fire is much
the same thing as to confound the auger or the saw with the
1833
carpenter or his craft, simply because the work is wrought by
the two in conjunction. So far then this much is plain, that all
animals must necessarily have a certain amount of heat. But as
all influences require to be counterbalanced, so that they may
be reduced to moderation and brought to the mean (for in the
mean, and not in either extreme, lies the true and rational
position), nature has contrived the brain as a counterpoise to
the region of the heart with its contained heat, and has given it
to animals to moderate the latter, combining in it the properties
of earth and water. For this reason it is, that every sanguineous
animal has a brain; whereas no bloodless creature has such an
organ, unless indeed it be, as the Poulp, by analogy. For where
there is no blood, there in consequence there is but little heat.
The brain, then, tempers the heat and seething of the heart. In
order, however, that it may not itself be absolutely without heat,
but may have a moderate amount, branches run from both
blood-vessels, that is to say from the great vessel and from what
is called the aorta, and end in the membrane which surrounds
the brain; while at the same time, in order to prevent any injury
from the heat, these encompassing vessels, instead of being few
and large, are numerous and small, and their blood scanty and
clear, instead of being abundant and thick. We can now
understand why defluxions have their origin in the head, and
occur whenever the parts about the brain have more than a due
proportion of coldness. For when the nutriment steams
upwards through the blood-vessels, its refuse portion is chilled
by the influence of this region, and forms defluxions of phlegm
and serum. We must suppose, to compare small things with
great, that the like happens here as occurs in the production of
showers. For when vapour steams up from the earth and is
carried by the heat into the upper regions, so soon as it reaches
the cold air that is above the earth, it condenses again into
water owing to the refrigeration, and falls back to the earth as
rain. These, however, are matters which may be suitably
1834
considered in the Principles of Diseases, so far as natural
philosophy has anything to say to them.
It is the brain again - or, in animals that have no brain, the part
analogous to it - which is the cause of sleep. For either by
chilling the blood that streams upwards after food, or by some
other similar influences, it produces heaviness in the region in
which it lies (which is the reason why drowsy persons hang the
head), and causes the heat to escape downwards in company
with the blood. It is the accumulation of this in excess in the
lower region that produces complete sleep, taking away the
power of standing upright from those animals to whom that
posture is natural, and from the rest the power of holding up
the head. These, however, are matters which have been
separately considered in the treatises on Sensation and on
Sleep.
That the brain is a compound of earth and water is shown by
what occurs when it is boiled. For, when so treated, it turns hard
and solid, inasmuch as the water is evaporated by the heat, and
leaves the earthy part behind. Just the same occurs when pulse
and other fruits are boiled. For these also are hardened by the
process, because the water which enters into their composition
is driven off and leaves the earth, which is their main
constituent, behind.
Of all animals, man has the largest brain in proportion to his
size; and it is larger in men than in women. This is because the
region of the heart and of the lung is hotter and richer in blood
in man than in any other animal; and in men than in women.
This again explains why man, alone of animals, stands erect.
For the heat, overcoming any opposite inclination, makes
growth take its own line of direction, which is from the centre of
the body upwards. It is then as a counterpoise to his excessive
heat that in man's brain there is this superabundant fluidity
1835
and coldness; and it is again owing to this superabundance that
the cranial bone, which some call the Bregma, is the last to
become solidified; so long does evaporation continue to occur
through it under the influence of heat. Man is the only
sanguineous animal in which this takes place. Man, again, has
more sutures in his skull than any other animal, and the male
more than the female. The explanation is again to be found in
the greater size of the brain, which demands free ventilation,
proportionate to its bulk. For if the brain be either too fluid or
too solid, it will not perform its office, but in the one case will
freeze the blood, and in the other will not cool it at all; and thus
will cause disease, madness, and death. For the cardiac heat
and the centre of life is most delicate in its sympathies, and is
immediately sensitive to the slightest change or affection of the
blood on the outer surface of the brain.
The fluids which are present in the animal body at the time of
birth have now nearly all been considered. Amongst those that
appear only at a later period are the residua of the food, which
include the deposits of the belly and also those of the bladder.
Besides these there is the semen and the milk, one or the other
of which makes its appearance in appropriate animals. Of these
fluids the excremental residua of the food may be suitably
discussed by themselves, when we come to examine and
consider the subject of nutrition. Then will be the time to
explain in what animals they are found, and what are the
reasons for their presence. Similarly all questions concerning
the semen and the milk may be dealt with in the treatise on
Generation, for the former of these fluids is the very starting-
point of the generative process, and the latter has no other
ground of existence than generative purposes.
1836
8
We have now to consider the remaining homogeneous parts,
and will begin with flesh, and with the substance that, in
animals that have no flesh, takes its place. The reason for so
beginning is that flesh forms the very basis of animals, and is
the essential constituent of their body. Its right to this
precedence can also be demonstrated logically. For an animal is
by our definition something that has sensibility and chief of all
the primary sensibility, which is that of Touch; and it is the
flesh, or analogous substance, which is the organ of this sense.
And it is the organ, either in the same way as the pupil is the
organ of sight, that is it constitutes the primary organ of the
sense; or it is the organ and the medium through which the
object acts combined, that is it answers to the pupil with the
whole transparent medium attached to it. Now in the case of
the other senses it was impossible for nature to unite the
medium with the sense-organ, nor would such a junction have
served any purpose; but in the case of touch she was compelled
by necessity to do so. For of all the sense-organs that of touch is
the only one that has corporeal substance, or at any rate it is
more corporeal than any other, and its medium must be
corporeal like itself.
It is obvious also to sense that it is for the sake of the flesh that
all the other parts exist. By the other parts I mean the bones,
the skin, the sinews, and the blood-vessels, and, again, the hair
and the various kinds of nails, and anything else there may be
of a like character. Thus the bones are a contrivance to give
security to the soft parts, to which purpose they are adapted by
their hardness; and in animals that have no bones the same
office is fulfilled by some analogous substance, as by fishspine
in some fishes, and by cartilage in others.
1837
Now in some animals this supporting substance is situated
within the body, while in some of the bloodless species it is
placed on the outside. The latter is the case in all the Crustacea,
as the Carcini (Crabs) and the Carabi (Prickly Lobsters); it is the
case also in the Testacea, as for instance in the several species
known by the general name of oysters. For in all these animals
the fleshy substance is within, and the earthy matter, which
holds the soft parts together and keeps them from injury, is on
the outside. For the shell not only enables the soft parts to hold
together, but also, as the animal is bloodless and so has but
little natural warmth, surrounds it, as a chaufferette does the
embers, and keeps in the smouldering heat. Similar to this
seems to be the arrangement in another and distinct tribe of
animals, namely the Tortoises, including the Chelone and the
several kinds of Emys. But in Insects and in Cephalopods the
plan is entirely different, there being moreover a contrast
between these two themselves. For in neither of these does
there appear to be any bony or earthy part, worthy of notice,
distinctly separated from the rest of the body. Thus in the
Cephalopods the main bulk of the body consists of a soft flesh-
like substance, or rather of a substance which is intermediate to
flesh and sinew, so as not to be so readily destructible as actual
flesh. I call this substance intermediate to flesh and sinew,
because it is soft like the former, while it admits of stretching
like the latter. Its cleavage, however, is such that it splits not
longitudinally, like sinew, but into circular segments, this being
the most advantageous condition, so far as strength is
concerned. These animals have also a part inside them
corresponding to the spinous bones of fishes. For instance, in
the Cuttle-fishes there is what is known as the os sepiae, and in
the Calamaries there is the so-called gladius. In the Poulps, on
the other hand, there is no such internal part, because the body,
or, as it is termed in them, the head, forms but a short sac,
whereas it is of considerable length in the other two; and it was
1838
this length which led nature to assign to them their hard
support, so as to ensure their straightness and inflexibility; just
as she has assigned to sanguineous animals their bones or their
fish-spines, as the case may be. To come now to Insects. In these
the arrangement is quite different from that of the
Cephalopods; quite different also from that which obtains in
sanguineous animals, as indeed has been already stated. For in
an insect there is no distinction into soft and hard parts, but the
whole body is hard, the hardness, however, being of such a
character as to be more flesh-like than bone, and more earthy
and bone-like than flesh. The purpose of this is to make the
body of the insect less liable to get broken into pieces.
There is a resemblance between the osseous and the vascular
systems; for each has a central part in which it begins, and each
forms a continuous whole. For no bone in the body exists as a
separate thing in itself, but each is either a portion of what may
be considered a continuous whole, or at any rate is linked with
the rest by contact and by attachments; so that nature may use
adjoining bones either as though they were actually continuous
and formed a single bone, or, for purposes of flexure, as though
they were two and distinct. And similarly no blood-vessel has in
itself a separate individuality; but they all form parts of one
whole. For an isolated bone, if such there were, would in the
first place be unable to perform the office for the sake of which
bones exist; for, were it discontinuous and separated from the
rest by a gap, it would be perfectly unable to produce either
flexure or extension; nor only so, but it would actually be
injurious, acting like a thorn or an arrow lodged in the flesh.
Similarly if a vessel were isolated, and not continuous with the
1839
vascular centre, it would be unable to retain the blood within it
in a proper state. For it is the warmth derived from this centre
that hinders the blood from coagulating; indeed the blood,
when withdrawn from its influence, becomes manifestly putrid.
Now the centre or origin of the blood-vessels is the heart, and
the centre or origin of the bones, in all animals that have bones,
is what is called the chine. With this all the other bones of the
body are in continuity; for it is the chine that holds together the
whole length of an animal and preserves its straightness. But
since it is necessary that the body of an animal shall bend
during locomotion, this chine, while it is one in virtue of the
continuity of its parts, yet its division into vertebrae is made to
consist of many segments. It is from this chine that the bones of
the limbs, in such animals as have these parts, proceed, and
with it they are continuous, being fastened together by the
sinews where the limbs admit of flexure, and having their
extremities adapted to each other, either by the one being
hollowed and the other rounded, or by both being hollowed and
including between them a hucklebone, as a connecting bolt, so
as to allow of flexure and extension. For without some such
arrangement these movements would be utterly impossible, or
at any rate would be performed with great difficulty. There are
some joints, again, in which the lower end of the one bone and
the upper end of the other are alike in shape. In these cases the
bones are bound together by sinews, and cartilaginous pieces
are interposed in the joint, to serve as a kind of padding, and
prevent the two extremities from grating against each other.
Round about the bones, and attached to them by thin fibrous
bands, grow the fleshy parts, for the sake of which the bones
themselves exist. For just as an artist, when he is moulding an
animal out of clay or other soft substance, takes first some solid
body as a basis, and round this moulds the clay, so also has
nature acted in fashioning the animal body out of flesh. Thus
we find all the fleshy parts, with one exception, supported by
1840
bones, which serve, when the parts are organs of motion, to
facilitate flexure, and, when the parts are motionless, act as a
protection. The ribs, for example, which enclose the chest are
intended to ensure the safety of the heart and neighbouring
viscera. The exception of which mention was made is the belly.
The walls of this are in all animals devoid of bones; in order
that there may be no hindrance to the expansion which
necessarily occurs in this part after a meal, nor, in females, any
interference with the growth of the foetus, which is lodged here.
Now the bones of viviparous animals, of such, that is, as are not
merely externally but also internally viviparous, vary but very
little from each other in point of strength, which in all of them
is considerable. For the Vivipara in their bodily proportions are
far above other animals, and many of them occasionally grow to
an enormous size, as is the case in Libya and in hot and dry
countries generally. But the greater the bulk of an animal, the
stronger, the bigger, and the harder, are the supports which it
requires; and comparing the big animals with each other, this
requirement will be most marked in those that live a life of
rapine. Thus it is that the bones of males are harder than those
of females; and the bones of flesh-eaters, that get their food by
fighting, are harder than those of Herbivora. Of this the Lion is
an example; for so hard are its bones, that, when struck, they
give off sparks, as though they were stones. It may be
mentioned also that the Dolphin, in as much as it is viviparous,
is provided with bones and not with fish-spines.
In those sanguineous animals, on the other hand, that are
oviparous, the bones present successive slight variations of
character. Thus in Birds there are bones, but these are not so
strong as the bones of the Vivipara. Then come the Oviparous
fishes, where there is no bone, but merely fish-spine. In the
Serpents too the bones have the character of fish-spine,
excepting in the very large species, where the solid foundation
1841
of the body requires to be stronger, in order that the animal
itself may be strong, the same reason prevailing as in the case
of the Vivipara. Lastly, in the Selachia, as they are called, the
fish-spines are replaced by cartilage. For it is necessary that the
movements of these animals shall be of an undulating
character; and this again requires the framework that supports
the body to be made of a pliable and not of a brittle substance.
Moreover, in these Selachia nature has used all the earthy
matter on the skin; and she is unable to allot to many different
parts one and the same superfluity of material. Even in
viviparous animals many of the bones are cartilaginous. This
happens in those parts where it is to the advantage of the
surrounding flesh that its solid base shall be soft and
mucilaginous. Such, for instance, is the case with the ears and
nostrils; for in projecting parts, such as these, brittle substances
would soon get broken. Cartilage and bone are indeed
fundamentally the same thing, the differences between them
being merely matters of degree. Thus neither cartilage nor bone,
when once cut off, grows again. Now the cartilages of these land
animals are without marrow, that is without any distinctly
separate marrow. For the marrow, which in bones is distinctly
separate, is here mixed up with the whole mass, and gives a soft
and mucilaginous consistence to the cartilage. But in the
Selachia the chine, though it is cartilaginous, yet contains
marrow; for here it stands in the stead of a bone.
Very nearly resembling the bones to the touch are such parts as
nails, hoofs, whether solid or cloven, horns, and the beaks of
birds, all of which are intended to serve as means of defence.
For the organs which are made out of these substances, and
which are called by the same names as the substances
themselves, the organ hoof, for instance, and the organ horn,
are contrivances to ensure the preservation of the animals to
which they severally belong. In this class too must be reckoned
the teeth, which in some animals have but a single function,
1842
namely the mastication of the food, while in others they have
an additional office, namely to serve as weapons; as is the case
with all animals that have sharp interfitting teeth or that have
tusks. All these parts are necessarily of solid and earthy
character; for the value of a weapon depends on such
properties. Their earthy character explains how it is that all
such parts are more developed in four-footed vivipara than in
man. For there is always more earth in the composition of these
animals than in that of the human body. However, not only all
these parts but such others as are nearly connected with them,
skin for instance, bladder, membrane, hairs, feathers, and their
analogues, and any other similar parts that there may be, will
be considered farther on with the heterogeneous parts. There
we shall inquire into the causes which produce them, and into
the objects of their presence severally in the bodies of animals.
For, as with the heterogeneous parts, so with these, it is from a
consideration of their functions that alone we can derive any
knowledge of them. The reason for dealing with them at all in
this part of the treatise, and classifying them with the
homogeneous parts, is that under one and the same name are
confounded the entire organs and the substances of which they
are composed. But of all these substances flesh and bone form
the basis. Semen and milk were also passed over when we were
considering the homogeneous fluids. For the treatise on
Generation will afford a more suitable place for their
examination, seeing that the former of the two is the very
foundation of the thing generated, while the latter is its
nourishment.
1843
10
Let us now make, as it were, a fresh beginning, and consider the
heterogeneous parts, taking those first which are the first in
importance. For in all animals, at least in all the perfect kinds,
there are two parts more essential than the rest, namely the
part which serves for the ingestion of food, and the part which
serves for the discharge of its residue. For without food growth
and even existence is impossible. Intervening again between
these two parts there is invariably a third, in which is lodged the
vital principle. As for plants, though they also are included by us
among things that have life, yet are they without any part for
the discharge of waste residue. For the food which they absorb
from the ground is already concocted, and they give off as its
equivalent their seeds and fruits. Plants, again, inasmuch as
they are without locomotion, present no great variety in their
heterogeneous parts. For, where the functions are but few, few
also are the organs required to effect them. The configuration of
plants is a matter then for separate consideration. Animals,
however, that not only live but feel, present a greater
multiformity of parts, and this diversity is greater in some
animals than in others, being most varied in those to whose
share has fallen not mere life but life of high degree. Now such
an animal is man. For of all living beings with which we are
acquainted man alone partakes of the divine, or at any rate
partakes of it in a fuller measure than the rest. For this reason,
then, and also because his external parts and their forms are
more familiar to us than those of other animals, we must speak
of man first; and this the more fitly, because in him alone do the
natural parts hold the natural position; his upper part being
turned towards that which is upper in the universe. For, of all
animals, man alone stands erect.
In man, then, the head is destitute of flesh; this being the
necessary consequence of what has already been stated
1844
concerning the brain. There are, indeed, some who hold that the
life of man would be longer than it is, were his head more
abundantly furnished with flesh; and they account for the
absence of this substance by saying that it is intended to add to
the perfection of sensation. For the brain they assert to be the
organ of sensation; and sensation, they say, cannot penetrate to
parts that are too thickly covered with flesh. But neither part of
this statement is true. On the contrary, were the region of the
brain thickly covered with flesh, the very purpose for which
animals are provided with a brain would be directly
contravened. For the brain would itself be heated to excess and
so unable to cool any other part; and, as to the other half of
their statement, the brain cannot be the cause of any of the
sensations, seeing that it is itself as utterly without feeling as
any one of the excretions. These writers see that certain of the
senses are located in the head, and are unable to discern the
reason for this; they see also that the brain is the most peculiar
of all the animal organs; and out of these facts they form an
argument, by which they link sensation and brain together. It
has, however, already been clearly set forth in the treatise on
Sensation, that it is the region of the heart that constitutes the
sensory centre. There also it was stated that two of the senses,
namely touch and taste, are manifestly in immediate connexion
with the heart; and that as regards the other three, namely
hearing, sight, and the centrally placed sense of smell, it is the
character of their sense-organs which causes them to be lodged
as a rule in the head. Vision is so placed in all animals. But such
is not invariably the case with hearing or with smell. For fishes
and the like hear and smell, and yet have no visible organs for
these senses in the head; a fact which demonstrates the
accuracy of the opinion here maintained. Now that vision,
whenever it exists, should be in the neighbourhood of the brain
is but what one would rationally expect. For the brain is fluid
and cold, and vision is of the nature of water, water being of all
1845
transparent substances the one most easily confined. Moreover
it cannot but necessarily be that the more precise senses will
have their precision rendered still greater if ministered to by
parts that have the purest blood. For the motion of the heat of
blood destroys sensory activity. For these reasons the organs of
the precise senses are lodged in the head.
It is not only the fore part of the head that is destitute of flesh,
but the hind part also. For, in all animals that have a head, it is
this head which more than any other part requires to be held
up. But, were the head heavily laden with flesh, this would be
impossible; for nothing so burdened can be held upright. This is
an additional proof that the absence of flesh from the head has
no reference to brain sensation. For there is no brain in the
hinder part of the head, and yet this is as much without flesh as
is the front.
In some animals hearing as well as vision is lodged in the
region of the head. Nor is this without a rational explanation.
For what is called the empty space is full of air, and the organ of
hearing is, as we say, of the nature of air. Now there are
channels which lead from the eyes to the blood-vessels that
surround the brain; and similarly there is a channel which leads
back again from each ear and connects it with the hinder part
of the head. But no part that is without blood is endowed with
sensation, as neither is the blood itself, but only some one of
the parts that are formed of blood.
The brain in all animals that have one is placed in the front part
of the head; because the direction in which sensation acts is in
front; and because the heart, from which sensation proceeds, is
in the front part of the body; and lastly because the instruments
of sensation are the blood-containing parts, and the cavity in
the posterior part of the skull is destitute of blood-vessels.
1846
As to the position of the sense-organs, they have been arranged
by nature in the following well-ordered manner. The organs of
hearing are so placed as to divide the circumference of the head
into two equal halves; for they have to hear not only sounds
which are directly in line with themselves, but sounds from all
quarters. The organs of vision are placed in front, because sight
is exercised only in a straight line, and moving as we do in a
forward direction it is necessary that we should see before us, in
the direction of our motion. Lastly, the organs of smell are
placed with good reason between the eyes. For as the body
consists of two parts, a right half and a left, so also each organ
of sense is double. In the case of touch this is not apparent, the
reason being that the primary organ of this sense is not the
flesh or analogous part, but lies internally. In the case of taste,
which is merely a modification of touch and which is placed in
the tongue, the fact is more apparent than in the case of touch,
but still not so manifest as in the case of the other senses.
However, even in taste it is evident enough; for in some animals
the tongue is plainly forked. The double character of the
sensations is, however, more conspicuous in the other organs of
sense. For there are two ears and two eyes, and the nostrils,
though joined together, are also two. Were these latter
otherwise disposed, and separated from each other as are the
ears, neither they nor the nose in which they are placed would
be able to perform their office. For in such animals as have
nostrils olfaction is effected by means of inspiration, and the
organ of inspiration is placed in front and in the middle line.
This is the reason why nature has brought the two nostrils
together and placed them as the central of the three sense-
organs, setting them side by side on a level with each other, to
avail themselves of the inspiratory motion. In other animals
than man the arrangement of these sense-organs is also such
as is adapted in each case to the special requirements.
1847
11
For instance, in quadrupeds the ears stand out freely from the
head and are set to all appearance above the eyes. Not that they
are in reality above the eyes; but they seem to be so, because the
animal does not stand erect, but has its head hung downwards.
This being the usual attitude of the animal when in motion, it is
of advantage that its ears shall be high up and movable; for by
turning themselves about they can the better take in sounds
from every quarter.
12
In birds, on the other hand, there are no ears, but only the
auditory passages. This is because their skin is hard and
because they have feathers instead of hairs, so that they have
not got the proper material for the formation of ears. Exactly the
same is the case with such oviparous quadrupeds as are clad
with scaly plates, and the same explanation applies to them.
There is also one of the viviparous quadrupeds, namely the seal,
that has no ears but only the auditory passages. The
explanation of this is that the seal, though a quadruped, is a
quadruped of stunted formation.
13
Men, and Birds, and Quadrupeds, viviparous and oviparous
alike, have their eyes protected by lids. In the Vivipara there are
1848
two of these; and both are used by these animals not only in
closing the eyes, but also in the act of blinking; whereas the
oviparous quadrupeds, and the heavy-bodied birds as well as
some others, use only the lower lid to close the eye; while birds
blink by means of a membrane that issues from the canthus.
The reason for the eyes being thus protected is that nature has
made them of fluid consistency, in order to ensure keenness of
vision. For had they been covered with hard skin, they would, it
is true, have been less liable to get injured by anything falling
into them from without, but they would not have been sharp-
sighted. It is then to ensure keenness of vision that the skin
over the pupil is fine and delicate; while the lids are superadded
as a protection from injury. It is as a still further safeguard that
all these animals blink, and man most of all; this action (which
is not performed from deliberate intention but from a natural
instinct) serving to keep objects from falling into the eyes; and
being more frequent in man than in the rest of these animals,
because of the greater delicacy of his skin. These lids are made
of a roll of skin; and it is because they are made of skin and
contain no flesh that neither they, nor the similarly constructed
prepuce, unite again when once cut.
As to the oviparous quadrupeds, and such birds as resemble
them in closing the eye with the lower lid, it is the hardness of
the skin of their heads which makes them do so. For such birds
as have heavy bodies are not made for flight; and so the
materials which would otherwise have gone to increase the
growth of the feathers are diverted thence, and used to
augment the thickness of the skin. Birds therefore of this kind
close the eye with the lower lid; whereas pigeons and the like
use both upper and lower lids for the purpose. As birds are
covered with feathers, so oviparous quadrupeds are covered
with scaly plates; and these in all their forms are harder than
hairs, so that the skin also to which they belong is harder than
the skin of hairy animals. In these animals, then, the skin on
1849
the head is hard, and so does not allow of the formation of an
upper eyelid, whereas lower down the integument is of a flesh-
like character, so that the lower lid can be thin and extensible.
The act of blinking is performed by the heavy-bodied birds by
means of the membrane already mentioned, and not by this
lower lid. For in blinking rapid motion is required, and such is
the motion of this membrane, whereas that of the lower lid is
slow. It is from the canthus that is nearest to the nostrils that
the membrane comes. For it is better to have one starting-point
for nictitation than two; and in these birds this starting-point is
the junction of eye and nostrils, an anterior starting-point being
preferable to a lateral one. Oviparous quadrupeds do not blink
in like manner as the birds; for, living as they do on the ground,
they are free from the necessity of having eyes of fluid
consistency and of keen sight, whereas these are essential
requisites for birds, inasmuch as they have to use their eyes at
long distances. This too explains why birds with talons, that
have to search for prey by eye from aloft, and therefore soar to
greater heights than other birds, are sharpsighted; while
common fowls and the like, that live on the ground and are not
made for flight, have no such keenness of vision. For there is
nothing in their mode of life which imperatively requires it.
Fishes and Insects and the hard-skinned Crustacea present
certain differences in their eyes, but so far resemble each other
as that none of them have eyelids. As for the hard-skinned
Crustacea it is utterly out of the question that they should have
any; for an eyelid, to be of use, requires the action of the skin to
be rapid. These animals then have no eyelids and, in default of
this protection, their eyes are hard, just as though the lid were
attached to the surface of the eye, and the animal saw through
it. Inasmuch, however, as such hardness must necessarily blunt
the sharpness of vision, nature has endowed the eyes of Insects,
and still more those of Crustacea, with mobility (just as she has
1850
given some quadrupeds movable ears), in order that they may
be able to turn to the light and catch its rays, and so see more
plainly. Fishes, however, have eyes of a fluid consistency. For
animals that move much about have to use their vision at
considerable distances. If now they live on land, the air in which
they move is transparent enough. But the water in which fishes
live is a hindrance to sharp sight, though it has this advantage
over the air, that it does not contain so many objects to knock
against the eyes. The risk of collision being thus small, nature,
who makes nothing in vain, has given no eyelids to fishes, while
to counterbalance the opacity of the water she has made their
eyes of fluid consistency.
14
All animals that have hairs on the body have lashes on the
eyelids; but birds and animals with scale-like plates, being
hairless, have none. The Libyan ostrich, indeed, forms an
exception; for, though a bird, it is furnished with eyelashes. This
exception, however, will be explained hereafter. Of hairy
animals, man alone has lashes on both lids. For in quadrupeds
there is a greater abundance of hair on the back than on the
under side of the body; whereas in man the contrary is the case,
and the hair is more abundant on the front surface than on the
back. The reason for this is that hair is intended to serve as a
protection to its possessor. Now, in quadrupeds, owing to their
inclined attitude, the under or anterior surface does not require
so much protection as the back, and is therefore left
comparatively bald, in spite of its being the nobler of the two
sides. But in man, owing to his upright attitude, the anterior and
posterior surfaces of the body are on an equality as regards
need of protection. Nature therefore has assigned the protective
1851
covering to the nobler of the two surfaces; for invariably she
brings about the best arrangement of such as are possible. This
then is the reason that there is no lower eyelash in any
quadruped; though in some a few scattered hairs sprout out
under the lower lid. This also is the reason that they never have
hair in the axillae, nor on the pubes, as man has. Their hair,
then, instead of being collected in these parts, is either thickly
set over the whole dorsal surface, as is the case for instance in
dogs, or, sometimes, forms a mane, as in horses and the like, or
as in the male lion where the mane is still more flowing and
ample. So, again, whenever there is a tail of any length, nature
decks it with hair, with long hair if the stem of the tail be short,
as in horses, with short hair if the stem be long, regard also
being had to the condition of the rest of the body. For nature
invariably gives to one part what she subtracts from another.
Thus when she has covered the general surface of an animal's
body with an excess of hair, she leaves a deficiency in the region
of the tail. This, for instance, in the case with bears.
No animal has so much hair on the head as man. This, in the
first place, is the necessary result of the fluid character of his
brain, and of the presence of so many sutures in his skull. For
wherever there is the most fluid and the most heat, there also
must necessarily occur the greatest outgrowth. But, secondly,
the thickness of the hair in this part has a final cause, being
intended to protect the head, by preserving it from excess of
either heat or cold. And as the brain of man is larger and more
fluid than that of any other animal, it requires a proportionately
greater amount of protection. For the more fluid a substance is,
the more readily does it get excessively heated or excessively
chilled, while substances of an opposite character are less liable
to such injurious affections.
These, however, are matters which by their close connexion
with eyelashes have led us to digress from our real topic,
1852
namely the cause to which these lashes owe their existence. We
must therefore defer any further remarks we may have to make
on these matters till the proper occasion arises and then return
to their consideration.
15
Both eyebrows and eyelashes exist for the protection of the
eyes; the former that they may shelter them, like the eaves of a
house, from any fluids that trickle down from the head; the
latter to act like the palisades which are sometimes placed in
front of enclosures, and keep out any objects which might
otherwise get in. The brows are placed over the junction of two
bones, which is the reason that in old age they often become so
bushy as to require cutting. The lashes are set at the
terminations of small blood-vessels. For the vessels come to an
end where the skin itself terminates; and, in all places where
these endings occur, the exudation of moisture of a corporeal
character necessitates the growth of hairs, unless there be some
operation of nature which interferes, by diverting the moisture
to another purpose.
16
Viviparous quadrupeds, as a rule, present no great variety of
form in the organ of smell. In those of them, however, whose
jaws project forwards and taper to a narrow end, so as to form
what is called a snout, the nostrils are placed in this projection,
there being no other available plan; while, in the rest, there is a
1853
more definite demarcation between nostrils and jaws. But in no
animal is this part so peculiar as in the elephant, where it
attains an extraordinary and strength. For the elephant uses its
nostril as a hand; this being the instrument with which it
conveys food, fluid and solid alike, to its mouth. With it, too, it
tears up trees, coiling it round their stems. In fact it applies it
generally to the purposes of a hand. For the elephant has the
double character of a land animal, and of one that lives in
swamps. Seeing then that it has to get its food from the water,
and yet must necessarily breathe, inasmuch as it is a land
animal and has blood; seeing, also, that its excessive weight
prevents it from passing rapidly from water to land, as some
other sanguineous vivipara that breathe can do, it becomes
necessary that it shall be suited alike for life in the water and
for life on dry land, just then as divers are sometimes provided
with instruments for respiration, through which they can draw
air from above the water, and thus may remain for a long time
under the sea, so also have elephants been furnished by nature
with their lengthened nostril; and, whenever they have to
traverse the water, they lift this up above the surface and
breathe through it. For the elephant's proboscis, as already said,
is a nostril. Now it would have been impossible for this nostril to
have the form of a proboscis, had it been hard and incapable of
bending. For its very length would then have prevented the
animal from supplying itself with food, being as great an
impediment as the of certain oxen, that are said to be obliged to
walk backwards while they are grazing. It is therefore soft and
flexible, and, being such, is made, in addition to its own proper
functions, to serve the office of the fore-feet; nature in this
following her wonted plan of using one and the same part for
several purposes. For in polydactylous quadrupeds the fore-feet
are intended not merely to support the weight of the body, but
to serve as hands. But in elephants, though they must be
reckoned polydactylous, as their foot has neither cloven nor
1854
solid hoof, the fore-feet, owing to the great size and weight of
the body, are reduced to the condition of mere supports; and
indeed their slow motion and unfitness for bending make them
useless for any other purpose. A nostril, then, is given to the
elephant for respiration, as to every other animal that has a
lung, and is lengthened out and endowed with its power of
coiling because the animal has to remain for considerable
periods of time in the water, and is unable to pass thence to dry
ground with any rapidity. But as the feet are shorn of their full
office, this same part is also, as already said, made by nature to
supply their place, and give such help as otherwise would be
rendered by them.
As to other sanguineous animals, the Birds, the Serpents, and
the Oviparous quadrupeds, in all of them there are the nostril-
holes, placed in front of the mouth; but in none are there any
distinctly formed nostrils, nothing in fact which can be called
nostrils except from a functional point of view. A bird at any rate
has nothing which can properly be called a nose. For its so-
called beak is a substitute for jaws. The reason for this is to be
found in the natural conformation of birds. For they are winged
bipeds; and this makes it necessary that their heads and neck
shall be of light weight; just as it makes it necessary that their
breast shall be narrow. The beak therefore with which they are
provided is formed of a bone-like substance, in order that it may
serve as a weapon as well as for nutritive purposes, but is made
of narrow dimensions to suit the small size of the head. In this
beak are placed the olfactory passages. But there are no nostrils;
for such could not possibly be placed there.
As for those animals that have no respiration, it has already
been explained why it is that they are without nostrils, and
perceive odours either through gills, or through a blowhole, or, if
they are insects, by the hypozoma; and how the power of
smelling depends, like their motion, upon the innate spirit of
1855
their bodies, which in all of them is implanted by nature and
not introduced from without.
Under the nostrils are the lips, in such sanguineous animals,
that is, as have teeth. For in birds, as already has been said, the
purposes of nutrition and defence are fulfilled by a bonelike
beak, which forms a compound substitute for teeth and lips. For
supposing that one were to cut off a man's lips, unite his upper
teeth together, and similarly his under ones, and then were to
lengthen out the two separate pieces thus formed, narrowing
them on either side and making them project forwards,
supposing, I say, this to be done, we should at once have a bird-
like beak.
The use of the lips in all animals except man is to preserve and
guard the teeth; and thus it is that the distinctness with which
the lips are formed is in direct proportion to the degree of nicety
and perfection with which the teeth are fashioned. In man the
lips are soft and flesh-like and capable of separating from each
other. Their purpose, as in other animals, is to guard the teeth,
but they are more especially intended to serve a higher office,
contributing in common with other parts to man's faculty of
speech. For just as nature has made man's tongue unlike that of
other animals, and, in accordance with what I have said is her
not uncommon practice, has used it for two distinct operations,
namely for the perception of savours and for speech, so also has
she acted with regard to the lips, and made them serve both for
speech and for the protection of the teeth. For vocal speech
consists of combinations of the letters, and most of these would
be impossible to pronounce, were the lips not moist, nor the
tongue such as it is. For some letters are formed by closures of
the lips and others by applications of the tongue. But what are
the differences presented by these and what the nature and
extent of such differences, are questions to which answers must
be sought from those who are versed in metrical science. It was
1856
necessary that the two parts which we are discussing should, in
conformity with the requirements, be severally adapted to fulfil
the office mentioned above, and be of appropriate character.
Therefore are they made of flesh, and flesh is softer in man
than in any other animal, the reason for this being that of all
animals man has the most delicate sense of touch.
17
The tongue is placed under the vaulted roof of the mouth. In
land animals it presents but little diversity. But in other animals
it is variable, and this whethe+r we compare them as a class
with such as live on land, or compare their several species with
each other. It is in man that the tongue attains its greatest
degree of freedom, of softness, and of breadth; the object of this
being to render it suitable for its double function. For its
softness fits it for the perception of savours, a sense which is
more delicate in man than in any other animal, softness being
most impressionable by touch, of which sense taste is but a
variety. This same softness again, together with its breadth,
adapts it for the articulation of letters and for speech. For these
qualities, combined with its freedom from attachment, are
those which suit it best for advancing and retiring in every
direction. That this is so is plain, if we consider the case of those
who are tongue-tied in however slight a degree. For their speech
is indistinct and lisping; that is to say there are certain letters
which they cannot pronounce. In being broad is comprised the
possibility of becoming narrow; for in the great the small is
included, but not the great in the small.
What has been said explains why, among birds, those that are
most capable of pronouncing letters are such as have the
1857
broadest tongues; and why the viviparous and sanguineous
quadrupeds, where the tongue is hard and thick and not free in
its motions, have a very limited vocal articulation. Some birds
have a considerable variety of notes. These are the smaller
kinds. But it is the birds with talons that have the broader
tongues. All birds use their tongues to communicate with each
other. But some do this in a greater degree than the rest; so that
in some cases it even seems as though actual instruction were
imparted from one to another by its agency. These, however, are
matters which have already been discussed in the Researches
concerning Animals.
As to those oviparous and sanguineous animals that live not in
the air but on the earth, their tongue in most cases is tied down
and hard, and is therefore useless for vocal purposes; in the
serpents, however, and in the lizards it is long and forked, so as
to be suited for the perception of savours. So long indeed is this
part in serpents, that though small while in the mouth it can be
protruded to a great distance. In these animals it is forked and
has a fine and hair-like extremity, because of their great liking
for dainty food. For by this arrangement they derive a twofold
pleasure from savours, their gustatory sensation being as it
were doubled.
Even some bloodless animals have an organ that serves for the
perception of savours; and in sanguineous animals such an
organ is invariably variably For even in such of these as would
seem to an ordinary observer to have nothing of the kind, some
of the fishes for example, there is a kind of shabby
representative of a tongue, much like what exists in river
crocodiles. In most of these cases the apparent absence of the
part can be rationally explained on some ground or other. For in
the first place the interior of the mouth in animals of this
character is invariably spinous. Secondly, in water animals there
is but short space of time for the perception of savours, and as
1858
the use of this sense is thus of short duration, shortened also is
the separate part which subserves it. The reason for their food
being so rapidly transmitted to the stomach is that they cannot
possibly spend any time in sucking out the juices; for were they
to attempt to do so, the water would make its way in during the
process. Unless therefore one pulls their mouth very widely
open, the projection of this part is quite invisible. The region
exposed by thus opening the mouth is spinous; for it is formed
by the close apposition of the gills, which are of a spinous
character.
In crocodiles the immobility of the lower jaw also contributes in
some measure to stunt the development of the tongue. For the
crocodile's tongue is adherent to the lower jaw. For its upper
and lower jaws are, as it were, inverted, it being the upper jaw
which in other animals is the immovable one. The tongue,
however, on this animal is not attached to the upper jaw,
because that would interfere with the ingestion of food, but
adheres to the lower jaw, because this is, as it were, the upper
one which has changed its place. Moreover, it is the crocodile's
lot, though a land animal, to live the life of a fish, and this again
necessarily involves an indistinct formation of the part in
question.
The roof of the mouth resembles flesh, even in many of the
fishes; and in some of the river species, as for instance in the
fishes known as Cyprini, is so very flesh-like and soft as to be
taken by careless observers for a tongue. The tongue of fishes,
however, though it exists as a separate part, is never formed
with such distinctness as this, as has been already explained.
Again, as the gustatory sensibility is intended to serve animals
in the selection of food, it is not diffused equally over the whole
surface of the tongue-like organ, but is placed chiefly in the tip;
and for this reason it is the tip which is the only part of the
tongue separated in fishes from the rest of the mouth. As all
1859
animals are sensible to the pleasure derivable from food, they
all feel a desire for it. For the object of desire is the pleasant. The
part, however, by which food produces the sensation is not
precisely alike in all of them, but while in some it is free from
attachments, in others, where it is not required for vocal pur,
poses, it is adherent. In some again it is hard, in others soft or
flesh-like. Thus even the Crustacea, the Carabi for instance and
the like, and the Cephalopods, such as the Sepias and the
Poulps, have some such part inside the mouth. As for the
Insects, some of them have the part which serves as tongue
inside the mouth, as is the case with ants, and as is also the
case with many Testacea, while in others it is placed externally.
In this latter case it resembles a sting, and is hollow and spongy,
so as to serve at one and the same time for the tasting and for
the sucking up of nutriment. This is plainly to be seen in flies
and bees and all such animals, and likewise in some of the
Testacea. In the Purpurae, for instance, so strong is this part
that it enables them to bore holes through the hard covering of
shell-fish, of the spiral snails, for example, that are used as bait
to catch them. So also the gad-flies and cattle-flies can pierce
through the skin of man, and some of them even through the
skins of other animals. Such, then, in these animals is the
nature of the tongue, which is thus as it were the counterpart of
the elephant's nostril. For as in the elephant the nostril is used
as a weapon, so in these animals the tongue serves as a sting.
In all other animals the tongue agrees with description already
given.
I860
Book III
We have next to consider the teeth, and with these the mouth,
that is the cavity which they enclose and form. The teeth have
one invariable office, namely the reduction of food; but besides
this general function they have other special ones, and these
differ in different groups. Thus in some animals the teeth serve
as weapons; but this with a distinction. For there are offensive
weapons and there are defensive weapons; and while in some
animals, as the wild Carnivora, the teeth answer both purposes,
in many others, both wild and domesticated, they serve only for
defence. In man the teeth are admirably constructed for their
general office, the front ones being sharp, so as to cut the food
into bits, and the hinder ones broad and flat, so as to grind it to
a pulp; while between these and separating them are the dog-
teeth, which, in accordance with the rule that the mean
partakes of both extremes, share in the characters of those on
either side, being broad in one part but sharp in another. Similar
distinctions of shape are presented by the teeth of other
animals, with the exception of those whose teeth are one and
all of the sharp kind. In man, however, the number and the
character even of these sharp teeth have been mainly
determined by the requirements of speech. For the front teeth
of man contribute in many ways to the formation of letter-
sounds.
In some animals, however, the teeth, as already said, serve
merely for the reduction of food. When, besides this, they serve
as offensive and defensive weapons, they may either be formed
into tusks, as for instance is the case in swine, or may be sharp-
1861
pointed and interlock with those of the opposite jaw, in which
case the animal is said to be saw-toothed. The explanation of
this latter arrangement is as follows. The strength of such an
animal is in its teeth, and these depend for their efficiency on
their sharpness. In order, then, to prevent their getting blunted
by mutual friction, such of them as serve for weapons fit into
each other's interspaces, and are so kept in proper condition. No
animal that has sharp interfitting teeth is at the same time
furnished with tusks. For nature never makes anything
superfluous or in vain. She gives, therefore, tusks to such
animals as strike in fighting, and serrated teeth to such as bite.
Sows, for instance, have no tusks, and accordingly sows bite
instead of striking.
A general principle must here be noted, which will be found
applicable not only in this instance but in many others that will
occur later on. Nature allots each weapon, offensive and
defensive alike, to those animals alone that can use it; or, if not
to them alone, to them in a more marked degree; and she allots
it in its most perfect state to those that can use it best; and this
whether it be a sting, or a spur, or horns, or tusks, or what it
may of a like kind.
Thus as males are stronger and more choleric than females, it is
in males that such parts as those just mentioned are found,
either exclusively, as in some species, or more fully developed,
as in others. For though females are of course provided with
such parts as are no less necessary to them than to males, the
parts, for instance, which subserve nutrition, they have even
these in an inferior degree, and the parts which answer no such
necessary purpose they do not possess at all. This explains why
stags have horns, while does have none; why the horns of cows
are different from those of bulls, and, similarly, the horns of
ewes from those of rams. It explains also why the females are
often without spurs in species where the males are provided
1862
with them, and accounts for similar facts relating to all other
such parts.
All fishes have teeth of the serrated form, with the single
exception of the fish known as the Scarus. In many of them
there are teeth even on the tongue and on the roof of the
mouth. The reason for this is that, living as they do in the water,
they cannot but allow this fluid to pass into the mouth with the
food. The fluid thus admitted they must necessarily discharge
again without delay. For were they not to do so, but to retain it
for a time while triturating the food, the water would run into
their digestive cavities. Their teeth therefore are all sharp, being
adapted only for cutting, and are numerous and set in many
parts, that their abundance may serve in lieu of any grinding
faculty, to mince the food into small bits. They are also curved,
because these are almost the only weapons which fishes
possess.
In all these offices of the teeth the mouth also takes its part; but
besides these functions it is subservient to respiration, in all
such animals as breathe and are cooled by external agency. For
nature, as already said, uses the parts which are common to all
animals for many special purposes, and this of her own accord.
Thus the mouth has one universal function in all animals alike,
namely its alimentary office; but in some, besides this, the
special duty of serving as a weapon is attached to it; in others
that of ministering to speech; and again in many, though not in
all, the office of respiration. All these functions are thrown by
nature upon one single organ, the construction of which she
varies so as to suit the variations of office. Therefore it is that in
some animals the mouth is contracted, while in others it is of
wide dimensions. The contracted form belongs to such animals
as use the mouth merely for nutritive, respiratory, and vocal
purposes; whereas in such as use it as a means of defence it has
a wide gape. This is its invariable form in such animals as are
1863
saw-toothed. For seeing that their mode of warfare consists in
biting, it is advantageous to them that their mouth shall have a
wide opening; for the wider it opens, the greater will be the
extent of the bite, and the more numerous will be the teeth
called into play.
What has just been said applies to fishes as well as to other
animals; and thus in such of them as are carnivorous, and made
for biting, the mouth has a wide gape; whereas in the rest it is
small, being placed at the extremity of a tapering snout. For this
form is suited for their purposes, while the other would be
useless.
In birds the mouth consists of what is called the beak, which in
them is a substitute for lips and teeth. This beak presents
variations in harmony with the functions and protective
purposes which it serves. Thus in those birds that are called
Crooked-clawed it is invariably hooked, inasmuch as these birds
are carnivorous, and eat no kind of vegetable food whatsoever.
For this form renders it serviceable to them in obtaining the
mastery over their prey, and is better suited for deeds of
violence than any other. Moreover, as their weapons of offence
consist of this beak and of their claws, these latter also are more
crooked in them than in the generality of birds. Similarly in
each other kind of bird the beak is suited to the mode of life.
Thus, in woodpeckers it is hard and strong, as also in crows and
birds of crowlike habit, while in the smaller birds it is delicate,
so as to be of use in collecting seeds and picking up minute
animals. In such birds, again, as eat herbage, and such as live
about marshes - those, for example, that swim and have
webbed feet - the bill is broad, or adapted in some other way to
the mode of life. For a broad bill enables a bird to dig into the
ground with ease, just as, among quadrupeds, does the broad
snout of the pig, an animal which, like the birds in question,
lives on roots. Moreover, in these root-eating birds and in some
1864
others of like habits of life, the tips of the bill end in hard points,
which gives them additional facility in dealing with herbaceous
food.
The several parts which are set on the head have now, pretty
nearly all, been considered. In man, however, the part which lies
between the head and the neck is called the face, this name,
(prosopon) being, it would seem, derived from the function of
the part. For as man is the only animal that stands erect, he is
also the only one that looks directly in front (proso) and the
only one whose voice is emitted in that direction.
We have now to treat of horns; for these also, when present, are
appendages of the head. They exist in none but viviparous
animals; though in some ovipara certain parts are
metaphorically spoken of as horns, in virtue of a certain
resemblance. To none of such parts, however, does the proper
office of a horn belong; for they are never used, as are the horns
of vivipara, for purposes which require strength, whether it be
in self-protection or in offensive strife. So also no polydactylous
animal is furnished with horns. For horns are defensive
weapons, and these polydactylous animals possess other
means of security. For to some of them nature has given claws,
to others teeth suited for combat, and to the rest some other
adequate defensive appliance. There are horns, however, in
most of the cloven-hoofed animals, and in some of those that
have a solid hoof, serving them as an offensive weapon, and in
some cases also as a defensive one. There are horns also in all
animals that have not been provided by nature with some other
means of security; such means, for instance, as speed, which
1865
has been given to horses; or great size, as in camels; for
excessive bulk, such as has been given to these animals, and in
a still greater measure to elephants, is sufficient in itself to
protect an animal from being destroyed by others. Other
animals again are protected by the possession of tusks; and
among these are the swine, though they have a cloven hoof.
All animals again, whose horns are but useless appendages,
have been provided by nature with some additional means of
security. Thus deer are endowed with speed; for the large size
and great branching of their horns makes these a source of
detriment rather than of profit to their possessors. Similarly
endowed are the Bubalus and gazelle; for though these animals
will stand up against some enemies and defend themselves
with their horns, yet they run away from such as are fierce and
pugnacious. The Bonasus again, whoe horns curve inwards
towards each other, is provided with a means of protection in
the discharge of its excrement; and of this it avails itself when
frightened. There are some other animals besides the Bonasus
that have a similar mode of defence. In no case, however, does
nature ever give more than one adequate means of protection
to one and the same animal.
Most of the animals that have horns are cloven-hoofed; but the
Indian ass, as they call it, is also reported to be horned, though
its hoof is solid.
Again as the body, so far as regards its organs of motion,
consists of two distinct parts, the right and the left, so also and
for like reasons the horns of animals are, in the great majority
of cases, two in number. Still there are some that have but a
single horn; the Oryx, for instance, and the so-called Indian ass;
in the former of which the hoof is cloven, while in the latter it is
solid. In such animals the horn is set in the centre of the head;
for as the middle belongs equally to both extremes, this
1866
arrangement is the one that comes nearest to each side having
its own horn.
Again, it would appear consistent with reason that the single
horn should go with the solid rather than with the cloven hoof.
For hoof, whether solid or cloven, is of the same nature as horn;
so that the two naturally undergo division simultaneously and
in the same animals. Again, since the division of the cloven
hoof depends on deficiency of material, it is but rationally
consistent, that nature, when she gave an animal an excess of
material for the hoofs, which thus became solid, should have
taken away something from the upper parts and so made the
animal to have but one horn. Rightly too did she act when she
chose the head whereon to set the horns; and AEsop's Momus is
beside the mark, when he finds fault with the bull for not
having its horns upon its shoulders. For from this position, says
he, they would have delivered their blow with the greatest force,
whereas on the head they occupy the weakest part of the whole
body. Momus was but dull-sighted in making this hostile
criticism. For had the horns been set on the shoulders, or had
they been set on any other part than they are, the encumbrance
of their weight would have been increased, not only without
any compensating gain whatsoever, but with the disadvantage
of impeding many bodily operations. For the point whence the
blows could be delivered with the greatest force was not the
only matter to be considered, but the point also whence they
could be delivered with the widest range. But as the bull has no
hands and cannot possibly have its horns on its feet or on its
knees, where they would prevent flexion, there remains no
other site for them but the head; and this therefore they
necessarily occupy. In this position, moreover, they are much
less in the way of the movements of the body than they would
be elsewhere.
1867
Deer are the only animals in which the horns are solid
throughout, and are also the only animals that cast them. This
casting is not simply advantageous to the deer from the
increased lightness which it produces, but, seeing how heavy
the horns are, is a matter of actual necessity.
In all other animals the horns are hollow for a certain distance,
and the end alone is solid, this being the part of use in a blow.
At the same time, to prevent even the hollow part from being
weak, the horn, though it grows out of the skin, has a solid piece
from the bones fitted into its cavity. For this arrangement is not
only that which makes the horns of the greatest service in
fighting, but that which causes them to be as little of an
impediment as possible in the other actions of life.
Such then are the reasons for which horns exist; and such the
reasons why they are present in some animals, absent from
others.
Let us now consider the character of the material nature whose
necessary results have been made available by rational nature
for a final cause.
In the first place, then, the larger the bulk of animals, the
greater is the proportion of corporeal and earthy matter which
they contain. Thus no very small animal is known to have
horns, the smallest horned animal that we are acquainted with
being the gazelle. But in all our speculations concerning nature,
what we have to consider is the general rule; for that is natural
which applies either universally or generally. And thus when we
say that the largest animals have most earthy matter, we say so
because such is the general rule. Now this earthy matter is used
in the animal body to form bone. But in the larger animals there
is an excess of it, and this excess is turned by nature to useful
account, being converted into weapons of defence. Part of it
necessarily flows to the upper portion of the body, and this is
1868
allotted by her in some cases to the formation of tusks and
teeth, in others to the formation of horns. Thus it is that no
animal that has horns has also front teeth in both jaws, those in
the upper jaw being deficient. For nature by subtracting from
the teeth adds to the horns; the nutriment which in most
animals goes to the former being here spent on the
augmentation of the latter. Does, it is true, have no horns and
yet are equally deficient with the males as regards the teeth.
The reason, however, for this is that they, as much as the males,
are naturally horn-bearing animals; but they have been stripped
of their horns, because these would not only be useless to them
but actually baneful; whereas the greater strength of the males
causes these organs, though equally useless, to be less of an
impediment. In other animals, where this material is not
secreted from the body in the shape of horns, it is used to
increase the size of the teeth; in some cases of all the teeth, in
others merely of the tusks, which thus become so long as to
resemble horns projecting from the jaws.
So much, then, of the parts which appertain to the head.
Below the head lies the neck, in such animals as have one. This
is the case with those only that have the parts to which a neck
is subservient. These parts are the larynx and what is called the
oesophagus. Of these the former, or larynx, exists for the sake of
respiration, being the instrument by which such animals as
breathe inhale and discharge the air. Therefore it is that, when
there is no lung, there is also no neck. Of this condition the
Fishes are an example. The other part, or oesophagus, is the
channel through which food is conveyed to the stomach; so that
1869
all animals that are without a neck are also without a distinct
oesophagus; Such a part is in fact not required of necessity for
nutritive purposes; for it has no action whatsoever on the food.
Indeed there is nothing to prevent the stomach from being
placed directly after the mouth. This, however, is quite
impossible in the case of the lung. For there must be some sort
of tube common to the two divisions of the lung, by which - it
being bipartite - the breath may be apportioned to their
respective bronchi, and thence pass into the air-pipes; and such
an arrangement will be the best for giving perfection to
inspiration and expiration. The organ then concerned in
respiration must of necessity be of some length; and this, again,
necessitates there being an oesophagus to unite mouth and
stomach. This oesophagus is of a flesh-like character, and yet
admits of extension like a sinew. This latter property is given to
it, that it may stretch when food is introduced; while the flesh-
like character is intended to make it soft and yielding, and to
prevent it from being rasped by particles as they pass
downwards, and so suffering damage. On the other hand, the
windpipe and the so-called larynx are constructed out of a
cartilaginous substance. For they have to serve not only for
respiration, but also for vocal purposes; and an instrument that
is to produce sounds must necessarily be not only smooth but
firm. The windpipe lies in front of the oesophagus, although this
position causes it to be some hindrance to the latter in the act
of deglutition. For if a morsel of food, fluid or solid, slips into it
by accident, choking and much distress and violent fits of
coughing ensue. This must be a matter of astonishment to any
of those who assert that it is by the windpipe that an animal
imbibes fluid. For the consequences just mentioned occur
invariably, whenever a particle of food slips in, and are quite
obvious. Indeed on many grounds it is ridiculous to say that this
is the channel through which animals imbibe fluid. For there is
no passage leading from the lung to the stomach, such as the
1870
oesophagus which we see leading thither from the mouth.
Moreover, when any cause produces sickness and vomiting, it is
plain enough when the fluid is discharged. It is manifest also
that fluid, when swallowed, does not pass directly into the
bladder and collect there, but goes first into the stomach. For,
when red wine is taken, the dejections of the stomach are seen
to be coloured by its dregs; and such discoloration has been
even seen on many occasions inside the stomach itself, in cases
where there have been wounds opening into that organ.
However, it is perhaps silly to be minutely particular in dealing
with silly statements such as this.
The windpipe then, owing to its position in front of the
oesophagus, is exposed, as we have said, to annoyance from the
food. To obviate this, however, nature has contrived the
epiglottis. This part is not found in all sanguineous animals, but
only in such of them as have a lung; nor in all of these, but only
in such as at the same time have their skin covered with hairs,
and not either with scaly plates or with feathers. In such scaly
and feathered animals there is no epiglottis, but its office is
supplied by the larynx, which closes and opens, just as in the
other case the epiglottis falls down and rises up; rising up
during the ingress or egress of breath, and falling down during
the ingestion of food, so as to prevent any particle from slipping
into the windpipe. Should there be the slightest want of
accuracy in this movement, or should an inspiration be made
during the ingestion of food, choking and coughing ensue, as
already has been noticed. So admirably contrived, however, is
the movement both of the epiglottis and of the tongue, that,
while the food is being ground to a pulp in the mouth, the
tongue very rarely gets caught between the teeth; and, while the
food is passing over the epiglottis seldom does a particle of it
slip into the windpipe.
1871
The animals which have been mentioned as having no
epiglottis owe this deficiency to the dryness of their flesh and to
the hardness of their skin. For an epiglottis made of such
materials would not admit of easy motion. It would, indeed,
take a longer time to shut down an epiglottis made of the
peculiar flesh of these animals, and shaped like that of those
with hairy skins, than to bring the edges of the windpipe itself
into contact with each other.
Thus much then as to the reason why some animals have an
epiglottis while others have none, and thus much also as to its
use. It is a contrivance of nature to remedy the vicious position
of the windpipe in front of the oesophagus. That position is the
result of necessity. For it is in the front and centre of the body
that the heart is situated, in which we say is the principle of life
and the source of all motion and sensation. (For sensation and
motion are exercised in the direction which we term forwards,
and it is on this very relation that the distinction of before and
behind is founded.) But where the heart is, there and
surrounding it is the lung. Now inspiration, which occurs for the
sake of the lung and for the sake of the principle which has its
seat in the heart, is effected through the windpipe. Since then
the heart must of necessity lie in the very front place of all, it
follows that the larynx also and the windpipe must of necessity
lie in front of the oesophagus. For they lead to the lung and
heart, whereas the oesophagus leads to the stomach. And it is a
universal law that, as regards above and below, front and back,
right and left, the nobler and more honourable part invariably is
placed uppermost, in front, and on the right, rather than in the
opposite positions, unless some more important object stands
in the way.
1872
We have now dealt with the neck, the oesophagus, and the
windpipe, and have next to treat of the viscera. These are
peculiar to sanguineous animals, some of which have all of
them, others only a part, while no bloodless animals have any
at all. Democritus then seems to have been mistaken in the
notion he formed of the viscera, if, that is to say, he fancied that
the reason why none were discoverable in bloodless animals
was that these animals were too small to allow them to be seen.
For, in sanguineous animals, both heart and liver are visible
enough when the body is only just formed, and while it is still
extremely small. For these parts are to be seen in the egg
sometimes as early as the third day, being then no bigger than a
point; and are visible also in aborted embryos, while still
excessively minute. Moreover, as the external organs are not
precisely alike in all animals, but each creature is provided with
such as are suited to its special mode of life and motion, so is it
with the internal parts, these also differing in different animals.
Viscera, then, are peculiar to sanguineous animals; and
therefore are each and all formed from sanguineous material, as
is plainly to be seen in the new-born young of these animals.
For in such the viscera are more sanguineous, and of greater
bulk in proportion to the body, than at any later period of life, it
being in the earliest stage of formation that the nature of the
material and its abundance are most conspicuous. There is a
heart, then, in all sanguineous animals, and the reason for this
has already been given. For that sanguineous animals must
necessarily have blood is self-evident. And, as the blood is fluid,
it is also a matter of necessity that there shall be a receptacle
for it; and it is apparently to meet this requirement that nature
has devised the blood-vessels. These, again, must necessarily
have one primary source. For it is preferable that there shall be
one such, when possible, rather than several. This primary
source of the vessels is the heart. For the vessels manifestly
1873
issue from it and do not go through it. Moreover, being as it is
homogeneous, it has the character of a blood-vessel. Again its
position is that of a primary or dominating part. For nature,
when no other more important purpose stands in her way,
places the more honourable part in the more honourable
position; and the heart lies about the centre of the body, but
rather in its upper than its lower half, and also more in front
than behind. This is most evident in the case of man, but even
in other animals there is a tendency in the heart to assume a
similar position, in the centre of the necessary part of the body,
that is to say of the part which terminates in the vent for
excrement. For the limbs vary in position in different animals,
and are not to be counted with the parts which are necessary
for life. For life can be maintained even when they are removed;
while it is self-evident that the addition of them to an animal is
not destructive of it.
There are some who say that the vessels commence in the
head. In this they are clearly mistaken. For in the first place,
according to their representation, there would be many sources
for the vessels, and these scattered; and secondly, these sources
would be in a region that is manifestly cold, as is shown by its
intolerance of chill, whereas the region of the heart is as
manifestly hot. Again, as already said, the vessels continue their
course through the other viscera, but no vessel spreads through
the heart. From this it is quite evident that the heart is a part of
the vessels and their origin; and for this it is well suited by its
structure. For its central part consists of a dense and hollow
substance, and is moreover full of blood, as though the vessels
took thence their origin. It is hollow to serve for the reception of
the blood, while its wall is dense, that it may serve to protect
the source of heat. For here, and here alone in all the viscera
and indeed in all the body, there is blood without blood-vessels,
the blood elsewhere being always contained within vessels. Nor
is this but consistent with reason. For the blood is conveyed into
1874
the vessels from the heart, but none passes into the heart from
without. For in itself it constitutes the origin and fountain, or
primary receptacle, of the blood. It is however, from dissections
and from observations on the process of development that the
truth of these statements receives its clearest demonstration.
For the heart is the first of all the parts to be formed; and no
sooner is it formed than it contains blood. Moreover, the
motions of pain and pleasure, and generally of all sensation,
plainly have their source in the heart, and find in it their
ultimate termination. This, indeed, reason would lead us to
expect. For the source must, when, ever possible, be one; and, of
all places, the best suited for a source is the centre. For the
centre is one, and is equally or almost equally within reach of
every part. Again, as neither the blood itself, nor yet any part
which is bloodless, is endowed with sensation, it is plain that
that part which first has blood, and which holds it as it were in
a receptacle, must be the primary source of sensation. And that
this part is the heart is not only a rational inference, but also
evident to the senses. For no sooner is the embryo formed, than
its heart is seen in motion as though it were a living creature,
and this before any of the other parts, it being, as thus shown,
the starting-point of their nature in all animals that have blood.
A further evidence of the truth of what has been stated is the
fact that no sanguineous animal is without a heart. For the
primary source of blood must of necessity be present in them
all. It is true that sanguineous animals not only have a heart but
also invariably have a liver. But no one could ever deem the liver
to be the primary organ either of the whole body or of the blood.
For the position in which it is placed is far from being that of a
primary or dominating part; and, moreover, in the most
perfectly finished animals there is another part, the spleen,
which as it were counterbalances it. Still further, the liver
contains no spacious receptacle in its substance, as does the
heart; but its blood is in a vessel as in all the other viscera. The
1875
vessel, moreover, extends through it, and no vessel whatsoever
originates in it; for it is from the heart that all the vessels take
their rise. Since then one or other of these two parts must be
the central source, and since it is not the liver which is such, it
follows of necessity that it is the heart which is the source of
the blood, as also the primary organ in other respects. For the
definitive characteristic of an animal is the possession of
sensation; and the first sensory part is that which first has
blood; that is to say is the heart, which is the source of blood
and the first of the parts to contain it.
The apex of the heart is pointed and more solid than the rest of
the organ. It lies against the breast, and entirely in the anterior
part of the body, in order to prevent that region from getting
chilled. For in all animals there is comparatively little flesh over
the breast, whereas there is a more abundant covering of that
substance on the posterior surface, so that the heat has in the
back a sufficient amount of protection. In all animals but man
the heart is placed in the centre of the pectoral region; but in
man it inclines a little towards the left, so that it may
counterbalance the chilliness of that side. For the left side is
colder in man, as compared with the right, than in any other
animal. It has been stated in an earlier treatise that even in
fishes the heart holds the same position as in other animals;
and the reason has been given why it appears not to do so. The
apex of the heart, it is true, is in them turned towards the head,
but this in fishes is the front aspect, for it is the direction in
which their motion occurs.
The heart again is abundantly supplied with sinews, as might
reasonably be expected. For the motions of the body commence
from the heart, and are brought about by traction and
relaxation. The heart therefore, which, as already said,' as it
were a living creature inside its possessor, requires some such
subservient and strengthening parts.
1876
In no animals does the heart contain a bone, certainly in none
of those that we have ourselves inspected, with the exception of
the horse and a certain kind of ox. In these exceptional cases
the heart, owing to its large bulk, is provided with a bone as a
support; just as the bones serve as supports for the body
generally.
In animals of great size the heart has three cavities; in smaller
animals it has two; and in all has at least one, for, as already
stated, there must be some place in the heart to serve as a
receptacle for the first blood; which, as has been mentioned
more than once, is formed in this organ. But inasmuch as the
main blood-vessels are two in number, namely the so-called
great vessel and the aorta, each of which is the origin of other
vessels; inasmuch, moreover, as these two vessels present
differences, hereafter to be discussed, when compared with
each other, it is of advantage that they also shall themselves
have distinct origins. This advantage will be obtained if each
side have its own blood, and the blood of one side be kept
separate from that of the other. For this reason the heart,
whenever it is possible, has two receptacles. And this possibility
exists in the case of large animals, for in them the heart, as the
body generally, is of large size. Again it is still better that there
shall be three cavities, so that the middle and odd one may
serve as a centre common to both sides. But this requires the
heart to be of greater magnitude, so that it is only in the largest
hearts that there are three cavities.
Of these three cavities it is the right that has the most abundant
and the hottest blood, and this explains why the limbs also on
the right side of the body are warmer than those on the left. The
left cavity has the least blood of all, and the coldest; while in the
middle cavity the blood, as regards quantity and heat, is
intermediate to the other two, being however of purer quality
than either. For it behoves the supreme part to be as tranquil as
1877
possible, and this tranquillity can be ensured by the blood being
pure, and of moderate amount and warmth.
In the heart of animals there is also a kind of joint-like division,
something like the sutures of the skull. This is not, however,
attributable to the heart being formed by the union of several
parts into a compound whole, but is rather, as already said, the
result of a joint-like division. These jointings are most distinct
in animals of keen sensibility, and less so in those that are of
duller feeling, in swine for instance. Different hearts differ also
from each other in their sizes, and in their degrees of firmness;
and these differences somehow extend their influence to the
temperaments of the animals. For in animals of low sensibility
the heart is hard and dense in texture, while it is softer in such
as are endowed with keener feeling. So also when the heart is of
large size the animal is timorous, while it is more courageous if
the organ be smaller and of moderate bulk. For in the former
the bodily affection which results from terror already pre-exists;
for the bulk of the heart is out of all proportion to the animal's
heat, which being small is reduced to insignificance in the large
space, and thus the blood is made colder than it would
otherwise be.
The heart is of large size in the hare, the deer, the mouse, the
hyena, the ass, the leopard, the marten, and in pretty nearly all
other animals that either are manifestly timorous, or betray
their cowardice by their spitefulness.
What has been said of the heart as a whole is no less true of its
cavities and of the blood-vessels; these also if of large size being
cold. For just as a fire of equal size gives less heat in a large
room than in a small one, so also does the heat in a large cavity
or a large blood-vessel, that is in a large receptacle, have less
effect than in a small one. Moreover, all hot bodies are cooled by
motions external to themselves, and the more spacious the
1878
cavities and vessels are, the greater the amount of spirit they
contain, and the more potent its action. Thus it is that no
animal that has large cavities in its heart, or large blood-vessels,
is ever fat, the vessels being indistinct and the cavities small in
all or most fat animals.
The heart again is the only one of the viscera, and indeed the
only part of the body, that is unable to tolerate any serious
affection. This is but what might reasonably be expected. For, if
the primary or dominant part be diseased, there is nothing from
which the other parts which depend upon it can derive succour.
A proof that the heart is thus unable to tolerate any morbid
affection is furnished by the fact that in no sacrificial victim has
it ever been seen to be affected with those diseases that are
observable in the other viscera. For the kidneys are frequently
found to be full of stones, and growths, and small abscesses, as
also are the liver, the lung, and more than all the spleen. There
are also many other morbid conditions which are seen to occur
in these parts, those which are least liable to such being the
portion of the lung which is close to the windpipe, and the
portion of the liver which lies about the junction with the great
blood-vessel. This again admits of a rational explanation. For it
is in these parts that the lung and liver are most closely in
communion with the heart. On the other hand, when animals
die not by sacrifice but from disease, and from affections such
as are mentioned above, they are found on dissection to have
morbid affections of the heart.
Thus much of the heart, its nature, and the end and cause of its
existence in such animals as have it.
1879
In due sequence we have next to discuss the blood-vessels, that
is to say the great vessel and the aorta. For it is into these two
that the blood first passes when it quits the heart; and all the
other vessels are but offshoots from them. Now that these
vessels exist on account of the blood has already been stated.
For every fluid requires a receptacle, and in the case of the blood
the vessels are that receptacle. Let us now explain why these
vessels are two, and why they spring from one single source,
and extend throughout the whole body.
The reason, then, why these two vessels coalesce into one
centre, and spring from one source, is that the sensory soul is in
all animals actually one; and this one-ness of the sensory soul
determines a corresponding one-ness of the part in which it
primarily abides. In sanguineous animals this one-ness is not
only actual but potential, whereas in some bloodless animals it
is only actual. Where, however, the sensory soul is lodged, there
also and in the selfsame place must necessarily be the source of
heat; and, again, where this is there also must be the source of
the blood, seeing that it thence derives its warmth and fluidity.
Thus, then, in the oneness of the part in which is lodged the
prime source of sensation and of heat is involved the one-ness
of the source in which the blood originates; and this, again,
explains why the blood-vessels have one common starting-
point.
The vessels, again, are two, because the body of every
sanguineous animal that is capable of locomotion is bilateral;
for in all such animals there is a distinguishable before and
behind, a right and left, an above and below. Now as the front is
more honourable and of higher supremacy than the hinder
aspect, so also and in like degree is the great vessel superior to
the aorta. For the great vessel is placed in front, while the aorta
1880
is behind; the former again is plainly visible in all sanguineous
animals, while the latter is in some indistinct and in some not
discernible at all.
Lastly, the reason for the vessels being distributed throughout
the entire body is that in them, or in parts analogous to them, is
contained the blood, or the fluid which in bloodless animals
takes the place of blood, and that the blood or analogous fluid is
the material from which the whole body is made. Now as to the
manner in which animals are nourished, and as to the source
from which they obtain nutriment and as to the way in which
they absorb this from the stomach, these are matters which
may be more suitably considered and explained in the treatise
on Generation. But inasmuch as the parts are, as already said,
formed out of the blood, it is but rational that the flow of the
blood should extend, as it does, throughout the whole of the
body. For since each part is formed of blood, each must have
blood about and in its substance.
To give an illustration of this. The water-courses in gardens are
so constructed as to distribute water from one single source or
fount into numerous channels, which divide and subdivide so
as to convey it to all parts; and, again, in house-building stones
are thrown down along the whole ground-plan of the
foundation walls; because the garden-plants in the one case
grow at the expense of the water, and the foundation walls in
the other are built out of the stones. Now just after the same
fashion has nature laid down channels for the conveyance of
the blood throughout the whole body, because this blood is the
material out of which the whole fabric is made. This becomes
very evident in bodies that have undergone great emaciation.
For in such there is nothing to be seen but the blood-vessels;
just as when fig-leaves or vine-leaves or the like have dried up,
there is nothing left of them but their vessels. The explanation
of this is that the blood, or fluid which takes its place, is
1881
potentially body and flesh, or substance analogous to flesh. Now
just as in irrigation the largest dykes are permanent, while the
smallest are soon filled up with mud and disappear, again to
become visible when the deposit of mud ceases; so also do the
largest blood-vessels remain permanently open, while the
smallest are converted actually into flesh, though potentially
they are no whit less vessels than before. This too explains why,
so long as the flesh of an animal is in its integrity, blood will
flow from any part of it whatsoever that is cut, though no
vessel, however small, be visible in it. Yet there can be no blood,
unless there be a blood-vessel. The vessels then are there, but
are invisible owing to their being clogged up, just as the dykes
for irrigation are invisible until they have been cleared of mud.
As the blood-vessels advance, they become gradually smaller
and smaller, until at last their tubes are too fine to admit the
blood. This fluid can therefore no longer find its way through
them, though they still give passage to the humour which we
call sweat; and especially so when the body is heated, and the
mouths of the small vessels are dilated. Instances, indeed, are
not unknown of persons who in consequence of a cachectic
state have secreted sweat that resembled blood, their body
having become loose and flabby, and their blood watery, owing
to the heat in the small vessels having been too scanty for its
concoction. For, as was before said, every compound of earth
and water - and both nutriment and blood are such - becomes
thicker from concoction. The inability of the heat to effect
concoction may be due either to its being absolutely small in
amount, or to its being small in proportion to the quantity of
food, when this has been taken excess. This excess again may
be of two kinds, either quantitative or qualitative; for all
substances are not equally amenable to concoction.
The widest passages in the body are of all parts the most liable
to haemorrhage; so that bleeding occurs not infrequently from
1882
the nostrils, the gums, and the fundament, occasionally also
from the mouth. Such haemorrhages are of a passive kind, and
not violent as are those from the windpipe.
The great vessel and the aorta, which above lie somewhat apart,
lower down exchange positions, and by so doing give
compactness to the body. For when they reach the point where
the legs diverge, they each split into two, and the great vessel
passes from the front to the rear, and the aorta from the rear to
the front. By this they contribute to the unity of the whole
fabric. For as in plaited work the parts hold more firmly together
because of the interweaving, so also by the interchange of
position between the blood-vessels are the anterior and
posterior parts of the body more closely knit together. A similar
exchange of position occurs also in the upper part of the body,
between the vessels that have issued from the heart. The details
however of the mutual relations of the different vessels must be
looked for in the treatises on Anatomy and the Researches
concerning Animals.
So much, then, as concerns the heart and the blood-vessels. We
must now pass on to the other viscera and apply the same
method of inquiry to them.
The lung, then, is an organ found in all the animals of a certain
class, because they live on land. For there must of necessity be
some means or other of tempering the heat of the body; and in
sanguineous animals, as they are of an especially hot nature,
the cooling agency must be external, whereas in the bloodless
kinds the innate spirit is sufficient of itself for the purpose. The
external cooling agent must be either air or water. In fishes the
1883
agent is water. Fishes therefore never have a lung, but have gills
in its place, as was stated in the treatise on Respiration. But
animals that breathe are cooled by air. These therefore are all
provided with a lung.
All land animals breathe, and even some water animals, such as
the whale, the dolphin, and all the spouting Cetacea. For many
animals lie half-way between terrestrial and aquatic; some that
are terrestrial and that inspire air being nevertheless of such a
bodily constitution that they abide for the most time in the
water; and some that are aquatic partaking so largely of the
land character, that respiration constitutes for them the man
condition of life.
The organ of respiration is the lung. This derives its motion
from the heart; but it is its own large size and spongy texture
that affords amplitude of space for entrance of the breath. For
when the lung rises up the breath streams in, and is again
expelled when the lung collapses. It has been said that the lung
exists as a provision to meet the jumping of the heart. But this
is out of the question. For man is practically the only animal
whose heart presents this phenomenon of jumping, inasmuch
as he alone is influenced by hope and anticipation of the future.
Moreover, in most animals the lung is separated from the heart
by a considerable interval and lies above it, so that it can
contribute nothing to mitigate any jumping.
The lung differs much in different animals. For in some it is of
large size and contains blood; while in others it is smaller and
of spongy texture. In the vivipara it is large and rich in blood,
because of their natural heat; while in the ovipara it is small
and dry but capable of expanding to a vast extent when
inflated. Among terrestrial animals, the oviparous quadrupeds,
such as lizards, tortoises, and the like, have this kind of lung;
and, among inhabitants of the air, the animals known as birds.
1884
For in all these the lung is spongy, and like foam. For it is
membranous and collapses from a large bulk to a small one, as
does foam when it runs together. In this too lies the explanation
of the fact that these animals are little liable to thirst and drink
but sparingly, and that they are able to remain for a
considerable time under water. For, inasmuch as they have but
little heat, the very motion of the lung, airlike and void, suffices
by itself to cool them for a considerable period.
These animals, speaking generally, are also distinguished from
others by their smaller bulk. For heat promotes growth, and
abundance of blood is a sure indication of heat. Heat, again,
tends to make the body erect; and thus it is that man is the
most erect of animals, and the vivipara more erect than other
quadrupeds. For no viviparous animal, be it apodous or be it
possessed of feet, is so given to creep into holes as are the
ovipara.
The lung, then, exists for respiration; and this is its universal
office; but in one order of animals it is bloodless and has the
structure described above, to suit the special requirements
There is, however, no one term to denote all animals that have a
lung; no designation, that is, like the term Bird, applicable to the
whole of a certain class. Yet the possession of a lung is a part of
their essence, just as much as the presence of certain characters
constitutes the essence of a bird.
Of the viscera some appear to be single, as the heart and lung;
others to be double, as the kidneys; while of a third kind it is
doubtful in which class they should be reckoned. For the liver
and the spleen would seem to lie half-way between the single
1885
and the double organs. For they may be regarded either as
constituting each a single organ, or as a pair of organs
resembling each other in character.
In reality, however, all the organs are double. The reason for this
is that the body itself is double, consisting of two halves, which
are however combined together under one supreme centre. For
there is an upper and a lower half, a front and a rear, a right side
and a left.
This explains why it is that even the brain and the several
organs of sense tend in all animals to consist of two parts; and
the same explanation applies to the heart with its cavities. The
lung again in Ovipara is divided to such an extent that these
animals look as though they had actually two lungs. As to the
kidneys, no one can overlook their double character. But when
we come to the liver and the spleen, any one might fairly be in
doubt. The reason of this is, that, in animals that necessarily
have a spleen, this organ is such that it might be taken for a
kind of bastard liver; while in those in which a spleen is not an
actual necessity but is merely present, as it were, by way of
token, in an extremely minute form, the liver plainly consists of
two parts; of which the larger tends to lie on the right side and
the smaller on the left. Not but what there are some even of the
Ovipara in which this condition is comparatively indistinctly
marked; while, on the other hand, there are some Vivipara in
which the liver is manifestly divided into two parts. Examples of
such division are furnished by the hares of certain regions,
which have the appearance of having two livers, and by the
cartilaginous and some other fishes.
It is the position of the liver on the right side of the body that is
the main cause for the formation of the spleen; the existence of
which thus becomes to a certain extent a matter of necessity in
all animals, though not of very stringent necessity.
1886
The reason, then, why the viscera are bilateral is, as we have
said, that there are two sides to the body, a right and a left. For
each of these sides aims at similarity with the other, and so
likewise do their several viscera; and as the sides, though dual,
are knit together into unity, so also do the viscera tend to be
bilateral and yet one by unity of constitution.
Those viscera which lie below the diaphragm exist one and all
on account of the blood-vessels; serving as a bond, by which
these vessels, while floating freely, are yet held in connexion
with the body. For the vessels give off branches which run to the
body through the outstretched structures, like so many
anchorlines thrown out from a ship. The great vessel sends such
branches to the liver and the spleen; and these viscera - the
liver and spleen on either side with the kidneys behind - attach
the great vessel to the body with the firmness of nails. The aorta
sends similar branches to each kidney, but none to the liver or
spleen.
These viscera, then, contribute in this manner to the
compactness of the animal body. The liver and spleen assist,
moreover, in the concoction of the food; for both are of a hot
character, owing to the blood which they contain. The kidneys,
on the other hand, take part in the separation of the excretion
which flows into the bladder.
The heart then and the liver are essential constituents of every
animal; the liver that it may effect concoction, the heart that it
may lodge the central source of heat. For some part or other
there must be which, like a hearth, shall hold the kindling fire;
and this part must be well protected, seeing that it is, as it were,
the citadel of the body.
All sanguineous animals, then, need these two parts; and this
explains why these two viscera, and these two alone, are
invariably found in them all. In such of them, however, as
1887
breathe, there is also as invariably a third, namely the lung. The
spleen, on the other hand, is not invariably present; and, in
those animals that have it, is only present of necessity in the
same sense as the excretions of the belly and of the bladder are
necessary, in the sense, that is, of being an inevitable
concomitant. Therefore it is that in some animals the spleen is
but scantily developed as regards size. This, for instance, is the
case in such feathered animals as have a hot stomach. Such are
the pigeon, the hawk, and the kite. It is the case also in
oviparous quadrupeds, where the spleen is excessively minute,
and in many of the scaly fishes. These same animals are also
without a bladder, because the loose texture of their flesh
allows the residual fluid to pass through and to be applied to
the formation of feathers and scales. For the spleen attracts the
residual humours from the stomach, and owing to its bloodlike
character is enabled to assist in their concoction. Should,
however, this residual fluid be too abundant, or the heat of the
spleen be too scanty, the body becomes sickly from over-
repletion with nutriment. Often, too, when the spleen is
affected by disease, the belly becomes hard owing to the reflux
into it of the fluid; just as happens to those who form too much
urine, for they also are liable to a similar diversion of the fluids
into the belly. But in those animals that have but little
superfluous fluid to excrete, such as birds and fishes, the spleen
is never large, and in some exists no more than by way of token.
So also in the oviparous quadrupeds it is small, compact, and
like a kidney. For their lung is spongy, and they drink but little,
and such superfluous fluid as they have is applied to the growth
of the body and the formation of scaly plates, just as in birds it
is applied to the formation of feathers.
On the other hand, in such animals as have a bladder, and
whose lung contains blood, the spleen is watery, both for the
reason already mentioned, and also because the left side of the
body is more watery and colder than the right. For each of two
1888
contraries has been so placed as to go together with that which
is akin to it in another pair of contraries. Thus right and left, hot
and cold, are pairs of contraries; and right is conjoined with hot,
after the manner described, and left with cold.
The kidneys when they are present exist not of actual necessity,
but as matters of greater finish and perfection. For by their
special character they are suited to serve in the excretion of the
fluid which collects in the bladder. In animals therefore where
this fluid is very abundantly formed, their presence enables the
bladder to perform its proper office with greater perfection.
Since then both kidneys and bladder exist in animals for one
and the same function, we must next treat of the bladder,
though in so doing we disregard the due order of succession in
which the parts should be enumerated. For not a word has yet
been said of the midriff, which is one of the parts that environ
the viscera and therefore has to be considered with them.
8
It is not every animal that has a bladder; those only being
apparently intended by nature to have one, whose lung contains
blood. To such it was but reasonable that she should give this
part. For the superabundance in their lung of its natural
constituents causes them to be the thirstiest of animals, and
makes them require a more than ordinary quantity not merely
of solid but also of liquid nutriment. This increased
consumption necessarily entails the production of an increased
amount of residue; which thus becomes too abundant to be
concocted by the stomach and excreted with its own residual
matter. The residual fluid must therefore of necessity have a
receptacle of its own; and thus it comes to pass that all animals
1889
whose lung contains blood are provided with a bladder. Those
animals, on the other hand, that are without a lung of this
character, and that either drink but sparingly owing to their
lung being of a spongy texture, or never imbibe fluid at all for
drinking's sake but only as nutriment, insects for instance and
fishes, and that are moreover clad with feathers or scales or
scaly plates - all these animals, owing to the small amount of
fluid which they imbibe, and owing also to such residue as there
may be being converted into feathers and the like, are invariably
without a bladder. The Tortoises, which are comprised among
animals with scaly plates, form the only exception; and this is
merely due to the imperfect development of their natural
conformation; the explanation of the matter being that in the
sea-tortoises the lung is flesh-like and contains blood,
resembling the lung of the ox, and that in the land-tortoises it is
of disproportionately large size. Moreover, inasmuch as the
covering which invests them is dense and shell-like, so that the
moisture cannot exhale through the porous flesh, as it does in
birds and in snakes and other animals with scaly plates, such
an amount of secretion is formed that some special part is
required to receive and hold it. This then is the reason why
these animals, alone of their kind, have a bladder, the sea-
tortoise a large one, the land-tortoises an extremely small one.
What has been said of the bladder is equally true of the kidneys.
For these also are wanting in all animals that are clad with
feathers or with scales or with scale-like plates; the sea and
land tortoises forming the only exception. In some of the birds,
however, there are flattened kidney like bodies, as though the
1890
flesh allotted to the formation of the kidneys, unable to find one
single place of sufficient size, had been scattered over several.
The Emys has neither bladder nor kidneys. For the softness of
its shell allows of the ready transpiration of fluid; and for this
reason neither of the organs mentioned exists in this animal.
All other animals, however, whose lung contains blood are, as
before said, provided with kidneys. For nature uses these organs
for two separate purposes, namely for the excretion of the
residual fluid, and to subserve the blood-vessels, a channel
leading to them from the great vessel.
In the centre of the kidney is a cavity of variable size. This is the
case in all animals, excepting the seal. The kidneys of this
animal are more solid than those of any other, and in form
resemble the kidneys of the ox. The human kidneys are of
similar shape; being as it were made up of numerous small
kidneys, and not presenting one unbroken surface like the
kidneys of sheep and other quadrupeds. For this reason, should
the kidneys of a man be once attacked by disease, the malady is
not easily expelled. For it is as though many kidneys were
diseased and not merely one; which naturally enhances the
difficulties of a cure.
The duct which runs to the kidney from the great vessel does
not terminate in the central cavity, but is expended on the
substance of the organ, so that there is no blood in the cavity,
nor is any coagulum found there after death. A pair of stout
ducts, void of blood, run, one from the cavity of each kidney, to
the bladder; and other ducts, strong and continuous, lead into
the kidneys from the aorta. The purpose of this arrangement is
to allow the superfluous fluid to pass from the blood-vessel into
the kidney, and the resulting renal excretion to collect by the
percolation of the fluid through the solid substance of the
organ, in its centre, where as a general rule there is a cavity.
1891
(This by the way explains why the kidney is the most ill-
savoured of all the viscera.) From the central cavity the fluid is
discharged into the bladder by the ducts that have been
mentioned, having already assumed in great degree the
character of excremental residue. The bladder is as it were
moored to the kidneys; for, as already has been stated, it is
attached to them by strong ducts. These then are the purposes
for which the kidneys exist, and such the functions of these
organs.
In all animals that have kidneys, that on the right is placed
higher than that on the left. For inasmuch as motion
commences from the right, and the organs on this side are in
consequence stronger than those on the left, they must all push
upwards in advance of their opposite fellows; as may be seen in
the fact that men even raise the right eyebrow more than the
left, and that the former is more arched than the latter. The
right kidney being thus drawn upwards is in all animals brought
into contact with the liver; for the liver lies on the right side.
Of all the viscera the kidneys are those that have the most fat.
This is in the first place the result of necessity, because the
kidneys are the parts through which the residual matters
percolate. For the blood which is left behind after this excretion,
being of pure quality, is of easy concoction, and the final result
of thorough blood-concoction is lard and suet. For just as a
certain amount of fire is left in the ashes of solid substances
after combustion, so also does a remnant of the heat that has
been developed remain in fluids after concoction; and this is the
reason why oily matter is light, and floats on the surface of
other fluids. The fat is not formed in the kidneys themselves,
the density of their substance forbidding this, but is deposited
about their external surface. It consists of lard or of suet,
according as the animal's fat is of the former or latter character.
The difference between these two kinds of fat has already been
1892
set forth in other passages. The formation, then, of fat in the
kidneys is the result of necessity; being, as explained, a
consequence of the necessary conditions which accompany the
possession of such organs. But at the same time the fat has a
final cause, namely to ensure the safety of the kidneys, and to
maintain their natural heat. For placed, as these organs are,
close to the surface, they require a greater supply of heat than
other parts. For while the back is thickly covered with flesh, so
as to form a shield for the heart and neighbouring viscera, the
loins, in accordance with a rule that applies to all bendings, are
destitute of flesh; and fat is therefore formed as a substitute for
it, so that the kidneys may not be without protection. The
kidneys, moreover, by being fat are the better enabled to secrete
and concoct their fluid; for fat is hot, and it is heat that effects
concoction.
Such, then, are the reasons why the kidneys are fat. But in all
animals the right kidney is less fat than its fellow. The reason
for this is, that the parts on the right side are naturally more
solid and more suited for motion than those on the left. But
motion is antagonistic to fat, for it tends to melt it.
Animals then, as a general rule, derive advantage from their
kidneys being fat; and the fat is often very abundant and
extends over the whole of these organs. But, should the like
occur in the sheep, death ensues. Be its kidneys, however, as fat
as they may, they are never so fat but that some part, if not in
both at any rate in the right one, is left free. The reason why
sheep are the only animals that suffer in this manner, or suffer
more than others, is that in animals whose fat is composed of
lard this is of fluid consistency, so that there is not the same
chance in their case of wind getting shut in and causing
mischief. But it is to such an enclosure of wind that rot is due.
And thus even in men, though it is beneficial to them to have
fat kidneys, yet should these organs become over-fat and
1893
diseased, deadly pains ensue. As to those animals whose fat
consists of suet, in none is the suet so dense as in the sheep,
neither is it nearly so abundant; for of all animals there is none
in which the kidneys become so soon gorged with fat as in the
sheep. Rot, then, is produced by the moisture and the wind
getting shut up in the kidneys, and is a malady that carries off
sheep with great rapidity. For the disease forthwith reaches the
heart, passing thither by the aorta and the great vessel, the
ducts which connect these with the kidneys being of unbroken
continuity.
10
We have now dealt with the heart and the lung, as also with the
liver, spleen, and kidneys. The latter are separated from the
former by the midriff or, as some call it, the Phrenes. This
divides off the heart and lung, and, as already said, is called
Phrenes in sanguineous animals, all of which have a midriff,
just as they all have a heart and a liver. For they require a
midriff to divide the region of the heart from the region of the
stomach, so that the centre wherein abides the sensory soul
may be undisturbed, and not be overwhelmed, directly food is
taken, by its up-steaming vapour and by the abundance of heat
then superinduced. For it was to guard against this that nature
made a division, constructing the midriff as a kind of partition-
wall and fence, and so separated the nobler from the less noble
parts, in all cases where a separation of upper from lower is
possible. For the upper part is the more honourable, and is that
for the sake of which the rest exists; while the lower part exists
for the sake of the upper and constitutes the necessary element
in the body, inasmuch as it is the recipient of the food.
1894
That portion of the midriff which is near the ribs is fleshier and
stronger than the rest, but the central part has more of a
membranous character; for this structure conduces best to its
strength and its extensibility. Now that the midriff, which is a
kind of outgrowth from the sides of the thorax, acts as a screen
to prevent heat mounting up from below, is shown by what
happens, should it, owing to its proximity to the stomach,
attract thence the hot and residual fluid. For when this occurs
there ensues forthwith a marked disturbance of intellect and of
sensation. It is indeed because of this that the midriff is called
Phrenes, as though it had some share in the process of thinking
(Phronein). in reality, however, it has no part whatsoever itself in
the matter, but, lying in close proximity to organs that have, it
brings about the manifest changes of intelligence in question by
acting upon them. This too explains why its central part is thin.
For though this is in some measure the result of necessity,
inasmuch as those portions of the fleshy whole which lie
nearest to the ribs must necessarily be fleshier than the rest, yet
besides this there is a final cause, namely to give it as small a
proportion of humour as possible; for, had it been made of flesh
throughout, it would have been more likely to attract and hold a
large amount of this. That heating of it affects sensation rapidly
and in a notable manner is shown by the phenomena of
laughing. For when men are tickled they are quickly set a-
laughing, because the motion quickly reaches this part, and
heating it though but slightly nevertheless manifestly so
disturbs the mental action as to occasion movements that are
independent of the will. That man alone is affected by tickling is
due firstly to the delicacy of his skin, and secondly to his being
the only animal that laughs. For to be tickled is to be set in
laughter, the laughter being produced such a motion as
mentioned of the region of the armpit.
It is said also that when men in battle are wounded anywhere
near the midriff, they are seen to laugh, owing to the heat
1895
produced by the wound. This may possibly be the case. At any
rate it is a statement made by much more credible persons than
those who tell the story of the human head, how it speaks after
it is cut off. For so some assert, and even call in Homer to
support them, representing him as alluding to this when he
wrote, 'His head still speaking rolled into the dust,' instead of
'The head of the speaker'. So fully was the possibility of such an
occurrence accepted in Caria, that one of that country was
actually brought to trial under the following circumstances. The
priest of Zeus Hoplosmios had been murdered; but as yet it had
not been ascertained who was the assassin; when certain
persons asserted that they had heard the murdered man's head,
which had been severed from the body, repeat several times the
words, 'Cercidas slew man on mam.' Search was thereupon
made and a man of those parts who bore the name of Cercidas
hunted out and put upon his trial. But it is impossible that any
one should utter a word when the windpipe is severed and no
motion any longer derived from the lung. Moreover, among the
Barbarians, where heads are chopped off with great rapidity,
nothing of the kind has ever yet occurred. Why, again, does not
the like occur in the case of other animals than man? For that
none of them should laugh, when their midriff is wounded, is
but what one would expect; for no animal but man ever laughs.
So, too, there is nothing irrational in supposing that the trunk
may run forwards to a certain distance after the head has been
cut seeing that bloodless animals at any rate can live, and that
for a considerable time, after decapitation, as has been set forth
and explained in other passages.
The purposes, then, for which the viscera severally exist have
now been stated. It is of necessity upon the inner terminations
of the vessels that they are developed; for humour, and that of a
bloody character, cannot but exude at these points, and it is of
this, solidified and coagulated, that the substance of the viscera
1896
is formed. Thus they are of a bloody character, and in substance
resemble each other while they differ from other parts.
11
The viscera are enclosed each in a membrane. For they require
some covering to protect them from injury, and require,
moreover, that this covering shall be light. To such requirements
membrane is well adapted; for it is close in texture so as to form
a good protection, destitute of flesh so as neither to attract
humour nor retain it, and thin so as to be light and not add to
the weight of the body. Of the membranes those are the stoutest
and strongest which invest the heart and the brain; as is but
consistent with reason. For these are the parts which require
most protection, seeing that they are the main governing
powers of life, and that it is to governing powers that guard is
due.
12
Some animals have all the viscera that have been enumerated;
others have only some of them. In what kind of animals this
latter is the case, and what is the explanation, has already been
stated. Moreover, the self-same viscera present differences in
different possessors. For the heart is not precisely alike in all
animals that have one; nor, in fact, is any viscus whatsoever.
Thus the liver is in some animals split into several parts, while
in others it is comparatively undivided. Such differences in its
form present themselves even among those sanguineous
1897
animals that are viviparous, but are more marked in fishes and
in the oviparous quadrupeds, and this whether we compare
them with each other or with the Vivipara. As for birds, their
liver very nearly resembles that of the Vivipara; for in them, as
in these, it is of a pure and blood-like colour. The reason of this
is that the body in both these classes of animals admits of the
freest exhalation, so that the amount of foul residual matter
within is but small. Hence it is that some of the Vivipara are
without any gall-bladder at all. For the liver takes a large share
in maintaining the purity of composition and the healthiness of
the body. For these are conditions that depend finally and in the
main upon the blood, and there is more blood in the liver than
in any of the other viscera, the heart only excepted. On the
other hand, the liver of oviparous quadrupeds and fishes
inclines, as a rule, to a yellow hue, and there are even some of
them in which it is entirely of this bad colour, in accordance
with the bad composition of their bodies generally. Such, for
instance, is the case in the toad, the tortoise, and other similar
animals.
The spleen, again, varies in different animals. For in those that
have horns and cloven hoofs, such as the goat, the sheep, and
the like, it is of a rounded form; excepting when increased size
has caused some part of it to extend its growth longitudinally,
as has happened in the case of the ox. On the other hand, it is
elongated in all polydactylous animals. Such, for instance, is the
case in the pig, in man, and in the dog. While in animals with
solid hoofs it is of a form intermediate to these two, being broad
in one part, narrow in another. Such, for example, is its shape in
the horse, the mule, and the ass.
1898
13
The viscera differ from the flesh not only in the turgid aspect of
their substance, but also in position; for they lie within the body,
whereas the flesh is placed on the outside. The explanation of
this is that these parts partake of the character of blood-vessels,
and that while the former exist for the sake of the vessels, the
latter cannot exist without them.
14
Below the midriff lies the stomach, placed at the end of the
oesophagus when there is one, and in immediate contiguity
with the mouth when the oesophagus is wanting. Continuous
with this stomach is what is called the gut. These parts are
present in all animals, for reasons that are self-evident. For it is
a matter of necessity that an animal shall receive the incoming
food; and necessary also that it shall discharge the same when
its goodness is exhausted. This residual matter, again, must not
occupy the same place as the yet unconcocted nutriment. For as
the ingress of food and the discharge of the residue occur at
distinct periods, so also must they necessarily occur in distinct
places. Thus there must be one receptacle for the ingoing food
and another for the useless residue, and between these,
therefore, a part in which the change from one condition to the
other may be effected. These, however, are matters which will
be more suitably set forth when we come to deal with
Generation and Nutrition. What we have at present to consider
are the variations presented by the stomach and its subsidiary
parts. For neither in size nor in shape are these parts uniformly
alike in all animals. Thus the stomach is single in all such
sanguineous and viviparous animals as have teeth in front of
1899
both jaws. It is single therefore in all the polydactylous kinds,
such as man, dog, lion, and the rest; in all the solid-hoofed
animals also, such as horse, mule, ass; and in all those which,
like the pig, though their hoof is cloven, yet have front teeth in
both jaws. When, however, an animal is of large size, and feeds
on substances of so thorny and ligneous a character as to be
difficult of concoction, it may in consequence have several
stomachs, as for instance is the case with the camel. A similar
multiplicity of stomachs exists also in the horned animals; the
reason being that horn-bearing animals have no front teeth in
the upper jaw. The camel also, though it has no horns, is yet
without upper front teeth. The explanation of this is that it is
more essential for the camel to have a multiple stomach than to
have these teeth. Its stomach, then, is constructed like that of
animals without upper front teeth, and, its dental arrangements
being such as to match its stomach, the teeth in question are
wanting. They would indeed be of no service. Its food, moreover,
being of a thorny character, and its tongue necessarily made of
a fleshy substance, nature uses the earthy matter which is
saved from the teeth to give hardness to the palate. The camel
ruminates like the horned animals, because its multiple
stomach resembles theirs. For all animals that have horns, the
sheep for instance, the ox, the goat, the deer, and the like, have
several stomachs. For since the mouth, owing to its lack of
teeth, only imperfectly performs its office as regards the food,
this multiplicity of stomachs is intended to make up for its
shortcomings; the several cavities receiving the food one from
the other in succession; the first taking the unreduced
substances, the second the same when somewhat reduced, the
third when reduction is complete, and the fourth when the
whole has become a smooth pulp. Such is the reason why there
is this multiplicity of parts and cavities in animals with such
dentition. The names given to the several cavities are the
paunch, the honeycomb bag, the manyplies, and the reed. How
1900
these parts are related to each other, in position and in shape,
must be looked for in the treatises on Anatomy and the
Researches concerning Animals.
Birds also present variations in the part which acts as a
recipient of the food; and the reason for these variations is the
same as in the animals just mentioned. For here again it is
because the mouth fails to perform its office and fails even
more completely - for birds have no teeth at all, nor any
instrument whatsoever with which to comminute or grind
down their food - it is, I say, because of this, that in some of
them what is called the crop precedes the stomach and does
the work of the mouth; while in others the oesophagus is either
wide throughout or a part of it bulges just before it enters the
stomach, so as to form a preparatory store-house for the
unreduced food; or the stomach itself has a protuberance in
some part, or is strong and fleshy, so as to be able to store up
the food for a considerable period and to concoct it, in spite of
its not having been ground into a pulp. For nature retrieves the
inefficiency of the mouth by increasing the efficiency and heat
of the stomach. Other birds there are, such, namely, as have
long legs and live in marshes, that have none of these
provisions, but merely an elongated oesophagus. The
explanation of this is to be found in the moist character of their
food. For all these birds feed on substances easy of reduction,
and their food being moist and not requiring much concoction,
their digestive cavities are of a corresponding character.
Fishes are provided with teeth, which in almost all of them are
of the sharp interfitting kind. For there is but one small section
in which it is otherwise. Of these the fish called Scarus (Parrot-
fish) is an example. And this is probably the reason why this
fish apparently ruminates, though no other fishes do so. For
those horned animals that have no front teeth in the upper jaw
also ruminate.
1901
In fishes the teeth are all sharp; so that these animals can
divide their food, though imperfectly. For it is impossible for a
fish to linger or spend time in the act of mastication, and
therefore they have no teeth that are flat or suitable for
grinding; for such teeth would be to no purpose. The
oesophagus again in some fishes is entirely wanting, and in the
rest is but short. In order, however, to facilitate the concoction of
the food, some of them, as the Cestreus (mullet), have a fleshy
stomach resembling that of a bird; while most of them have
numerous processes close against the stomach, to serve as a
sort of antechamber in which the food may be stored up and
undergo putrefaction and concoction. There is contrast between
fishes and birds in the position of these processes. For in fishes
they are placed close to the stomach; while in birds, if present
at all, they are lower down, near the end of the gut. Some of the
Vivipara also have processes connected with the lower part of
the gut which serve the same purpose as that stated above.
The whole tribe of fishes is of gluttonous appetite, owing to the
arrangements for the reduction of their food being very
imperfect, and much of it consequently passing through them
without undergoing concoction; and, of all, those are the most
gluttonous that have a straight intestine. For as the passage of
food in such cases is rapid, and the enjoyment derived from it in
consequence but brief, it follows of necessity that the return of
appetite is also speedy.
It has already been mentioned that in animals with front teeth
in both jaws the stomach is of small size. It may be classed
pretty nearly always under one or other of two headings,
namely as resembling the stomach of the dog, or as resembling
the stomach of the pig. In the pig the stomach is larger than in
the dog, and presents certain folds of moderate size, the
purpose of which is to lengthen out the period of concoction;
1902
while the stomach of the dog is of small size, not much larger in
calibre than the gut, and smooth on the internal surface.
Not much larger, I say, than the gut; for in all animals after the
stomach comes the gut. This, like the stomach, presents
numerous modifications. For in some animals it is uniform,
when uncoiled, and alike throughout, while in others it differs
in different portions. Thus in some cases it is wider in the
neighbourhood of the stomach, and narrower towards the other
end; and this explains by the way why dogs have to strain so
much in discharging their excrement. But in most animals it is
the upper portion that is the narrower and the lower that is of
greater width.
Of greater length than in other animals, and much convoluted,
are the intestines of those that have horns. These intestines,
moreover, as also the stomach, are of ampler volume, in
accordance with the larger size of the body. For animals with
horns are, as a rule, animals of no small bulk, because of the
thorough elaboration which their food undergoes. The gut,
except in those animals where it is straight, invariably widens
out as we get farther from the stomach and come to what is
called the colon, and to a kind of caecal dilatation. After this it
again becomes narrower and convoluted. Then succeeds a
straight portion which runs right on to the vent. This vent is
known as the anus, and is in some animals surrounded by fat,
in others not so. All these parts have been so contrived by
nature as to harmonize with the various operations that relate
to the food and its residue. For, as the residual food gets farther
on and lower down, the space to contain it enlarges, allowing it
to remain stationary and undergo conversion. Thus is it in those
animals which, owing either to their large size, or to the heat of
the parts concerned, require more nutriment, and consume
more fodder than the rest.
1903
Neither is it without a purpose, that, just as a narrower gut
succeeds to the upper stomach, so also does the residual food,
when its goodness is thoroughly exhausted, pass from the colon
and the ample space of the lower stomach into a narrower
channel and into the spiral coil. For so nature can regulate her
expenditure and prevent the excremental residue from being
discharged all at once.
In all such animals, however, as have to be comparatively
moderate in their alimentation, the lower stomach presents no
wide and roomy spaces, though their gut is not straight, but has
a number of convolutions. For amplitude of space causes desire
for ample food, and straightness of the intestine causes quick
return of appetite. And thus it is that all animals whose food
receptacles are either simple or spacious are of gluttonous
habits, the latter eating enormously at a meal, the former
making meals at short intervals.
Again, since the food in the upper stomach, having just been
swallowed, must of necessity be quite fresh, while that which
has reached the lower stomach must have had its juices
exhausted and resemble dung, it follows of necessity that there
must also be some intermediate part, in which the change may
be effected, and where the food will be neither perfectly fresh
nor yet dung. And thus it is that, in all such animals as we are
now considering, there is found what is called the jejunum;
which is a part of the small gut, of the gut, that is, which comes
next to the stomach. For this jejunum lies between the upper
cavity which contains the yet unconcocted food and the lower
cavity which holds the residual matter, which by the time it has
got here has become worthless. There is a jejunum in all these
animals, but it is only plainly discernible in those of large size,
and this only when they have abstained from food for a certain
time. For then alone can one hit on the exact period when the
food lies half-way between the upper and lower cavities; a
1904
period which is very short, for the time occupied in the
transition of food is but brief. In females this jejunum may
occupy any part whatsoever of the upper intestine, but in males
it comes just before the caecum and the lower stomach.
15
What is known as rennet is found in all animals that have a
multiple stomach, and in the hare among animals whose
stomach is single. In the former the rennet neither occupies the
large paunch, nor the honeycomb bag, nor the terminal reed,
but is found in the cavity which separates this terminal one
from the two first, namely in the so-called manyplies. It is the
thick character of their milk which causes all these animals to
have rennet; whereas in animals with a single stomach the milk
is thin, and consequently no rennet is formed. It is this
difference in thickness which makes the milk of horned
animals coagulate, while that of animals without horns does
not. Rennet forms in the hare because it feeds on herbage that
has juice like that of the fig; for juice of this kind coagulates the
milk in the stomach of the sucklings. Why it is in the manyplies
that rennet is formed in animals with multiple stomachs has
been stated in the Problems.
1905
Book IV
The account which has now been given of the viscera, the
stomach, and the other several parts holds equally good not
only for the oviparous quadrupeds, but also for such apodous
animals as the Serpents. These two classes of animals are
indeed nearly akin, a serpent resembling a lizard which has
been lengthened out and deprived of its feet. Fishes, again,
resemble these two groups in all their parts, excepting that,
while these, being land animals, have a lung, fishes have no
lung, but gills in its place. None of these animals, excepting the
tortoise, as also no fish, has a urinary bladder. For owing to the
bloodlessness of their lung, they drink but sparingly; and such
fluid as they have is diverted to the scaly plates, as in birds it is
diverted to the feathers, and thus they come to have the same
white matter on the surface of their excrement as we see on
that of birds. For in animals that have a bladder, its excretion
when voided throws down a deposit of earthy brine in the
containing vessel. For the sweet and fresh elements, being light,
are expended on the flesh.
Among the Serpents, the same peculiarity attaches to vipers, as
among fishes attaches to Selachia. For both these and vipers are
externally viviparous, but previously produce ova internally.
The stomach in all these animals is single, just as it is single in
all other animals that have teeth in front of both jaws; and their
viscera are excessively small, as always happens when there is
no bladder. In serpents these viscera are, moreover, differently
shaped from those of other animals. For, a serpent's body being
1906
long and narrow, its contents are as it were moulded into a
similar form, and thus come to be themselves elongated.
All animals that have blood possess an omentum, a mesentery,
intestines with their appendages, and, moreover, a diaphragm
and a heart; and all, excepting fishes, a lung and a windpipe.
The relative positions, moreover, of the windpipe and the
oesophagus are precisely similar in them all; and the reason is
the same as has already been given.
Almost all sanguineous animals have a gall-bladder. In some
this is attached to the liver, in others separated from that organ
and attached to the intestines, being apparently in the latter
case no less than in the former an appendage of the lower
stomach. It is in fishes that this is most clearly seen. For all
fishes have a gall-bladder; and in most of them it is attached to
the intestine, being in some, as in the Amia, united with this,
like a border, along its whole length. It is similarly placed in
most serpents There are therefore no good grounds for the view
entertained by some writers, that the gall exists for the sake of
some sensory action. For they say that its use is to affect that
part of the soul which is lodged in the neighbourhood of the
liver, vexing this part when it is congealed, and restoring it to
cheerfulness when it again flows free. But this cannot be. For in
some animals there is absolutely no gall-bladder at all - in the
horse, for instance, the mule, the ass, the deer, and the roe; and
in others, as the camel, there is no distinct bladder, but merely
small vessels of a biliary character. Again, there is no such organ
in the seal, nor, of purely sea-animals, in the dolphin. Even
within the limits of the same genus, some animals appear to
1907
have and others to be without it. Such, for instance, is the case
with mice; such also with man. For in some individuals there is
a distinct gall-bladder attached to the liver, while in others
there is no gall-bladder at all. This explains how the existence of
this part in the whole genus has been a matter of dispute. For
each observer, according as he has found it present or absent in
the individual cases he has examined, has supposed it to be
present or absent in the whole genus. The same has occurred in
the case of sheep and of goats. For these animals usually have a
gall-bladder; but, while in some localities it is so enormously big
as to appear a monstrosity, as is the case in Naxos, in others it is
altogether wanting, as is the case in a certain district belonging
to the inhabitants of Chalcis in Euboea. Moreover, the gall-
bladder in fishes is separated, as already mentioned, by a
considerable interval from the liver. No less mistaken seems to
be the opinion of Anaxagoras and his followers, that the gall-
bladder is the cause of acute diseases, inasmuch as it becomes
over-full, and spirts out its excess on to the lung, the blood-
vessels, and the ribs. For, almost invariably, those who suffer
from these forms of disease are persons who have no gall-
bladder at all, as would be quite evident were they to be
dissected. Moreover, there is no kind of correspondence
between the amount of bile which is present in these diseases
and the amount which is exuded. The most probable opinion is
that, as the bile when it is present in any other part of the body
is a mere residuum or a product of decay, so also when it is
present in the region of the liver it is equally excremental and
has no further use; just as is the case with the dejections of the
stomach and intestines. For though even the residua are
occasionally used by nature for some useful purpose, yet we
must not in all cases expect to find such a final cause; for
granted the existence in the body of this or that constituent,
with such and such properties, many results must ensue merely
as necessary consequences of these properties. All animals,
1908
then, whose is healthy in composition and supplied with none
but sweet blood, are either entirely without a gall-bladder on
this organ, or have merely small bile-containing vessels; or are
some with and some without such parts. Thus it is that the liver
in animals that have no gall-bladder is, as a rule, of good colour
and sweet; and that, when there is a gall-bladder, that part of
the liver is sweetest which lies immediately underneath it. But,
when animals are formed of blood less pure in composition, the
bile serves for the excretion of its impure residue. For the very
meaning of excrement is that it is the opposite of nutriment,
and of bitter that it is the opposite of sweet; and healthy blood
is sweet. So that it is evident that the bile, which is bitter,
cannot have any use, but must simply be a purifying excretion.
It was therefore no bad saying of old writers that the absence of
a gall-bladder gave long life. In so saying they had in mind deer
and animals with solid hoofs. For such have no gall-bladder and
live long. But besides these there are other animals that have no
gall-bladder, though those old writers had not noticed the fact,
such as the camel and the dolphin; and these also are, as it
happens, long-lived. Seeing, indeed, that the liver is not only
useful, but a necessary and vital part in all animals that have
blood, it is but reasonable that on its character should depend
the length or the shortness of life. Nor less reasonable is it that
this organ and none other should have such an excretion as the
bile. For the heart, unable as it is to stand any violent affection,
would be utterly intolerant of the proximity of such a fluid; and,
as to the rest of the viscera, none excepting the liver are
necessary parts of an animal. It is the liver therefore that alone
has this provision. In conclusion, wherever we see bile we must
take it to be excremental. For to suppose that it has one
character in this part, another in that, would be as great an
absurdity as to suppose mucus or the dejections of the stomach
to vary in character according to locality and not to be
excremental wherever found.
1909
So much then of the gall-bladder, and of the reasons why some
animals have one, while others have not. We have still to speak
of the mesentery and the omentum; for these are associated
with the parts already described and contained in the same
cavity. The omentum, then, is a membrane containing fat; the
fat being suet or lard, according as the fat of the animal
generally is of the former or latter description. What kinds of
animals are so distinguished has been already set forth in an
earlier part of this treatise. This membrane, alike in animals
that have a single and in those that have a multiple stomach,
grows from the middle of that organ, along a line which is
marked on it like a seam. Thus attached, it covers the rest of the
stomach and the greater part of the bowels, and this alike in all
sanguineous animals, whether they live on land or in water.
Now the development of this part into such a form as has been
described is the result of necessity. For, whenever solid and fluid
are mixed together and heated, the surface invariably becomes
membranous and skin-like. But the region in which the
omentum lies is full of nutriment of such a mixed character.
Moreover, in consequence of the close texture of the membrane,
that portion of the sanguineous nutriment will alone filter into
it which is of a greasy character; for this portion is composed of
the finest particles; and when it has so filtered in, it will be
concocted by the heat of the part, and will be converted into
suet or lard, and will not acquire a flesh-like or sanguineous
constitution. The development, then, of the omentum is simply
the result of necessity. But when once formed, it is used by
nature for an end, namely, to facilitate and to hasten the
concoction of food. For all that is hot aids concoction; and fat is
1910
hot, and the omentum is fat. This too explains why it hangs
from the middle of the stomach; for the upper part of the
stomach has no need of it, being assisted in concoction by the
adjacent liver. Thus much as concerns the omentum.
The so-called mesentery is also a membrane; and extends
continuously from the long stretch of intestine to the great
vessel and the aorta. In it are numerous and close-packed
vessels, which run from the intestines to the great vessel and to
the aorta. The formation of this membrane we shall find to be
the result of necessity, as is that of the other [similar] parts.
What, however, is the final cause of its existence in sanguineous
animals is manifest on reflection. For it is necessary that
animals shall get nutriment from without; and, again, that this
shall be converted into the ultimate nutriment, which is then
distributed as sustenance to the various parts; this ultimate
nutriment being, in sanguineous animals, what we call blood,
and having, in bloodless animals, no definite name. This being
so, there must be channels through which the nutriment shall
pass, as it were through roots, from the stomach into the blood-
vessels. Now the roots of plants are in the ground; for thence
their nutriment is derived. But in animals the stomach and
intestines represent the ground from which the nutriment is to
be taken. The mesentery, then, is an organ to contain the roots;
and these roots are the vessels that traverse it. This then is the
final cause of its existence. But how it absorbs nutriment, and
how that portion of the food which enters into the vessels is
distributed by them to the various parts of the body, are
questions which will be considered when we come to deal with
the generation and nutrition of animals.
1911
The constitution of sanguineous animals, so far as the parts as
yet mentioned are concerned, and the reasons for such
constitution, have now been set forth. In natural sequence we
should next go on to the organs of generation, as yet
undescribed, on which depend the distinctions of male and
female. But, inasmuch as we shall have to deal specially with
generation hereafter, it will be more convenient to defer the
consideration of these parts to that occasion.
Very different from the animals we have as yet considered are
the Cephalopoda and the Crustacea. For these have absolutely
no viscera whatsoever; as is indeed the case with all bloodless
animals, in which are included two other genera, namely the
Testacea and the Insects. For in none of them does the material
out of which viscera are formed exist. None of them, that is,
have blood. The cause of this lies in their essential constitution.
For the presence of blood in some animals, its absence from
others, must be included in the conception which determines
their respective essences. Moreover, in the animals we are now
considering, none of those final causes will be found to exist
which in sanguineous animals determine the presence of
viscera. For they have no blood vessels nor urinary bladder, nor
do they breathe; the only part that it is necessary for them to
have being that which is analogous to a heart. For in all animals
there must be some central and commanding part of the body,
to lodge the sensory portion of the soul and the source of life.
The organs of nutrition are also of necessity present in them all.
They differ, however, in character because of differences of the
habitats in which they get their subsistence.
1912
In the Cephalopoda there are two teeth, enclosing what is called
the mouth; and inside this mouth is a flesh-like substance
which represents a tongue and serves for the discrimination of
pleasant and unpleasant food. The Crustacea have teeth
corresponding to those of the Cephalopoda, namely their
anterior teeth, and also have the fleshy representative of a
tongue. This latter part is found, moreover, in all Testacea, and
serves, as in sanguineous animals, for gustatory sensations.
Similarly provided also are the Insects. For some of these, such
as the Bees and the Flies, have, as already described, their
proboscis protruding from the mouth; while those others that
have no such instrument in front have a part which acts as a
tongue inside the mouth. Such, for instance, is the case in the
Ants and the like. As for teeth, some insects have them, the
Bees and the Ants for instance, though in a somewhat modified
form, while others that live on fluid nutriment are without
them. For in many insects the teeth are not meant to deal with
the food, but to serve as weapons.
In some Testacea, as was said in the first treatise, the organ
which is called the tongue is of considerable strength; and in
the Cochli (Sea-snails) there are also two teeth, just as in the
Crustacea. The mouth in the Cephalopoda is succeeded by a
long gullet. This leads to a crop, like that of a bird, and directly
continuous with this is the stomach, from which a gut runs
without windings to the vent. The Sepias and the Poulps
resemble each other completely, so far as regards the shape and
consistency of these parts. But not so the Teuthides
(Calamaries). Here, as in the other groups there are the two
stomach-like receptacles; but the first of these cavities has less
resemblance to a crop, and in neither is the form [or the
consistency] the same as in the other kinds, the whole body
indeed being made of a softer kind of flesh.
1913
The object of this arrangement of the parts in question is the
same in the Cephalopoda as in Birds; for these also are all
unable to masticate their food; and therefore it is that a crop
precedes their stomach.
For purposes of defence, and to enable them to escape from
their foes, the Cephalopoda have what is called their ink. This is
contained in a membranous pouch, which is attached to the
body and provided with a terminal outlet just at the point
where what is termed the funnel gives issue to the residua of
the stomach. This funnel is placed on the ventral surface of the
animal. All Cephalopoda alike have this characteristic ink, but
chief of all the Sepia, where it is more abundant than in the rest.
When the animal is disturbed and frightened it uses this ink to
make the surrounding water black and turbid, and so, as it were,
puts a shield in front of its body.
In the Calamaries and the Poulps the ink-bag is placed in the
upper part of the body, in close proximity to the mytis, whereas
in the Sepia it is lower down, against the stomach. For the Sepia
has a more plentiful supply of ink than the rest, inasmuch as it
makes more use of it. The reasons for this are, firstly, that it
lives near the shore, and, secondly, that it has no other means
of protection; whereas the Poulp has its long twining feet to use
in its defence, and is, moreover, endowed with the power of
changing colour. This changing of colour, like the discharge of
ink, occurs as the result of fright. As to the Calamary, it lives far
out at sea, being the only one of the Cephalopoda that does so;
and this gives it protection. These then are the reasons why the
ink is more abundant in the Sepia than in the Calamary, and
this greater abundance explains the lower position; for it allows
the ink to be ejected with ease even from a distance. The ink
itself is of an earthy character, in this resembling the white
deposit on the surface of a bird's excrement and the
explanation in both cases is the same, namely, the absence of a
1914
urinary bladder. For, in default of this, it is the ink that serves
for the excretion of the earthiest matter. And this is more
especially the case in the Sepia, because there is a greater
proportion of earth in its composition than in that of the other
Cephalopoda. The earthy character of its bone is a clear
indication of this. For in the Poulp there is no bone at all, and in
the Calamary it is thin and cartilaginous. Why this bone should
be present in some Cephalopoda, and wanting in others, and
how its character varies in those that have it, has now been set
forth.
These animals, having no blood, are in consequence cold and of
a timid character. Now, in some animals, fear causes a
disturbance of the bowels, and, in others, a flow of urine from
the bladder. Similarly in these it produces a discharge of ink,
and, though the ejection of this ink in fright, like that of the
urine, is the result of necessity, and, though it is of excremental
character, yet it is used by nature for a purpose, namely, the
protection and safety of the animal that excretes it.
The Crustacea also, both the Caraboid forms and the Crabs, are
provided with teeth, namely their two anterior teeth; and
between these they also present the tongue-like piece of flesh,
as has indeed been already mentioned. Directly after their
mouth comes a gullet, which, if we compare relative sizes, is but
small in proportion to the body: and then a stomach, which in
the Carabi and some of the Crabs is furnished with a second set
of teeth, the anterior teeth being insufficient for adequate
mastication. From the stomach a uniform gut runs in a direct
line to the excremental vent.
The parts described are to be found also in all the various
Testacea. The degree of distinctness, however, with which they
are formed varies in the different kinds, and the larger the size
of the animal the more easily distinguishable are all these parts
1915
severally. In the Sea-snails, for example, we find teeth, hard and
sharp, as before mentioned, and between them the flesh-like
substance, just as in the Crustacea and Cephalopoda, and again
the proboscis, which, as has been stated, is something between
a sting and a tongue. Directly after the mouth comes a kind of
bird-like crop, then a gullet, succeeded by a stomach, in which is
the mecon, as it is styled; and continuous with this mecon is an
intestine, starting directly from it. It is this residual substance
which appears in all the Testacea to form the most palatable
morsel. Purpuras and Whelks, and all other Testacea that have
turbinate shells, in structure resemble the Sea-snail. The genera
and species of Testacea are very numerous. For there are those
with turbinate shells, of which some have just been mentioned;
and, besides these, there are bivalves and univalves. Those with
turbinate shells may, indeed, after a certain fashion be said to
resemble bivalves. For they all from their very birth have an
operculum to protect that part of their body which is exposed to
view. This is the case with the Purpuras, with Whelks, with the
Nerites, and the like. Were it not for this, the part which is
undefended by the shell would be very liable to injury by
collision with external objects. The univalves also are not
without protection. For on their dorsal surface they have a shell,
and by the under surface they attach themselves to the rocks,
and so after a manner become bivalved, the rock representing
the second valve. Of these the animals known as Limpets are an
example. The bivalves, scallops and mussels, for instance, are
protected by the power they have of closing their valves; and
the Turbinata by the operculum just mentioned, which
transforms them, as it were, crom univalves into bivalves. But of
all there is none so perfectly protected as the sea-urchin. For
here there is a globular shell which encloses the body
completely, and which is, moreover, set with sharp spines. This
peculiarity distinguishes the sea-urchin from all other Testacea,
as has already been mentioned.
1916
The structure of the Testacea and of the Crustacea is exactly the
reverse of that of the Cephalopoda. For in the latter the fleshy
substance is on the outside and the earthy substance within,
whereas in the former the soft parts are inside and the hard
part without. In the sea-urchin, however, there is no fleshy part
whatsoever.
All the Testacea then, those that have not been mentioned as
well as those that have, agree as stated in possessing a mouth
with the tongue-like body, a stomach, and a vent for excrement,
but they differ from each other in the positions and proportions
of these parts. The details, however, of these differences must
be looked for in the Researches concerning Animals and the
treatises on Anatomy. For while there are some points which
can be made clear by verbal description, there are others which
are more suited for ocular demonstration.
Peculiar among the Testacea are the sea-urchins and the
animals known as Tethya (Ascidians). The sea-urchins have five
teeth, and in the centre of these the fleshy body which is
common to all the animals we have been discussing.
Immediately after this comes a gullet, and then the stomach,
divided into a number of separate compartments, which look
like so many distinct stomachs; for the cavities are separate and
all contain abundant residual matter. They are all, however,
connected with one and the same oesophagus, and they all end
in one and the same excremental vent. There is nothing besides
the stomach of a fleshy character, as has already been stated.
All that can be seen are the so-called ova, of which there are
several, contained each in a separate membrane, and certain
black bodies which have no name, and which, beginning at the
animal's mouth, are scattered round its body here and there
promiscuously. These sea-urchins are not all of one species, but
there are several different kinds, and in all of them the parts
mentioned are to be found. It is not, however, in every kind that
1917
the so-called ova are edible. Neither do these attain to any size
in any other species than that with which we are all familiar. A
similar distinction may be made generally in the case of all
Testacea. For there is a great difference in the edible qualities of
the flesh of different kinds; and in some, moreover, the residual
substance known as the mecon is good for food, while in others
it is uneatable. This mecon in the turbinated genera is lodged in
the spiral part of the shell, while in univalves, such as limpets, it
occupies the fundus, and in bivalves is placed near the hinge,
the so-called ovum lying on the right; while on the opposite side
is the vent. The former is incorrectly termed ovum, for it merely
corresponds to what in well-fed sanguineous animals is fat; and
thus it is that it makes its appearance in Testacea at those
seasons of the year when they are in good condition, namely,
spring and autumn. For no Testacea can abide extremes of
temperature, and they are therefore in evil plight in seasons of
great cold or heat. This is clearly shown by what occurs in the
case of the sea-urchins. For though the ova are to be found in
these animals even directly they are born, yet they acquire a
greater size than usual at the time of full moon; not, as some
think, because sea-urchins eat more at that season, but because
the nights are then warmer, owing to the moonlight. For these
creatures are bloodless, and so are unable to stand cold and
require warmth. Therefore it is that they are found in better
condition in summer than at any other season; and this all over
the world excepting in the Pyrrhean tidal strait. There the sea-
urchins flourish as well in winter as in summer. But the reason
for this is that they have a greater abundance of food in the
winter, because the fish desert the strait at that season.
The number of the ova is the same in all sea-urchins, and is an
odd one. For there are five ova, just as there are also five teeth
and five stomachs; and the explanation of this is to be found in
the fact that the so-called ova are not really ova, but merely, as
was said before, the result of the animal's well-fed condition.
1918
Oysters also have a so-called ovum, corresponding in character
to that of the sea-urchins, but existing only on one side of their
body. Now inasmuch as the sea-urchin is of a spherical form,
and not merely a single disk like the oyster, and in virtue of its
spherical shape is the same from whatever side it be examined,
its ovum must necessarily be of a corresponding symmetry. For
the spherical shape has not the asymmetry of the disk-shaped
body of the oysters. For in all these animals the head is central,
but in the sea-urchin the so-called ovum is above [and
symmetrical, while in the oyster it is only one side]. Now the
necessary symmetry would be observed were the ovum to form
a continuous ring. But this may not be. For it would be in
opposition to what prevails in the whole tribe of Testacea; for in
all the ovum is discontinuous, and in all excepting the sea-
urchins asymmetrical, being placed only on one side of the
body. Owing then to this necessary discontinuity of the ovum,
which belongs to the sea-urchin as a member of the class, and
owing to the spherical shape of its body, which is its individual
peculiarity, this animal cannot possibly have an even number of
ova. For were they an even number, they would have to be
arranged exactly opposite to each other, in pairs, so as to keep
the necessary symmetry; one ovum of each pair being placed at
one end, the other ovum at the other end of a transverse
diameter. This again would violate the universal provision in
Testacea. For both in the oysters and in the scallops we find the
ovum only on one side of the circumference. The number then
of the ova must be uneven, three for instance, or five. But if
there were only three they would be much too far apart; while,
if there were more than five, they would come to form a
continuous mass. The former arrangement would be
disadvantageous to the animal, the latter an impossibility. There
can therefore be neither more nor less than five. For the same
reason the stomach is divided into five parts, and there is a
corresponding number of teeth. For seeing that the ova
1919
represent each of them a kind of body for the animal, their
disposition must conform to that of the stomach, seeing that it
is from this that they derive the material for their growth. Now
if there were only one stomach, either the ova would be too far
off from it, or it would be so big as to fill up the whole cavity,
and the sea-urchin would have great difficulty in moving about
and finding due nourishment for its repletion. As then there are
five intervals between the five ova, so are there of necessity five
divisions of the stomach, one for each interval. So also, and on
like grounds, there are five teeth. For nature is thus enabled to
allot to each stomachal compartment and ovum its separate
and similar tooth. These, then, are the reasons why the number
of ova in the sea-urchin is an odd one, and why that odd
number is five. In some sea-urchins the ova are excessively
small, in others of considerable size, the explanation being that
the latter are of a warmer constitution, and so are able to
concoct their food more thoroughly; while in the former
concoction is less perfect, so that the stomach is found full of
residual matter, while the ova are small and uneatable. Those of
a warmer constitution are, moreover, in virtue of their warmth
more given to motion, so that they make expeditions in search
of food, instead of remaining stationary like the rest. As
evidence of this, it will be found that they always have
something or other sticking to their spines, as though they
moved much about; for they use their spines as feet.
The Ascidians differ but slightly from plants, and yet have more
of an animal nature than the sponges, which are virtually
plants and nothing more. For nature passes from lifeless objects
to animals in such unbroken sequence, interposing between
them beings which live and yet are not animals, that scarcely
any difference seems to exist between two neighbouring groups
owing to their close proximity.
1920
A sponge, then, as already said, in these respects completely
resembles a plant, that throughout its life it is attached to a
rock, and that when separated from this it dies. Slightly
different from the sponges are the so-called Holothurias and
the sea-lungs, as also sundry other sea-animals that resemble
them. For these are free and unattached. Yet they have no
feeling, and their life is simply that of a plant separated from
the ground. For even among land-plants there are some that are
independent of the soil, and that spring up and grow, either
upon other plants, or even entirely free. Such, for example, is
the plant which is found on Parnassus, and which some call the
Epipetrum. This you may hang up on a peg and it will yet live
for a considerable time. Sometimes it is a matter of doubt
whether a given organism should be classed with plants or with
animals. The Ascidians, for instance, and the like so far
resemble plants as that they never live free and unattached, but,
on the other hand, inasmuch as they have a certain flesh-like
substance, they must be supposed to possess some degree of
sensibility.
An Ascidian has a body divided by a single septum and with two
orifices, one where it takes in the fluid matter that ministers to
its nutrition, the other where it discharges the surplus of
unused juice, for it has no visible residual substance, such as
have the other Testacea. This is itself a very strong justification
for considering an Ascidian, and anything else there may be
among animals that resembles it, to be of a vegetable character;
for plants also never have any residuum. Across the middle of
the body of these Ascidians there runs a thin transverse
partition, and here it is that we may reasonably suppose the
part on which life depends to be situated.
The Acalephae, or Sea-nettles, as they are variously called, are
not Testacea at all, but lie outside the recognized groups. Their
constitution, like that of the Ascidians, approximates them on
1921
one side to plants, on the other to animals. For seeing that some
of them can detach themselves and can fasten upon their food,
and that they are sensible of objects which come in contact
with them, they must be considered to have an animal nature.
The like conclusion follows from their using the asperity of
their bodies as a protection against their enemies. But, on the
other hand, they are closely allied to plants, firstly by the
imperfection of their structure, secondly by their being able to
attach themselves to the rocks, which they do with great
rapidity, and lastly by their having no visible residuum
notwithstanding that they possess a mouth.
Very similar again to the Acalephae are the Starfishes. For these
also fasten on their prey, and suck out its juices, and thus
destroy a vast number of oysters. At the same time they present
a certain resemblance to such of the animals we have described
as the Cephalopoda and Crustacea, inasmuch as they are free
and unattached. The same may also be said of theTestacea.
Such, then, is the structure of the parts that minister to
nutrition and which every animal must possess. But besides
these organs it is quite plain that in every animal there must be
some part or other which shall be analogous to what in
sanguineous animals is the presiding seat of sensation.
Whether an animal has or has not blood, it cannot possibly be
without this. In the Cephalopoda this part consists of a fluid
substance contained in a membrane, through which runs the
gullet on its way to the stomach. It is attached to the body
rather towards its dorsal surface, and by some is called the
mytis. Just such another organ is found also in the Crustacea
and there too is known by the same name. This part is at once
fluid and corporeal and, as before said, is traversed by the gullet.
For had the gullet been placed between the mytis and the dorsal
surface of the animal, the hardness of the back would have
interfered with its due dilatation in the act of deglutition. On
1922
the outer surface of the mytis runs the intestine; and in contact
with this latter is placed the ink-bag, so that it may be removed
as far as possible from the mouth and its obnoxious fluid be
kept at a distance from the nobler and sovereign part. The
position of the mytis shows that it corresponds to the heart of
sanguineous animals; for it occupies the self-same place. The
same is shown by the sweetness of its fluid, which has the
character of concocted matter and resembles blood.
In the Testacea the presiding seat of sensation is in a
corresponding position, but is less easily made out. It should,
however, always be looked for in some midway position;
namely, in such Testacea as are stationary, midway between the
part by which food is taken in and the channel through which
either the excrement or the spermatic fluid is voided, and, in
those species which are capable of locomotion, invariably
midway between the right and left sides.
In Insects this organ, which is the seat of sensation, lies, as was
stated in the first treatise, between the head and the cavity
which contains the stomach. In most of them it consists of a
single part; but in others, for instance in such as have long
bodies and resemble the Juli (Millipedes), it is made up of
several parts, so that such insects continue to live after they
have been cut in pieces. For the aim of nature is to give to each
animal only one such dominant part; and when she is unable to
carry out this intention she causes the parts, though potentially
many, to work together actually as one. This is much more
clearly marked in some insects than in others.
The parts concerned in nutrition are not alike in all insects, but
show considerable diversity. Thus some have what is called a
sting in the mouth, which is a kind of compound instrument
that combines in itself the character of a tongue and of lips. In
others that have no such instrument in front there is a part
1923
inside the mouth that answers the same sensory purposes.
Immediately after the mouth comes the intestine, which is
never wanting in any insect. This runs in a straight line and
without further complication to the vent; occasionally, however,
it has a spiral coil. There are, moreover, some insects in which a
stomach succeeds to the mouth, and is itself succeeded by a
convoluted intestine, so that the larger and more voracious
insects may be enabled to take in a more abundant supply of
food. More curious than any are the Cicadae. For here the mouth
and the tongue are united so as to form a single part, through
which, as through a root, the insect sucks up the fluids on
which it lives. Insects are always small eaters, not so much
because of their diminutive size as because of their cold
temperament. For it is heat which requires sustenance; just as it
is heat which speedily concocts it. But cold requires no
sustenance. In no insects is this so conspicuous as in these
Cicadae. For they find enough to live on in the moisture which
is deposited from the air. So also do the Ephemera that are
found about the Black sea. But while these latter only live for a
single day, the Cicadae subsist on such food for several days,
though still not many.
We have now done with the internal parts of animals, and must
therefore return to the consideration of the external parts
which have not yet been described. It will be better to change
our order of exposition and begin with the animals we have just
been describing, so that proceeding from these, which require
less discussion, our account may have more time to spend on
the perfect kinds of animals, those namely that have blood.
1924
We will begin with Insects. These animals, though they present
no great multiplicity of parts, are not without diversities when
compared with each other. They are all manyfooted; the object
of this being to compensate their natural slowness and frigidity,
and give greater activity to their motions. Accordingly we find
that those which, as the (Millipedes), have long bodies, and are
therefore the most liable to refrigeration, have also the greatest
number of feet. Again, the body in these animals is insected -
the reason for this being that they have not got one vital centre
but many - and the number of their feet corresponds to that of
the insections.
Should the feet fall short of this, their deficiency is
compensated by the power of flight. Of such flying insects some
live a wandering life, and are forced to make long expeditions in
search of food. These have a body of light weight, and four
feathers, two on either side, to support it. Such are bees and the
insects akin to them. When, however, such insects are of very
small bulk, their feathers are reduced to two, as is the case with
flies. Insects with heavy bodies and of stationary habits, though
not polypterous in the same way as bees, yet have sheaths to
their feathers to maintain their efficiency. Such are the
Melolonthae and the like. For their stationary habits expose
their feathers to much greater risks than are run by those of
insects that are more constantly in flight, and on this account
they are provided with this protecting shield. The feather of an
insect has neither barbs nor shaft. For, though it is called a
feather, it is no feather at all, but merely a skin-like membrane
that, owing to its dryness, necessarily becomes detached from
the surface of the body, as the fleshy substance grows cold.
These animals then have their bodies insected, not only for the
reasons already assigned, but also to enable them to curl round
1925
in such a manner as may protect them from injury; for such
insects as have long bodies can roll themselves up, which would
be impossible were it not for the insections; and those that
cannot do this can yet draw their segments up into the insected
spaces, and so increase the hardness of their bodies. This can be
felt quite plainly by putting the finger on one of the insects, for
instance, known as Canthari. The touch frightens the insect,
and it remains motionless, while its body becomes hard. The
division of the body into segments is also a necessary result of
there being several supreme organs in place of one; and this
again is a part of the essential constitution of insects, and is a
character which approximates them to plants. For as plants,
though cut into pieces, can still live, so also can insects. There
is, however, this difference between the two cases, that the
portions of the divided insect live only for a limited time,
whereas the portions of the plant live on and attain the perfect
form of the whole, so that from one single plant you may obtain
two or more.
Some insects are also provided with another means of
protection against their enemies, namely a sting. In some this is
in front, connected with the tongue, in others behind at the
posterior end. For just as the organ of smell in elephants
answers several uses, serving alike as a weapon and for
purposes of nutrition, so does also the sting, when placed in
connexion with the tongue, as in some insects, answer more
than one end. For it is the instrument through which they
derive their sensations of food, as well as that with which they
suck it up and bring it to the mouth. Such of these insects as
have no anterior sting are provided with teeth, which serve in
some of them for biting the food, and in others for its
prehension and conveyance to the mouth. Such are their uses,
for instance, in ants and all the various kinds of bees. As for the
insects that have a sting behind, this weapon is given them
because they are of a fierce disposition. In some of them the
1926
sting is lodged inside the body, in bees, for example, and wasps.
For these insects are made for flight, and were their sting
external and of delicate make it would soon get spoiled; and if,
on the other hand, it were of thicker build, as in scorpions, its
weight would be an incumbrance. As for scorpions that live on
the ground and have a tail, their sting must be set upon this, as
otherwise it would be of no use as a weapon. Dipterous insects
never have a posterior sting. For the very reason of their being
dipterous is that they are small and weak, and therefore require
no more than two feathers to support their light weight; and the
same reason which reduces their feathers to two causes their
sting to be in front; for their strength is not sufficient to allow
them to strike efficiently with the hinder part of the body.
Polypterous insects, on the other hand, are of greater bulk -
indeed it is this which causes them to have so many feathers;
and their greater size makes them stronger in their hinder
parts. The sting of such insects is therefore placed behind. Now
it is better, when possible, that one and the same instrument
shall not be made to serve several dissimilar uses; but that
there shall be one organ to serve as a weapon, which can then
be very sharp, and a distinct one to serve as a tongue, which can
then be of spongy texture and fit to absorb nutriment.
Whenever, therefore, nature is able to provide two separate
instruments for two separate uses, without the one hampering
the other, she does so, instead of acting like a coppersmith who
for cheapness makes a spit and lampholder in one. It is only
when this is impossible that she uses one organ for several
functions.
The anterior legs are in some cases longer than the others, that
they may serve to wipe away any foreign matter that may lodge
on the insect's eyes and obstruct its sight, which already is not
very distinct owing to the eyes being made of a hard substance.
Flies and bees and the like may be constantly seen thus
dressing themselves with crossed forelegs. Of the other legs, the
1927
hinder are bigger than the middle pair, both to aid in running
and also that the insect, when it takes flight, may spring more
easily from the ground. This difference is still more marked in
such insects as leap, in locusts for instance, and in the various
kinds of fleas. For these first bend and then extend the legs,
and, by doing so, are necessarily shot up from the ground. It is
only the. hind legs of locusts, and not the front ones, that
resemble the steering oars of a ship. For this requires that the
joint shall be deflected inwards, and such is never the case with
the anterior limbs. The whole number of legs, including those
used in leaping, is six in all these insects.
In the Testacea the body consists of but few parts, the reason
being that these animals live a stationary life. For such animals
as move much about must of necessity have more numerous
parts than such as remain quiet; for their activities are many,
and the more diversified the movements the greater the
number of organs required to effect them. Some species of
Testacea are absolutely motionless, and others not quite but
nearly so. Nature, however, has provided them with a protection
in the hardness of the shell with which she has invested their
body. This shell, as already has been said, may have one valve,
or two valves, or be turbinate. In the latter case it may be either
spiral, as in whelks, or merely globular, as in sea-urchins. When
it has two valves, these may be gaping, as in scallops and
mussels, where the valves are united together on one side only,
so as to open and shut on the other; or they may be united
together on both sides, as in the Solens (razor- fishes). In all
cases alike the Testacea have, like plants, the head downwards.
The reason for this is, that they take in their nourishment from
1928
below, just as do plants with their roots. Thus the under parts
come in them to be above, and the upper parts to be below. The
body is enclosed in a membrane, and through this the animal
filters fluid free from salt and absorbs its nutriment. In all there
is a head; but none of the parts, excepting this recipient of food,
has any distinctive name.
8
All the Crustacea can crawl as well as swim, and accordingly
they are provided with numerous feet. There are four main
genera, viz. the Carabi, as they are called, the Astaci, the
Carides, and the Carcini. In each of these genera, again, there
are numerous species, which differ from each other not only as
regards shape, but also very considerably as regards size. For,
while in some species the individuals are large, in others they
are excessively minute. The Carcinoid and Caraboid Crustacea
resemble each other in possessing claws. These claws are not
for locomotion, but to serve in place of hands for seizing and
holding objects; and they are therefore bent in the opposite
direction to the feet, being so twisted as to turn their convexity
towards the body, while their feet turn towards it their
concavity. For in this position the claws are best suited for
laying hold of the food and carrying it to the mouth. The
distinction between the Carabi and the Carcini (Crabs) consists
in the former having a tail while the latter have none. For the
Carabi swim about and a tail is therefore of use to them, serving
for their propulsion like the blade of an oar. But it would be of
no use to the Crabs; for these animals live habitually close to
the shore, and creep into holes and corners. In such of them as
live out at sea, the feet are much less adapted for locomotion
than in the rest, because they are little given to moving about
1929
but depend for protection on their shell-like covering. The Maiae
and the crabs known as Heracleotic are examples of this; the
legs in the former being very thin, in the latter very short.
The very minute crabs that are found among the small fry at
the bottom of the net have their hindermost feet flattened out
into the semblance of fins or oar-blades, so as to help the
animal in swimming.
The Carides are distinguished from the Carcinoid species by the
presence of a tail; and from the Caraboids by the absence of
claws. This is explained by their large number of feet, on which
has been expended the material for the growth of claws. Their
feet again are numerous to suit their mode of progression,
which is mainly by swimming.
Of the parts on the ventral surface, those near the head are in
some of these animals formed like gills, for the admission and
discharge of water; while the parts lower down differ in the two
sexes. For in the female Carabi these are more laminar than in
the males, and in the female crabs the flap is furnished with
hairier appendages. This gives ampler space for the disposal of
the ova, which the females retain in these parts instead of
letting them go free, as do fishes and all other oviparous
animals. In the Carabi and in the Crabs the right claw is
invariably the larger and the stronger. For it is natural to every
animal in active operations to use the parts on its right side in
preference to those on its left; and nature, in distributing the
organs, invariably assigns each, either exclusively or in a more
perfect condition, to such animals as can use it. So it is with
tusks, and teeth, and horns, and spurs, and all such defensive
and offensive weapons.
In the Lobsters alone it is a matter of chance which claw is the
larger, and this in either sex. Claws they must have, because
they belong to a genus in which this is a constant character; but
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they have them in this indeterminate way, owing to imperfect
formation and to their not using them for their natural purpose,
but for locomotion.
For a detailed account of the several parts of these animals, of
their position and their differences, those parts being also
included which distinguish the sexes, reference must be made
to the treatises on Anatomy and to the Researches concerning
Animals.
We come now to the Cephalopoda. Their internal organs have
already been described with those of other animals. Externally
there is the trunk of the body, not distinctly defined, and in
front of this the head surrounded by feet, which form a circle
about the mouth and teeth, and are set between these and the
eyes. Now in all other animals the feet, if there are any, are
disposed in one of two ways; either before and behind or along
the sides, the latter being the plan in such of them, for instance,
as are bloodless and have numerous feet. But in the
Cephalopoda there is a peculiar arrangement, different from
either of these. For their feet are all placed at what may be
called the fore end. The reason for this is that the hind part of
their body has been drawn up close to the fore part, as is also
the case in the turbinated Testacea. For the Testacea, while in
some points they resemble the Crustacea, in others resemble
the Cephalopoda. Their earthy matter is on the outside, and
their fleshy substance within. So far they are like the Crustacea.
But the general plan of their body is that of the Cephalopoda;
and, though this is true in a certain degree of all the Testacea, it
is more especially true of those turbinated species that have a
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spiral shell. Of this general plan, common to the two, we will
speak presently. But let us first consider the case of quadrupeds
and of man, where the arrangement is that of a straight line. Let
A at the upper end of such a line be supposed to represent the
mouth, then B the gullet, and C the stomach, and the intestine
to run from this C to the excremental vent where D is inscribed.
Such is the plan in sanguineous animals; and round this
straight line as an axis are disposed the head and so-called
trunk; the remaining parts, such as the anterior and posterior
limbs, having been superadded by nature, merely to minister to
these and for locomotion.
In the Crustacea also and in Insects there is a tendency to a
similar arrangement of the internal parts in a straight line; the
distinction between these groups and the sanguineous animals
depending on differences of the external organs which minister
to locomotion. But the Cephalopoda and the turbinated
Testacea have in common an arrangement which stands in
contrast with this. For here the two extremities are brought
together by a curve, as if one were to bend the straight line
marked E until D came close to Such, then, is the disposition of
the internal parts; and round these, in the Cephalopoda, is
placed the sac (in the Poulps alone called a head), and, in the
Testacea, the turbinate shell which corresponds to the sac.
There is, in fact, only this difference between them, that the
investing substance of the Cephalopoda is soft while the shell of
the Testacea is hard, nature having surrounded their fleshy part
with this hard coating as a protection because of their limited
power of locomotion. In both classes, owing to this arrangement
of the internal organs, the excrement is voided near the mouth;
at a point below this orifice in the Cephalopoda, and in the
Turbinata on one side of it.
Such, then, is the explanation of the position of the feet in the
Cephalopoda, and of the contrast they present to other animals
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in this matter. The arrangement, however, in the Sepias and the
Calamaries is not precisely the same as in the Poulps, owing to
the former having no other mode of progression than by
swimming, while the latter not only swim but crawl. For in the
former six of the feet are above the teeth and small, the outer
one on either side being the biggest; while the remaining two,
which make up the total weight, are below the mouth and are
the biggest of all, just as the hind limbs in quadrupeds are
stronger than the fore limbs. For it is these that have to support
the weight, and to take the main part in locomotion. And the
outer two of the upper six are bigger than the pair which
intervene between them and the uppermost of all, because they
have to assist the lowermost pair in their office. In the Poulps,
on the other hand, the four central feet are the biggest. Again,
though the number of feet is the same in all the Cephalopoda,
namely eight, their length varies in different kinds, being short
in the Sepias and the Calamaries, but greater in the Poulps. For
in these latter the trunk of the body is of small bulk, while in
the former it is of considerable size; and so in the one case
nature has used the materials subtracted from the body to give
length to the feet, while in the other she has acted in precisely
the opposite way, and has given to the growth of the body what
she has first taken from the feet. The Poulps, then, owing to the
length of their feet, can not only swim but crawl, whereas in the
other genera the feet are useless for the latter mode of
progression, being small while the bulk of the body is
considerable. These short feet would not enable their possessors
to cling to the rocks and keep themselves from being torn off by
the waves when these run high in times of storm; neither would
they serve to lay hold of objects at all remote and bring them in;
but, to supply these defects, the animal is furnished with two
long proboscises, by which it can moor itself and ride at anchor
like a ship in rough weather. These same processes serve also to
catch prey at a distance and to bring it to the mouth. They are
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so used by both the Sepias and the Calamaries. In the Poulps
the feet are themselves able to perform these offices, and there
are consequently no proboscises. Proboscises and twining
tentacles, with acetabula set upon them, act in the same way
and have the same structure as those plaited instruments
which were used by physicians of old to reduce dislocations of
the fingers. Like these they are made by the interlacing of their
fibres, and they act by pulling upon pieces of flesh and yielding
substances. For the plaited fibres encircle an object in a
slackened condition, and when they are put on the stretch they
grasp and cling tightly to whatever it may be that is in contact
with their inner surface. Since, then, the Cephalopoda have no
other instruments with which to convey anything to themselves
from without, than either twining tentacles, as in some species,
or proboscises as in others, they are provided with these to
serve as hands for offence and defence and other necessary
uses.
The acetabula are set in double line in all the Cephalopoda
excepting in one kind of poulp, where there is but a single row.
The length and the slimness which is part of the nature of this
kind of poulp explain the exception. For a narrow space cannot
possibly admit of more than a single row. This exceptional
character, then, belongs to them, not because it is the most
advantageous arrangement, but because it is the necessary
consequence of their essential specific constitution.
In all these animals there is a fin, encircling the sac. In the
Poulps and the Sepias this fin is unbroken and continuous, as is
also the case in the larger calamaries known as Teuthi. But in
the smaller kind, called Teuthides, the fin is not only broader
than in the Sepias and the Poulps, where it is very narrow, but,
moreover, does not encircle the entire sac, but only begins in
the middle of the side. The use of this fin is to enable the animal
to swim, and also to direct its course. It acts, that is, like the
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rump-feathers in birds, or the tail-fin in fishes. In none is it so
small or so indistinct as in the Poulps. For in these the body is of
small bulk and can be steered by the feet sufficiently well
without other assistance.
The Insects, the Crustacea, the Testacea, and the Cephalopoda,
have now been dealt with in turn; and their parts have been
described, whether internal or external.
10
We must now go back to the animals that have blood, and
consider such of their parts, already enumerated, as were before
passed over. We will take the viviparous animals first, and, we
have done with these, will pass on to the oviparous, and treat of
them in like manner.
The parts that border on the head, and on what is known as the
neck and throat, have already been taken into consideration. All
animals that have blood have a head; whereas in some
bloodless animals, such as crabs, the part which represents a
head is not clearly defined. As to the neck, it is present in all the
Vivipara, but only in some of the Ovipara; for while those that
have a lung also have a neck, those that do not inhale the outer
air have none. The head exists mainly for the sake of the brain.
For every animal that has blood must of necessity have a brain;
and must, moreover, for reasons already given, have it placed in
an opposite region to the heart. But the head has also been
chosen by nature as the part in which to set some of the senses;
because its blood is mixed in such suitable proportions as to
ensure their tranquillity and precision, while at the same time it
can supply the brain with such warmth as it requires. There is
yet a third constituent superadded to the head, namely the part
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which ministers to the ingestion of food. This has been placed
here by nature, because such a situation accords best with the
general configuration of the body. For the stomach could not
possibly be placed above the heart, seeing that this is the
sovereign organ; and if placed below, as in fact it is, then the
mouth could not possibly be placed there also. For this would
have necessitated a great increase in the length of the body; and
the stomach, moreover, would have been removed too far from
the source of motion and of concoction.
The head, then, exists for the sake of these three parts; while
the neck, again, exists for the sake of the windpipe. For it acts as
a defence to this and to the oesophagus, encircling them and
keeping them from injury. In all other animals this neck is
flexible and contains several vertebrae; but in wolves and lions
it contains only a single bone. For the object of nature was to
give these animals an organ which should be serviceable in the
way of strength, rather than one that should be useful for any of
the other purposes to which necks are subservient.
Continuous with the head and neck is the trunk with the
anterior limbs. In man the forelegs and forefeet are replaced by
arms and by what we call hands. For of all animals man alone
stands erect, in accordance with his godlike nature and essence.
For it is the function of the god-like to think and to be wise; and
no easy task were this under the burden of a heavy body,
pressing down from above and obstructing by its weight the
motions of the intellect and of the general sense. When,
moreover, the weight and corporeal substance become
excessive, the body must of necessity incline towards the
ground. In such cases therefore nature, in order to give support
to the body, has replaced the arms and hands by forefeet, and
has thus converted the animal into a quadruped. For, as every
animal that walks must of necessity have the two hinder feet,
such an animal becomes a quadruped, its body inclining
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downwards in front from the weight which its soul cannot
sustain. For all animals, man alone excepted, are dwarf-like in
form. For the dwarf-like is that in which the upper part is large,
while that which bears the weight and is used in progression is
small. This upper part is what we call the trunk, which reaches
from the mouth to the vent. In man it is duly proportionate to
the part below, and diminishes much in its comparative size as
the man attains to full growth. But in his infancy the contrary
obtains, and the upper parts are large, while the lower part is
small; so that the infant can only crawl, and is unable to walk;
nay, at first cannot even crawl, but remains without motion. For
all children are dwarfs in shape, but cease to be so as they
become men, from the growth of their lower part; whereas in
quadrupeds the reverse occurs, their lower parts being largest in
youth, and advance of years bringing increased growth above,
that is in the trunk, which extends from the rump to the head.
Thus it is that colts are scarcely, if at all, below full-grown
horses in height; and that while still young they can touch their
heads with the hind legs, though this is no longer possible
when they are older. Such, then, is the form of animals that
have either a solid or a cloven hoof. But such as are
polydactylous and without horns, though they too are of dwarf-
like shape, are so in a less degree; and therefore the greater
growth of the lower parts as compared with the upper is also
small, being proportionate to this smaller deficiency.
Dwarf-like again is the race of birds and fishes; and so in fact, as
already has been said, is every animal that has blood. This is the
reason why no other animal is so intelligent as man. For even
among men themselves if we compare children with adults, or
such adults as are of dwarf-like shape with such as are not, we
find that, whatever other superiority the former may possess,
they are at any rate deficient as compared with the latter in
intelligence. The explanation, as already stated, is that their
psychical principle is corporeal, and much impeded in its
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motions. Let now a further decrease occur in the elevating heat,
and a further increase in the earthy matter, and the animals
become smaller in bulk, and their feet more numerous, until at
a later stage they become apodous, and extended full length on
the ground. Then, by further small successions of change, they
come to have their principal organ below; and at last their
cephalic part becomes motionless and destitute of sensation.
Thus the animal becomes a plant, that has its upper parts
downwards and its lower parts above. For in plants the roots are
the equivalents of mouth and head, while the seed has an
opposite significance, for it is produced above it the extremities
of the twigs.
The reasons have now been stated why some animals have
many feet, some only two, and others none; why, also, some
living things are plants and others animals; and, lastly, why
man alone of all animals stands erect. Standing thus erect, man
has no need of legs in front, and in their stead has been
endowed by nature with arms and hands. Now it is the opinion
of Anaxagoras that the possession of these hands is the cause
of man being of all animals the most intelligent. But it is more
rational to suppose that his endowment with hands is the
consequence rather than the cause of his superior intelligence.
For the hands are instruments or organs, and the invariable
plan of nature in distributing the organs is to give each to such
animal as can make use of it; nature acting in this matter as
any prudent man would do. For it is a better plan to take a
person who is already a flute-player and give him a flute, than
to take one who possesses a flute and teach him the art of flute-
playing. For nature adds that which is less to that which is
greater and more important, and not that which is more
valuable and greater to that which is less. Seeing then that such
is the better course, and seeing also that of what is possible
nature invariably brings about the best, we must conclude that
man does not owe his superior intelligence to his hands, but his
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hands to his superior intelligence. For the most intelligent of
animals is the one who would put the most organs to use; and
the hand is not to be looked on as one organ but as many; for it
is, as it were, an instrument for further instruments. This
instrument, therefore, - the hand - of all instruments the most
variously serviceable, has been given by nature to man, the
animal of all animals the most capable of acquiring the most
varied handicrafts.
Much in error, then, are they who say that the construction of
man is not only faulty, but inferior to that of all other animals;
seeing that he is, as they point out, bare-footed, naked, and
without weapon of which to avail himself. For other animals
have each but one mode of defence, and this they can never
change; so that they must perform all the offices of life and
even, so to speak, sleep with sandals on, never laying aside
whatever serves as a protection to their bodies, nor changing
such single weapon as they may chance to possess. But to man
numerous modes of defence are open, and these, moreover, he
may change at will; as also he may adopt such weapon as he
pleases, and at such times as suit him. For the hand is talon,
hoof, and horn, at will. So too it is spear, and sword, and
whatsoever other weapon or instrument you please; for all
these can it be from its power of grasping and holding them all.
In harmony with this varied office is the form which nature has
contrived for it. For it is split into several divisions, and these
are capable of divergence. Such capacity of divergence does not
prevent their again converging so as to form a single compact
body, whereas had the hand been an undivided mass,
divergence would have been impossible. The divisions also may
be used singly or two together and in various combinations. The
joints, moreover, of the fingers are well constructed for
prehension and for pressure. One of these also, and this not
long like the rest but short and thick, is placed laterally. For
were it not so placed all prehension would be as impossible, as
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were there no hand at all. For the pressure of this digit is
applied from below upwards, while the rest act from above
downwards; an arrangement which is essential, if the grasp is
to be firm and hold like a tight clamp. As for the shortness of
this digit, the object is to increase its strength, so that it may be
able, though but one, to counterbalance its more numerous
opponents. Moreover, were it long it would be of no use. This is
the explanation of its being sometimes called the great digit, in
spite of its small size; for without it all the rest would be
practically useless. The finger which stands at the other end of
the row is small, while the central one of all is long, like a centre
oar in a ship. This is rightly so; for it is mainly by the central
part of the encircling grasp that a tool must be held when put to
use.
No less skilfully contrived are the nails. For, while in man these
serve simply as coverings to protect the tips of the fingers, in
other animals they are also used for active purposes; and their
form in each case is suited to their office.
The arms in man and the fore limbs in quadrupeds bend in
contrary directions, this difference having reference to the
ingestion of food and to the other offices which belong to these
parts. For quadrupeds must of necessity bend their anterior
limbs inwards that they may serve in locomotion, for they use
them as feet. Not but what even among quadrupeds there is at
any rate a tendency for such as are polydactylous to use their
forefeet not only for locomotion but as hands. And they are in
fact so used, as any one may see. For these animals seize hold of
objects, and also repel assailants with their anterior limbs;
whereas quadrupeds with solid hoofs use their hind legs for
this latter purpose. For their fore limbs are not analogous to the
arms and hands of man.
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It is this hand-like office of the anterior limbs which explains
why in some of the polydactylous quadrupeds, such as wolves,
lions, dogs, and leopards, there are actually five digits on each
forefoot, though there are only four on each hind one. For the
fifth digit of the foot corresponds to the fifth digit of the hand,
and like it is called the big one. It is true that in the smaller
polydactylous quadrupeds the hind feet also have each five
toes. But this is because these animals are creepers; and the
increased number of nails serves to give them a tighter grip, and
so enables them to creep up steep places with greater facility, or
even to run head downwards.
In man between the arms, and in other animals between the
forelegs, lies what is called the breast. This in man is broad, as
one might expect; for as the arms are set laterally on the body,
they offer no impediment to such expansion in this part. But in
quadrupeds the breast is narrow, owing to the legs having to be
extended in a forward direction in progression and locomotion.
Owing to this narrowness the mammae of quadrupeds are
never placed on the breast. But in the human body there is
ample space in this part; moreover, the heart and neighbouring
organs require protection, and for these reasons this part is
fleshy and the mammae are placed upon it separately, side by
side, being themselves of a fleshy substance in the male and
therefore of use in the way just stated; while in the female,
nature, in accordance with what we say is her frequent practice,
makes them minister to an additional function, employing
them as a store-place of nutriment for the offspring. The human
mammae are two in number, in accordance with the division of
the body into two halves, a right and a left. They are somewhat
firmer than they would otherwise be, because the ribs in this
region are joined together; while they form two separate
masses, because their presence is in no wise burdensome. In
other animals than man, it is impossible for the mammae to be
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placed on the breast between the forelegs, for they would
interfere with locomotion; they are therefore disposed of
otherwise, and in a variety of ways. Thus in such animals as
produce but few at a birth, whether horned quadrupeds or
those with solid hoofs, the mammae are placed in the region of
the thighs, and are two in number, while in such as produce
litters, or such as are polydactylous, the dugs are either
numerous and placed laterally on the belly, as in swine and
dogs, or are only two in number, being set, however, in the
centre of the abdomen, as is the case in the lion. The
explanation of this latter condition is not that the lion produces
few at a birth, for sometimes it has more than two cubs at a
time, but is to be found in the fact that this animal has no
plentiful supply of milk. For, being a flesheater, it gets food at
but rare intervals, and such nourishment as it obtains is all
expended on the growth of its body.
In the elephant also there are but two mammae, which are
placed under the axillae of the fore limbs. The mammae are not
more than two, because this animal has only a single young one
at a birth; and they are not placed in the region of the thighs,
because they never occupy that position in any polydactylous
animal such as this. Lastly, they are placed above, close to the
axillae, because this is the position of the foremost dugs in all
animals whose dugs are numerous, and the dugs so placed give
the most milk. Evidence of this is furnished by the sow. For she
always presents these foremost dugs to the first-born of her
litter. A single young one is of course a first-born, and so such
animals as only produce a single young one must have these
anterior dugs to present to it; that is they must have the dugs
which are under the axillae. This, then, is the reason why the
elephant has but two mammae, and why they are so placed.
But, in such animals as have litters of young, the dugs are
disposed about the belly; the reason being that more dugs are
required by those that will have more young to nourish. Now it
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is impossible that these dugs should be set transversely in rows
of more than two, one, that is, for each side of the body, the
right and the left; they must therefore be placed lengthways,
and the only place where there is sufficient length for this is the
region between the front and hind legs. As to the animals that
are not polydactylous but produce few at a birth, or have horns,
their dugs are placed in the region of the thighs. The horse, the
ass, the camel are examples; all of which bear but a single
young one at a time, and of which the two former have solid
hoofs, while in the last the hoof is cloven. As still further
examples may be mentioned the deer, the ox, the goat, and all
other similar animals.
The explanation is that in these animals growth takes place in
an upward direction; so that there must be an abundant
collection of residual matter and of blood in the lower region,
that is to say in the neighbourhood of the orifices for efflux, and
here therefore nature has placed the mammae. For the place in
which the nutriment is set in motion must also be the place
whence nutriment can be derived by them. In man there are
mammae in the male as well as in the female; but some of the
males of other animals are without them. Such, for instance, is
the case with horses, some stallions being destitute of these
parts, while others that resemble their dams have them. Thus
much then concerning the mammae.
Next after the breast comes the region of the belly, which is left
unenclosed by the ribs for a reason which has already been
given; namely that there may be no impediment to the swelling
which necessarily occurs in the food as it gets heated, nor to the
expansion of the womb in pregnancy.
At the extreme end of what is called the trunk are the parts
concerned in the evacuation of the solid and also of the fluid
residue. In all sanguineous animals with some few exceptions,
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and in all Vivipara without any exception at all, the same part
which serves for the evacuation of the fluid residue is also
made by nature to serve in sexual congress, and this alike in
male and female. For the semen is a kind of fluid and residual
matter. The proof of this will be given hereafter, but for the
present let it taken for granted. (The like holds good of the
menstrual fluid in women, and of the part where they emit
semen. This also, however, is a matter of which a more accurate
account will be given hereafter. For the present let it be simply
stated as a fact, that the catamenia of the female like the semen
of the male are residual matter. Both of them, moreover, being
fluid, it is only natural that the parts which serve for voidance
of the urine should give issue to residues which resemble it in
character.) Of the internal structure of these parts, and of the
differences which exist between the parts concerned with
semen and the parts concerned with conception, a clear
account is given in the book of Researches concerning Animals
and in the treatises on Anatomy. Moreover, I shall have to speak
of them again when I come to deal with Generation. As regards,
however, the external shape of these parts, it is plain enough
that they are adapted to their operations, as indeed of necessity
they must be. There are, however, differences in the male organ
corresponding to differences in the body generally. For all
animals are not of an equally sinewy nature. This organ, again,
is the only one that, independently of any morbid change,
admits of augmentation and of diminution of bulk. The former
condition is of service in copulation, while the other is required
for the advantage of the body at large. For, were the organ
constantly in the former condition, it would be an incumbrance.
The organ therefore has been formed of such constituents as
will admit of either state. For it is partly sinewy, partly
cartilaginous, and thus is enabled either to contract or to
become extended, and is capable of admitting air.
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All female quadrupeds void their urine backwards, because the
position of the parts which this implies is useful to them in the
act of copulation. This is the case with only some few males,
such as the lynx, the lion, the camel, and the hare. No
quadruped with a solid hoof is retromingent.
The posterior portion of the body and the parts about the legs
are peculiar in man as compared with quadrupeds. Nearly all
these latter have a tail, and this whether they are viviparous or
oviparous. For, even if the tail be of no great size, yet they have a
kind of scut, as at any rate a small representative of it. But man
is tail-less. He has, however, buttocks, which exist in none of the
quadrupeds. His legs also are fleshy (as too are his thighs and
feet); while the legs in all other animals that have any, whether
viviparous or not, are fleshless, being made of sinew and bone
and spinous substance. For all these differences there is, so to
say, one common explanation, and this is that of all animals
man alone stands erect. It was to facilitate the maintenance of
this position that Nature made his upper parts light, taking
away some of their corporeal substance, and using it to increase
the weight of lithe parts below, so that the buttocks, the thighs,
and the calves of the legs were all made fleshy. The character
which she thus gave to the buttocks renders them at the same
time useful in resting the body. For standing causes no fatigue
to quadrupeds, and even the long continuance of this posture
produces in them no weariness; for they are supported the
whole time by four props, which is much as though they were
lying down. But to man it is no task to remain for any length of
time on his feet, his body demanding rest in a sitting position.
This, then, is the reason why man has buttocks and fleshy legs;
and the presence of these fleshy parts explains why he has no
tail. For the nutriment which would otherwise go to the tail is
used up in the production of these parts, while at the same time
the existence of buttocks does away with the necessity of a tail.
But in quadrupeds and other animals the reverse obtains. For
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they are of dwarf-like form, so that all the pressure of their
weight and corporeal substance is on their upper part, and is
withdrawn from the parts below. On this account they are
without buttocks and have hard legs. In order, however, to cover
and protect that part which serves for the evacuation of
excrement, nature has given them a tail of some kind or other,
subtracting for the purpose some of the nutriment which would
otherwise go to the legs. Intermediate in shape between man
and quadrupeds is the ape, belonging therefore to neither or to
both, and having on this account neither tail nor buttocks; no
tail in its character of biped, no buttocks in its character of
quadruped. There is great diversity of so-called tails; and this
organ like others is sometimes used by nature for by-purposes,
being made to serve not only as a covering and protection to the
fundament, but also for other uses and advantages of its
possessor.
There are differences in the feet of quadrupeds. For in some of
these animals there is a solid hoof, and in others a hoof cloven
into two, and again in others a foot divided into many parts.
The hoof is solid when the body is large and the earthy matter
present in great abundance; in which case the earth, instead of
forming teeth and horns, is separated in the character of a nail,
and being very abundant forms one continuous nail, that is a
hoof, in place of several. This consumption of the earthy matter
on the hoof explains why these animals, as a rule, have no
huckle-bones; a second reason being that the presence of such a
bone in the joint of the hind leg somewhat impedes its free
motion. For extension and flexion can be made more rapidly in
parts that have but one angle than in parts that have several.
But the presence of a huckle-bone, as a connecting bolt, is the
introduction as it were of a new limb-segment between the two
ordinary ones. Such an addition adds to the weight of the foot,
but renders the act of progression more secure. Thus it is that in
1946
such animals as have a hucklebone, it is only in the posterior
and not in the anterior limbs that this bone is found. For the
anterior limbs, moving as they do in advance of the others,
require to be light and capable of ready flexion, whereas
firmness and extensibility are what are wanted in the hind
limbs. Moreover, a huckle-bone adds weight to the blow of a
limb, and so renders it a suitable weapon of defence; and these
animals all use their hind legs to protect themselves, kicking
out with their heels against anything which annoys them. In
the cloven-hoofed quadrupeds the lighter character of the hind
legs admits of there being a huckle-bone; and the presence of
the huckle-bone prevents them from having a solid hoof, the
bony substance remaining in the joint, and therefore being
deficient in the foot. As to the polydactylous quadrupeds, none
of them have huckle-bones. For if they had they would not be
polydactylous, but the divisions of the foot would only extend to
that amount of its breadth which was covered by the huckle-
bone. Thus it is that most of the animals that have huckle-
bones are cloven-hoofed.
Of all animals man has the largest foot in proportion to the size
of the body. This is only what might be expected. For seeing that
he is the only animal that stands erect, the two feet which are
intended to bear all the weight of the body must be both long
and broad. Equally intelligible is it that the proportion between
the size of the fingers and that of the whole hand should be
inverted in the case of the toes and feet. For the function of the
hands is to take hold of objects and retain them by pressure; so
that the fingers require to be long. For it is by its flexed portion
that the hand grasps an object. But the function of the feet is to
enable us to stand securely, and for this the undivided part of
the foot requires to be of larger size than the toes. However, it is
better for the extremity to be divided than to be undivided. For
in an undivided foot disease of any one part would extend to
the whole organ; whereas, if the foot be divided into separate
1947
digits, there is not an equal liability to such an occurrence. The
digits, again, by being short would be less liable to injury. For
these reasons the feet in man are many-toed, while the
separate digits are of no great length. The toes, finally, are
furnished with nails for the same reason as are the fingers,
namely because such projecting parts are weak and therefore
require special protection.
11
We have now done with such sanguineous animals as live on
land and bring forth their young alive; and, having dealt with all
their main kinds, we may pass on to such sanguineous animals
as are oviparous. Of these some have four feet, while others
have none. The latter form a single genus, namely the Serpents;
and why these are apodous has been already explained in the
dissertation on Animal Progression. Irrespective of this absence
of feet, serpents resemble the oviparous quadrupeds in their
conformation.
In all these animals there is a head with its component parts;
its presence being determined by the same causes as obtain in
the case of other sanguineous animals; and in all, with the
single exception of the river crocodile, there is a tongue inside
the mouth. In this one exception there would seem to be no
actual tongue, but merely a space left vacant for it. The reason is
that a crocodile is in a way a land-animal and a water-animal
combined. In its character of land-animal it has a space for a
tongue; but in its character of water-animal it is without the
tongue itself. For in some fishes, as has already been
mentioned, there is no appearance whatsoever of a tongue,
unless the mouth be stretched open very widely indeed; while
1948
in others it is indistinctly separated from the rest of the mouth.
The reason for this is that a tongue would be of but little service
to such animals, seeing that they are unable to chew their food
or to taste it before swallowing, the pleasurable sensations they
derive from it being limited to the act of deglutition. For it is in
their passage down the gullet that solid edibles cause
enjoyment, while it is by the tongue that the savour of fluids is
perceived. Thus it is during deglutition that the oiliness, the
heat, and other such qualities of food are recognized; and, in
fact, the satisfaction from most solid edibles and dainties is
derived almost entirely from the dilatation of the oesophagus
during deglutition. This sensation, then, belongs even to
animals that have no tongue, but while other animals have in
addition the sensations of taste, tongueless animals have, we
may say, no other satisfaction than it. What has now been said
explains why intemperance as regards drinks and savoury fluids
does not go hand in hand with intemperance as regards eating
and solid relishes.
In some oviparous quadrupeds, namely in lizards, the tongue is
bifid, as also it is in serpents, and its terminal divisions are of
hair-like fineness, as has already been described. (Seals also
have a forked tongue.) This it is which accounts for all these
animals being so fond of dainty food. The teeth in the four-
footed Ovipara are of the sharp interfitting kind, like the teeth
of fishes. The organs of all the senses are present and resemble
those of other animals. Thus there are nostrils for smell, eves
for vision, and ears for hearing. The latter organs, however, do
not project from the sides of the head, but consist simply of the
duct, as also is the case in birds. This is due in both cases to the
hardness of the integument; birds having their bodies covered
with feathers, and these oviparous quadrupeds with horny
plates. These plates are equivalent to scales, but of a harder
character. This is manifest in tortoises and river crocodiles, and
also in the large serpents. For here the plates become stronger
1949
than the bones, being seemingly of the same substance as
these.
These animals have no upper eyelid, but close the eye with the
lower lid In this they resemble birds, and the reason is the same
as was assigned in their case. Among birds there are some that
can not only thus close the eye, but can also blink by means of a
membrane which comes from its corner. But none of the
oviparous quadrupeds blink; for their eyes are harder than
those of birds. The reason for this is that keen vision and far-
sightedness are of very considerable service to birds, flying as
they do in the air, whereas they would be of comparatively
small use to the oviparous quadrupeds, seeing that they are all
of troglodytic habits.
Of the two separate portions which constitute the head, namely
the upper part and the lower jaw, the latter in man and in the
viviparous quadrupeds moves not only upwards and
downwards, but also from side to side; while in fishes, and birds
and oviparous quadrupeds, the only movement is up and down.
The reason is that this latter movement is the one required in
biting and dividing food, while the lateral movement serve to
reduce substances to a pulp. To such animals, therefore, as have
grinder-teeth this lateral motion is of service; but to those
animals that have no grinders it would be quite useless, and
they are therefore invariably without it. For nature never makes
anything that is superfluous. While in all other animals it is the
lower jaw that is movable, in the river crocodile it is
exceptionally the upper. This is because the feet in this creature
are so excessively small as to be useless for seizing and holding
prey; on which account nature has given it a mouth that can
serve for these purposes in their stead. For that direction of
motion which will give the greater force to a blow will be the
more serviceable one in holding or in seizing prey; and a blow
from above is always more forcible than one from below. Seeing,
1950
then, that both the prehension and the mastication of food are
offices of the mouth, and that the former of these two is the
more essential in an animal that has neither hands nor suitably
formed feet, these crocodiles will derive greater benefit from a
motion of the upper jaw downwards than from a motion of the
lower jaw upwards. The same considerations explain why crabs
also move the upper division of each claw and not the lower. For
their claws are substitutes for hands, and so require to be
suitable for the prehension of food, and not for its
comminution; for such comminution and biting is the office of
teeth. In crabs, then, and in such other animals as are able to
seize their food in a leisurely manner, inasmuch as their mouth
is not called on to perform its office while they are still in the
water, the two functions are assigned to different parts,
prehension to the hands or feet, biting and comminution of
food to the mouth. But in crocodiles the mouth has been so
framed by nature as to serve both purposes, the jaws being
made to move in the manner just described.
Another part present in these animals is a neck, this being the
necessary consequence of their having a lung. For the windpipe
by which the air is admitted to the lung is of some length. If,
however, the definition of a neck be correct, which calls it the
portion between the head and the shoulders, a serpent can
scarcely be said with the same right as the rest of these animals
to have a neck, but only to have something analogous to that
part of the body. It is a peculiarity of serpents, as compared with
other animals allied to them, that they are able to turn their
head backwards without stirring the rest of the body. The reason
of this is that a serpent, like an insect, has a body that admits of
being curled up, its vertebrae being cartilaginous and easily
bent. The faculty in question belongs then to serpents simply as
a necessary consequence of this character of their vertebrae;
but at the same time it has a final cause, for it enables them to
guard against attacks from behind. For their body, owing to its
1951
length and the absence of feet, is ill-suited for turning round
and protecting the hinder parts; and merely to lift the head,
without the power of turning it round, would be of no use
whatsoever.
The animals with which we are dealing have, moreover, a part
which corresponds to the breast; but neither here nor elsewhere
in their body have they any mammae, as neither has any bird or
fish. This is a consequence of their having no milk; for a
mamma is a receptacle for milk and, as it were, a vessel to
contain it. This absence of milk is not peculiar to these animals,
but is common to all such as are not internally viviparous. For
all such produce eggs, and the nutriment which in Vivipara has
the character of milk is in them engendered in the egg. Of all
this, however, a clearer account will be given in the treatise on
Generation. As to the mode in which the legs bend, a general
account, in which all animals are considered, has already been
given in the dissertation on Progression. These animals also
have a tail, larger in some of them, smaller in others, and the
reason for this has been stated in general terms in an earlier
passage.
Of all oviparous animals that live on land there is none so lean
as the Chamaeleon. For there is none that has so little blood.
The explanation of this is to be found in the psychical
temperament of the creature. For it is of a timid nature, as the
frequent changes it undergoes in its outward aspect testify. But
fear is a refrigeration, and results from deficiency of natural
heat and scantiness of blood. We have now done with such
sanguineous animals as are quadrupedous and also such as are
apodous, and have stated with sufficient completeness what
external parts they possess, and for what reason they have
them.
1952
12
The differences of birds compared one with another are
differences of magnitude, and of the greater or smaller
development of parts. Thus some have long legs, others short
legs; some have a broad tongue, others a narrow tongue; and so
on with the other parts. There are few of their parts that differ
save in size, taking birds by themselves. But when birds are
compared with other animals the parts present differences of
form also. For in some animals these are hairy, in others scaly,
and in others have scale-like plates, while birds are feathered.
Birds, then, are feathered, and this is a character common to
them all and peculiar to them. Their feathers, too, are split and
distinct in kind from the undivided feathers of insects; for the
bird's feather is barbed, these are not; the bird's feather has a
shaft, these have none. A second strange peculiarity which
distinguishes birds from all other animals is their beak. For as in
elephants the nostril serves in place of hands, and as in some
insects the tongue serves in place of mouth, so in birds there is
a beak, which, being bony, serves in place of teeth and lips.
Their organs of sense have already been considered.
All birds have a neck extending from the body; and the purpose
of this neck is the same as in such other animals as have one.
This neck in some birds is long, in others short; its length, as a
general rule, being pretty nearly determined by that of the legs.
For long-legged birds have a long neck, short-legged birds a
short one, to which rule, however, the web-footed birds form an
exception. For to a bird perched up on long legs a short neck
would be of no use whatsoever in collecting food from the
ground; and equally useless would be a long neck, if the legs
were short. Such birds, again, as are carnivorous would find
length in this part interfere greatly with their habits of life. For a
1953
long neck is weak, and it is on their superior strength that
carnivorous birds depend for their subsistence. No bird,
therefore, that has talons ever has an elongated neck. In web-
footed birds, however, and in those other birds belonging to the
same class, whose toes though actually separate have flat
marginal lobes, the neck is elongated, so as to be suitable for
collecting food from the water; while the legs are short, so as to
serve in swimming. The beaks of birds, as their feet, vary with
their modes of life. For in some the beak is straight, in others
crooked; straight, in those who use it merely for eating; crooked,
in those that live on raw flesh. For a crooked beak is an
advantage in fighting; and these birds must, of course, get their
food from the bodies of other animals, and in most cases by
violence. In such birds, again, as live in marshes and are
herbivorous the beak is broad and flat, this form being best
suited for digging and cropping, and for pulling up plants. In
some of these marsh birds, however, the beak is elongated, as
too is the neck, the reason for this being that the bird get its
food from some depth below the surface. For most birds of this
kind, and most of those whose feet are webbed, either in their
entirety or each part separately, live by preying on some of the
smaller animals that are to be found in water, and use these
parts for their capture, the neck acting as a fishing-rod, and the
beak representing the line and hook.
The upper and under sides of the body, that is of what in
quadrupeds is called the trunk, present in birds one unbroken
surface, and they have no arms or forelegs attached to it, but in
their stead wings, which are a distinctive peculiarity of these
animals; and, as these wings are substitutes for arms, their
terminal segments lie on the back in the place of a shoulder-
blade.
The legs are two in number, as in man; not however, as in man,
bent outwards, but bent inwards like the legs of a quadruped.
1954
The wings are bent like the forelegs of a quadruped, having
their convexity turned outwards. That the feet should be two in
number is a matter of necessity. For a bird is essentially a
sanguineous animal, and at the same time essentially a winged
animal; and no sanguineous animal has more than four points
for motion In birds, then, as in those other sanguineous animals
that live and move upon the ground, the limbs attached to the
trunk are four in number. But, while in all the rest these four
limbs consist of a pair of arms and a pair of legs, or of four legs
as in quadrupeds, in birds the arms or forelegs are replaced by a
pair of wings, and this is their distinctive character. For it is of
the essence of a bird that it shall be able to fly; and it is by the
extension of wings that this is made possible. Of all
arrangements, then, the only possible, and so the necessary, one
is that birds shall have two feet; for this with the wings will give
them four points for motion. The breast in all birds is sharp-
edged, and fleshy. The sharp edge is to minister to flight, for
broad surfaces move with considerable difficulty, owing to the
large quantity of air which they have to displace; while the
fleshy character acts as a protection, for the breast, owing to its
form, would be weak, were it not amply covered.
Below the breast lies the belly, extending, as in quadrupeds and
in man, to the vent and to the place where the legs are jointed
to the trunk.
Such, then, are the parts which lie between the wings and the
legs. Birds like all other animals, whether produced viviparously
or from eggs, have an umbilicus during their development, but,
when the bird has attained to fuller growth, no signs of this
remain visible. The cause of this is plainly to be seen during the
process of development; for in birds the umbilical cord unites
with the intestine, and is not a portion of the vascular system,
as is the case in viviparous animals.
1955
Some birds, again, are well adapted for flight, their wings being
large and strong. Such, for instance, are those that have talons
and live on flesh. For their mode of life renders the power of
flight a necessity, and it is on this account that their feathers
are so abundant and their wings so large. Besides these,
however, there are also other genera of birds that can fly well;
all those, namely, that depend on speed for security, or that are
of migratory habits. On the other hand, some kinds of birds
have heavy bodies and are not constructed for flight. These are
birds that are frugivorous and live on the ground, or that are
able to swim and get their living in watery places. In those that
have talons the body, without the wings, is small; for the
nutriment is consumed in the production of these wings, and of
the weapons and defensive appliances; whereas in birds that
are not made for flight the contrary obtains, and the body is
bulky and so of heavy weight. In some of these heavy-bodied
birds the legs are furnished with what are called spurs, which
replace the wings as a means of defence. Spurs and talons never
co-exist in the same bird. For nature never makes anything
superfluous; and if a bird can fly, and has talons, it has no use
for spurs; for these are weapons for fighting on the ground, and
on this account are an appanage of certain heavy-bodied birds.
These latter, again, would find the possession of talons not only
useless but actually injurious; for the claws would stick into the
ground and interfere with progression. This is the reason why
all birds with talons walk so badly, and why they never settle
upon rocks. For the character of their claws is ill-suited for
either action.
All this is the necessary consequence of the process of
development. For the earthy matter in the body issuing from it
is converted into parts that are useful as weapons. That which
flows upwards gives hardness or size to the beak; and, should
any flow downwards, it either forms spurs upon the legs or
gives size and strength to the claws upon the feet. But it does
1956
not at one and the same time produce both these results, one in
the legs, the other in the claws; for such a dispersion of this
residual matter would destroy all its efficiency. In other birds
this earthy residue furnishes the legs with the material for their
elongation; or sometimes, in place of this, fills up the
interspaces between the toes. Thus it is simply a matter of
necessity, that such birds as swim shall either be actually web-
footed, or shall have a kind of broad blade-like margin running
along the whole length of each distinct toe. The forms, then, of
these feet are simply the necessary results of the causes that
have been mentioned. Yet at the same time they are intended
for the animal's advantage. For they are in harmony with the
mode of life of these birds, who, living on the water, where their
wings are useless, require that their feet shall be such as to
serve in swimming. For these feet are so developed as to
resemble the oars of a boat, or the fins of a fish; and the
destruction of the foot-web has the same effect as the
destruction of the fins; that is to say, it puts an end to all power
of swimming.
In some birds the legs are very long, the cause of this being that
they inhabit marshes. I say the cause, because nature makes the
organs for the function, and not the function for the organs. It
is, then, because these birds are not meant for swimming that
their feet are without webs, and it is because they live on
ground that gives way under the foot that their legs and toes are
elongated, and that these latter in most of them have an extra
number of joints. Again, though all birds have the same material
composition, they are not all made for flight; and in these,
therefore, the nutriment that should go to their tail-feathers is
spent on the legs and used to increase their size. This is the
reason why these birds when they fly make use of their legs as a
tail, stretching them out behind, and so rendering them
serviceable, whereas in any other position they would be simply
an impediment.
1957
In other birds, where the legs are short, these are held close
against the belly during flight. In some cases this is merely to
keep the feet out of the way, but in birds that have talons the
position has a further purpose, being the one best suited for
rapine. Birds that have a long and a thick neck keep it stretched
out during flight; but those whose neck though long is slender
fly with it coiled up. For in this position it is protected, and less
likely to get broken, should the bird fly against any obstacle.
In all birds there is an ischium, but so placed and of such length
that it would scarcely be taken for an ischium, but rather for a
second thigh-bone; for it extends as far as to the middle of the
belly. The reason for this is that the bird is a biped, and yet is
unable to stand erect. For if its ischium extended but a short
way from the fundament, and then immediately came the leg,
as is the case in man and in quadrupeds, the bird would be
unable to stand up at all. For while man stands erect, and while
quadrupeds have their heavy bodies propped up in front by the
forelegs, birds can neither stand erect owing to their dwarf-like
shape, nor have anterior legs to prop them up, these legs being
replaced by wings. As a remedy for this Nature has given them a
long ischium, and brought it to the centre of the body, fixing it
firmly; and she has placed the legs under this central point, that
the weight on either side may be equally balanced, and
standing or progression rendered possible. Such then is the
reason why a bird, though it is a biped, does not stand erect.
Why its legs are destitute of flesh has also already been stated;
for the reasons are the same as in the case of quadrupeds.
In all birds alike, whether web-footed or not, the number of toes
in each foot is four. For the Libyan ostrich may be disregarded
for the present, and its cloven hoof and other discrepancies of
structure as compared with the tribe of birds will be considered
further on. Of these four toes three are in front, while the fourth
points backward, serving, as a heel, to give steadiness. In the
1958
long-legged birds this fourth toe is much shorter than the
others, as is the case with the Crex, but the number of their toes
is not increased. The arrangement of the toes is such as has
been described in all birds with the exception of the wryneck.
Here only two of the toes are in front, the other two behind; and
the reason for this is that the body of the wryneck is not
inclined forward so much as that of other birds. All birds have
testicles; but they are inside the body. The reason for this will be
given in the treatise On the Generation of Animals.
13
Thus then are fashioned the parts of birds. But in fishes a still
further stunting has occurred in the external parts. For here, for
reasons already given, there are neither legs nor hands nor
wings, the whole body from head to tail presenting one
unbroken surface. This tail differs in different fishes, in some
approximating in character to the fins, while in others, namely
in some of the flat kinds, it is spinous and elongated, because
the material which should have gone to the tail has been
diverted thence and used to increase the breadth of the body.
Such, for instance, is the case with the Torpedos, the Trygons,
and whatever other Selachia there may be of like nature. In
such fishes, then, the tail is spinous and long; while in some
others it is short and fleshy, for the same reason which makes it
spinous and long in the Torpedo. For to be short and fleshy
comes to the same thing as to be long and less amply furnished
with flesh.
What has occurred in the Fishing- frog is the reverse of what has
occurred in the other instances just given. For here the anterior
and broad part of the body is not of a fleshy character, and so all
1959
the fleshy substance which has been thence diverted has been
placed by nature in the tail and hinder portion of the body.
In fishes there are no limbs attached to the body. For in
accordance with their essential constitution they are swimming
animals; and nature never makes anything superfluous or void
of use. Now inasmuch as fishes are made swimming they have
fins, and as they are not made for walking they are without feet;
for feet are attached to the body that they may be of use in
progression on land. Moreover, fishes cannot have feet, or any
other similar limbs, as well as four fins; for they are essentially
sanguineous animals. The Cordylus, though it has gills, has feet,
for it has no fins but merely has its tail flattened out and loose
in texture.
Fishes, unless, like the Batos and the Trygon, they are broad and
flat, have four fins, two on the upper and two on the under side
of the body; and no fish ever has more than these. For, if it had,
it would be a bloodless animal.
The upper pair of fins is present in nearly all fishes, but not so
the under pair; for these are wanting in some of those fishes
that have long thick bodies, such as the eel, the conger, and a
certain kind of Cestreus that is found in the lake at Siphae.
When the body is still more elongated, and resembles that of a
serpent rather than that of a fish, as is the case in the
Smuraena, there are absolutely no fins at all; and locomotion is
effected by the flexures of the body, the water being put to the
same use by these fishes as is the ground by serpents. For
serpents swim in water exactly in the same way as they glide on
the ground. The reason for these serpent-like fishes being
without fins is the same as that which causes serpents to be
without feet; and what this is has been already stated in the
dissertations on the Progression and the Motion of Animals. The
reason was this. If the points of motion were four, motion would
I960
be effected under difficulties; for either the two pairs of fins
would be close to each other, in which case motion would
scarcely be possible, or they would be at a very considerable
distance apart, in which case the long interval between them
would be just as great an evil. On the other hand, to have more
than four such motor points would convert the fishes into
bloodless animals. A similar explanation applies to the case of
those fishes that have only two fins. For here again the body is
of great length and like that of a serpent, and its undulations do
the office of the two missing fins. It is owing to this that such
fishes can even crawl on dry ground, and can live there for a
considerable time; and do not begin to gasp until they have
been for a considerable time out of the water, while others,
whose nature is akin to that of land-animals, do not even do as
much as that. In such fishes as have but two fins it is the upper
pair (pectorals) that is present, excepting when the flat broad
shape of the body prevents this. The fins in such cases are
placed at the head, because in this region there is no elongation,
which might serve in the absence of fins as a means of
locomotion; whereas in the direction of the tail there is a
considerable lengthening out in fishes of this conformation. As
for the Bati and the like, they use the marginal part of their
flattened bodies in place of fins for swimming.
In the Torpedo and the Fishing-frog the breadth of the anterior
part of the body is not so great as to render locomotion by fins
impossible, but in consequence of it the upper pair (pectorals)
are placed further back and the under pair (ventrals) are placed
close to the head, while to compensate for this advancement
they are reduced in size so as to be smaller than the upper ones.
In the Torpedo the two upper fins (pectorals) are placed on the
tail, and the fish uses the broad expansion of its body to supply
their place, each lateral half of its circumference serving the
office of a fin.
1961
The head, with its several parts, as also the organs of sense,
have already come under consideration.
There is one peculiarity which distinguishes fishes from all
other sanguineous animals, namely, the possession of gills. Why
they have these organs has been set forth in the treatise on
Respiration. These gills are in most fishes covered by opercula,
but in the Selachia, owing to the skeleton being cartilaginous,
there are no such coverings. For an operculum requires fish-
spine for its formation, and in other fishes the skeleton is made
of this substance, whereas in the Selachia it is invariably formed
of cartilage. Again, while the motions of spinous fishes are
rapid, those of the Selachia are sluggish, inasmuch as they have
neither fish-spine nor sinew; but an operculum requires
rapidity of motion, seeing that the office of the gills is to
minister as it were to expiration. For this reason in Selachia the
branchial orifices themselves effect their own closure, and thus
there is no need for an operculum to ensure its taking place
with due rapidity. In some fishes the gills are numerous, in
others few in number; in some again they are double, in others
single. The last gill in most cases is single. For a detailed
account of all this, reference must be made to the treatises on
Anatomy, and to the book of Researches concerning Animals.
It is the abundance or the deficiency of the cardiac heat which
determines the numerical abundance or deficiency of the gills.
For, the greater an animal's heat, the more rapid and the more
forcible does it require the branchial movement to be; and
numerous and double gills act with more force and rapidity
than such as are few and single. Thus, too, it is that some fishes
that have but few gills, and those of comparatively small
efficacy, can live out of water for a considerable time; for in
them there is no great demand for refrigeration. Such, for
example, are the eel and all other fishes of serpent-like form.
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Fishes also present diversities as regards the mouth. For in
some this is placed in front, at the very extremity of the body,
while in others, as the dolphin and the Selachia, it is placed on
the under surface; so that these fishes turn on the back in order
to take their food. The purpose of Nature in this was apparently
not merely to provide a means of salvation for other animals, by
allowing them opportunity of escape during the time lost in the
act of turning - for all the fishes with this kind of mouth prey
on living animals - but also to prevent these fishes from giving
way too much to their gluttonous ravening after food. For had
they been able to seize their prey more easily than they do, they
would soon have perished from over-repletion. An additional
reason is that the projecting extremity of the head in these
fishes is round and small, and therefore cannot admit of a wide
opening.
Again, even when the mouth is not placed on the under surface,
there are differences in the extent to which it can open. For in
some cases it can gape widely, while in others it is set at the
point of a small tapering snout; the former being the case in
carnivorous fishes, such as those with sharp interfitting teeth,
whose strength lies in their mouth, while the latter is its form
in all such as are not carnivorous.
The skin is in some fishes covered with scales (the scale of a
fish is a thin and shiny film, and therefore easily becomes
detached from the surface of the body). In others it is rough, as
for instance in the Rhine, the Batos, and the like. Fewest of all
are those whose skin is smooth. The Selachia have no scales,
but a rough skin. This is explained by their cartilaginous
skeleton. For the earthy material which has been thence
diverted is expended by nature upon the skin.
No fish has testicles either externally or internally; as indeed
have no apodous animals, among which of course are included
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the serpents. One and the same orifice serves both for the
excrement and for the generative secretions, as is the case also
in all other oviparous animals, whether two-footed or four-
footed, inasmuch as they have no urinary bladder and form no
fluid excretion.
Such then are the characters which distinguish fishes from all
other animals. But dolphins and whales and all such Cetacea
are without gills; and, having a lung, are provided with a blow-
hole; for this serves them to discharge the sea-water which has
been taken into the mouth. For, feeding as they do in the water,
they cannot but let this fluid enter into their mouth, and, having
let it in, they must of necessity let it out again. The use of gills,
however, as has been explained in the treatise on Respiration, is
limited to such animals as do not breathe; for no animal can
possibly possess gills and at the same time be a respiratory
animal. In order, therefore, that these Cetacea may discharge
the water, they are provided with a blow-hole. This is placed in
front of the brain; for otherwise it would have cut off the brain
from the spine. The reason for these animals having a lung and
breathing, is that animals of large size require an excess of heat,
to facilitate their motion. A lung, therefore, is placed within
their body, and is fully supplied with blood-heat. These
creatures are after a fashion land and water animals in one. For
so far as they are inhalers of air they resemble land-animals,
while they resemble water-animals in having no feet and in
deriving their food from the sea. So also seals lie halfway
between land and water animals, and bats half-way between
animals that live on the ground and animals that fly; and so
belong to both kinds or to neither. For seals, if looked on as
water-animals, are yet found to have feet; and, if looked on as
land-animals, are yet found to have fins. For their hind feet are
exactly like the fins of fishes; and their teeth also are sharp and
interfitting as in fishes. Bats again, if regarded as winged
animals, have feet; and, if regarded as quadrupeds, are without
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them. So also they have neither the tail of a quadruped nor the
tail of a bird; no quadruped's tail, because they are winted
animals; no bird's tail, because they are terrestrial. This absence
of tail is the result of necessity. For bats fly by means of a
membrane, but no animal, unless it has barbed feathers, has the
tail of a bird; for a bird's tail is composed of such feathers. As for
a quadruped's tail, it would be an actual impediment, if present
among the feathers.
14
Much the same may be said also of the Libyan ostrich. For it has
some of the characters of a bird, some of the characters of a
quadruped. It differs from a quadruped in being feathered; and
from a bird in being unable to soar aloft and in having feathers
that resemble hair and are useless for flight. Again, it agrees
with quadrupeds in having upper eyelashes, which are the more
richly supplied with hairs because the parts about the head and
the upper portion of the neck are bare; and it agrees with birds
in being feathered in all the parts posterior to these. Further, it
resembles a bird in being a biped, and a quadruped in having a
cloven hoof; for it has hoofs and not toes. The explanation of
these peculiarities is to be found in its bulk, which is that of a
quadruped rather than that of a bird. For, speaking generally, a
bird must necessarily be of very small size. For a body of heavy
bulk can with difficulty be raised into the air.
Thus much then as regards the parts of animals. We have
discussed them all, and set forth the cause why each exists; and
in so doing we have severally considered each group of animals.
We must now pass on, and in due sequence must next deal
with the question of their generation.
1965
Aristotle - On the Motion of Animals
[Translated by A. S. L. Farquharson]
Elsewhere we have investigated in detail the movement of
animals after their various kinds, the differences between them,
and the reasons for their particular characters (for some
animals fly, some swim, some walk, others move in various
other ways); there remains an investigation of the common
ground of any sort of animal movement whatsoever.
Now we have already determined (when we were discussing
whether eternal motion exists or not, and its definition, if it
does exist) that the origin of all other motions is that which
moves itself, and that the origin of this is the immovable, and
that the prime mover must of necessity be immovable. And we
must grasp this not only generally in theory, but also by
reference to individuals in the world of sense, for with these in
view we seek general theories, and with these we believe that
general theories ought to harmonize. Now in the world of sense
too it is plainly impossible for movement to be initiated if there
is nothing at rest, and before all else in our present subject -
animal life. For if one of the parts of an animal be moved,
another must be at rest, and this is the purpose of their joints;
animals use joints like a centre, and the whole member, in
which the joint is, becomes both one and two, both straight and
bent, changing potentially and actually by reason of the joint.
And when it is bending and being moved one of the points in
the joint is moved and one is at rest, just as if the points A and
D of a diameter were at rest, and B were moved, and DAC were
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generated. However, in the geometrical illustration, the centre is
held to be altogether indivisible (for in mathematics motion is a
fiction, as the phrase goes, no mathematical entity being really
moved), whereas in the case of joints the centres become now
one potentially and divided actually, and now one actually and
divided potentially. But still the origin of movement, qua origin,
always remains at rest when the lower part of a limb is moved;
for example, the elbow joint, when the forearm is moved, and
the shoulder, when the whole arm; the knee when the tibia is
moved, and the hip when the whole leg. Accordingly it is plain
that each animal as a whole must have within itself a point at
rest, whence will be the origin of that which is moved, and
supporting itself upon which it will be moved both as a
complete whole and in its members.
But the point of rest in the animal is still quite ineffectual
unless there be something without which is absolutely at rest
and immovable. Now it is worth while to pause and consider
what has been said, for it involves a speculation which extends
beyond animals even to the motion and march of the universe.
For just as there must be something immovable within the
animal, if it is to be moved, so even more must there be without
it something immovable, by supporting itself upon which that
which is moved moves. For were that something always to give
way (as it does for mice walking in grain or persons walking in
sand) advance would be impossible, and neither would there be
any walking unless the ground were to remain still, nor any
flying or swimming were not the air and the sea to resist. And
this which resists must needs be different from what is moved,
the whole of it from the whole of that, and what is thus
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immovable must be no part of what is moved; otherwise there
will be no movement. Evidence of this lies in the problem why it
is that a man easily moves a boat from outside, if he push with
a pole, putting it against the mast or some other part, but if he
tried to do this when in the boat itself he would never move it,
no not giant Tityus himself nor Boreas blowing from inside the
ship, if he really were blowing in the way painters represent
him; for they paint him sending the breath out from the boat.
For whether one blew gently or so stoutly as to make a very
great wind, and whether what were thrown or pushed were
wind or something else, it is necessary in the first place to be
supported upon one of one's own members which is at rest and
so to push, and in the second place for this member, either
itself, or that of which it is a part, to remain at rest, fixing itself
against something external to itself. Now the man who is
himself in the boat, if he pushes, fixing himself against the boat,
very naturally does not move the boat, because what he pushes
against should properly remain at rest. Now what he is trying to
move, and what he is fixing himself against is in his case the
same. If, however, he pushes or pulls from outside he does move
it, for the ground is no part of the boat.
Here we may ask the difficult question whether if something
moves the whole heavens this mover must be immovable, and
moreover be no part of the heavens, nor in the heavens. For
either it is moved itself and moves the heavens, in which case it
must touch something immovable in order to create movement,
and then this is no part of that which creates movement; or if
the mover is from the first immovable it will equally be no part
of that which is moved. In this point at least they argue
1968
correctly who say that as the Sphere is carried round in a circle
no single part remains still, for then either the whole would
necessarily stand still or its continuity be torn asunder; but they
argue less well in supposing that the poles have a certain force,
though conceived as having no magnitude, but as merely
termini or points. For besides the fact that no such things have
any substantial existence it is impossible for a single movement
to be initiated by what is twofold; and yet they make the poles
two. From a review of these difficulties we may conclude that
there is something so related to the whole of Nature, as the
earth is to animals and things moved by them.
And the mythologists with their fable of Atlas setting his feet
upon the earth appear to have based the fable upon intelligent
grounds. They make Atlas a kind of diameter twirling the
heavens about the poles. Now as the earth remains still this
would be reasonable enough, but their theory involves them in
the position that the earth is no part of the universe. And
further the force of that which initiates movement must be
made equal to the force of that which remains at rest. For there
is a definite quantity of force or power by dint of which that
which remains at rest does so, just as there is of force by dint of
which that which initiates movement does so; and as there is a
necessary proportion between opposite motions, so there is
between absences of motion. Now equal forces are unaffected
by one another, but are overcome by a superiority of force. And
so in their theory Atlas, or whatever similar power initiates
movement from within, must exert no more force than will
exactly balance the stability of the earth - otherwise the earth
will be moved out of her place in the centre of things. For as the
pusher pushes so is the pushed pushed, and with equal force.
But the prime mover moves that which is to begin with at rest,
so that the power it exerts is greater, rather than equal and like
to the power which produces absence of motion in that which is
moved. And similarly also the power of what is moved and so
1969
moves must be greater than the power of that which is moved
but does not initiate movement. Therefore the force of the earth
in its immobility will have to be as great as the force of the
whole heavens, and of that which moves the heavens. But if
that is impossible, it follows that the heavens cannot possibly
be moved by any force of this kind inside them.
There is a further difficulty about the motions of the parts of
the heavens which, as akin to what has gone before, may be
considered next. For if one could overcome by force of motion
the immobility of the earth he would clearly move it away from
the centre. And it is plain that the power from which this force
would originate will not be infinite, for the earth is not infinite
and therefore its weight is not. Now there are more senses than
one of the word 'impossible'. When we say it is impossible to
see a sound, and when we say it is impossible to see the men in
the moon, we use two senses of the word; the former is of
necessity, the latter, though their nature is to be seen, cannot as
a fact be seen by us. Now we suppose that the heavens are of
necessity impossible to destroy and to dissolve, whereas the
result of the present argument would be to do away with this
necessity. For it is natural and possible for a motion to exist
greater than the force by dint of which the earth is at rest, or
than that by dint of which Fire and Aether are moved. If then
there are superior motions, these will be dissolved in succession
by one another: and if there actually are not, but might possibly
be (for the earth cannot be infinite because no body can
possibly be infinite), there is a possibility of the heavens being
dissolved. For what is to prevent this coming to pass, unless it
1970
be impossible? And it is not impossible unless the opposite is
necessary. This difficulty, however, we will discuss elsewhere.
To resume, must there be something immovable and at rest
outside of what is moved, and no part of it, or not? And must
this necessarily be so also in the case of the universe? Perhaps it
would be thought strange were the origin of movement inside.
And to those who so conceive it the word of Homer would
appear to have been well spoken:
'Nay, ye would not pull Zeus, highest of all from heaven to the
plain, no not even if ye toiled right hard; come, all ye gods and
goddesses! Set hands to the chain'; for that which is entirely
immovable cannot possibly be moved by anything. And herein
lies the solution of the difficulty stated some time back, the
possibility or impossibility of dissolving the system of the
heavens, in that it depends from an original which is
immovable.
Now in the animal world there must be not only an immovable
without, but also within those things which move in place, and
initiate their own movement. For one part of an animal must be
moved, and another be at rest, and against this the part which
is moved will support itself and be moved; for example, if it
move one of its parts; for one part, as it were, supports itself
against another part at rest.
But about things without life which are moved one might ask
the question whether all contain in themselves both that which
is at rest and that which initiates movement, and whether they
also, for instance fire, earth, or any other inanimate thing, must
support themselves against something outside which is at rest.
Or is this impossible and must it not be looked for rather in
those primary causes by which they are set in motion? For all
things without life are moved by something other, and the
origin of all things so moved are things which move themselves.
1971
And out of these we have spoken about animals (for they must
all have in themselves that which is at rest, and without them
that against which they are supported); but whether there is
some higher and prime mover is not clear, and an origin of that
kind involves a different discussion. Animals at any rate which
move themselves are all moved supporting themselves on what
is outside them, even when they inspire and expire; for there is
no essential difference between casting a great and a small
weight, and this is what men do when they spit and cough and
when they breathe in and breathe out.
But is it only in that which moves itself in place that there must
be a point at rest, or does this hold also of that which causes its
own qualitative changes, and its own growth? Now the question
of original generation and decay is different; for if there is, as
we hold, a primary movement, this would be the cause of
generation and decay, and probably of all the secondary
movements too. And as in the universe, so in the animal world
this is the primary movement, when the creature attains
maturity; and therefore it is the cause of growth, when the
creature becomes the cause of its own growth, and the cause
too of alteration. But if this is not the primary movement then
the point at rest is not necessary. However, the earliest growth
and alteration in the living creature arise through another and
by other channels, nor can anything possibly be the cause of its
own generation and decay, for the mover must exist before the
moved, the begetter before the begotten, and nothing is prior to
itself.
1972
Now whether the soul is moved or not, and how it is moved if it
be moved, has been stated before in our treatise concerning it.
And since all inorganic things are moved by some other thing -
and the manner of the movement of the first and eternally
moved, and how the first mover moves it, has been determined
before in our Metaphysics, it remains to inquire how the soul
moves the body, and what is the origin of movement in a living
creature. For, if we except the movement of the universe, things
with life are the causes of the movement of all else, that is of all
that are not moved by one another by mutual impact. And so all
their motions have a term or limit, inasmuch as the movements
of things with life have such. For all living things both move and
are moved with some object, so that this is the term of all their
movement, the end, that is, in view. Now we see that the living
creature is moved by intellect, imagination, purpose, wish, and
appetite. And all these are reducible to mind and desire. For
both imagination and sensation are on common ground with
mind, since all three are faculties of judgement though differing
according to distinctions stated elsewhere. Will, however,
impulse, and appetite, are all three forms of desire, while
purpose belongs both to intellect and to desire. Therefore the
object of desire or of intellect first initiates movement, not, that
is, every object of intellect, only the end in the domain of
conduct. Accordingly among goods that which moves is a
practical end, not the good in its whole extent. For it initiates
movement only so far as something else is for its sake, or so far
as it is the object of that which is for the sake of something else.
And we must suppose that a seeming good may take the room
of actual good, and so may the pleasant, which is itself a
seeming good. From these considerations it is clear that in one
regard that which is eternally moved by the eternal mover is
1973
moved in the same way as every living creature, in another
regard differently, and so while it is moved eternally, the
movement of living creatures has a term. Now the eternal
beautiful, and the truly and primarily good (which is not at one
time good, at another time not good), is too divine and precious
to be relative to anything else. The prime mover then moves,
itself being unmoved, whereas desire and its faculty are moved
and so move. But it is not necessary for the last in the chain of
things moved to move something else; wherefore it is plainly
reasonable that motion in place should be the last of what
happens in the region of things happening, since the living
creature is moved and goes forward by reason of desire or
purpose, when some alteration has been set going on the
occasion of sensation or imagination.
But how is it that thought (viz. sense, imagination, and thought
proper) is sometimes followed by action, sometimes not;
sometimes by movement, sometimes not? What happens
seems parallel to the case of thinking and inferring about the
immovable objects of science. There the end is the truth seen
(for, when one conceives the two premisses, one at once
conceives and comprehends the conclusion), but here the two
premisses result in a conclusion which is an action - for
example, one conceives that every man ought to walk, one is a
man oneself: straightway one walks; or that, in this case, no
man should walk, one is a man: straightway one remains at
rest. And one so acts in the two cases provided that there is
nothing in the one case to compel or in the other to prevent.
Again, I ought to create a good, a house is good: straightway I
make a house. I need a covering, a coat is a covering: I need a
1974
coat. What I need I ought to make, I need a coat: I make a coat.
And the conclusion I must make a coat is an action. And the
action goes back to the beginning or first step. If there is to be a
coat, one must first have B, and if B then A, so one gets A to
begin with. Now that the action is the conclusion is clear. But
the premisses of action are of two kinds, of the good and of the
possible.
And as in some cases of speculative inquiry we suppress one
premise so here the mind does not stop to consider at all an
obvious minor premise; for example if walking is good for man,
one does not dwell upon the minor 'I am a man'. And so what
we do without reflection, we do quickly. For when a man
actualizes himself in relation to his object either by perceiving,
or imagining or conceiving it, what he desires he does at once.
For the actualizing of desire is a substitute for inquiry or
reflection. I want to drink, says appetite; this is drink, says sense
or imagination or mind: straightway I drink. In this way living
creatures are impelled to move and to act, and desire is the last
or immediate cause of movement, and desire arises after
perception or after imagination and conception. And things that
desire to act now create and now act under the influence of
appetite or impulse or of desire or wish.
The movements of animals may be compared with those of
automatic puppets, which are set going on the occasion of a
tiny movement; the levers are released, and strike the twisted
strings against one another; or with the toy wagon. For the child
mounts on it and moves it straight forward, and then again it is
moved in a circle owing to its wheels being of unequal diameter
(the smaller acts like a centre on the same principle as the
cylinders). Animals have parts of a similar kind, their organs,
the sinewy tendons to wit and the bones; the bones are like the
wooden levers in the automaton, and the iron; the tendons are
like the strings, for when these are tightened or leased
1975
movement begins. However, in the automata and the toy wagon
there is no change of quality, though if the inner wheels became
smaller and greater by turns there would be the same circular
movement set up. In an animal the same part has the power of
becoming now larger and now smaller, and changing its form,
as the parts increase by warmth and again contract by cold and
change their quality. This change of quality is caused by
imaginations and sensations and by ideas. Sensations are
obviously a form of change of quality, and imagination and
conception have the same effect as the objects so imagined and
conceived For in a measure the form conceived be it of hot or
cold or pleasant or fearful is like what the actual objects would
be, and so we shudder and are frightened at a mere idea. Now
all these affections involve changes of quality, and with those
changes some parts of the body enlarge, others grow smaller.
And it is not hard to see that a small change occurring at the
centre makes great and numerous changes at the
circumference, just as by shifting the rudder a hair's breadth
you get a wide deviation at the prow. And further, when by
reason of heat or cold or some kindred affection a change is set
up in the region of the heart, even in an imperceptibly small
part of the heart, it produces a vast difference in the periphery
of the body, - blushing, let us say, or turning white, goose-skin
and shivers and their opposites.
8
But to return, the object we pursue or avoid in the field of action
is, as has been explained, the original of movement, and upon
the conception and imagination of this there necessarily follows
a change in the temperature of the body. For what is painful we
avoid, what is pleasing we pursue. We are, however,
1976
unconscious of what happens in the minute parts; still anything
painful or pleasing is generally speaking accompanied by a
definite change of temperature in the body. One may see this by
considering the affections. Blind courage and panic fears, erotic
motions, and the rest of the corporeal affections, pleasant and
painful, are all accompanied by a change of temperature, some
in a particular member, others in the body generally. So,
memories and anticipations, using as it were the reflected
images of these pleasures and pains, are now more and now
less causes of the same changes of temperature. And so we see
the reason of nature's handiwork in the inward parts, and in the
centres of movement of the organic members; they change from
solid to moist, and from moist to solid, from soft to hard and
vice versa. And so when these are affected in this way, and
when besides the passive and active have the constitution we
have many times described, as often as it comes to pass that
one is active and the other passive, and neither of them falls
short of the elements of its essence, straightway one acts and
the other responds. And on this account thinking that one
ought to go and going are virtually simultaneous, unless there
be something else to hinder action. The organic parts are
suitably prepared by the affections, these again by desire, and
desire by imagination. Imagination in its turn depends either
upon conception or sense-perception. And the simultaneity and
speed are due to the natural correspondence of the active and
passive.
However, that which first moves the animal organism must be
situate in a definite original. Now we have said that a joint is
the beginning of one part of a limb, the end of another. And so
nature employs it sometimes as one, sometimes as two. When
movement arises from a joint, one of the extreme points must
remain at rest, and the other be moved (for as we explained
above the mover must support itself against a point at rest);
accordingly, in the case of the elbow-joint, the last point of the
1977
forearm is moved but does not move anything, while, in the
flexion, one point of the elbow, which lies in the whole forearm
that is being moved, is moved, but there must also be a point
which is unmoved, and this is our meaning when we speak of a
point which is in potency one, but which becomes two in actual
exercise. Now if the arm were the living animal, somewhere in
its elbow-joint would be situate the original seat of the moving
soul. Since, however, it is possible for a lifeless thing to be so
related to the hand as the forearm is to the upper (for example,
when a man moves a stick in his hand), it is evident that the
soul, the original of movement, could not lie in either of the two
extreme points, neither, that is, in the last point of the stick
which is moved, nor in the original point which causes
movement. For the stick too has an end point and an originative
point by reference to the hand. Accordingly, this example shows
that the moving original which derives from the soul is not in
the stick and if not, then not in the hand; for a precisely similar
relation obtains between the hand and the wrist, as between
the wrist and the elbow. In this matter it makes no difference
whether the part is a continuous part of the body or not; the
stick may be looked at as a detached part of the whole. It
follows then of necessity that the original cannot lie in any
individual origin which is the end of another member, even
though there may lie another part outside the one in question.
For example, relatively to the end point of the stick the hand is
the original, but the original of the hand's movement is in the
wrist. And so if the true original is not in the hand, be-there is
still something higher up, neither is the true original in the
wrist, for once more if the elbow is at rest the whole part below
it can be moved as a continuous whole.
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Now since the left and the right sides are symmetrical, and
these opposites are moved simultaneously, it cannot be that the
left is moved by the right remaining stationary, nor vice versa;
the original must always be in what lies above both. Therefore,
the original seat of the moving soul must be in that which lies
in the middle, for of both extremes the middle is the limiting
point; and this is similarly related to the movements from
above [and below,] those that is from the head, and to the bones
which spring from the spinal column, in creatures that have a
spinal column.
And this is a reasonable arrangement. For the sensorium is in
our opinion in the centre too; and so, if the region of the original
of movement is altered in structure through sense-perception
and thus changes, it carries with it the parts that depend upon
it and they too are extended or contracted, and in this way the
movement of the creature necessarily follows. And the middle
of the body must needs be in potency one but in action more
than one; for the limbs are moved simultaneously from the
original seat of movement, and when one is at rest the other is
moved. For example, in the line BAC, B is moved, and A is the
mover. There must, however, be a point at rest if one is to move,
the other to be moved. A (AE) then being one in potency must be
two in action, and so be a definite spatial magnitude not a
mathematical point. Again, C may be moved simultaneously
with B. Both the originals then in A must move and be, and so
there must be something other than them which moves but is
not moved. For otherwise, when the movement begins, the
extremes, i.e. the originals, in A would rest upon one another,
like two men putting themselves back to back and so moving
their legs. There must then be some one thing which moves
both. This something is the soul, distinct from the spatial
magnitude just described and yet located therein.
1979
10
Although from the point of view of the definition of movement
- a definition which gives the cause - desire is the middle term
or cause, and desire moves being moved, still in the material
animated body there must be some material which itself moves
being moved. Now that which is moved, but whose nature is not
to initiate movement, is capable of being passive to an external
force, while that which initiates movement must needs possess
a kind of force and power. Now experience shows us that
animals do both possess connatural spirit and derive power
from this. (How this connatural spirit is maintained in the body
is explained in other passages of our works.) And this spirit
appears to stand to the soul-centre or original in a relation
analogous to that between the point in a joint which moves
being moved and the unmoved. Now since this centre is for
some animals in the heart, in the rest in a part analogous with
the heart, we further see the reason for the connatural spirit
being situate where it actually is found. The question whether
the spirit remains always the same or constantly changes and is
renewed, like the cognate question about the rest of the parts of
the body, is better postponed. At all events we see that it is well
disposed to excite movement and to exert power; and the
functions of movement are thrusting and pulling. Accordingly,
the organ of movement must be capable of expanding and
contracting; and this is precisely the characteristic of spirit. It
contracts and expands naturally, and so is able to pull and to
thrust from one and the same cause, exhibiting gravity
compared with the fiery element, and levity by comparison with
the opposites of fire. Now that which is to initiate movement
without change of structure must be of the kind described, for
1980
the elementary bodies prevail over one another in a compound
body by dint of disproportion; the light is overcome and kept
down by the heavier, and the heavy kept up by the lighter.
We have now explained what the part is which is moved when
the soul originates movement in the body, and what is the
reason for this. And the animal organism must be conceived
after the similitude of a well-governed commonwealth. When
order is once established in it there is no more need of a
separate monarch to preside over each several task. The
individuals each play their assigned part as it is ordered, and
one thing follows another in its accustomed order. So in
animals there is the same orderliness - nature taking the place
of custom - and each part naturally doing his own work as
nature has composed them. There is no need then of a soul in
each part, but she resides in a kind of central governing place of
the body, and the remaining parts live by continuity of natural
structure, and play the parts Nature would have them play.
11
So much then for the voluntary movements of animal bodies,
and the reasons for them. These bodies, however, display in
certain members involuntary movements too, but most often
non-voluntary movements. By involuntary I mean motions of
the heart and of the privy member; for often upon an image
arising and without express mandate of the reason these parts
are moved. By non-voluntary I mean sleep and waking and
respiration, and other similar organic movements. For neither
imagination nor desire is properly mistress of any of these; but
since the animal body must undergo natural changes of quality,
and when the parts are so altered some must increase and
1981
other decrease, the body must straightway be moved and
change with the changes that nature makes dependent upon
one another. Now the causes of the movements are natural
changes of temperature, both those coming from outside the
body, and those taking place within it. So the involuntary
movements which occur in spite of reason in the aforesaid
parts occur when a change of quality supervenes. For
conception and imagination, as we said above, produce the
conditions necessary to affections, since they bring to bear the
images or forms which tend to create these states. And the two
parts aforesaid display this motion more conspicuously than
the rest, because each is in a sense a separate vital organism,
the reason being that each contains vital moisture. In the case
of the heart the cause is plain, for the heart is the seat of the
senses, while an indication that the generative organ too is vital
is that there flows from it the seminal potency, itself a kind of
organism. Again, it is a reasonable arrangement that the
movements arise in the centre upon movements in the parts,
and in the parts upon movements in the centre, and so reach
one another. Conceive A to be the centre or starting point. The
movements then arrive at the centre from each letter in the
diagram we have drawn, and flow back again from the centre
which is moved and changes, (for the centre is potentially
multiple) the movement of B goes to B, that of C to C, the
movement of both to both; but from B to C the movements flow
by dint of going from B to A as to a centre, and then from A to C
as from a centre.
Moreover a movement contrary to reason sometimes does and
sometimes does not arise in the organs on the occasion of the
same thoughts; the reason is that sometimes the matter which
is passive to the impressions is there in sufficient quantity and
of the right quality and sometimes not.
1982
And so we have finished our account of the reasons for the
parts of each kind of animal, of the soul, and furthere of sense-
perception, of sleep, of memory, and of movement in general; it
remains to speak of animal generation.
1983
Aristotle - On the Gait of Animals
[Translated by A. S. L. Farquharson]
We have now to consider the parts which are useful to animals
for movement in place (locomotion); first, why each part is such
as it is and to what end they possess them; and second, the
differences between these parts both in one and the same
creature, and again by comparison of the parts of creatures of
different species with one another. First then let us lay down
how many questions we have to consider.
The first is what are the fewest points of motion necessary to
animal progression, the second why sanguineous animals have
four points and not more, but bloodless animals more than four,
and generally why some animals are footless, others bipeds,
others quadrupeds, others polypods, and why all have an even
number of feet, if they have feet at all; why in fine the points on
which progression depends are even in number.
Next, why are man and bird bipeds, but fish footless; and why
do man and bird, though both bipeds, have an opposite
curvature of the legs. For man bends his legs convexly, a bird
has his bent concavely; again, man bends his arms and legs in
opposite directions, for he has his arms bent convexly, but his
legs concavely. And a viviparous quadruped bends his limbs in
opposite directions to a man's, and in opposite directions to one
another; for he has his forelegs bent convexly, his hind legs
concavely. Again, quadrupeds which are not viviparous but
oviparous have a peculiar curvature of the limbs laterally away
1984
from the body. Again, why do quadrupeds move their legs criss-
cross?
We have to examine the reasons for all these facts, and others
cognate to them; that the facts are such is clear from our
Natural History, we have now to ask reasons for the facts.
At the beginning of the inquiry we must postulate the principles
we are accustomed constantly to use for our scientific
investigation of nature, that is we must take for granted
principles of this universal character which appear in all
Nature's work. Of these one is that Nature creates nothing
without a purpose, but always the best possible in each kind of
living creature by reference to its essential constitution.
Accordingly if one way is better than another that is the way of
Nature. Next we must take for granted the different species of
dimensions which inhere in various things; of these there are
three pairs of two each, superior and inferior, before and behind,
to the right and to the left. Further we must assume that the
originals of movements in place are thrusts and pulls. (These
are the essential place-movements, it is only accidentally that
what is carried by another is moved; it is not thought to move
itself, but to be moved by something else.)
After these preliminaries, we go on to the next questions in
order.
1985
Now of animals which change their position some move with
the whole body at once, for example jumping animals, others
move one part first and then the other, for example walking
(and running) animals. In both these changes the moving
creature always changes its position by pressing against what
lies below it. Accordingly if what is below gives way too quickly
for that which is moving upon it to lean against it, or if it affords
no resistance at all to what is moving, the latter can of itself
effect no movement upon it. For an animal which jumps makes
its jump both by leaning against its own upper part and also
against what is beneath its feet; for at the joints the parts do in
a sense lean upon one another, and in general that which
pushes down leans upon what is pushed down. That is why
athletes jump further with weights in their hands than without,
and runners run faster if they swing their arms; there is in
extending the arms a kind of leaning against the hands and
wrists. In all cases then that which moves makes its change of
position by the use of at least two parts of the body; one part so
to speak squeezes, the other is squeezed; for the part that is still
is squeezed as it has to carry the weight, the part that is lifted
strains against that which carries the weight. It follows then
that nothing without parts can move itself in this way, for it has
not in it the distinction of the part which is passive and that
which is active.
Again, the boundaries by which living beings are naturally
determined are six in number, superior and inferior, before and
behind, right and left. Of these all living beings have a superior
and an inferior part; for superior and inferior is in plants too,
not only in animals. And this distinction is one of function, not
1986
merely of position relatively to our earth and the sky above our
heads. The superior is that from which flows in each kind the
distribution of nutriment and the process of growth; the inferior
is that to which the process flows and in which it ends. One is a
starting-point, the other an end, and the starting-point is the
superior. And yet it might be thought that in the case of plants
at least the inferior is rather the appropriate starting-point, for
in them the superior and inferior are in position other than in
animals. Still they are similarly situated from the point of view
of function, though not in their position relatively to the
universe. The roots are the superior part of a plant, for from
them the nutriment is distributed to the growing members, and
a plant takes it with its roots as an animal does with its mouth.
Things that are not only alive but are animals have both a front
and a back, because they all have sense, and front and back are
distinguished by reference to sense. The front is the part in
which sense is innate, and whence each thing gets its
sensations, the opposite parts are the back.
All animals which partake not only in sense, but are able of
themselves to make a change of place, have a further
distinction of left and right besides those already enumerated;
like the former these are distinctions of function and not of
position. The right is that from which change of position
naturally begins, the opposite which naturally depends upon
this is the left.
This distinction (of right and left) is more articulate and detailed
in some than in others. For animals which make the aforesaid
change (of place) by the help of organized parts (I mean feet for
example, or wings or similar organs) have the left and right
distinguished in greater detail, while those which are not
differentiated into such parts, but make the differentiation in
the body itself and so progress, like some footless animals (for
1987
example snakes and caterpillars after their kind, and besides
what men call earth-worms), all these have the distinction
spoken of, although it is not made so manifest to us. That the
beginning of movement is on the right is indicated by the fact
that all men carry burdens on the left shoulder; in this way they
set free the side which initiates movement and enable the side
which bears the weight to be moved. And so men hop easier on
the left leg; for the nature of the right is to initiate movement,
that of the left to be moved. The burden then must rest on the
side which is to be moved, not on that which is going to cause
movement, and if it be set on the moving side, which is the
original of movement, it will either not be moved at all or with
more labour. Another indication that the right is the source of
movement is the way we put our feet forward; all men lead off
with the left, and after standing still prefer to put the left foot
forward, unless something happens to prevent it. The reason is
that their movement comes from the leg they step off, not from
the one put forward. Again, men guard themselves with their
right. And this is the reason why the right is the same in all, for
that from which motion begins is the same for all, and has its
natural position in the same place, and for this reason the
spiral-shaped Testaceans have their shells on the right, for they
do not move in the direction of the spire, but all go forward in
the direction opposite to the spire. Examples are the murex and
the ceryx. As all animals then start movement from the right,
and the right moves in the same direction as the whole, it is
necessary for all to be alike right-handed. And man has the left
limbs detached more than any other animal because he is
natural in a higher degree than the other animals; now the right
is naturally both better than the left and separate from it, and
so in man the right is more especially the right, more dextrous
that is, than in other animals. The right then being
differentiated it is only reasonable that in man the left should
be most movable, and most detached. In man, too, the other
1988
starting-points are found most naturally and clearly distinct,
the superior part that is and the front.
Animals which, like men and birds, have the superior part
distinguished from the front are two-footed (biped). In them, of
the four points of motion, two are wings in the one, hands and
arms in the other. Animals which have the superior and the
front parts identically situated are four-footed, many-footed, or
footless (quadruped, polypod, limbless). I use the term foot for a
member employed for movement in place connected with a
point on the ground, for the feet appear to have got their name
from the ground under our feet.
Some animals, too, have the front and back parts identically
situated, for example, Cephalopods (molluscs) and spiral-
shaped Testaceans, and these we have discussed elsewhere in
another connexion.
Now there is in place a superior, an intermediate, and an
inferior; in respect to place bipeds have their superior part
corresponding to the part of the universe; quadrupeds,
polypods, and footless animals to the intermediate part, and
plants to the inferior. The reason is that these have no power of
locomotion, and the superior part is determined relatively to the
nutriment, and their nutriment is from the earth. Quadrupeds,
polypods, and footless animals again have their superior part
corresponding to the intermediate, because they are not erect.
Bipeds have theirs corresponding to the superior part of the
universe because they are erect, and of bipeds, man par
excellence; for man is the most natural of bipeds. And it is
reasonable for the starting points to be in these parts; for the
1989
starting-point is honourable, and the superior is more
honourable than the inferior, the front than the back, and the
right than the left. Or we may reverse the argument and say
quite well that these parts are more honourable than their
opposites just because the starting-points are in them.
The above discussion has made it clear that the original of
movement is in the parts on the right. Now every continuous
whole, one part of which is moved while the other remains at
rest must, in order to be able to move as a whole while one part
stands still, have in the place where both parts have opposed
movements some common part which connects the moving
parts with one another. Further in this common part the
original of the motion (and similarly of the absence of motion)
of each of the parts must lie.
Clearly then if any of the opposite pairs of parts (right and left,
that is, superior and inferior, before and behind) have a
movement of their own, each of them has for common original
of its movements the juncture of the parts in question.
Now before and behind are not distinctions relatively to that
which sets up its own motion, because in nature nothing has a
movement backwards, nor has a moving animal any division
whereby it may make a change of position towards its front or
back; but right and left, superior and inferior are so
distinguished. Accordingly, all animals which progress by the
use of distinct members have these members distinguished not
by the differences of before and behind, but only of the
remaining two pairs; the prior difference dividing these
members into right and left (a difference which must appear as
1990
soon as you have division into two), and the other difference
appearing of necessity where there is division into four.
Since then these two pairs, the superior and inferior and the
right and left, are linked to one another by the same common
original (by which I mean that which controls their movement),
and further, everything which is intended to make a movement
in each such part properly must have the original cause of all
the said movements arranged in a certain definite position
relatively to the distances from it of the originals of the
movements of the individual members (and these centres of the
individual parts are in pairs arranged coordinately or diagonally,
and the common centre is the original from which the animal's
movements of right and left, and similarly of superior and
inferior, start); each animal must have this original at a point
where it is equally or nearly equally related to each of the
centres in the four parts described.
It is clear then how locomotion belongs to those animals only
which make their changes of place by means of two or four
points in their structure, or to such animals par excellence.
Moreover, since this property belongs almost peculiarly to
Sanguineous animals, we see that no Sanguineous animal can
progress at more points than four, and that if it is the nature of
anything so to progress at four points it must of necessity be
Sanguineous.
What we observe in the animal world is in agreement with the
above account. For no Sanguineous animal if it be divided into
more parts can live for any appreciable length of time, nor can it
enjoy the power of locomotion which it possessed while it was a
1991
continuous and undivided whole. But some bloodless animals
and polypods can live a long time, if divided, in each of the
severed parts, and can move in the same way as before they
were dismembered. Examples are what is termed the centipede
and other insects that are long in shape, for even the hinder
portion of all these goes on progressing in the same direction as
before when they are cut in two.
The explanation of their living when thus divided is that each of
them is constructed like a continuous body of many separate
living beings. It is plain, too, from what was said above why they
are like this. Animals constructed most naturally are made to
move at two or four points, and even limbless Sanguinea are no
exception. They too move by dint of four points, whereby they
achieve progression. They go forward by means of two flexions.
For in each of their flexions there is a right and a left, both
before and behind in their flat surface, in the part towards the
head a right and a left front point, and in the part towards the
tail the two hinder points. They look as if they moved at two
points only, where they touch before and behind, but that is
only because they are narrow in breadth. Even, in them the right
is the sovereign part, and there is an alternate correspondence
behind, exactly as in quadrupeds. The reason of their flexions is
their great length, for just as tall men walk with their spines
bellied (undulated) forward, and when their right shoulder is
leading in a forward direction their left hip rather inclined
backwards, so that their middle becomes hollow and bellied
(undulated), so we ought to conceive snakes as moving in
concave curves (undulations) upon the ground. And this is
evidence that they move themselves like the quadrupeds, for
they make the concave in its turn convex and the convex
concave. When in its turn the left of the forward parts is
leading, the concavity is in its turn reversed, for the right
becomes the inner. (Let the right front point be A, the left B, the
right hind C, the left D.)
1992
Among land animals this is the character of the movement of
snakes, and among water animals of eels, and conger-eels and
also lampreys, in fact of all that have their form snakelike.
However, some marine animals of this shape have no fin,
lampreys for example, but put the sea to the same use as
snakes do both land and water (for snakes swim precisely as
they move on the ground). Others have two fins only, for
example conger-eels and eels and a kind of cestreus which
breeds in the lake of Siphae. On this account too those that are
accustomed to live on land, for example all the eels, move with
fewer flexions in a fluid than on land, while the kind of cestreus
which has two fins, by its flexion in a fluid makes up the
remaining points.
8
The reason why snakes are limbless is first that nature makes
nothing without purpose, but always regards what is the best
possible for each individual, preserving the peculiar essence of
each and its intended character, and secondly the principle we
laid down above that no Sanguineous creature can move itself
at more than four points. Granting this it is evident that
Sanguineous animals like snakes, whose length is out of
proportion to the rest of their dimensions, cannot possibly have
limbs; for they cannot have more than four (or they would be
bloodless), and if they had two or four they would be practically
stationary; so slow and unprofitable would their movement
necessarily be.
But every limbed animal has necessarily an even number of
such limbs. For those which only jump and so move from place
to place do not need limbs for this movement at least, but those
1993
which not only jump but also need to walk, finding that
movement not sufficient for their purposes, evidently either are
better able to progress with even limbs or cannot otherwise
progress at all every animal which has limbs must have an even
us for as this kind of movement is effected by part of the body
at a time, and not by the whole at once as in the movement of
leaping, some of the limbs must in turn remain at rest, and
others be moved, and the animal must act in each of these
cases with opposite limbs, shifting the weight from the limbs
that are being moved to those at rest. And so nothing can walk
on three limbs or on one; in the latter case it has no support at
all on which to rest the body's weight, in the former only in
respect of one pair of opposites, and so it must necessarily fall
in endeavouring so to move.
Polypods however, like the Centipede, can indeed make progress
on an odd number of limbs, as may be seen by the experiment
of wounding one of their limbs; for then the mutilation of one
row of limbs is corrected by the number of limbs which remain
on either side. Such mutilated creatures, however, drag the
wounded limb after them with the remainder, and do not
properly speaking walk. Moreover, it is plain that they, too,
would make the change of place better if they had an even
number, in fact if none were missing and they had the limbs
which correspond to one another. In this way they could
equalize their own weight, and not oscillate to one side, if they
had corresponding supports instead of one section of the
opposite sides being unoccupied by a limb. A walking creature
advances from each of its members alternately, for in this way it
recovers the same figure that it had at first.
1994
The fact that all animals have an even number of feet, and the
reasons for the fact have been set forth. What follows will
explain that if there were no point at rest flexion and
straightening would be impossible. Flexion is a change from a
right line to an arc or an angle, straightening a change from
either of these to a right line. Now in all such changes the
flexion or the straightening must be relative to one point.
Moreover, without flexion there could not be walking or
swimming or flying. For since limbed creatures stand and take
their weight alternately on one or other of the opposite legs, if
one be thrust forward the other of necessity must be bent. For
the opposite limbs are naturally of equal length, and the one
which is under the weight must be a kind of perpendicular at
right angles to the ground.
When then one leg is advanced it becomes the hypotenuse of a
right-angled triangle. Its square then is equal to the square on
the other side together with the square on the base. As the legs
then are equal, the one at rest must bend either at the knee or,
if there were any kneeless animal which walked, at some other
articulation. The following experiment exhibits the fact. If a
man were to walk parallel to a wall in sunshine, the line
described (by the shadow of his head> would be not straight but
zigzag, becoming lower as he bends, and higher when he stands
and lifts himself up.
It is, indeed, possible to move oneself even if the leg be not bent,
in the way in which children crawl. This was the old though
erroneous account of the movement of elephants. But these
kinds of movements involve a flexion in the shoulders or in the
hips. Nothing at any rate could walk upright continuously and
securely without flexions at the knee, but would have to move
like men in the wrestling schools who crawl forward through
1995
the sand on their knees. For the upper part of the upright
creature is long so that its leg has to be correspondingly long; in
consequence there must be flexion. For since a stationary
position is perpendicular, if that which moves cannot bend it
will either fall forward as the right angle becomes acute or will
not be able to progress. For if one leg is at right angles to the
ground and the other is advanced, the latter will be at once
equal and greater. For it will be equal to the stationary leg and
also equivalent to the hypotenuse of a right-angled triangle.
That which goes forward therefore must bend, and while
bending one, extend the other leg simultaneously, so as to
incline forward and make a stride and still remain above the
perpendicular; for the legs form an isosceles triangle, and the
head sinks lower when it is perpendicularly above the base on
which it stands.
Of limbless animals, some progress by undulations (and this
happens in two ways, either they undulate on the ground, like
snakes, or up and down, like caterpillars), and undulation is a
flexion; others by a telescopic action, like what are called
earthworms and leeches. These go forward, first one part
leading and then drawing the whole of the rest of the body up
to this, and so they change from place to place. It is plain too
that if the two curves were not greater than the one line which
subtends them undulating animals could not move themselves;
when the flexure is extended they would not have moved
forward at all if the flexure or arc were equal to the chord
subtended; as it is, it reaches further when it is straightened
out, and then this part stays still and it draws up what is left
behind.
In all the changes described that which moves now extends
itself in a straight line to progress, and now is hooped; it
straightens itself in its leading part, and is hooped in what
follows behind. Even jumping animals all make a flexion in the
1996
part of the body which is underneath, and after this fashion
make their leaps. So too flying and swimming things progress,
the one straightening and bending their wings to fly, the other
their fins to swim. Of the latter some have four fins, others
which are rather long, for example eels, have only two. These
swim by substituting a flexion of the rest of their body for the
(missing) pair of fins to complete the movement, as we have
said before. Flat fish use two fins, and the flat of their body as a
substitute for the absent pair of fins. Quite flat fish, like the Ray,
produce their swimming movement with the actual fins and
with the two extremes or semicircles of their body, bending and
straightening themselves alternately.
10
A difficulty might perhaps be raised about birds. How, it may be
said, can they, either when they fly or when they walk, be said
to move at four points? Now we did not say that all Sanguinea
move at four points, but merely at not more than four.
Moreover, they cannot as a fact fly if their legs be removed, nor
walk without their wings. Even a man does not walk without
moving his shoulders. Everything indeed, as we have said,
makes a change of place by flexion and straightening, for all
things progress by pressing upon what being beneath them up
to a point gives way as it were gradually; accordingly, even if
there be no flexion in another member, there must be at least in
the point whence motion begins, is in feathered (flying) insects
at the base of the 'scale-wing', in birds at the base of the wing,
in others at the base of the corresponding member, the fins, for
instance, in fish. In others, for example snakes, the flexion
begins in the joints of the body.
1997
In winged creatures the tail serves, like a ship's rudder, to keep
the flying thing in its course. The tail then must like other limbs
be able to bend at the point of attachment. And so flying
insects, and birds (Schizoptera) whose tails are ill-adapted for
the use in question, for example peacocks, and domestic cocks,
and generally birds that hardly fly, cannot steer a straight
course. Flying insects have absolutely no tail, and so drift along
like a rudderless vessel, and beat against anything they happen
upon; and this applies equally to sharded insects, like the
scarab-beetle and the chafer, and to unsharded, like bees and
wasps. Further, birds that are not made for flight have a tail that
is of no use; for instance the purple coot and the heron and all
water-fowl. These fly stretching out their feet as a substitute for
a tail, and use their legs instead of a tail to direct their flight.
The flight of insects is slow and frail because the character of
their feathery wings is not proportionate to the bulk of their
body; this is heavy, their wings small and frail, and so the flight
they use is like a cargo boat attempting to make its voyage with
oars; now the frailty both of the actual wings and of the
outgrowths upon them contributes in a measure to the flight
described. Among birds, the peacock's tail is at one time useless
because of its size, at another because it is shed. But birds are in
general at the opposite pole to flying insects as regards their
feathers, but especially the swiftest flyers among them. (These
are the birds with curved talons, for swiftness of wing is useful
to their mode of life.) The rest of their bodily structure is in
harmony with their peculiar movement, the small head, the
slight neck, the strong and acute breastbone (acute like the
prow of a clipper-built vessel, so as to be well-girt, and strong by
dint of its mass of flesh), in order to be able to push away the air
that beats against it, and that easily and without exhaustion.
The hind-quarters, too, are light and taper again, in order to
conform to the movement of the front and not by their breadth
to suck the air.
1998
11
So much then for these questions. But why an animal that is to
stand erect must necessarily be not only a biped, but must also
have the superior parts of the body lighter, and those that lie
under these heavier, is plain. Only if situated like this could it
possibly carry itself easily. And so man, the only erect animal,
has legs longer and stouter relatively to the upper parts of his
body than any other animal with legs. What we observe in
children also is evidence of this. Children cannot walk erect
because they are always dwarf-like, the upper parts of their
bodies being longer and stouter than the lower. With advancing
years the lower increase disproportionately, until the children
get their appropriate size, and then and not till then they
succeed in walking erect. Birds are hunchbacked yet stand on
two legs because their weight is set back, after the principle of
horses fashioned in bronze with their forelegs prancing. But
their being bipeds and able to stand is above all due to their
having the hip-bone shaped like a thigh, and so large that it
looks as if they had two thighs, one in the leg before the knee-
joint, the other joining his part to the fundament. Really this is
not a thigh but a hip, and if it were not so large the bird could
not be a biped. As in a man or a quadruped, the thigh and the
rest of the leg would be attached immediately to quite a small
hip; consequently the whole body would be tilted forward. As it
is, however, the hip is long and extends right along to the
middle of the belly, so that the legs are attached at that point
and carry as supports the whole frame. It is also evident from
these considerations that a bird cannot possibly be erect in the
sense in which man is. For as it holds its body now the wings
are naturally useful to it, but if it were erect they would be as
1999
useless as the wings of Cupids we see in pictures. It must have
been clear as soon as we spoke that the form of no human nor
any similar being permits of wings; not only because it would,
though Sanguineous, be moved at more than four points, but
also because to have wings would be useless to it when moving
naturally. And Nature makes nothing contrary to her own
nature.
12
We have stated above that without flexion in the legs or
shoulders and hips no Sanguineous animal with feet could
progress, and that flexion is impossible except some point be at
rest, and that men and birds, both bipeds, bend their legs in
opposite directions, and further that quadrupeds bend their in
opposite directions, and each pair in the opposite way to a
man's limbs. For men bend their arms backwards, their legs
forwards; quadrupeds their forelegs forwards, their back legs
backwards, and in like manner also birds bend theirs. The
reason is that Nature's workmanship is never purposeless, as
we said above, but everything for the best possible in the
circumstances. Inasmuch, therefore, as all creatures which
naturally have the power of changing position by the use of
limbs, must have one leg stationary with the weight of the body
on it, and when they move forward the leg which has the
leading position must be unencumbered, and the progression
continuing the weight must shift and be taken off on this
leading leg, it is evidently necessary for the back leg from being
bent to become straight again, while the point of movement of
the leg thrust forward and its lower part remain still. And so the
legs must be jointed. And it is possible for this to take place and
at the same time for the animal to go forward, if the leading leg
2000
has its articulation forwards, impossible if it be backwards. For,
if it be forwards, the stretching out of the leg will be while the
body is going forwards, but, if the other way, while it is going
backwards. And again, if the flexion were backwards, the
placing of the foot would be made by two movements and those
contrary to one another, one, that is, backwards and one
forwards; for in the bending together of the limb the lower end
of the thigh would go backwards, and the shin would move the
foot forwards away from the flexion; whereas, with the flexion
forwards, the progression described will be performed not with
contrary motions, but with one forward motion.
Now man, being a biped and making his change of position in
the natural way with his two legs, bends them forward for the
reasons set forth, but his arms bend backwards reasonably
enough. If they bent the opposite way they would be useless for
the work of the hands, and for taking food. But quadrupeds
which are also viviparous necessarily bend their front legs
forwards. For these lead off first when they move, and are also
in the forepart of their body. The reason that they bend forward
is the same as in the case of man, for in this respect they are
like mankind. And so quadrupeds as well as men bend these
legs forward in the manner described. Moreover, if the flexion is
like this, they are enabled to lift their feet high; if they bent
them in the opposite way they would only lift them a little way
from the ground, because the whole thigh and the joint from
which the shin-bone springs would lie under the belly as the
beast moved forward. If, however, the flexion of the hind legs
were forwards the lifting of these feet would be similar to that
of the forefeet (for the hind legs, too, would in this case have
only a little room for their lifting inasmuch as both the thigh
and the knee-joint would fall under the position of the belly);
but the flexion being backwards, as in fact it is, nothing comes
in the way of their progression with this mode of moving the
feet. Moreover, it is necessary or at least better for their legs to
2001
bend thus when they are suckling their young, with a view to
such ministrations. If the flexion were inwards it would be
difficult to keep their young under them and to shelter them.
13
Now there are four modes of flexion if we take the
combinations in pairs. Fore and hind may bend either both
backwards, as the figures marked A, or in the opposite way both
forwards, as in B, or in converse ways and not in the same
direction, as in C where the fore bend forwards and the hind
bend backwards, or as in D, the opposite way to C, where the
convexities are turned towards one another and the concavities
outwards. Now no biped or quadruped bends his limbs like the
figures A or B, but the quadrupeds like C, and like D only the
elephant among quadrupeds and man if you consider his arms
as well as his legs. For he bends his arms concavely and his legs
convexly.
In man, too, the flexions of the limbs are always alternately
opposite, for example the elbow bends back, but the wrist of the
hand forwards, and again the shoulder forwards. In like fashion,
too, in the case of the legs, the hip backwards, the knee
forwards, the ankle in the opposite way backwards. And plainly
the lower limbs are opposed in this respect to the upper,
because the first joints are opposites, the shoulder bending
forwards, the hip backwards; wherefore also the ankle bends
backwards, and the wrist of the hand forwards.
2002
14
This is the way then the limbs bend, and for the reasons given.
But the hind limbs move criss-cross with the fore limbs; after
the off fore they move the near hind, then the near fore, and
then the off hind. The reason is that (a) if they moved the
forelegs together and first, the animal would be wrenched, and
the progression would be a stumbling forwards with the hind
parts as it were dragged after. Again, that would not be walking
but jumping, and it is hard to make a continuous change of
place, jumping all the time. Here is evidence of what I say; even
as it is, all horses that move in this way soon begin to refuse, for
example the horses in a religious procession. For these reasons
the fore limbs and the hind limbs move in this separate way.
Again, (b) if they moved both the right legs first the weight
would be outside the supporting limbs and they would fall. If
then it is necessary to move in one or other of these ways or
criss-cross fashion, and neither of these two is satisfactory, they
must move criss-cross; for moving in the way we have said they
cannot possibly experience either of these untoward results.
And this is why horses and such-like animals stand still with
their legs put forward criss-cross, not with the right or the left
put forward together at once. In the same fashion animals with
more than four legs make their movements; if you take two
consecutive pairs of legs the hind move criss-cross with the
forelegs; you can see this if you watch them moving slowly.
Even crabs move in this way, and they are polypods. They, too,
always move criss-cross in whichever direction they are making
progress. For in direction this animal has a movement all its
own; it is the only animal that moves not forwards, but
obliquely. Yet since forwards is a distinction relative to the line
of vision, Nature has made its eyes able to conform to its limbs,
for its eyes can move themselves obliquely, and therefore after a
fashion crabs are no exception but in this sense move forwards.
2003
15
Birds bend their legs in the same way as quadrupeds. For their
natural construction is broadly speaking nearly the same. That
is, in birds the wings are a substitute for the forelegs; and so
they are bent in the same way as the forelegs of a quadruped,
since when they move to progress the natural beginning of
change is from the wings (as in quadrupeds from the forelegs).
Flight in fact is their appropriate movement. And so if the wings
be cut off a bird can neither stand still nor go forwards.
Again, the bird though a biped is not erect, and has the forward
parts of the body lighter than the hind, and so it is necessary (or
at least preferable for the standing posture) to have the thigh so
placed below the body as it actually is, I mean growing towards
the back. If then it must have this situation the flexion of the leg
must be backwards, as in the hind legs of quadrupeds. The
reasons are the same as those given in the case of viviparous
quadrupeds.
If now we survey generally birds and winged insects, and
animals which swim in a watery medium, all I mean that make
their progress in water by dint of organs of movement, it is not
difficult to see that it is better to have the attachment of the
parts in question oblique to the frame, exactly as in fact we see
it to be both in birds and insects. And this same arrangement
obtains also among fishes. Among birds the wings are attached
obliquely; so are the fins in water animals, and the feather-like
wings of insects. In this way they divide the air or water most
quickly and with most force and so effect their movement. For
the hinder parts in this way would follow forwards as they are
2004
carried along in the yielding medium, fish in the water, birds in
the air.
Of oviparous quadrupeds all those that live in holes, like
crocodiles, lizards, spotted lizards, freshwater tortoises, and
turtles, have their legs attached obliquely as their whole body
sprawls over the ground, and bend them obliquely. The reason is
that this is useful for ease in creeping into holes, and for sitting
upon their eggs and guarding them. And as they are splayed
outwards they must of necessity tuck in their thighs and put
them under them in order to achieve the lifting of the whole
body. In view of this they cannot bend them otherwise than
outwards.
16
We have already stated the fact that non-sanguineous animals
with limbs are polypods and none of them quadrupeds. And the
reason why their legs, except the extreme pairs, were
necessarily attached obliquely and had their flexions upwards,
and the legs themselves were somewhat turned under (bandy-
shape) and backwards is plain. In all such creatures the
intermediate legs both lead and follow. If then they lay under
them, they must have had their flexion both forwards and
backwards; on account of leading, forwards; and on account of
following, backwards. Now since they have to do both, for this
reason their limbs are turned under and bent obliquely, except
the two extreme pairs. (These two are more natural in their
movement, the front leading and the back following.) Another
reason for this kind of flexion is the number of their legs;
arranged in this way they would interfere less with one another
in progression and not knock together. But the reason that they
2005
are bandy is that all of them or most of them live in holes, for
creatures living so cannot possibly be high above the ground.
But crabs are in nature the oddest of all polypods; they do not
progress forwards except in the sense explained above, they are
the only animals which have more than one pair of leading
limbs. The explanation of this is the hardness of their limbs,
and the fact that they use them not for swimming but for
walking; they always keep on the ground. However, the flexion
of the limbs of all polypods is oblique, like that of the
quadrupeds which live in holes - for example lizards and
crocodiles and most of the oviparous quadrupeds. And the
explanation is that some of them in their breeding periods, and
some all their life, live in holes.
17
Now the rest have bandy legs because they are soft-skinned, but
the crayfish is hard-skinned and its limbs are for swimming and
not for walking (and so are not bandy). Crabs, too, have their
limbs bent obliquely, but not bandy like oviparous quadrupeds
and non-sanguineous polypods, because their limbs have a hard
and shell-like skin, although they don't swim but live in holes;
they live in fact on the ground. Moreover, their shape is like a
disk, as compared with the crayfish which is elongated, and
they haven't a tail like the crayfish; a tail is useful to the
crayfish for swimming, but the crab is not a swimming creature.
Further, it alone has its side equivalent to a hinder part, because
it has many leading feet. The explanation of this is that its
flexions are not forward nor its legs turned in under (bandy). We
have given above the reason why its legs are not turned in
2006
under, that is the hardness and shell-like character of its
integument.
For these reasons then it must lead off with more than one
limb, and move obliquely; obliquely, because the flexion is
oblique; and with more than one limb, because otherwise the
limbs that were still would have got in the way of those that
were moving.
Fishes of the flat kind swim with their heads twisted, as one-
eyed men walk; they have their natural shape distorted. Web-
footed birds swim with their feet; because they breath the air
and have lungs they are bipeds, but because they have their
home in the water they are webbed; by this arrangement their
feet serve them instead of fins. They have their legs too, not like
the rest of birds in the centre of their body, but rather set back.
Their legs are short, and being set back are serviceable for
swimming. The reason for their having short legs is that nature
has added to their feet by subtracting from the length of their
limbs; instead of length she gives stoutness to the legs and
breadth to the feet. Broad feet are more useful than long for
pushing away the water when they are swimming.
18
There is reason, too, for winged creatures having feet, but fish
none. The former have their home in the dry medium, and
cannot remain always in mid air; they must therefore have feet.
Fish on the contrary live in the wet medium, and take in water,
not air. Fins are useful for swimming, but feet not. And if they
had both they would be non-sanguineous. There is a broad
similarity between birds and fishes in the organs of locomotion.
Birds have their wings on the superior part, similarly fish have
2007
two pectoral fins; again, birds have legs on their under parts and
near the wings; similarly, most fish have two fins on the under
parts and near the pectorals. Birds, too, have a tail and fish a
tail-fin.
19
A difficulty may be suggested as to the movements of molluscs,
that is, as to where that movement originates; for they have no
distinction of left and right. Now observation shows them
moving. We must, I think, treat all this class as mutilated, and
as moving in the way in which limbed creatures do when one
cuts off their legs, or as analogous with the seal and the bat.
Both the latter are quadrupeds but misshapen. Now molluscs
do move, but move in a manner contrary to nature. They are not
moving things, but are moving if as sedentary creatures they are
compared with zoophytes, and sedentary if classed with
progressing animals.
As to right and left, crabs, too, show the distinction poorly, still
they do show it. You can see it in the claw; the right claw is
larger and stronger, as though the right and left sides were
trying to get distinguished.
The structure of animals, both in their other parts, and
especially in those which concern progression and any
movement in place, is as we have now described. It remains,
after determining these questions, to investigate the problems
of Life and Death.
2008
Aristotle - On the Generation of Animals
[Translated by Arthur Piatt]
Book I
We have now discussed the other parts of animals, both
generally and with reference to the peculiarities of each kind,
explaining how each part exists on account of such a cause, and
I mean by this the final cause.
There are four causes underlying everything: first, the final
cause, that for the sake of which a thing exists; secondly, the
formal cause, the definition of its essence (and these two we
may regard pretty much as one and the same); thirdly, the
material; and fourthly, the moving principle or efficient cause.
We have then already discussed the other three causes, for the
definition and the final cause are the same, and the material of
animals is their parts of the whole animal the non-
homogeneous parts, of these again the homogeneous, and of
these last the so-called elements of all matter. It remains to
speak of those parts which contribute to the generation of
animals and of which nothing definite has yet been said, and to
explain what is the moving or efficient cause. To inquire into
this last and to inquire into the generation of each animal is in
a way the same thing; and, therefore, my plan has united them
together, arranging the discussion of these parts last, and the
beginning of the question of generation next to them.
2009
Now some animals come into being from the union of male and
female, i.e. all those kinds of animal which possess the two
sexes. This is not the case with all of them; though in the
sanguinea with few exceptions the creature, when its growth is
complete, is either male or female, and though some bloodless
animals have sexes so that they generate offspring of the same
kind, yet other bloodless animals generate indeed, but not
offspring of the same kind; such are all that come into being not
from a union of the sexes, but from decaying earth and
excrements. To speak generally, if we take all animals which
change their locality, some by swimming, others by flying,
others by walking, we find in these the two sexes, not only in
the sanguinea but also in some of the bloodless animals; and
this applies in the case of the latter sometimes to the whole
class, as the cephalopoda and Crustacea, but in the class of
insects only to the majority. Of these, all which are produced by
union of animals of the same kind generate also after their
kind, but all which are not produced by animals, but from
decaying matter, generate indeed, but produce another kind,
and the offspring is neither male nor female; such are some of
the insects. This is what might have been expected, for if those
animals which are not produced by parents had themselves
united and produced others, then their offspring must have
been either like or unlike to themselves. If like, then their
parents ought to have come into being in the same way; this is
only a reasonable postulate to make, for it is plainly the case
with other animals. If unlike, and yet able to copulate, then
there would have come into being again from them another
kind of creature and again another from these, and this would
have gone on to infinity. But Nature flies from the infinite, for
the infinite is unending or imperfect, and Nature ever seeks an
end.
But all those creatures which do not move, as the testacea and
animals that live by clinging to something else, inasmuch as
2010
their nature resembles that of plants, have no sex any more
than plants have, but as applied to them the word is only used
in virtue of a similarity and analogy. For there is a slight
distinction of this sort, since even in plants we find in the same
kind some trees which bear fruit and others which, while
bearing none themselves, yet contribute to the ripening of the
fruits of those which do, as in the case of the fig-tree and
caprifig.
The same holds good also in plants, some coming into being
from seed and others, as it were, by the spontaneous action of
Nature, arising either from decomposition of the earth or of
some parts in other plants, for some are not formed by
themselves separately but are produced upon other trees, as the
mistletoe. Plants, however, must be investigated separately.
Of the generation of animals we must speak as various
questions arise in order in the case of each, and we must
connect our account with what has been said. For, as we said
above, the male and female principles may be put down first
and foremost as origins of generation, the former as containing
the efficient cause of generation, the latter the material of it.
The most conclusive proof of this is drawn from considering
how and whence comes the semen; for there is no doubt that it
is out of this that those creatures are formed which are
produced in the ordinary course of Nature; but we must observe
carefully the way in which this semen actually comes into being
from the male and female. For it is just because the semen is
secreted from the two sexes, the secretion taking place in them
and from them, that they are first principles of generation. For
2011
by a male animal we mean that which generates in another,
and by a female that which generates in itself; wherefore men
apply these terms to the macrocosm also, naming Earth mother
as being female, but addressing Heaven and the Sun and other
like entities as fathers, as causing generation.
Male and female differ in their essence by each having a
separate ability or faculty, and anatomically by certain parts;
essentially the male is that which is able to generate in another,
as said above; the female is that which is able to generate in
itself and out of which comes into being the offspring
previously existing in the parent. And since they are
differentiated by an ability or faculty and by their function, and
since instruments or organs are needed for all functioning, and
since the bodily parts are the instruments or organs to serve the
faculties, it follows that certain parts must exist for union of
parents and production of offspring. And these must differ from
each other, so that consequently the male will differ from the
female. (For even though we speak of the animal as a whole as
male or female, yet really it is not male or female in virtue of
the whole of itself, but only in virtue of a certain faculty and a
certain part - just as with the part used for sight or locomotion
- which part is also plain to sense-perception.)
Now as a matter of fact such parts are in the female the so-
called uterus, in the male the testes and the penis, in all the
sanguinea; for some of them have testes and others the
corresponding passages. There are corresponding differences of
male and female in all the bloodless animals also which have
this division into opposite sexes. But if in the sanguinea it is the
parts concerned in copulation that differ primarily in their
forms, we must observe that a small change in a first principle
is often attended by changes in other things depending on it.
This is plain in the case of castrated animals, for, though only
the generative part is disabled, yet pretty well the whole form of
2012
the animal changes in consequence so much that it seems to be
female or not far short of it, and thus it is clear than an animal
is not male or female in virtue of an isolated part or an isolated
faculty. Clearly, then, the distinction of sex is a first principle; at
any rate, when that which distinguishes male and female
suffers change, many other changes accompany it, as would be
the case if a first principle is changed.
The sanguinea are not all alike as regards testes and uterus.
Taking the former first, we find that some of them have not
testes at all, as the classes of fish and of serpents, but only two
spermatic ducts. Others have testes indeed, but internally by
the loin in the region of the kidneys, and from each of these a
duct, as in the case of those animals which have no testes at all,
these ducts unite also as with those animals; this applies
(among animals breathing air and having a lung) to all birds and
oviparous quadrupeds. For all these have their testes internal
near the loin, and two ducts from these in the same way as
serpents; I mean the lizards and tortoises and all the scaly
reptiles. But all the vivipara have their testes in front; some of
them inside at the end of the abdomen, as the dolphin, not with
ducts but with a penis projecting externally from them; others
outside, either pendent as in man or towards the fundament as
in swine. They have been discriminated more accurately in the
Enquiries about Animals.
The uterus is always double, just as the testes are always two in
the male. It is situated either near the pudendum (as in women,
and all those animals which bring forth alive not only externally
but also internally, and all fish that lay eggs externally) or up
2013
towards the hypozoma (as in all birds and in viviparous fishes).
The uterus is also double in the Crustacea and the cephalopoda,
for the membranes which include their so-called eggs are of the
nature of a uterus. It is particularly hard to distinguish in the
case of the poulps, so that it seems to be single, but the reason
of this is that the bulk of the body is everywhere similar.
It is double also in the larger insects; in the smaller the question
is uncertain owing to the small size of the body.
Such is the description of the aforesaid parts of animals.
With regard to the difference of the spermatic organs in males,
if we are to investigate the causes of their existence, we must
first grasp the final cause of the testes. Now if Nature makes
everything either because it is necessary or because it is better
so, this part also must be for one of these two reasons. But that
it is not necessary for generation is plain; else had it been
possessed by all creatures that generate, but as it is neither
serpents have testes nor have fish; for they have been seen
uniting and with their ducts full of milt. It remains then that it
must be because it is somehow better so. Now it is true that the
business of most animals is, you may say, nothing else than to
produce young, as the business of a plant is to produce seed and
fruit. But still as, in the case of nutriment, animals with straight
intestines are more violent in their desire for food, so those
which have not testes but only ducts, or which have them
indeed but internally, are all quicker in accomplishing
copulation. But those which are to be more temperate in the
one case have not straight intestines, and in the other have
their ducts twisted to prevent their desire being too violent and
2014
hasty. It is for this that the testes are contrived; for they make
the movement of the spermatic secretion steadier, preserving
the folding back of the passages in the vivipara, as horses and
the like, and in man. (For details see the Enquiries about
Animals.) For the testes are no part of the ducts but are only
attached to them, as women fasten stones to the loom when
weaving; if they are removed the ducts are drawn up internally,
so that castrated animals are unable to generate; if they were
not drawn up they would be able, and before now a bull
mounting immediately after castration has caused conception
in the cow because the ducts had not yet been drawn up. In
birds and oviparous quadrupeds the testes receive the
spermatic secretion, so that its expulsion is slower than in
fishes. This is clear in the case of birds, for their testes are much
enlarged at the time of copulation, and all those which pair at
one season of the year have them so small when this is past
that they are almost indiscernible, but during the season they
are very large. When the testes are internal the act of copulation
is quicker than when they are external, for even in the latter
case the semen is not emitted before the testes are drawn up.
Besides, quadrupeds have the organ of copulation, since it is
possible for them to have it, but for birds and the footless
animals it is not possible, because the former have their legs
under the middle of the abdomen and the latter have no legs at
all; now the penis depends from that region and is situated
there. (Wherefore also the legs are strained in intercourse, both
the penis and the legs being sinewy.) So that, since it is not
possible for them to have this organ, they must necessarily
either have no testes also, or at any rate not have them there, as
2015
those animals that have both penis and testes have them in the
same situation.
Further, with those animals at any rate that have external
testes, the semen is collected together before emission, and
emission is due to the penis being heated by its movement; it is
not ready for emission at immediate contact as in fishes.
All the vivipira have their testes in front, internally or externally,
except the hedgehog; he alone has them near the loin. This is
for the same reason as with birds, because their union must be
quick, for the hedgehog does not, like the other quadrupeds,
mount upon the back of the female, but they conjugate standing
upright because of their spines.
So much for the reasons why those animals have testes which
have them, and why they are sometimes external and
sometimes internal.
All those animals which have no testes are deficient in this part,
as has been said, not because it is better to be so but simply
because of necessity, and secondly because it is necessary that
their copulation should be speedy. Such is the nature of fish and
serpents. Fish copulate throwing themselves alongside of the
females and separating again quickly. For as men and all such
creatures must hold their breath before emitting the semen, so
fish at such times must cease taking in the sea-water, and then
they perish easily. Therefore they must not mature the semen
during copulation, as viviparous land-animals do, but they have
it all matured together before the time, so as not to be maturing
it while in contact but to emit it ready matured. So they have no
2016
testes, and the ducts are straight and simple. There is a small
part similar to this connected with the testes in the system of
quadrupeds, for part of the reflected duct is sanguineous and
part is not; the fluid is already semen when it is received by and
passes through this latter part, so that once it has arrived there
it is soon emitted in these quadrupeds also. Now in fishes the
whole passage resembles the last section of the reflected part of
the duct in man and similar animals.
Serpents copulate twining round one another, and, as said
above, have neither testes nor penis, the latter because they
have no legs, the former because of their length, but they have
ducts like for on account of their extreme length the seminal
fluid would take too long in its passage and be cooled if it were
further delayed by testes. (This happens also if the penis is
large; such men are less fertile than when it is smaller because
the semen, if cold, is not generative, and that which is carried
too far is cooled.) So much for the reason why some animals
have testes and others not. Serpents intertwine because of their
inaptitude to cast themselves alongside of one another. For they
are too long to unite closely with so small a part and have no
organs of attachment, so they make use of the suppleness of
their bodies, intertwining. Wherefore also they seem to be
slower in copulation than fish, not only on account of the
length of the ducts but also of this elaborate arrangement in
uniting.
2017
8
It is not easy to state the facts about the uterus in female
animals, for there are many points of difference. The vivipara
are not alike in this part; women and all the vivipara with feet
have the uterus low down by the pudendum, but the
cartilaginous viviparous fish have it higher up near the
hypozoma. In the ovipara, again, it is low in fish (as in women
and the viviparous quadrupeds), high in birds and all oviparous
quadrupeds. Yet even these differences are on a principle. To
begin with the ovipara, they differ in the manner of laying their
eggs, for some produce them imperfect, as fishes whose eggs
increase and are finally developed outside of them. The reason
is that they produce many young, and this is their function as it
is with plants. If then they perfected the egg in themselves they
must needs be few in number, but as it is, they have so many
that each uterus seems to be an egg, at any rate in the small
fishes. For these are the most productive, just as with the other
animals and plants whose nature is analogous to theirs, for the
increase of size turns with them to seed.
But the eggs of birds and the quadrupedal ovipara are perfect
when produced. In order that these may be preserved they must
have a hard covering (for their envelope is soft so long as they
are increasing in size), and the shell is made by heat squeezing
out the moisture for the earthy material; consequently the place
must be hot in which this is to happen. But the part about the
hypozoma is hot, as is shown by that being the part which
concocts the food. If then the eggs must be within the uterus,
then the uterus must be near the hypozoma in those creatures
which produce their eggs in a perfect form. Similarly it must be
low down in those which produce them imperfect, for it is
profitable that it should be so. And it is more natural for the
uterus to be low down than high up, when Nature has no other
business in hand to hinder it; for its end is low down, and where
2018
is the end, there is the function, and the uterus itself is
naturally where the function is.
We find differences in the vivipara also as compared with one
another. Some produce their young alive, not only externally,
but also internally, as men, horses, dogs, and all those which
have hair, and among aquatic animals, dolphins, whales, and
such cetacea.
10
But the cartilaginous fish and the vipers produce their young
alive externally, but first produce eggs internally. The egg is
perfect, for so only can an animal be generated from an egg, and
nothing comes from an imperfect one. It is because they are of a
cold nature, not hot as some assert, that they do not lay their
eggs externally.
11
At least they certainly produce their eggs in a soft envelope, the
reason being that they have but little heat and so their nature
does not complete the process of drying the egg-shell. Because,
then, they are cold they produce soft-shelled eggs, and because
2019
the eggs are soft they do not produce them externally; for that
would have caused their destruction.
The process is for the most part the same as in birds, for the egg
descends and the young is hatched from it near the vagina,
where the young is produced in those animals which are
viviparous from the beginning. Therefore in such animals the
uterus is dissimilar to that of both the vivipara and ovipara,
because they participate in both classes; for it is at once near
the hypozoma and also stretching along downwards in all the
cartilaginous fishes. But the facts about this and the other kinds
of uterus must be gathered from inspection of the drawings of
dissections and from the Enquiries. Thus, because they are
oviparous, laying perfect eggs, they have the uterus placed high,
but, as being viviparous, low, participating in both classes.
Animals that are viviparous from the beginning all have it low,
Nature here having no other business to interfere with her, and
their production having no double character. Besides this, it is
impossible for animals to be produced alive near the hypozoma,
for the foetus must needs be heavy and move, and that region
in the mother is vital and would not be able to bear the weight
and the movement. Thirdly, parturition would be difficult
because of the length of the passage to be traversed; even as it
is there is difficulty with women if they draw up the uterus in
parturition by yawning or anything of the kind, and even when
empty it causes a feeling of suffocation if moved upwards. For if
a uterus is to hold a living animal it must be stronger than in
ovipara, and therefore in all the vivipara it is fleshy, whereas
when the uterus is near the hypozoma it is membranous. And
this is clear also in the case of the animals which produce
young by the mixed method, for their eggs are high up and
sideways, but the living young are produced in the lower part of
the uterus.
2020
So much for the reason why differences are found in the uterus
of various animals, and generally why it is low in some and high
in others near the hypozoma.
12
Why is the uterus always internal, but the testes sometimes
internal, sometimes external? The reason for the uterus always
being internal is that in this is contained the egg or foetus,
which needs guarding, shelter, and maturation by concoction,
while the outer surface of the body is easily injured and cold.
The testes vary in position because they also need shelter and a
covering to preserve them and to mature the semen; for it
would be impossible for them, if chilled and stiffened, to be
drawn up and discharge it. Therefore, whenever the testes are
visible, they have a cuticular covering known as the scrotum. If
the nature of the skin is opposed to this, being too hard to be
adapted for enclosing them or for being soft like a true 'skin', as
with the scaly integument of fish and reptiles, then the testes
must needs be internal. Therefore they are so in dolphins and
all the cetacea which have them, and in the oviparous
quadrupeds among the scaly animals. The skin of birds also is
hard so that it will not conform to the size of anything and
enclose it neatly. (This is another reason with all these animals
for their testes being internal besides those previously
mentioned as arising necessarily from the details of copulation.)
For the same reason they are internal in the elephant and
hedgehog, for the skin of these, too, is not well suited to keep
the protective part separate.
[The position of the uterus differs in animals viviparous within
themselves and those externally oviparous, and in the latter
2021
class again it differs in those which have the uterus low and
those which have it near the hypozoma, as in fishes compared
with birds and oviparous quadrupeds. And it is different again
in those which produce young in both ways, being oviparous
internally and viviparous externally. For those which are
viviparous both internally and externally have the uterus placed
on the abdomen, as men, cattle, dogs, and the like, since it is
expedient for the safety and growth of the foetus that no weight
should be upon the uterus.]
13
The passages also are different through which the solid and
liquid excreta pass out in all the vivipara. Wherefore both males
and females in this class all have a part whereby the urine is
voided, and this serves also for the issue of the semen in males,
of the offspring in females. This passage is situated above and
in front of the passage of the solid excreta. The passage is the
same as that of the solid nutriment in all those animals that
have no penis, in all the ovipara, even those of them that have a
bladder, as the tortoises. For it is for the sake of generation, not
for the evacuation of the urine, that the passages are double;
but because the semen is naturally liquid, the liquid excretion
also shares the same passage. This is clear from the fact that all
animals produce semen, but all do not void liquid excrement.
Now the spermatic passages of the male must be fixed and
must not wander, and the same applies to the uterus of the
female, and this fixing must take place at either the front or the
back of the body. To take the uterus first, it is in the front of the
body in vivipara because of the foetus, but at the loin and the
back in ovipara. All animals which are internally oviparous and
externally viviparous are in an intermediate condition because
2022
they participate in both classes, being at once oviparous and
viviparous. For the upper part of the uterus, where the eggs are
produced, is under the hypozoma by the loin and the back, but
as it advances is low at the abdomen; for it is in that part that
the animal is viviparous. In these also the passage for solid
excrement and for copulation is the same, for none of these, as
has been said already, has a separate pudendum.
The same applies to the passages in the male, whether they
have testes or no, as to the uterus of the ovipara. For in all of
them, not only in the ovipara, the ducts adhere to the back and
the region of the spine. For they must not wander but be settled,
and that is the character of the region of the back, which gives
continuity and stability. Now in those which have internal
testes, the ducts are fixed from the first, and they are fixed in
like manner if the testes are external; then they meet together
towards the region of the penis.
The like applies to the ducts in the dolphins, but they have their
testes hidden under the abdominal cavity.
We have now discussed the situation of the parts contributing
to generation, and the causes thereof.
14
The bloodless animals do not agree either with the sanguinea or
with each other in the fashion of the parts contributing to
generation. There are four classes still left to deal with, first the
Crustacea, secondly the cephalopoda, thirdly the insects, and
fourthly the testacea. We cannot be certain about all of them,
but that most of them copulate is plain; in what manner they
unite must be stated later.
2023
The Crustacea copulate like the retromingent quadrupeds,
fitting their tails to one another, the one supine and the other
prone. For the flaps attached to the sides of the tail being long
prevent them from uniting with the belly against the back. The
males have fine spermatic ducts, the females a membranous
uterus alongside the intestine, cloven on each side, in which the
egg is produced.
15
The cephalopoda entwine together at the mouth, pushing
against one another and enfolding their arms. This attitude is
necessary, because Nature has bent backwards the end of the
intestine and brought it round near the mouth, as has been said
before in the treatise on the parts of animals. The female has a
part corresponding to the uterus, plainly to be seen in each of
these animals, for it contains an egg which is at first indivisible
to the eye but afterwards splits up into many; each of these eggs
is imperfect when deposited, as with the oviparous fishes. In
the cephalopoda (as also in the Crustacea) the same passage
serves to void the excrement and leads to the part like a uterus,
for the male discharges the seminal fluid through this passage.
And it is on the lower surface of the body, where the mantle is
open and the sea-water enters the cavity. Hence the union of
the male with the female takes place at this point, for it is
necessary, if the male discharges either semen or a part of
himself or any other force, that he should unite with her at the
uterine passage. But the insertion, in the case of the poulps, of
the arm of the male into the funnel of the female, by which arm
the fishermen say the male copulates with her, is only for the
sake of attachment, and it is not an organ useful for generation,
2024
for it is outside the passage in the male and indeed outside the
body of the male altogether.
Sometimes also cephalopoda unite by the male mounting on
the back of the female, but whether for generation or some
other cause has not yet been observed.
16
Some insects copulate and the offspring are produced from
animals of the same name, just as with the sanguinea; such are
the locusts, cicadae, spiders, wasps, and ants. Others unite
indeed and generate; but the result is not a creature of the same
kind, but only a scolex, and these insects do not come into
being from animals but from putrefying matter, liquid or solid;
such are fleas, flies, and cantharides. Others again are neither
produced from animals nor unite with each other; such are
gnats, 'conopes', and many similar kinds. In most of those
which unite the female is larger than the male. The males do
not appear to have spermatic passages. In most cases the male
does not insert any part into the female, but the female from
below upwards into the male; this has been observed in many
cases (as also that the male mounts the female), the opposite in
few cases; but observations are not yet comprehensive enough
to enable us to make a distinction of classes. And generally it is
the rule with most of the oviparous fish and oviparous
quadrupeds that the female is larger than the because this is
expedient in view of the increase of bulk in conception by
reason of the eggs. In the female the part analogous to the
uterus is cleft and extends along the intestine, as with the other
animals; in this are produced the results of conception. This is
2025
clear in locusts and all other large insects whose nature it is to
unite; most insects are too small to be observed in this respect.
Such is the character of the generative organs in animals which
were not spoken of before. It remains now to speak of the
homogeneous parts concerned, the seminal fluid and milk. We
will take the former first, and treat of milk afterwards.
17
Some animals manifestly emit semen, as all the sanguinea, but
whether the insects and cephalopoda do so is uncertain.
Therefore this is a question to be considered, whether all males
do so, or not all; and if not all, why some do and some not; and
whether the female also contributes any semen or not; and, if
not semen, whether she does not contribute anything else
either, or whether she contributes something else which is not
semen. We must also inquire what those animals which emit
semen contribute by means of it to generation, and generally
what is the nature of semen, and of the so-called catamenia in
all animals which discharge this liquid.
Now it is thought that all animals are generated out of semen,
and that the semen comes from the parents. Wherefore it is
part of the same inquiry to ask whether both male and female
produce it or only one of them, and to ask whether it comes
from the whole of the body or not from the whole; for if the
latter is true it is reasonable to suppose that it does not come
from both parents either. Accordingly, since some say that it
comes from the whole of the body, we must investigate this
question first.
2026
The proofs from which it can be argued that the semen comes
from each and every part of the body may be reduced to four.
First, the intensity of the pleasure of coition; for the same state
of feeling is more pleasant if multiplied, and that which affects
all the parts is multiplied as compared with that which affects
only one or a few. Secondly, the alleged fact that mutilations are
inherited, for they argue that since the parent is deficient in this
part the semen does not come from thence, and the result is
that the corresponding part is not formed in the offspring.
Thirdly, the resemblances to the parents, for the young are born
like them part for part as well as in the whole body; if then the
coming of the semen from the whole body is cause of the
resemblance of the whole, so the parts would be like because it
comes from each of the parts. Fourthly, it would seem to be
reasonable to say that as there is some first thing from which
the whole arises, so it is also with each of the parts, and
therefore if semen or seed is cause of the whole so each of the
parts would have a seed peculiar to itself. And these opinions
are plausibly supported by such evidence as that children are
born with a likeness to their parents, not in congenital but also
in acquired characteristics; for before now, when the parents
have had scars, the children have been born with a mark in the
form of the scar in the same place, and there was a case at
Chalcedon where the father had a brand on his arm and the
letter was marked on the child, only confused and not clearly
articulated. That is pretty much the evidence on which some
believe that the semen comes from all the body.
18
On examining the question, however, the opposite appears
more likely, for it is not hard to refute the above arguments and
2027
the view involves impossibilities. First, then, the resemblance of
children to parents is no proof that the semen comes from the
whole body, because the resemblance is found also in voice,
nails, hair, and way of moving, from which nothing comes. And
men generate before they yet have certain characters, such as a
beard or grey hair. Further, children are like their more remote
ancestors from whom nothing has come, for the resemblances
recur at an interval of many generations, as in the case of the
woman in Elis who had intercourse with the Aethiop; her
daughter was not an Aethiop but the son of that daughter was.
The same thing applies also to plants, for it is clear that if this
theory were true the seed would come from all parts of plants
also; but often a plant does not possess one part, and another
part may be removed, and a third grows afterwards. Besides, the
seed does not come from the pericarp, and yet this also comes
into being with the same form as in the parent plant.
We may also ask whether the semen comes from each of the
homogeneous parts only, such as flesh and bone and sinew, or
also from the heterogeneous, such as face and hands. For if
from the former only, we object that resemblance exists rather
in the heterogeneous parts, such as face and hands and feet; if
then it is not because of the semen coming from all parts that
children resemble their parents in these, what is there to stop
the homogeneous parts also from being like for some other
reason than this? If the semen comes from the heterogeneous
alone, then it does not come from all parts; but it is more fitting
that it should come from the homogeneous parts, for they are
prior to the heterogeneous which are composed of them; and as
children are born like their parents in face and hands, so they
are, necessarily, in flesh and nails. If the semen comes from
both, what would be the manner of generation? For the
heteroeneous parts are composed of the homogneous, so that to
come from the former would be to come from the latter and
from their composition. To make this clearer by an illustration,
2028
take a written name; if anything came from the whole of it, it
would be from each of the syllables, and if from these, from the
letters and their composition. So that if really flesh and bones
are composed of fire and the like elements, the semen would
come rather from the elements than anything else, for how can
it come from their composition? Yet without this composition
there would be no resemblance. If again something creates this
composition later, it would be this that would be the cause of
the resemblance, not the coming of the semen from every part
of the body.
Further, if the parts of the future animal are separated in the
semen, how do they live? and if they are connected, they would
form a small animal.
And what about the generative parts? For that which comes
from the male is not similar to what comes from the female.
Again, if the semen comes from all parts of both parents alike,
the result is two animals, for the offspring will have all the parts
of both. Wherefore Empedocles seems to say what agrees pretty
well with this view (if we are to adopt it), to a certain extent at
any rate, but to be wrong if we think otherwise. What he says
agrees with it when he declares that there is a sort of tally in
the male and female, and that the whole offspring does not
come from either, 'but sundered is the fashion of limbs, some in
man's...' For why does not the female generate from herself if
the semen comes from all parts alike and she has a receptacle
ready in the uterus? But, it seems, either it does not come from
all the parts, or if it does it is in the way Empedocles says, not
the same parts coming from each parent, which is why they
need intercourse with each other.
Yet this also is impossible, just as much as it is impossible for
the parts when full grown to survive and have life in them
when torn apart, as Empedocles accounts for the creation of
2029
animals; in the time of his 'Reign of Love', says he, 'many heads
sprang up without necks,' and later on these isolated parts
combined into animals. Now that this is impossible is plain, for
neither would the separate parts be able to survive without
having any soul or life in them, nor if they were living things, so
to say, could several of them combine so as to become one
animal again. Yet those who say that semen comes from the
whole of the body really have to talk in that way, and as it
happened then in the earth during the 'Reign of Love', so it
happens according to them in the body. Now it is impossible
that the parts should be united together when they come into
being and should come from different parts of the parent,
meeting together in one place. Then how can the upper and
lower, right and left, front and back parts have been 'sundered?
All these points are unintelligible. Further, some parts are
distinguished by possessing a faculty, others by being in certain
states or conditions; the heterogeneous, as tongue and hand, by
the faculty of doing something, the homogeneous by hardness
and softness and the other similar states. Blood, then, will not
be blood, nor flesh flesh, in any and every state. It is clear, then,
that that which comes from any part, as blood from blood or
flesh from flesh, will not be identical with that part. But if it is
something different from which the blood of the offspring
comes, the coming of the semen from all the parts will not be
the cause of the resemblance, as is held by the supporters of
this theory. For if blood is formed from something which is not
blood, it is enough that the semen come from one part only, for
why should not all the other parts of the offspring as well as
blood be formed from one part of the parent? Indeed, this
theory seems to be the same as that of Anaxagoras, that none of
the homogeneous parts come into being, except that these
theorists assume, in the case of the generation of animals, what
he assumed of the universe.
2030
Then, again, how will these parts that came from all the body of
the parent be increased or grow? It is true that Anaxagoras
plausibly says that particles of flesh out of the food are added to
the flesh. But if we do not say this (while saying that semen
comes from all parts of the body), how will the foetus become
greater by the addition of something else if that which is added
remain unchanged? But if that which is added can change, then
why not say that the semen from the very first is of such a kind
that blood and flesh can be made out of it, instead of saying
that it itself is blood and flesh? Nor is there any other
alternative, for surely we cannot say that it is increased later by
a process of mixing, as wine when water is poured into it. For in
that case each element of the mixture would be itself at first
while still unmixed, but the fact rather is that flesh and bone
and each of the other parts is such later. And to say that some
part of the semen is sinew and bone is quite above us, as the
saying is.
Besides all this there is a difficulty if the sex is determined in
conception (as Empedocles says: 'it is shed in clean vessels;
some wax female, if they fall in with cold'). Anyhow, it is plain
that both men and women change not only from infertile to
fertile, but also from bearing female to bearing male offspring,
which looks as if the cause does not lie in the semen coming
from all the parent or not, but in the mutual proportion or
disproportion of that comes from the woman and the man, or in
something of this kind. It is clear, then, if we are to put this
down as being so, that the female sex is not determined by the
semen coming from any particular part, and consequently
neither is the special sexual part so determined (if really the
same semen can become either male or female child, which
shows that the sexual part does not exist in the semen). Why,
then, should we assert this of this part any more than of others?
For if semen does not come from this part, the uterus, the same
account may be given of the others.
2031
Again, some creatures come into being neither from parents of
the same kind nor from parents of a different kind, as flies and
the various kinds of what are called fleas; from these are
produced animals indeed, but not in this case of similar nature
but a kind of scolex. It is plain in this case that the young of a
different kind are not produced by semen coming from all parts
of the parent, for they would then resemble them, if indeed
resemblance is a sign of its coming from all parts.
Further even among animals some produce many young from a
single coition (and something like this is universal among
plants, for it is plain that they bear all the fruit of a whole
season from a single movement). And yet how would this be
possible if the semen were secreted from all the body? For from
a single coition and a single segregation of the semen scattered
throughout the body must needs follow only a single secretion.
Nor is it possible for it to be separated in the uterus, for this
would no longer be a mere separation of semen, but, as it were,
a severance from a new plant or animal.
Again, the cuttings from a plant bear seed; clearly, therefore,
even before they were cut from the parent plant, they bore their
fruit from their own mass alone, and the seed did not come
from all the plant.
But the greatest proof of all is derived from observations we
have sufficiently established on insects. For, if not in all, at least
in most of these, the female in the act of copulation inserts a
part of herself into the male. This, as we said before, is the way
they copulate, for the females manifestly insert this from below
into the males above, not in all cases, but in most of those
observed. Hence it seems clear that, when the males do emit
semen, then also the cause of the generation is not its coming
from all the body, but something else which must be
investigated hereafter. For even if it were true that it comes
2032
from all the body, as they say, they ought not to claim that it
comes from all parts of it, but only from the creative part - from
the workman, so to say, not the material he works in. Instead of
that, they talk as if one were to say that the semen comes from
the shoes, for, generally speaking, if a son is like his father, the
shoes he wears are like his father's shoes.
As to the vehemence of pleasure in sexual intercourse, it is not
because the semen comes from all the body, but because there
is a strong friction (wherefore if this intercourse is often
repeated the pleasure is diminished in the persons concerned).
Moreover, the pleasure is at the end of the act, but it ought, on
the theory, to be in each of the parts, and not at the same time,
but sooner in some and later in others.
If mutilated young are born of mutilated parents, it is for the
same reason as that for which they are like them. And the
young of mutilated parents are not always mutilated, just as
they are not always like their parents; the cause of this must be
inquired into later, for this problem is the same as that.
Again, if the female does not produce semen, it is reasonable to
suppose it does not come from all the body of the male either.
Conversely, if it does not come from all the male it is not
unreasonable to suppose that it does not come from the female,
but that the female is cause of the generation in some other
way. Into this we must next inquire, since it is plain that the
semen is not secreted from all the parts.
In this investigation and those which follow from it, the first
thing to do is to understand what semen is, for then it will be
easier to inquire into its operations and the phenomena
connected with it. Now the object of semen is to be of such a
nature that from it as their origin come into being those things
which are naturally formed, not because there is any agent
which makes them from it as simply because this is the semen.
2033
Now we speak of one thing coming from another in many
senses; it is one thing when we say that night comes from day
or a man becomes man from boy, meaning that A follows B; it is
another if we say that a statue is made from bronze and a bed
from wood, and so on in all the other cases where we say that
the thing made is made from a material, meaning that the
whole is formed from something preexisting which is only put
into shape. In a third sense a man becomes unmusical from
being musical, sick from being well, and generally in this sense
contraries arise from contraries. Fourthly, as in the 'climax' of
Epicharmus; thus from slander comes railing and from this
fighting, and all these are from something in the sense that it is
the efficient cause. In this last class sometimes the efficient
cause is in the things themselves, as in the last mentioned (for
the slander is a part of the whole trouble), and sometimes
external, as the art is external to the work of art or the torch to
the burning house. Now the offspring comes from the semen,
and it is plainly in one of the two following senses that it does
so - either the semen is the material from which it is made, or it
is the first efficient cause. For assuredly it is not in the sense of
A being after B, as the voyage comes from, i.e. after, the
Panathenaea; nor yet as contraries come from contraries, for
then one of the two contraries ceases to be, and a third
substance must exist as an immediate underlying basis from
which the new thing comes into being. We must discover then,
in which of the two other classes the semen is to be put,
whether it is to be regarded as matter, and therefore acted upon
by something else, or as a form, and therefore acting upon
something else, or as both at once. For perhaps at the same
time we shall see clearly also how all the products of semen
come into being from contraries, since coming into being from
contraries is also a natural process, for some animals do so, i.e.
from male and female, others from only one parent, as is the
case with plants and all those animals in which male and
2034
female are not separately differentiated. Now that which comes
from the generating parent is called the seminal fluid, being
that which first has in it a principle of generation, in the case of
all animals whose nature it is to unite; semen is that which has
in it the principles from both united parents, as the first
mixture which arises from the union of male and female, be it a
foetus or an ovum, for these already have in them that which
comes from both. (Semen, or seed, and grain differ only in the
one being earlier and the other later, grain in that it comes from
something else, i.e. the seed, and seed in that something else,
the grain, comes from it, for both are really the same thing.)
We must again take up the question what the primary nature of
what is called semen is. Needs must everything which we find
in the body either be (1) one of the natural parts, whether
homogeneous or heterogeneous, or (2) an unnatural part such
as a growth, or (3) a secretion or excretion, or (4) waste-product,
or (5) nutriment. (By secretion or excretion I mean the residue of
the nutriment, by waste-product that which is given off from
the tissues by an unnatural decomposition.)
Now that semen cannot be a part of the body is plain, for it is
homogeneous, and from the homogeneous nothing is
composed, e.g. from only sinew or only flesh; nor is it separated
as are all the other parts. But neither is it contrary to Nature nor
a defect, for it exists in all alike, and the development of the
young animal comes from it. Nutriment, again, is obviously
introduced from without.
It remains, then, that it must be either a waste-product or a
secretion or excretion. Now the ancients seem to think that it is
a waste-product, for when they say that it comes from all the
body by reason of the heat of the movement of the body in
copulation, they imply that it is a kind of waste-product. But
2035
these are contrary to Nature, and from such arises nothing
according to Nature. So then it must be a secretion or excretion.
But, to go further into it, every secretion or excretion is either of
useless or useful nutriment; by 'useless' I mean that from which
nothing further is contributed to natural growth, but which is
particularly mischievous to the body if too much of it is
consumed; by 'useful' I mean the opposite. Now it is evident
that it cannot be of the former character, for such is most
abundant in persons of the worst condition of body through age
or sickness; semen, on the contrary, is least abundant in them
for either they have none at all or it is not fertile, because a
useless and morbid secretion is mingled with it.
Semen, then, is part of a useful secretion. But the most useful is
the last and that from which finally is formed each of the parts
of the body. For secretions are either earlier or later; of the
nutriment in the first stage the secretion is phlegm and the like,
for phlegm also is a secretion of the useful nutriment, an
indication of this being that if it is mixed with pure nutriment it
is nourishing, and that it is used up in cases of illness. The final
secretion is the smallest in proportion to the quantity of
nutriment. But we must reflect that the daily nutriment by
which animals and plants grow is but small, for if a very little be
added continually to the same thing the size of it will become
excessive.
So we must say the opposite of what the ancients said. For
whereas they said that semen is that which comes from all the
body, we shall say it is that whose nature is to go to all of it, and
what they thought a waste-product seems rather to be a
secretion. For it is more reasonable to suppose that the last
extract of the nutriment which goes to all parts resembles that
which is left over from it, just as part of a painter's colour is
often left over resembling that which he has used up. Waste-
2036
products, on the contrary, are always due to corruption or decay
and to a departure from Nature.
A further proof that it is not a waste-product, but rather a
secretion, is the fact that the large animals have few young, the
small many For the large must have more waste and less
secretion, since the great size of the body causes most of the
nutriment to be used up, so that the residue or secretion is
small.
Again, no place has been set apart by Nature for waste-products
but they flow wherever they can find an easy passage in the
body, but a place has been set apart for all the natural
secretions; thus the lower intestine serves for the excretion of
the solid nutriment, the bladder for that of the liquid; for the
useful part of the nutriment we have the upper intestine, for the
spermatic secretions the uterus and pudenda and breasts, for it
is collected and flows together into them.
And the resulting phenomena are evidence that semen is what
we have said, and these result because such is the nature of the
secretion. For the exhaustion consequent on the loss of even a
very little of the semen is conspicuous because the body is
deprived of the ultimate gain drawn from the nutriment. With
some few persons, it is true, during a short time in the flower of
their youth the loss of it, if it be excessive in quantity, is an
alleviation (just as in the case of the nutriment in its first stage,
if too much have been taken, since getting rid of this also makes
the body more comfortable), and so it may be also when other
secretions come away with it, for in that case it is not only
semen that is lost but also other influences come away mingled
with it, and these are morbid. Wherefore, with some men at
least, that which comes from them proves sometimes incapable
of procreation because the seminal element in it is so small. But
still in most men and as a general rule the result of intercourse
2037
is exhaustion and weakness rather than relief, for the reason
given. Moreover, semen does not exist in them either in
childhood or in old age or in sickness - in the last case because
of weakness, in old age because they do not sufficiently concoct
their food, and in childhood because they are growing and so all
the nutriment is used up too soon, for in about five years, in the
case of human beings at any rate, the body seems to gain half
the height that is gained in all the rest of life.
In many animals and plants we find a difference in this
connexion not only between kinds as compared with kinds, but
also between similar individuals of the same kind as compared
with each other, e.g. man with man or vine with vine. Some
have much semen, others little, others again none at all, not
through weakness but the contrary, at any rate in some cases.
This is because the nutriment is used up to form the body, as
with some human beings, who, being in good condition and
developing much flesh or getting rather too fat, produce less
semen and are less desirous of intercourse. Like this is what
happens with those vines which 'play the goat', that is,
luxuriate wantonly through too much nutrition, for he-goats
when fat are less inclined to mount the female; for which
reason they thin them before breeding from them, and say that
the vines 'play the goat', so calling it from the condition of the
goats. And fat people, women as well as men, appear to be less
fertile than others from the fact that the secretion when in
process of concoction turns to fat with those who are too well-
nourished. For fat also is a healthy secretion due to good living.
In some cases no semen is produced at all, as by the willow and
poplar. This condition is due to each of the two causes,
weakness and strength; the former prevents concoction of the
nutriment, the latter causes it to be all consumed, as said above.
In like manner other animals produce much semen through
weakness as well as through strength, when a great quantity of
2038
a useless secretion is mixed with it; this sometimes results in
actual disease when a passage is not found to carry off the
impurity, and though some recover of this, others actually die of
it. For corrupt humours collect here as in the urine, which also
has been known to cause disease.
[Further the same passage serves for urine and semen; and
whatever animals have both kinds of excrement, that of liquid
and that of solid nutriment, discharge the semen by the same
passage as the liquid excrement (for it is a secretion of a liquid,
since the nutriment of all animals is rather liquid than solid),
but those which have no liquid excrement discharge it at the
passage of the solid residua. Moreover, waste-products are
always morbid, but the removal of the secretion is useful; now
the discharge of the semen participates in both characteristics
because it takes up some of the non-useful nutriment. But if it
were a waste-product it would be always harmful; as it is, it is
not so.]
From what has been said, it is clear that semen is a secretion of
useful nutriment, and that in its last stage, whether it is
produced by all or no.
19
After this we must distinguish of what sort of nutriment it is a
secretion, and must discuss the catamenia which occur in
certain of the vivipara. For thus we shall make it clear (1)
whether the female also produces semen like the male and the
foetus is a single mixture of two semens, or whether no semen
is secreted by the female, and, (2) if not, whether she
contributes nothing else either to generation but only provides a
2039
receptacle, or whether she does contribute something, and, if so,
how and in what manner she does so.
We have previously stated that the final nutriment is the blood
in the sanguinea and the analogous fluid in the other animals.
Since the semen is also a secretion of the nutriment, and that in
its final stage, it follows that it will be either (1) blood or that
which is analogous to blood, or (2) something formed from this.
But since it is from the blood, when concocted and somehow
divided up, that each part of the body is made, and since the
semen if properly concocted is quite of a different character
from the blood when it is separated from it, but if not properly
concocted has been known in some cases to issue in a bloody
condition if one forces oneself too often to coition, therefore it is
plain that semen will be a secretion of the nutriment when
reduced to blood, being that which is finally distributed to the
parts of the body. And this is the reason why it has so great
power, for the loss of the pure and healthy blood is an
exhausting thing; for this reason also it is natural that the
offspring should resemble the parents, for that which goes to all
the parts of the body resembles that which is left over. So that
the semen which is to form the hand or the face or the whole
animal is already the hand or face or whole animal
undifferentiated, and what each of them is actually such is the
semen potentially, either in virtue of its own mass or because it
has a certain power in itself. I mention these alternatives here
because we have not yet made it clear from the distinctions
drawn hitherto whether it is the matter of the semen that is the
cause of generation, or whether it has in it some faculty and
efficient cause thereof, for the hand also or any other bodily
part is not hand or other part in a true sense if it be without
soul or some other power, but is only called by the same name
as the living hand.
2040
On this subject, then, so much may be laid down. But since it is
necessary (1) that the weaker animal also should have a
secretion greater in quantity and less concocted, and (2) that
being of such a nature it should be a mass of sanguineous
liquid, and (3) since that which Nature endows with a smaller
portion of heat is weaker, and (4) since it has already been
stated that such is the character of the female - putting all
these considerations together we see that the sanguineous
matter discharged by the female is also a secretion. And such is
the discharge of the so-called catamenia.
It is plain, then, that the catamenia are a secretion, and that
they are analogous in females to the semen in males. The
circumstances connected with them are evidence that this view
is correct. For the semen begins to appear in males and to be
emitted at the same time of life that the catamenia begin to
flow in females, and that they change their voice and their
breasts begin to develop. So, too, in the decline of life the
generative power fails in the one sex and the catamenia in the
other.
The following signs also indicate that this discharge in females
is a secretion. Generally speaking women suffer neither from
haemorrhoids nor bleeding at the nose nor anything else of the
sort except when the catamenia are ceasing, and if anything of
the kind occurs the flow is interfered with because the
discharge is diverted to it.
Further, the blood-vessels of women stand out less than those
of men, and women are rounder and smoother because the
secretion which in men goes to these vessels is drained away
with the catamenia. We must suppose, too, that the same cause
accounts for the fact that the bulk of the body is smaller in
females than in males among the vivipara, since this is the only
class in which the catamenia are discharged from the body. And
2041
in this class the fact is clearest in women, for the discharge is
greater in women than in the other animals. Wherefore her
pallor and the absence of prominent blood-vessels is most
conspicuous, and the deficient development of her body
compared with a man's is obvious.
Now since this is what corresponds in the female to the semen
in the male, and since it is not possible that two such discharges
should be found together, it is plain that the female does not
contribute semen to the generation of the offspring. For if she
had semen she would not have the catamenia; but, as it is,
because she has the latter she has not the former.
It has been stated then that the catamenia are a secretion as
the semen is, and confirmation of this view may be drawn from
some of the phenomena of animals. For fat creatures produce
less semen than lean ones, as observed before. The reason is
that fat also, like semen, is a secretion, is in fact concocted
blood, only not concocted in the same way as the semen. Thus,
if the secretion is consumed to form fat the semen is naturally
deficient. And so among the bloodless animals the cephalopoda
and Crustacea are in best condition about the time of producing
eggs, for, because they are bloodless and no fat is formed in
them, that which is analogous in them to fat is at that season
drawn off to form the spermatic secretion.
And a proof that the female does not emit similar semen to the
male, and that the offspring is not formed by a mixture of both,
as some say, is that often the female conceives without the
sensation of pleasure in intercourse, and if again the pleasure is
experience by her no less than by the male and the two sexes
reach their goal together, yet often no conception takes place
unless the liquid of the so-called catamenia is present in a right
proportion. Hence the female does not produce young if the
catamenia are absent altogether, nor often when, they being
2042
present, the efflux still continues; but she does so after the
purgation. For in the one case she has not the nutriment or
material from which the foetus can be framed by the power
coming from the male and inherent in the semen, and in the
other it is washed away with the catamenia because of their
abundance. But when after their occurrence the greater part has
been evacuated, the remainder is formed into a foetus. Cases of
conception when the catamenia do not occur at all, or of
conception during their discharge instead of after it, are due to
the fact that in the former instance there is only so much liquid
to begin with as remains behind after the discharge in fertile
women, and no greater quantity is secreted so as to come away
from the body, while in the latter instance the mouth of the
uterus closes after the discharge. When, therefore, the quantity
already expelled from the body is great but the discharge still
continues, only not on such a scale as to wash away the semen,
then it is that conception accompanies coition. Nor is it at all
strange that the catamenia should still continue after
conception (for even after it they recur to some extent, but are
scanty and do not last during all the period of gestation; this,
however, is a morbid phenomenon, wherefore it is found only in
a few cases and then seldom, whereas it is that which happens
as a regular thing that is according to Nature).
It is clear then that the female contributes the material for
generation, and that this is in the substance of the catamenia,
and that they are a secretion.
20
Some think that the female contributes semen in coition
because the pleasure she experiences is sometimes similar to
2043
that of the male, and also is attended by a liquid discharge. But
this discharge is not seminal; it is merely proper to the part
concerned in each case, for there is a discharge from the uterus
which occurs in some women but not in others. It is found in
those who are fair-skinned and of a feminine type generally, but
not in those who are dark and of a masculine appearance. The
amount of this discharge, when it occurs, is sometimes on a
different scale from the emission of semen and far exceeds it.
Moreover, different kinds of food cause a great difference in the
quantity of such discharges; for instance some pungently-
flavoured foods cause them to be conspicuously increased. And
as to the pleasure which accompanies coition it is due to
emission not only of semen, but also of a spiritus, the coming
together of which precedes the emission. This is plain in the
case of boys who are not yet able to emit semen, but are near
the proper age, and of men who are impotent, for all these are
capable of pleasure by attrition. And those who have been
injured in the generative organs sometimes suffer from
diarrhoea because the secretion, which they are not able to
concoct and turn into semen, is diverted into the intestine. Now
a boy is like a woman in form, and the woman is as it were an
impotent male, for it is through a certain incapacity that the
female is female, being incapable of concocting the nutriment
in its last stage into semen (and this is either blood or that
which is analogous to it in animals which are bloodless owing
to the coldness of their nature). As then diarrhoea is caused in
the bowels by the insufficient concoction of the blood, so are
caused in the blood-vessels all discharges of blood, including
that of the catamenia, for this also is such a discharge, only it is
natural whereas the others are morbid.
Thus it is clear that it is reasonable to suppose that generation
comes from this. For the catamenia are semen not in a pure
state but in need of working up, as in the formation of fruits the
nutriment is present, when it is not yet sifted thoroughly, but
2044
needs working up to purify it. Thus the catamenia cause
generation mixture with the semen, as this impure nutriment
in plants is nutritious when mixed with pure nutriment.
And a sign that the female does not emit semen is the fact that
the pleasure of intercourse is caused by touch in the same
region of the female as of the male; and yet is it not from
thence that this flow proceeds. Further, it is not all females that
have it at all, but only the sanguinea, and not all even of these,
but only those whose uterus is not near the hypozoma and
which do not lay eggs; it is not found in the animals which have
no blood but only the analogous fluid (for what is blood in the
former is represented by another fluid in the latter). The reason
why neither the latter nor those sanguinea mentioned (i.e.
those whose uterus is low and which do not lay eggs) have this
effluxion is the dryness of their bodies; this allows but little
matter to be secreted, only enough for generation but not
enough to be discharged from the body. All animals that are
viviparous without producing eggs first (such are man and all
quadrupeds which bend their hind-legs outwards, for all these
are viviparous without producing eggs) - all these have the
catamenia, unless they are defective in development as the
mule, only the efflux is not abundant as in women. Details of
the facts in each animal have been given in the Enquiries
concerning animals.
The catamenia are more abundant in women than in the other
animals, and men emit the most semen in proportion to their
size. The reason is that the composition of their bodies is liquid
and hot compared to others, for more matter must be secreted
in such a case. Further, man has no such parts in his body as
those to which the superfluous matter is diverted in the other
animals; for he has no great quantity of hair in proportion to his
body, nor outgrowths of bones, horns, and teeth.
2045
There is evidence that the semen is in the catamenia, for, as
said before, this secretion appears in the male at the same time
of life as the catamenia in the female; this indicates that the
parts destined to receive each of these secretions are
differentiated at the same time in both sexes; and as the
neighboring parts in both become swollen the hair of puberty
springs forth in both alike. As the parts in question are on the
point of differentiating they are distended by the spiritus; this is
clearer in males in the testes, but appears also about the
breasts; in females it is more marked in the breasts, for it is
when they have risen two fingers' breadth that the catamenia
generally begin.
Now, in all living things in which the male and female are not
separated the semen (or seed) is a sort of embryo; by embryo I
mean the first mixture of male and female; hence, from one
semen comes one bodys - for example, one stalk of wheat from
one grain, as one animal from one egg (for twin eggs are really
two eggs). But in whatever kinds the sexes are distinguished, in
these many animals may come from one emission of semen,
showing that the semen differs in its nature in plants and
animals. A proof of this is that animals which can bear more
than one young one at a time do so in consequence of only one
coition. Whereby, too, it is plain that the semen does not come
from the whole of the body; for neither would the different
parts of the semen already be separated as soon as discharged
from the same part, nor could they be separated in the uterus if
they had once entered it all together; but what does happen is
just what one would expect, since what the male contributes to
generation is the form and the efficient cause, while the female
contributes the material. In fact, as in the coagulation of milk,
the milk being the material, the fig-juice or rennet is that which
contains the curdling principle, so acts the secretion of the
male, being divided into parts in the female. Why it is
sometimes divided into more or fewer parts, and sometimes not
2046
divided at all, will be the subject of another discussion. But
because it does not differ in kind at any rate this does not
matter, but what does matter is only that each part should
correspond to the material, being neither too little to concoct it
and fix it into form, nor too much so as to dry it up; it then
generates a number of offspring. But from this first formative
semen, if it remains one, and is not divided, only one young one
comes into being.
That, then, the female does not contribute semen to generation,
but does contribute something, and that this is the matter of
the catamenia, or that which is analogous to it in bloodless
animals, is clear from what has been said, and also from a
general and abstract survey of the question. For there must
needs be that which generates and that from which it
generates; even if these be one, still they must be distinct in
form and their essence must be different; and in those animals
that have these powers separate in two sexes the body and
nature of the active and the passive sex must also differ. If,
then, the male stands for the effective and active, and the
female, considered as female, for the passive, it follows that
what the female would contribute to the semen of the male
would not be semen but material for the semen to work upon.
This is just what we find to be the case, for the catamenia have
in their nature an affinity to the primitive matter.
21
So much for the discussion of this question. At the same time
the answer to the next question we have to investigate is clear
from these considerations, I mean how it is that the male
contributes to generation and how it is that the semen from the
2047
male is the cause of the offspring. Does it exist in the body of
the embryo as a part of it from the first, mingling with the
material which comes from the female? Or does the semen
communicate nothing to the material body of the embryo but
only to the power and movement in it? For this power is that
which acts and makes, while that which is made and receives
the form is the residue of the secretion in the female. Now the
latter alternative appears to be the right one both a priori and in
view of the facts. For, if we consider the question on general
grounds, we find that, whenever one thing is made from two of
which one is active and the other passive, the active agent does
not exist in that which is made; and, still more generally, the
same applies when one thing moves and another is moved; the
moving thing does not exist in that which is moved. But the
female, as female, is passive, and the male, as male, is active,
and the principle of the movement comes from him. Therefore,
if we take the highest genera under which they each fall, the
one being active and motive and the other passive and moved,
that one thing which is produced comes from them only in the
sense in which a bed comes into being from the carpenter and
the wood, or in which a ball comes into being from the wax and
the form. It is plain then that it is not necessary that anything
at all should come away from the male, and if anything does
come away it does not follow that this gives rise to the embryo
as being in the embryo, but only as that which imparts the
motion and as the form; so the medical art cures the patient.
This a priori argument is confirmed by the facts. For it is for this
reason that some males which unite with the female do not, it
appears, insert any part of themselves into the female, but on
the contrary the female inserts a part of herself into the male;
this occurs in some insects. For the effect produced by the
semen in the female (in the case of those animals whose males
do insert a part) is produced in the case of these insects by the
heat and power in the male animal itself when the female
2048
inserts that part of herself which receives the secretion. And
therefore such animals remain united a long time, and when
they are separated the young are produced quickly. For the
union lasts until that which is analogous to the semen has done
its work, and when they separate the female produces the
embryo quickly; for the young is imperfect inasmuch as all such
creatures give birth to scoleces.
What occurs in birds and oviparous fishes is the greatest proof
that neither does the semen come from all parts of the male
nor does he emit anything of such a nature as to exist within
that which is generated, as part of the material embryo, but that
he only makes a living creature by the power which resides in
the semen (as we said in the case of those insects whose
females insert a part of themselves into the male). For if a hen-
bird is in process of producing wind-eggs and is then trodden by
the cock before the egg has begun to whiten and while it is all
still yellow, then they become fertile instead of being wind-eggs.
And if while it is still yellow she be trodden by another cock, the
whole brood of chicks turn out like the second cock. Hence
some of those who are anxious to rear fine birds act thus; they
change the cocks for the first and second treading, not as if they
thought that the semen is mingled with the egg or exists in it,
or that it comes from all parts of the cock; for if it did it would
have come from both cocks, so that the chick would have all its
parts doubled. But it is by its force that the semen of the male
gives a certain quality to the material and the nutriment in the
female, for the second semen added to the first can produce
this effect by heat and concoction, as the egg acquires
nutriment so long as it is growing.
The same conclusion is to be drawn from the generation of
oviparous fishes. When the female has laid her eggs, the male
spinkles the milt over them, and those eggs are fertilized which
it reaches, but not the others; this shows that the male does not
2049
contribute anything to the quantity but only to the quality of
the embryo.
From what has been said it is plain that the semen does not
come from the whole of the body of the male in those animals
which emit it, and that the contribution of the female to the
generative product is not the same as that of the male, but the
male contributes the principle of movement and the female the
material. This is why the female does not produce offspring by
herself, for she needs a principle, i.e. something to begin the
movement in the embryo and to define the form it is to assume.
Yet in some animals, as birds, the nature of the female
unassisted can generate to a certain extent, for they do form
something, only it is incomplete; I mean the so-called wind-
eggs.
22
For the same reason the development of the embryo takes place
in the female; neither the male himself nor the female emits
semen into the male, but the female receives within herself the
share contributed by both, because in the female is the material
from which is made the resulting product. Not only must the
mass of material exist there from which the embryo is formed
in the first instance, but further material must constantly be
added that it may increase in size. Therefore the birth must take
place in the female. For the carpenter must keep in close
connexion with his timber and the potter with his clay, and
generally all workmanship and the ultimate movement
imparted to matter must be connected with the material
concerned, as, for instance, architecture is in the buildings it
makes.
2050
From these considerations we may also gather how it is that the
male contributes to generation. The male does not emit semen
at all in some animals, and where he does this is no part of the
resulting embryo; just so no material part comes from the
carpenter to the material, i.e. the wood in which he works, nor
does any part of the carpenter's art exist within what he makes,
but the shape and the form are imparted from him to the
material by means of the motion he sets up. It is his hands that
move his tools, his tools that move the material; it is his
knowledge of his art, and his soul, in which is the form, that
moves his hands or any other part of him with a motion of
some definite kind, a motion varying with the varying nature of
the object made. In like manner, in the male of those animals
which emit semen Nature uses the semen as a tool and as
possessing motion in actuality, just as tools are used in the
products of any art, for in them lies in a certain sense the
motion of the art. Such, then, is the way in which these males
contribute to generation. But when the male does not emit
semen, but the female inserts some part of herself into the
male, this is parallel to a case in which a man should carry the
material to the workman. For by reason of weakness in such
males Nature is not able to do anything by any secondary
means, but the movements imparted to the material are
scarcely strong enough when Nature herself watches over them.
Thus here she resembles a modeller in clay rather than a
carpenter, for she does not touch the work she is forming by
means of tools, but, as it were, with her own hands.
23
In all animals which can move about, the sexes are separated,
one individual being male and one female, though both are the
2051
same in species, as with man and horse. But in plants these
powers are mingled, female not being separated from male.
Wherefore they generate out of themselves, and do not emit
semen but produce an embryo, what is called the seed.
Empedocles puts this well in the line: 'and thus the tall trees
oviposit; first olives...' For as the egg is an embryo, a certain part
of it giving rise to the animal and the rest being nutriment, so
also from a part of the seed springs the growing plant, and the
rest is nutriment for the shoot and the first root.
In a certain sense the same thing happens also in those animals
which have the sexes separate. For when there is need for them
to generate the sexes are no longer separated any more than in
plants, their nature desiring that they shall become one; and
this is plain to view when they copulate and are united, that
one animal is made out of both.
It is the nature of those creatures which do not emit semen to
remain united a long time until the male element has formed
the embryo, as with those insects which copulate. The others so
remain only until the male has discharged from the parts of
himself introduced something which will form the embryo in a
longer time, as among the sanguinea. For the former remain
paired some part of a day, while the semen forms the embryo in
several days. And after emitting this they cease their union.
And animals seem literally to be like divided plants, as though
one should separate and divide them, when they bear seed, into
the male and female existing in them.
In all this Nature acts like an intelligent workman. For to the
essence of plants belongs no other function or business than
the production of seed; since, then, this is brought about by the
union of male and female, Nature has mixed these and set
them together in plants, so that the sexes are not divided in
them. Plants, however, have been investigated elsewhere. But
2052
the function of the animal is not only to generate (which is
common to all living things), but they all of them participate
also in a kind of knowledge, some more and some less, and
some very little indeed. For they have sense-perception, and
this is a kind of knowledge. (If we consider the value of this we
find that it is of great importance compared with the class of
lifeless objects, but of little compared with the use of the
intellect. For against the latter the mere participation in touch
and taste seems to be practically nothing, but beside absolute
insensibility it seems most excellent; for it would seem a
treasure to gain even this kind of knowledge rather than to lie
in a state of death and non-existence.) Now it is by sense-
perception that an animal differs from those organisms which
have only life. But since, if it is a living animal, it must also live;
therefore, when it is necessary for it to accomplish the function
of that which has life, it unites and copulates, becoming like a
plant, as we said before.
Testaceous animals, being intermediate between animals and
plants, perform the function of neither class as belonging to
both. As plants they have no sexes, and one does not generate
in another; as animals they do not bear fruit from themselves
like plants; but they are formed and generated from a liquid and
earthy concretion. However, we must speak later of the
generation of these animals.
2053
Book II
That the male and the female are the principles of generation
has been previously stated, as also what is their power and their
essence. But why is it that one thing becomes and is male,
another female? It is the business of our discussion as it
proceeds to try and point out (1) that the sexes arise from
Necessity and the first efficient cause, (2) from what sort of
material they are formed. That (3) they exist because it is better
and on account of the final cause, takes us back to a principle
still further remote.
Now (1) some existing things are eternal and divine whilst
others admit of both existence and non-existence. But (2) that
which is noble and divine is always, in virtue of its own nature,
the cause of the better in such things as admit of being better or
worse, and what is not eternal does admit of existence and non-
existence, and can partake in the better and the worse. And (3)
soul is better than body, and living, having soul, is thereby better
than the lifeless which has none, and being is better than not
being, living than not living. These, then, are the reasons of the
generation of animals. For since it is impossible that such a
class of things as animals should be of an eternal nature,
therefore that which comes into being is eternal in the only way
possible. Now it is impossible for it to be eternal as an
individual (though of course the real essence of things is in the
individual) - were it such it would be eternal - but it is possible
for it as a species. This is why there is always a class of men and
animals and plants. But since the male and female essences are
the first principles of these, they will exist in the existing
2054
individuals for the sake of generation. Again, as the first
efficient or moving cause, to which belong the definition and
the form, is better and more divine in its nature than the
material on which it works, it is better that the superior
principle should be separated from the inferior. Therefore,
wherever it is possible and so far as it is possible, the male is
separated from the female. For the first principle of the
movement, or efficient cause, whereby that which comes into
being is male, is better and more divine than the material
whereby it is female. The male, however, comes together and
mingles with the female for the work of generation, because
this is common to both.
A thing lives, then, in virtue of participating in the male and
female principles, wherefore even plants have some kind of life;
but the class of animals exists in virtue of sense-perception. The
sexes are divided in nearly all of these that can move about, for
the reasons already stated, and some of them, as said before,
emit semen in copulation, others not. The reason of this is that
the higher animals are more independent in their nature, so
that they have greater size, and this cannot exist without vital
heat; for the greater body requires more force to move it, and
heat is a motive force. Therefore, taking a general view, we may
say that sanguinea are of greater size than bloodless animals,
and those which move about than those which remain fixed.
And these are just the animals which emit semen on account of
their heat and size.
So much for the cause of the existence of the two sexes. Some
animals bring to perfection and produce into the world a
creature like themselves, as all those which bring their young
into the world alive; others produce something undeveloped
which has not yet acquired its own form; in this latter division
the sanguinea lay eggs, the bloodless animals either lay an egg
or give birth to a scolex. The difference between egg and scolex
2055
is this: an egg is that from a part of which the young comes into
being, the rest being nutriment for it; but the whole of a scolex
is developed into the whole of the young animal. Of the
vivipara, which bring into the world an animal like themselves,
some are internally viviparous (as men, horses, cattle, and of
marine animals dolphins and the other cetacea); others first lay
eggs within themselves, and only after this are externally
viviparous (as the cartilaginous fishes). Among the ovipara
some produce the egg in a perfect condition (as birds and all
oviparous quadrupeds and footless animals, e.g. lizards and
tortoises and most snakes; for the eggs of all these do not
increase when once laid). The eggs of others are imperfect; such
are those of fishes, crustaceans, and cephalopods, for their eggs
increase after being produced.
All the vivipara are sanguineous, and the sanguinea are either
viviparous or oviparous, except those which are altogether
infertile. Among bloodless animals the insects produce a scolex,
alike those that are generated by copulation and those that
copulate themselves though not so generated. For there are
some insects of this sort, which though they come into being by
spontaneous generation are yet male and female; from their
union something is produced, only it is imperfect; the reason of
this has been previously stated.
These classes admit of much cross-division. Not all bipeds are
viviparous (for birds are oviparous), nor are they all oviparous
(for man is viviparous), nor are all quadrupeds oviparous (for
horses, cattle, and countless others are viviparous), nor are they
all viviparous (for lizards, crocodiles, and many others lay eggs).
Nor does the presence or absence of feet make the difference
between them, for not only are some footless animals
viviparous, as vipers and the cartilaginous fishes, while others
are oviparous, as the other fishes and serpents, but also among
those which have feet many are oviparous and many
2056
viviparous, as the quadrupeds above mentioned. And some
which have feet, as man, and some which have not, as the
whale and dolphin, are internally viviparous. By this character
then it is not possible to divide them, nor is any of the
locomotive organs the cause of this difference, but it is those
animals which are more perfect in their nature and participate
in a purer element which are viviparous, for nothing is
internally viviparous unless it receive and breathe out air. But
the more perfect are those which are hotter in their nature and
have more moisture and are not earthy in their composition.
And the measure of natural heat is the lung when it has blood
in it, for generally those animals which have a lung are hotter
than those which have not, and in the former class again those
whose lung is not spongy nor solid nor containing only a little
blood, but soft and full of blood. And as the animal is perfect but
the egg and the scolex are imperfect, so the perfect is naturally
produced from the more perfect. If animals are hotter as shown
by their possessing a lung but drier in their nature, or are colder
but have more moisture, then they either lay a perfect egg or are
viviparous after laying an egg within themselves. For birds and
scaly reptiles because of their heat produce a perfect egg, but
because of their dryness it is only an egg; the cartilaginous
fishes have less heat than these but more moisture, so that they
are intermediate, for they are both oviparous and viviparous
within themselves, the former because they are cold, the latter
because of their moisture; for moisture is vivifying, whereas
dryness is furthest removed from what has life. Since they have
neither feathers nor scales such as either reptiles or other fishes
have, all which are signs rather of a dry and earthy nature, the
egg they produce is soft; for the earthy matter does not come to
the surface in their eggs any more than in themselves. This is
why they lay eggs in themselves, for if the egg were laid
externally it would be destroyed, having no protection.
2057
Animals that are cold and rather dry than moist also lay eggs,
but the egg is imperfect; at the same time, because they are of
an earthy nature and the egg they produce is imperfect,
therefore it has a hard integument that it may be preserved by
the protection of the shell-like covering. Hence fishes, because
they are scaly, and Crustacea, because they are of an earthy
nature, lay eggs with a hard integument.
The cephalopods, having themselves bodies of a sticky nature,
preserve in the same way the imperfect eggs they lay, for they
deposit a quantity of sticky material about the embryo. All
insects produce a scolex. Now all the insects are bloodless,
wherefore all creatures that produce a scolex from themselves
are so. But we cannot say simply that all bloodless animals
produce a scolex, for the classes overlap one another, (1) the
insects, (2) the animals that produce a scolex, (3) those that lay
their egg imperfect, as the scaly fishes, the Crustacea, and the
cephalopoda. I say that these form a gradation, for the eggs of
these latter resemble a scolex, in that they increase after
oviposition, and the scolex of insects again as it develops
resembles an egg; how so we shall explain later.
We must observe how rightly Nature orders generation in
regular gradation. The more perfect and hotter animals produce
their young perfect in respect of quality (in respect of quantity
this is so with no animal, for the young always increase in size
after birth), and these generate living animals within
themselves from the first. The second class do not generate
perfect animals within themselves from the first (for they are
only viviparous after first laying eggs), but still they are
externally viviparous. The third class do not produce a perfect
animal, but an egg, and this egg is perfect. Those whose nature
is still colder than these produce an egg, but an imperfect one,
which is perfected outside the body, as the class of scaly fishes,
the Crustacea, and the cephalopods. The fifth and coldest class
2058
does not even lay an egg from itself; but so far as the young ever
attain to this condition at all, it is outside the body of the
parent, as has been said already. For insects produce a scolex
first; the scolex after developing becomes egg-like (for the so-
called chrysalis or pupa is equivalent to an egg); then from this
it is that a perfect animal comes into being, reaching the end of
its development in the second change.
Some animals then, as said before, do not come into being from
semen, but all the sanguinea do so which are generated by
copulation, the male emitting semen into the female when this
has entered into her the young are formed and assume their
peculiar character, some within the animals themselves when
they are viviparous, others in eggs.
There is a considerable difficulty in understanding how the
plant is formed out of the seed or any animal out of the semen.
Everything that comes into being or is made must (1) be made
out of something, (2) be made by the agency of something, and
(3) must become something. Now that out of which it is made is
the material; this some animals have in its first form within
themselves, taking it from the female parent, as all those which
are not born alive but produced as a scolex or an egg; others
receive it from the mother for a long time by sucking, as the
young of all those which are not only externally but also
internally viviparous. Such, then, is the material out of which
things come into being, but we now are inquiring not out of
what the parts of an animal are made, but by what agency.
Either it is something external which makes them, or else
something existing in the seminal fluid and the semen; and this
must either be soul or a part of soul, or something containing
soul.
Now it would appear irrational to suppose that any of either the
internal organs or the other parts is made by something
2059
external, since one thing cannot set up a motion in another
without touching it, nor can a thing be affected in any way by
another if it does not set up a motion in it. Something then of
the sort we require exists in the embryo itself, being either a
part of it or separate from it. To suppose that it should be
something else separate from it is irrational. For after the
animal has been produced does this something perish or does it
remain in it? But nothing of the kind appears to be in it, nothing
which is not a part of the whole plant or animal. Yet, on the
other hand, it is absurd to say that it perishes after making
either all the parts or only some of them. If it makes some of
the parts and then perishes, what is to make the rest of them?
Suppose this something makes the heart and then perishes,
and the heart makes another organ, by the same argument
either all the parts must perish or all must remain. Therefore it
is preserved and does not perish. Therefore it is a part of the
embryo itself which exists in the semen from the beginning;
and if indeed there is no part of the soul which does not exist in
some part of the body, it would also be a part containing soul in
it from the beginning.
How, then, does it make the other parts? Either all the parts, as
heart, lung, liver, eye, and all the rest, come into being together
or in succession, as is said in the verse ascribed to Orpheus, for
there he says that an animal comes into being in the same way
as the knitting of a net. That the former is not the fact is plain
even to the senses, for some of the parts are clearly visible as
already existing in the embryo while others are not; that it is
not because of their being too small that they are not visible is
clear, for the lung is of greater size than the heart, and yet
appears later than the heart in the original development. Since,
then, one is earlier and another later, does the one make the
other, and does the later part exist on account of the part which
is next to it, or rather does the one come into being only after
the other? I mean, for instance, that it is not the fact that the
2060
heart, having come into being first, then makes the liver, and
the liver again another organ, but that the liver only comes into
being after the heart, and not by the agency of the heart, as a
man becomes a man after being a boy, not by his agency. An
explanation of this is that, in all the productions of Nature or of
art, what already exists potentially is brought into being only by
what exists actually; therefore if one organ formed another the
form and the character of the later organ would have to exist in
the earlier, e.g. the form of the liver in the heart. And otherwise
also the theory is strange and fictitious.
Yet again, if the whole animal or plant is formed from semen or
seed, it is impossible that any part of it should exist ready made
in the semen or seed, whether that part be able to make the
other parts or no. For it is plain that, if it exists in it from the
first, it was made by that which made the semen. But semen
must be made first, and that is the function of the generating
parent. So, then, it is not possible that any part should exist in
it, and therefore it has not within itself that which makes the
parts.
But neither can this agent be external, and yet it must needs be
one or other of the two. We must try, then, to solve this
difficulty, for perhaps some one of the statements made cannot
be made without qualification, e.g. the statement that the parts
cannot be made by what is external to the semen. For if in a
certain sense they cannot, yet in another sense they can. (Now
it makes no difference whether we say 'the semen' or 'that from
which the semen comes', in so far as the semen has in itself the
movement initiated by the other.) It is possible, then, that A
should move B, and B move C; that, in fact, the case should be
the same as with the automatic machines shown as curiosities.
For the parts of such machines while at rest have a sort of
potentiality of motion in them, and when any external force
puts the first of them in motion, immediately the next is moved
2061
in actuality. As, then, in these automatic machines the external
force moves the parts in a certain sense (not by touching any
part at the moment, but by having touched one previously), in
like manner also that from which the semen comes, or in other
words that which made the semen, sets up the movement in
the embryo and makes the parts of it by having first touched
something though not continuing to touch it. In a way it is the
innate motion that does this, as the act of building builds the
house. Plainly, then, while there is something which makes the
parts, this does not exist as a definite object, nor does it exist in
the semen at the first as a complete part.
But how is each part formed? We must answer this by starting
in the first instance from the principle that, in all products of
Nature or art, a thing is made by something actually existing
out of that which is potentially such as the finished product.
Now the semen is of such a nature, and has in it such a
principle of motion, that when the motion is ceasing each of the
parts comes into being, and that as a part having life or soul. For
there is no such thing as face or flesh without life or soul in it; it
is only equivocally that they will be called face or flesh if the life
has gone out of them, just as if they had been made of stone or
wood. And the homogeneous parts and the organic come into
being together. And just as we should not say that an axe or
other instrument or organ was made by the fire alone, so
neither shall we say that foot or hand were made by heat alone.
The same applies also to flesh, for this too has a function.
While, then, we may allow that hardness and softness,
stickiness and brittleness, and whatever other qualities are
found in the parts that have life and soul, may be caused by
mere heat and cold, yet, when we come to the principle in
virtue of which flesh is flesh and bone is bone, that is no longer
so; what makes them is the movement set up by the male
parent, who is in actuality what that out of which the offspring
is made is in potentiality. This is what we find in the products of
2062
art; heat and cold may make the iron soft and hard, but what
makes a sword is the movement of the tools employed, this
movement containing the principle of the art. For the art is the
starting-point and form of the product; only it exists in
something else, whereas the movement of Nature exists in the
product itself, issuing from another nature which has the form
in actuality.
Has the semen soul, or not? The same argument applies here as
in the question concerning the parts. As no part, if it participate
not in soul, will be a part except in an equivocal sense (as the
eye of a dead man is still called an 'eye'), so no soul will exist in
anything except that of which it is soul; it is plain therefore that
semen both has soul, and is soul, potentially.
But a thing existing potentially may be nearer or further from
its realization in actuality, as e.g. a mathematician when asleep
is further from his realization in actuality as engaged in
mathematics than when he is awake, and when awake again
but not studying mathematics he is further removed than when
he is so studying. Accordingly it is not any part that is the cause
of the soul's coming into being, but it is the first moving cause
from outside. (For nothing generates itself, though when it has
come into being it thenceforward increases itself.) Hence it is
that only one part comes into being first and not all of them
together. But that must first come into being which has a
principle of increase (for this nutritive power exists in all alike,
whether animals or plants, and this is the same as the power
that enables an animal or plant to generate another like itself,
that being the function of them all if naturally perfect). And this
is necessary for the reason that whenever a living thing is
produced it must grow. It is produced, then, by something else
of the same name, as e.g. man is produced by man, but it is
increased by means of itself. There is, then, something which
increases it. If this is a single part, this must come into being
2063
first. Therefore if the heart is first made in some animals, and
what is analogous to the heart in the others which have no
heart, it is from this or its analogue that the first principle of
movement would arise.
We have thus discussed the difficulties previously raised on the
question what is the efficient cause of generation in each case,
as the first moving and formative power.
The next question to be mooted concerns the nature of semen.
For whereas when it issues from the animal it is thick and
white, yet on cooling it becomes liquid as water, and its colour
is that of water. This would appear strange, for water is not
thickened by heat; yet semen is thick when it issues from
within the animal's body which is hot, and becomes liquid on
cooling. Again, watery fluids freeze, but semen, if exposed in
frosts to the open air, does not freeze but liquefies, as if it was
thickened by the opposite of cold. Yet it is unreasonable, again,
to suppose that it is thickened by heat. For it is only substances
having a predominance of earth in their composition that
coagulate and thicken on boiling, e.g. milk. It ought then to
solidify on cooling, but as a matter of fact it does not become
solid in any part but the whole of it goes like water.
This then is the difficulty. If it is water, water evidently does not
thicken through heat, whereas the semen is thick and both it
and the body whence it issues are hot. If it is made of earth or a
mixture of earth and water, it ought not to liquefy entirely and
turn to water.
2064
Perhaps, however, we have not discriminated all the
possibilities. It is not only the liquids composed of water and
earthy matter that thicken, but also those composed of water
and air; foam, for instance, becomes thicker and white, and the
smaller and less visible the bubbles in it, the whiter and firmer
does the mass appear. The same thing happens also with oil; on
mixing with air it thickens, wherefore that which is whitening
becomes thicker, the watery part in it being separated off by the
heat and turning to air. And if oxide of lead is mixed with water
or even with oil, the mass increases greatly and changes from
liquid and dark to firm and white, the reason being that air is
mixed in with it which increases the mass and makes the white
shine through, as in foam and snow (for snow is foam). And
water itself on mingling with oil becomes thick and white,
because air is entangled in it by the act of pounding them
together, and oil itself has much air in it (for shininess is a
property of air, not of earth or water). This too is why it floats on
the surface of the water, for the air contained in it as in a vessel
bears it up and makes it float, being the cause of its lightness.
So too oil is thickened without freezing in cold weather and
frosts; it does not freeze because of its heat (for the air is hot
and will not freeze), but because the air is forced together and
compressed, as..., by the cold, the oil becomes thicker. These are
the reasons why semen is firm and white when it issues from
within the animal; it has a quantity of hot air in it because of
the internal heat; afterwards, when the heat has evaporated
and the air has cooled, it turns liquid and dark; for the water,
and any small quantity of earthy matter there may be, remain
in semen as it dries, as they do in phlegm.
Semen, then, is a compound of spirit (pneuma) and water, and
the former is hot air (aerh); hence semen is liquid in its nature
because it is made of water. What Ctesias the Cnidian has
asserted of the semen of elephants is manifestly untrue; he
says that it hardens so much in drying that it becomes like
2065
amber. But this does not happen, though it is true that one
semen must be more earthy than another, and especially so
with animals that have much earthy matter in them because of
the bulk of their bodies. And it is thick and white because it is
mixed with spirit, for it is also an invariable rule that it is white,
and Herodotus does not report the truth when he says that the
semen of the Aethiopians is black, as if everything must needs
be black in those who have a black skin, and that too when he
saw their teeth were white. The reason of the whiteness of
semen is that it is a foam, and foam is white, especially that
which is composed of the smallest parts, small in the sense that
each bubble is invisible, which is what happens when water and
oil are mixed and shaken together, as said before. (Even the
ancients seem to have noticed that semen is of the nature of
foam; at least it was from this they named the goddess who
presides over union.)
This then is the explanation of the problem proposed, and it is
plain too that this is why semen does not freeze; for air will not
freeze.
The next question to raise and to answer is this. If, in the case
of those animals which emit semen into the female, that which
enters makes no part of the resulting embryo, where is the
material part of it diverted if (as we have seen) it acts by means
of the power residing in it? It is not only necessary to decide
whether what is forming in the female receives anything
material, or not, from that which has entered her, but also
concerning the soul in virtue of which an animal is so called
(and this is in virtue of the sensitive part of the soul) - does this
2066
exist originally in the semen and in the unfertilized embryo or
not, and if it does whence does it come? For nobody would put
down the unfertilized embryo as soulless or in every sense
bereft of life (since both the semen and the embryo of an
animal have every bit as much life as a plant), and it is
productive up to a certain point. That then they possess the
nutritive soul is plain (and plain is it from the discussions
elsewhere about soul why this soul must be acquired first). As
they develop they also acquire the sensitive soul in virtue of
which an animal is an animal. For e.g. an animal does not
become at the same time an animal and a man or a horse or
any other particular animal. For the end is developed last, and
the peculiar character of the species is the end of the generation
in each individual. Hence arises a question of the greatest
difficulty, which we must strive to solve to the best of our ability
and as far as possible. When and how and whence is a share in
reason acquired by those animals that participate in this
principle? It is plain that the semen and the unfertilized
embryo, while still separate from each other, must be assumed
to have the nutritive soul potentially, but not actually, except
that (like those unfertilized embryos that are separated from
the mother) it absorbs nourishment and performs the function
of the nutritive soul. For at first all such embryos seem to live
the life of a plant. And it is clear that we must be guided by this
in speaking of the sensitive and the rational soul. For all three
kinds of soul, not only the nutritive, must be possessed
potentially before they are possessed in actuality. And it is
necessary either (1) that they should all come into being in the
embryo without existing previously outside it, or (2) that they
should all exist previously, or (3), that some should so exist and
others not. Again, it is necessary that they should either (1)
come into being in the material supplied by the female without
entering with the semen of the male, or (2) come from the male
and be imparted to the material in the female. If the latter, then
2067
either all of them, or none, or some must come into being in the
male from outside.
Now that it is impossible for them all to preexist is clear from
this consideration. Plainly those principles whose activity is
bodily cannot exist without a body, e.g. walking cannot exist
without feet. For the same reason also they cannot enter from
outside. For neither is it possible for them to enter by
themselves, being inseparable from a body, nor yet in a body, for
the semen is only a secretion of the nutriment in process of
change. It remains, then, for the reason alone so to enter and
alone to be divine, for no bodily activity has any connexion with
the activity of reason.
Now it is true that the faculty of all kinds of soul seems to have
a connexion with a matter different from and more divine than
the so-called elements; but as one soul differs from another in
honour and dishonour, so differs also the nature of the
corresponding matter. All have in their semen that which
causes it to be productive; I mean what is called vital heat. This
is not fire nor any such force, but it is the spiritus included in
the semen and the foam-like, and the natural principle in the
spiritus, being analogous to the element of the stars. Hence,
whereas fire generates no animal and we do not find any living
thing forming in either solids or liquids under the influence of
fire, the heat of the sun and that of animals does generate
them. Not only is this true of the heat that works through the
semen, but whatever other residuum of the animal nature there
may be, this also has still a vital principle in it. From such
considerations it is clear that the heat in animals neither is fire
nor derives its origin from fire.
Let us return to the material of the semen, in and with which
comes away from the male the spiritus conveying the principle
of soul. Of this principle there are two kinds; the one is not
2068
connected with matter, and belongs to those animals in which
is included something divine (to wit, what is called the reason),
while the other is inseparable from matter. This material of the
semen dissolves and evaporates because it has a liquid and
watery nature. Therefore we ought not to expect it always to
come out again from the female or to form any part of the
embryo that has taken shape from it; the case resembles that of
the fig-juice which curdles milk, for this too changes without
becoming any part of the curdling masses.
It has been settled, then, in what sense the embryo and the
semen have soul, and in what sense they have not; they have it
potentially but not actually.
Now semen is a secretion and is moved with the same
movement as that in virtue of which the body increases (this
increase being due to subdivision of the nutriment in its last
stage). When it has entered the uterus it puts into form the
corresponding secretion of the female and moves it with the
same movement wherewith it is moved itself. For the female's
contribution also is a secretion, and has all the arts in it
potentially though none of them actually; it has in it potentially
even those parts which differentiate the female from the male,
for just as the young of mutilated parents are sometimes born
mutilated and sometimes not, so also the young born of a
female are sometimes female and sometimes male instead. For
the female is, as it were, a mutilated male, and the catamenia
are semen, only not pure; for there is only one thing they have
not in them, the principle of soul. For this reason, whenever a
wind-egg is produced by any animal, the egg so forming has in
it the parts of both sexes potentially, but has not the principle in
question, so that it does not develop into a living creature, for
this is introduced by the semen of the male. When such a
principle has ben imparted to the secretion of the female it
becomes an embryo.
2069
Liquid but corporeal substances become surrounded by some
kind of covering on heating, like the solid scum which forms on
boiled foods when cooling. All bodies are held together by the
glutinous; this quality, as the embryo develops and increases in
size, is acquired by the sinewy substance, which holds together
the parts of animals, being actual sinew in some and its
analogue in others. To the same class belong also skin, blood-
vessels, membranes, and the like, for these differ in being more
or less glutinous and generally in excess and deficiency.
In those animals whose nature is comparatively imperfect,
when a perfect embryo (which, however, is not yet a perfect
animal) has been formed, it is cast out from the mother, for
reasons previously stated. An embryo is then complete when it
is either male or female, in the case of those animals who
possess this distinction, for some (i.e. all those which are not
themselves produced from a male or female parent nor from a
union of the two) produce an offspring which is neither male
nor female. Of the generation of these we shall speak later.
The perfect animals, those internally viviparous, keep the
developing embryo within themselves and in close connexion
until they give birth to a complete animal and bring it to light.
A third class is externally viviparous but first internally
oviparous; they develop the egg into a perfect condition, and
then in some cases the egg is set free as with creatures
externally oviparous, and the animal is produced from the egg
within the mother's body; in other cases, when the nutriment
from the egg is consumed, development is completed by
connection with the uterus, and therefore the egg is not set free
2070
from the uterus. This character marks the cartilaginous fish, of
which we must speak later by themselves.
Here we must make our first start from the first class; these are
the perfect or viviparous animals, and of these the first is man.
Now the secretion of the semen takes place in all of them just
as does that of any other residual matter. For each is conveyed
to its proper place without any force from the breath or
compulsion of any other cause, as some assert, saying that the
generative parts attract the semen like cupping-glasses, aided
by the force of the breath, as if it were possible for either this
secretion or the residue of the solid and liquid nutriment to go
anywhere else than they do without the exertion of such a
force. Their reason is that the discharge of both is attended by
holding the breath, but this is a common feature of all cases
when it is necessary to move anything, because strength arises
through holding the breath. Why, even without this force the
secretions or excretions are discharged in sleep if the parts
concerned are full of them and are relaxed. One might as well
say that it is by the breath that the seeds of plants are always
segregated to the places where they are wont to bear fruit. No,
the real cause, as has been stated already, is that there are
special parts for receiving all the secretions, alike the useless (as
the residues of the liquid and solid nutriment), and the blood,
which has the so-called blood-vessels.
To consider now the region of the uterus in the female - the two
blood-vessels, the great vessel and the aorta, divide higher up,
and many fine vessels from them terminate in the uterus. These
become over-filled from the nourishment they convey, nor is the
female nature able to concoct it, because it is colder than man's;
so the blood is excreted through very fine vessels into the
uterus, these being unable on account of their narrowness to
receive the excessive quantity, and the result is a sort of
haemorrhage. The period is not accurately defined in women,
2071
but tends to return during the waning of the moon. This we
should expect, for the bodies of animals are colder when the
environment happens to become so, and the time of change
from one month to another is cold because of the absence of
the moon, whence also it results that this time is stormier than
the middle of the month. When then the residue of the
nourishment has changed into blood, the catamenia tend to
occur at the above-mentioned period, but when it is not
concocted a little matter at a time is always coming away, and
this is why 'whites' appear in females while still small, in fact
mere children. If both these discharges of the secretions are
moderate, the body remains in good health, for they act as a
purification of the secretions which are the causes of a morbid
state of body; if they do not occur at all or if they are excessive,
they are injurious, either causing illness or pulling down the
patient; hence whites, if continuous and excessive, prevent girls
from growing. This secretion then is necessarily discharged by
females for the reasons given; for, the female nature being
unable to concoct the nourishment thoroughly, there must not
only be left a residue of the useless nutriment, but also there
must be a residue in the blood-vessels, and this filling the
channels of the finest vessels must overflow. Then Nature,
aiming at the best end, uses it up in this place for the sake of
generation, that another creature may come into being of the
same kind as the former was going to be, for the menstrual
blood is already potentially such as the body from which it is
discharged.
In all females, then, there must necessarily be such a secretion,
more indeed in those that have blood and of these most of all in
man, but in the others also some matter must be collected in
the uterine region. The reason why there is more in those that
have blood and most in man has been already given, but why, if
all females have such a secretion, have not all males one to
correspond? For some of them do not emit semen but, just as
2072
those which do emit it fashion by the movement in the semen
the mass forming from the material supplied by the female, so
do the animals in question bring the same to pass and exert the
same formative power by the movement within themselves in
that part from whence the semen is secreted. This is the region
about the diaphragm in all those animals which have one, for
the heart or its analogue is the first principle of a natural body,
while the lower part is a mere addition for the sake of it. Now
the reason why it is not all males that have a generative
secretion, while all females do, is that the animal is a body with
Soul or life; the female always provides the material, the male
that which fashions it, for this is the power that we say they
each possess, and this is what is meant by calling them male
and female. Thus while it is necessary for the female to provide
a body and a material mass, it is not necessary for the male,
because it is not within the work of art or the embryo that the
tools or the maker must exist. While the body is from the
female, it is the soul that is from the male, for the soul is the
reality of a particular body. For this reason if animals of a
different kind are crossed (and this is possible when the periods
of gestation are equal and conception takes place nearly at the
same season and there is no great difference in the of the
animals), the first cross has a common resemblance to both
parents, as the hybrid between fox and dog, partridge and
domestic fowl, but as time goes on and one generation springs
from another, the final result resembles the female in form, just
as foreign seeds produce plants varying in accordance with the
country in which they are sown. For it is the soil that gives to
the seeds the material and the body of the plant. And hence the
part of the female which receives the semen is not a mere
passage, but the uterus has a considerable width, whereas the
males that emit semen have only passages for this purpose, and
these are bloodless.
2073
Each of the secretions becomes such at the moment when it is
in its proper place; before that there is nothing of the sort
unless with much violence and contrary to nature.
We have thus stated the reason for which the generative
secretions are formed in animals. But when the semen from the
male (in those animals which emit semen) has entered, it puts
into form the purest part of the female secretion (for the greater
part of the catamenia also is useless and fluid, as is the most
fluid part of the male secretion, i.e. in a single emission, the
earlier discharge being in most cases apt to be infertile rather
than the later, having less vital heat through want of
concoction, whereas that which is concocted is thick and of a
more material nature).
If there is no external discharge, either in women or other
animals, on account of there not being much useless and
superfluous matter in the secretion, then the quantity forming
within the female altogether is as much as what is retained
within those animals which have an external discharge; this is
put into form by the power of the male residing in the semen
secreted by him, or, as is clearly seen to happen in some insects,
by the part in the female analogous to the uterus being inserted
into the male.
It has been previously stated that the discharge accompanying
sexual pleasure in the female contributes nothing to the
embryo. The chief argument for the opposite view is that what
are called bad dreams occur by night with women as with men;
but this is no proof, for the same thing happens to young men
also who do not yet emit semen, and to those who do emit
semen but whose semen is infertile.
It is impossible to conceive without the emission of the male in
union and without the secretion of the corresponding female
material, whether it be discharged externally or whether there
2074
is only enough within the body. Women conceive, however,
without experiencing the pleasure usual in such intercourse, if
the part chance to be in heat and the uterus to have descended.
But generally speaking the opposite is the case, because the os
uteri is not closed when the discharge takes place which is
usually accompanied by pleasure in women as well as men, and
when this is so there is a readier way for the semen of the male
to be drawn into the uterus.
The actual discharge does not take place within the uterus as
some think, the os uteri being too narrow, but it is in the region
in front of this, where the female discharges the moisture found
in some cases, that the male emits the semen. Sometimes it
remains in this place; at other times, if the uterus chance to be
conveniently placed and hot on account of the purgation of the
catamenia, it draws it within itself. A proof of this is that
pessaries, though wet when applied, are removed dry. Moreover,
in all those animals which have the uterus near the hypozoma,
as birds and viviparous fishes, it is impossible that the semen
should be so discharged as to enter it; it must be drawn into it.
This region, on account of the heat which is in it, attracts the
semen. The discharge and collection of the catamenia also
excite heat in this part. Hence it acts like cone-shaped vessels
which, when they have been washed out with hot water, their
mouth being turned downwards, draw water into themselves.
And this is the way things are drawn up, but some say that
nothing of the kind happens with the organic parts concerned
in copulation. Precisely the opposite is the case of those who
say the woman emits semen as well as the man, for if she emits
it outside the uterus this must then draw it back again into
itself if it is to be mixed with the semen of the male. But this is
a superfluous proceeding, and Nature does nothing superfluous.
When the material secreted by the female in the uterus has
been fixed by the semen of the male (this acts in the same way
2075
as rennet acts upon milk, for rennet is a kind of milk containing
vital heat, which brings into one mass and fixes the similar
material, and the relation of the semen to the catamenia is the
same, milk and the catamenia being of the same nature) -
when, I say, the more solid part comes together, the liquid is
separated off from it, and as the earthy parts solidify
membranes form all round it; this is both a necessary result and
for a final cause, the former because the surface of a mass must
solidify on heating as well as on cooling, the latter because the
foetus must not be in a liquid but be separated from it. Some of
these are called membranes and others choria, the difference
being one of more or less, and they exist in ovipara and vivipara
alike.
When the embryo is once formed, it acts like the seeds of
plants. For seeds also contain the first principle of growth in
themselves, and when this (which previously exists in them
only potentially) has been differentiated, the shoot and the root
are sent off from it, and it is by the root that the plant gets
nourishment; for it needs growth. So also in the embryo all the
parts exist potentially in a way at the same time, but the first
principle is furthest on the road to realization. Therefore the
heart is first differentiated in actuality. This is clear not only to
the senses (for it is so) but also on theoretical grounds. For
whenever the young animal has been separated from both
parents it must be able to manage itself, like a son who has set
up house away from his father. Hence it must have a first
principle from which comes the ordering of the body at a later
stage also, for if it is to come in from outside at later period to
dwell in it, not only may the question be asked at what time it is
to do so, but also we may object that, when each of the parts is
separating from the rest, it is necessary that this principle
should exist first from which comes growth and movement to
the other parts. (Wherefore all who say, as did Democritus, that
the external parts of animals are first differentiated and the
2076
internal later, are much mistaken; it is as if they were talking of
animals of stone or wood. For such as these have no principle of
growth at all, but all animals have, and have it within
themselves.) Therefore it is that the heart appears first
distinctly marked off in all the sanguinea, for this is the first
principle or origin of both homogeneous and heterogeneous
parts, since from the moment that the animal or organism
needs nourishment, from that moment does this deserve to be
called its principle or origin. For the animal grows, and the
nutriment, in its final stage, of an animal is the blood or its
analogue, and of this the blood-vessels are the receptacle,
wherefore the heart is the principle or origin of these also. (This
is clear from the Enquiries and the anatomical drawings.)
Since the embryo is already potentially an animal but an
imperfect one, it must obtain its nourishment from elsewhere;
accordingly it makes use of the uterus and the mother, as a
plant does of the earth, to get nourishment, until it is perfected
to the point of being now an animal potentially locomotive. So
Nature has first designed the two blood-vessels from the heart,
and from these smaller vessels branch off to the uterus. These
are what is called the umbilicus, for this is a blood-vessel,
consisting of one or more vessels in different animals. Round
these is a skin-like integument, because the weakness of the
vessels needs protection and shelter. The vessels join on to the
uterus like the roots of plants, and through them the embryo
receives its nourishment. This is why the animal remains in the
uterus, not, as Democritus says, that the parts of the embryo
may be moulded in conformity with those of the mother. This is
plain in the ovipara, for they have their parts differentiated in
the egg after separation from the matrix.
Here a difficulty may be raised. If the blood is the nourishment,
and if the heart, which first comes into being, already contains
blood, and the nourishment comes from outside, whence did
2077
the first nourishment enter? Perhaps it is not true that all of it
comes from outside just as in the seeds of plants there is
something of this nature, the substance which at first appears
milky, so also in the material of the animal embryo the
superfluous matter of which it is formed is its nourishment
from the first.
The embryo, then, grows by means of the umbilicus in the same
way as a plant by its roots, or as animals themselves when
separated from the nutriment within the mother, of which we
must speak later at the time appropriate for discussing them.
But the parts are not differentiated, as some suppose, because
like is naturally carried to like. Besides many other difficulties
involved in this theory, it results from it that the homogeneous
parts ought to come into being each one separate from the rest,
as bones and sinews by themselves, and flesh by itself, if one
should accept this cause. The real cause why each of them
comes into being is that the secretion of the female is
potentially such as the animal is naturally, and all the parts are
potentially present in it, but none actually. It is also because
when the active and the passive come in contact with each
other in that way in which the one is active and the other
passive (I mean in the right manner, in the right place, and at
the right time), straightway the one acts and the other is acted
upon. The female, then, provides matter, the male the principle
of motion. And as the products of art are made by means of the
tools of the artist, or to put it more truly by means of their
movement, and this is the activity of the art, and the art is the
form of what is made in something else, so is it with the power
of the nutritive soul. As later on in the case of mature animals
and plants this soul causes growth from the nutriment, using
heat and cold as its tools (for in these is the movement of the
soul), and each thing comes into being in accordance with a
certain formula, so also from the beginning does it form the
product of nature. For the material by which this latter grows is
2078
the same as that from which it is constituted at first;
consequently also the power which acts upon it is identical
with that which originally generated it; if then this acting power
is the nutritive soul, this is also the generative soul, and this is
the nature of every organism, existing in all animals and plants.
[But the other parts of the soul exist in some animals, not in
others.] In plants, then, the female is not separated from the
male, but in those animals in which it is separated the male
needs the female besides.
And yet the question may be raised why it is that, if indeed the
female possesses the same soul and if it is the secretion of the
female which is the material of the embryo, she needs the male
besides instead of generating entirely from herself. The reason
is that the animal differs from the plant by having sense-
perception; if the sensitive soul is not present, either actually or
potentially, and either with or without qualification, it is
impossible for face, hand, flesh, or any other part to exist; it will
be no better than a corpse or part of a corpse. If then, when the
sexes are separated, it is the male that has the power of making
the sensitive soul, it is impossible for the female to generate an
animal from itself alone, for the process in question was seen to
involve the male quality. Certainly that there is a good deal in
the difficulty stated is plain in the case of the birds that lay
wind-eggs, showing that the female can generate up to a certain
point unaided. But this still involves a difficulty; in what way
are we to say that their eggs live? It neither possible that they
should live in the same way as fertile eggs (for then they would
produce a chick actually alive), nor yet can they be called eggs
only in the sense in which an egg of wood or stone is so called,
2079
for the fact that these eggs go bad shows that they previously
participate in some way in life. It is plain, then, that they have
some soul potentially. What sort of soul will this be? It must be
the lowest surely, and this is the nutritive, for this exists in all
animals and plants alike. Why then does it not perfect the parts
and the animal? Because they must have a sensitive soul, for
the parts of animals are not like those of a plant. And so the
female animal needs the help of the male, for in these animals
we are speaking of the male is separate. This is exactly what we
find, for the wind-eggs become fertile if the male tread the
female in a certain space of time. About the cause of these
things, however, we shall enter into detail later.
If there is any kind of animal which is female and has no male
separate from it, it is possible that this may generate a young
one from itself without copulation. No instance of this worthy
of credit has been observed up to the present at any rate, but
one case in the class of fishes makes us hesitate. No male of the
so-called erythrinus has ever yet been seen, but females, and
specimens full of roe, have been seen. Of this, however, we have
as yet no proof worthy of credit. Again, some members of the
class of fishes are neither male nor female, as eels and a kind of
mullets found in stagnant waters. But whenever the sexes are
separate the female cannot generate perfectly by herself alone,
for then the male would exist in vain, and Nature makes
nothing in vain. Hence in such animals the male always
perfects the work of generation, for he imparts the sensitive
soul, either by means of the semen or without it. Now the parts
of the embryo already exist potentially in the material, and so
when once the principle of movement has been imparted to
them they develop in a chain one after another, as the wheels
are moved one by another in the automatic machines. When
some of the natural philosophers say that like is brought to like,
this must be understood, not in the sense that the parts are
moved as changing place, but that they stay where they are and
2080
the movement is a change of quality (such as softness,
hardness, colour, and the other differences of the homogeneous
parts); thus they become in actuality what they previously were
in potentiality. And what comes into being first is the first
principle; this is the heart in the sanguinea and its analogue in
the rest, as has been often said already. This is plain not only to
the senses (that it is first to come into being), but also in view of
its end; for life fails in the heart last of all, and it happens in all
cases that what comes into being last fails first, and the first
last, Nature running a double course, so to say, and turning back
to the point from whence she started. For the process of
becoming is from the non-existent to the existent, and that of
perishing is back again from the existent to the non-existent.
After this, as said already, the internal parts come into being
before the external. The greater become visible before the less,
even if some of them do not come into being before them. First
the parts above the hypozoma are differentiated and are
superior in size; the part below is both smaller and less
differentiated. This happens in all animals in which exists the
distinction of upper and lower, except in the insects; the growth
of those that produce a scolex is towards the upper part, for this
is smaller in the beginning. The cephalopoda are the only
locomotive animals in which the distinction of upper and lower
does not exist.
What has been said applies to plants also, that the upper
portion is earlier in development than the lower, for the roots
push out from the seed before the shoots.
2081
The agency by which the parts of animals are differentiated is
air, not however that of the mother nor yet of the embryo itself,
as some of the physicists say. This is manifest in birds, fishes,
and insects. For some of these are separated from the mother
and produced from an egg, within which the differentiation
takes place; other animals do not breathe at all, but are
produced as a scolex or an egg; those which do breathe and
whose parts are differentiated within the mother's uterus yet do
not breathe until the lung is perfected, and the lung and the
preceding parts are differentiated before they breathe.
Moreover, all polydactylous quadrupeds, as dog, lion, wolf, fox,
jackal, produce their young blind, and the eyelids do not
separate till after birth. Manifestly the same holds also in all the
other parts; as the qualitative, so also the quantitative
differentia comes into being, pre-existing potentially but being
actualized later by the same causes by which the qualitative
distinction is produced, and so the eyelids become two instead
of one. Of course air must be present, because heat and
moisture are present, the former acting and the latter being
acted upon.
Some of the ancient nature-philosolphers made an attempt to
state which part comes into being after which, but were not
sufficiently acquainted with the facts. It is with the parts as
with other things; one naturally exists prior to another. But the
word 'prior' is used in more senses than one. For there is a
difference between the end or final cause and that which exists
for the sake of it; the latter is prior in order of development, the
former is prior in reality. Again, that which exists for the sake of
the end admits of division into two classes, (1) the origin of the
movement, (2) that which is used by the end; I mean, for
instance, (1) that which can generate, (2) that which serves as
an instrument to what is generated, for the one of these, that
which makes, must exist first, as the teacher before the learner,
and the other later, as the pipes are later than he who learns to
2082
play upon them, for it is superfluous that men who do not know
how to play should have pipes. Thus there are three things: first,
the end, by which we mean that for the sake of which
something else exists; secondly, the principle of movement and
of generation, existing for the sake of the end (for that which
can make and generate, considered simply as such, exists only
in relation to what is made and generated); thirdly, the useful,
that is to say what the end uses. Accordingly, there must first
exist some part in which is the principle of movement (I say a
part because this is from the first one part of the end and the
most important part too); next after this the whole and the end;
thirdly and lastly, the organic parts serving these for certain
uses. Hence if there is anything of this sort which must exist in
animals, containing the principle and end of all their nature,
this must be the first to come into being - first, that is,
considered as the moving power, but simultaneous with the
whole embryo if considered as a part of the end. Therefore all
the organic parts whose nature is to bring others into being
must always themselves exist before them, for they are for the
sake of something else, as the beginning for the sake of the end;
all those parts which are for the sake of something else but are
not of the nature of beginnings must come into being later. So it
is not easy to distinguish which of the parts are prior, those
which are for the sake of another or that for the sake of which
are the former. For the parts which cause the movement, being
prior to the end in order of development, come in to cause
confusion, and it is not easy to distinguish these as compared
with the organic parts. And yet it is in accordance with this
method that we must inquire what comes into being after what;
for the end is later than some parts and earlier than others. And
for this reason that part which contains the first principle
comes into being first, next to this the upper half of the body.
This is why the parts about the head, and particularly the eyes,
appear largest in the embryo at an early stage, while the parts
2083
below the umbilicus, as the legs, are small; for the lower parts
are for the sake of the upper, and are neither parts of the end
nor able to form it.
But they do not say well nor do they assign a necessary cause
who say simply that 'it always happens so', and imagine that
this is a first principle in these cases. Thus Democritus of
Abdera says that 'there is no beginning of the infinite; now the
cause is a beginning, and the eternal is infinite; in consequence,
to ask the cause of anything of this kind is to seek for a
beginning of the infinite'. Yet according to this argument, which
forbids us to seek the cause, there will be no proof of any
eternal truth whatever; but we see that there is a proof of many
such, whether by 'eternal' we mean what always happens or
what exists eternally; it is an eternal truth that the angles of a
triangle are always equal to two right angles, or that the
diagonal of a square is incommensurable with the side, and
nevertheless a cause and a proof can be given for these truths.
While, then, it is well said that we must not take on us to seek a
beginning (or first principle) of all things, yet this is not well
said of all things whatever that always are or always happen,
but only of those which really are first principles of the eternal
things; for it is by another method, not by proof, that we acquire
knowledge of the first principle. Now in that which is
immovable and unchanging the first principle is simply the
essence of the thing, but when we come to those things which
come into being the principles are more than one, varying in
kind and not all of the same kind; one of this number is the
principle of movement, and therefore in all the sanguinea the
heart is formed first, as was said at the beginning, and in the
other animals that which is analogous to the heart.
From the heart the blood-vessels extend throughout the body as
in the anatomical diagrams which are represented on the wall,
for the parts lie round these because they are formed out of
2084
them. The homogeneous parts are formed by heat and cold, for
some are put together and solidified by the one and some by
the other. The difference between these has already been
discussed elsewhere, and it has been stated what kinds of
things are soluble by liquid and fire, and what are not soluble by
liquid and cannot be melted by fire. The nutriment then oozes
through the blood-vessels and the passages in each of the parts,
like water in unbaked pottery, and thus is formed the flesh or its
analogues, being solidified by cold, which is why it is also
dissolved by fire. But all the particles given off which are too
earthy, having but little moisture and heat, cool as the moisture
evaporates along with the heat; so they become hard and earthy
in character, as nails, horns, hoofs, and beaks, and therefore
they are softened by fire but none of them is melted by it, while
some of them, as egg-shells, are soluble in liquids. The sinews
and bones are formed by the internal heat as the moisture dries,
and hence the bones are insoluble by fire like pottery, for like it
they have been as it were baked in an oven by the heat in the
process of development. But it is not anything whatever that is
made into flesh or bone by the heat, but only something
naturally fitted for the purpose; nor is it made in any place or
time whatever, but only in a place and time naturally so fitted.
For neither will that which exists potentially be made except by
that moving agent which possesses the actuality, nor will that
which possesses the actuality make anything whatever; the
carpenter would not make a box except out of wood, nor will a
box be made out of the wood without the carpenter. The heat
exists in the seminal secretion, and the movement and activity
in it is sufficient in kind and in quantity to correspond to each
of the parts. In so far as there is any deficiency or excess, the
resulting product is in worse condition or physically defective,
in like manner as in the case of external substances which are
thickened by boiling that they may be more palatable or for any
other purpose. But in the latter case it is we who apply the heat
2085
in due measure for the motion required; in the former it is the
nature of the male parent that gives it, or with animals
spontaneously generated it is the movement and heat imparted
by the right season of the year that it is the cause.
Cooling, again, is mere deprivation of heat. Nature makes use of
both; they have of necessity the power of bringing about
different results, but in the development of the embryo we find
that the one cools and the other heats for some definite
purpose, and so each of the parts is formed; thus it is in one
sense by necessity, in another for a final cause, that they make
the flesh soft, the sinews solid and elastic, the bones solid and
brittle. The skin, again, is formed by the drying of the flesh, like
the scum upon boiled substances; it is so formed not only
because it is on the outside, but also because what is glutinous,
being unable to evaporate, remains on the surface. While in
other animals the glutinous is dry, for which reason the
covering of the invertebrates is testaceous or crustaceous, in the
vertebrates it is rather of the nature of fat. In all of these which
are not of too earthy a nature the fat is collected under the
covering of the skin, a fact which points to the skin being
formed out of such a glutinous substance, for fat is somewhat
glutinous. As we said, all these things must be understood to be
formed in one sense of necessity, but in another sense not of
necessity but for a final cause.
The upper half of the body, then, is first marked out in the order
of development; as time goes on the lower also reaches its full
size in the sanguinea. All the parts are first marked out in their
outlines and acquire later on their colour and softness or
hardness, exactly as if Nature were a painter producing a work
of art, for painters, too, first sketch in the animal with lines and
only after that put in the colours.
2086
Because the source of the sensations is in the heart, therefore
this is the part first formed in the whole animal, and because of
the heat of this organ the cold forms the brain, where the blood-
vessels terminate above, corresponding to the heat of the heart.
Hence the parts about the head begin to form next in order after
the heart, and surpass the other parts in size, for the brain is
from the first large and fluid.
There is a difficulty about what happens with the eyes of
animals. Though from the beginning they appear very large in
all creatures, whether they walk or swim or fly, yet they are the
last of the parts to be formed completely, for in the intervening
time they collapse. The reason is this. The sense-organ of the
eyes is set upon certain passages, as are the other sense-organs.
Whereas those of touch and taste are simply the body itself or
some part of the body of animals, those of smell and hearing
are passages connecting with the external air and full
themselves of innate spiritus; these passages end at the small
blood-vessels about the brain which run thither from the heart.
But the eye is the only sense-organ that has a bodily
constitution peculiar to itself. It is fluid and cold, and does not
exist from the first in the place which it occupies later in the
same way as the other parts do, for they exist potentially to
begin with and actually come into being later, but the eye is the
purest part of the liquidity about the brain drained off through
the passages which are visible running from them to the
membrane round the brain. A proof of this is that, apart from
the brain, there is no other part in the head that is cold and
fluid except the eye. Of necessity therefore this region is large at
first but falls in later. For the same thing happens with the
brain; at first it is liquid and large, but in course of evaporation
and concoction it becomes more solid and falls in; this applies
both to the brain and the eyes. The head is very large at first, on
account of the brain, and the eyes appear large because of the
liquid in them. They are the last organs to reach completion
2087
because the brain is formed with difficulty; for it is at a late
period that it gets rid of its coldness and fluidity; this applies to
all animals possessing a brain, but especially to man. For this
reason the 'bregma' is the last of the bones to be formed; even
after birth this bone is still soft in children. The cause of this
being so with men more than with other animals is the fact that
their brain is the most fluid and largest. This again is because
the heat in man's heart is purest. His intellect shows how well
he is tempered, for man is the wisest of animals. And children
for a long time have no control over their heads on account of
the heaviness of the brain; and the same applies to the parts
which it is necessary to move, for it is late that the principle of
motion gets control over the upper parts, and last of all over
those whose motion is not connected directly with it, as that of
the legs is not. Now the eyelid is such a part. But since Nature
makes nothing superfluous nor in vain, it is clear also that she
makes nothing too late or too soon, for if she did the result
would be either in vain or superfluous. Hence it is necessary
that the eyelids should be separated at the same time as the
heart is able to move them. So then the eyes of animals are
perfected late because of the amount of concoction required by
the brain, and last of all the parts because the motion must be
very strong before it can affect parts so far from the first
principle of motion and so cold. And it is plain that such is the
nature of the eyelids, for if the head is affected by never so little
heaviness through sleepiness or drunkenness or anything else
of the kind, we cannot raise the eyelids though their own
weight is so small. So much for the question how the eyes come
into being, and why and for what cause they are the last to be
fully developed.
Each of the other parts is formed out of the nutriment, those
most honourable and participating in the sovereign principle
from the nutriment which is first and purest and fully
concocted, those which are only necessary for the sake of the
2088
former parts from the inferior nutriment and the residues left
over from the other. For Nature, like a good householder, is not
in the habit of throwing away anything from which it is possible
to make anything useful. Now in a household the best part of
the food that comes in is set apart for the free men, the inferior
and the residue of the best for the slaves, and the worst is given
to the animals that live with them. Just as the intellect acts thus
in the outside world with a view to the growth of the persons
concerned, so in the case of the embryo itself does Nature form
from the purest material the flesh and the body of the other
sense-organs, and from the residues thereof bones, sinews, hair,
and also nails and hoofs and the like; hence these are last to
assume their form, for they have to wait till the time when
Nature has some residue to spare.
The bones, then, are made in the first conformation of the parts
from the seminal secretion or residue. As the animal grows the
bones grow from the natural nourishment, being the same as
that of the sovereign parts, but of this they only take up the
superfluous residues. For everywhere the nutriment may be
divided into two kinds, the first and the second; the former is
'nutritious', being that which gives its essence both to the whole
and to the parts; the latter is concerned with growth, being that
which causes quantitative increase. But these must be
distinguished more fully later on. The sinews are formed in the
same way as the bones and out of the same materials, the
Seminal and nutritious residue. Nails, hair, hoofs, horns, beaks,
the spurs of cocks, and any other similar parts, are on the
contrary formed from the nutriment which is taken later and
only concerned with growth, in other words that which is
derived from the mother, or from the outer world after birth. For
this reason the bones on the one hand only grow up to a certain
point (for there is a limit of size in all animals, and therefore
also of the growth of the bones; if these had been always able to
grow, all animals that have bone or its analogue would grow as
2089
long as they lived, for these set the limit of size to animals.
What is the reason of their not always increasing in size must
be stated later.) Hair, on the contrary, and growths akin to hair
go on growing as long as they exist at all, and increase yet more
in diseases and when the body is getting old and wasting,
because more residual matter is left over, as owing to old age
and disease less is expended on the important parts, though
when the residual matter also fails through age the hair fails
with it. But the contrary is the case with the bones, for they
waste away along with the body and the other parts. Hair
actually goes on growing after death; it does not, however, begin
growing then.
About the teeth a difficulty may be raised. They have actually
the same nature as the bones, and are formed out of the bones,
but nails, hair, horns, and the like are formed out of the skin,
and that is why they change in colour along with it, for they
become white, black, and all sorts of colours according to that of
the skin. But the teeth do nothing of the sort, for they are made
out of the bones in all animals that have both bones and teeth.
Of all the bones they alone go on growing through life, as is
plain with the teeth which grow out of the straight line so as no
longer to touch each other. The reason for their growth, as a
final cause, is their function, for they would soon be worn down
if there were not some means of saving them; even as it is they
are altogether worn down in old age in some animals which eat
much and have not large teeth, their growth not being in
proportion to their detrition. And so Nature has contrived well
to meet the case in this also, for she causes the failure of the
teeth to synchronize with old age and death. If life lasted for a
thousand or ten thousand years the original teeth must have
been very large indeed, and many sets of them must have been
produced, for even if they had grown continuously they would
still have been worn smooth and become useless for their work.
The final cause of their growth has been now stated, but besides
2090
this as a matter of fact the growth of the teeth is not the same
as that of the other bones. The latter all come into being in the
first formation of the embryo and none of them later, but the
teeth do so later. Therefore it is possible for them to grow again
after the first set falls out, for though they touch the bones they
are not connate with them. They are formed, however, out of
the nutriment distributed to the bones, and so have the same
nature, even when the bones have their own number complete.
Other animals are born in possession of teeth or their analogue
(unless in cases contrary to Nature), because when they are set
free from the parent they are more perfect than man; but man
(also unless in cases contrary to Nature) is born without them.
The reason will be stated later why some teeth are formed and
fall out but others do not fall out.
It is because such parts are formed from a residue that man is
the most naked in body of all animals and has the smallest
nails in proportion to his size; he has the least amount of earthy
residue, but that part of the blood which is not concocted is the
residue, and the earthy part in the bodies of all animals is the
least concocted. We have now stated how each of the parts is
formed and what is the cause of their generation.
In viviparous animals, as said before, the embryo gets its growth
through the umbilical cord. For since the nutritive power of the
soul, as well as the others, is present in animals, it straightway
sends off this cord like a root to the uterus. The cord consists of
blood-vessels in a sheath, more numerous in the larger animals
as cattle and the like, one in the smallest, two in those of
2091
intermediate size. Through this cord the embryo receives its
nourishment in the form of blood, for the uterus is the
termination of many blood-vessels. All animals with no front
teeth in the upper jaw, and all those which have them in both
jaws and whose uterus has not one great blood-vessel running
through it but many close together instead - all these have in
the uterus the so-called cotyledons (with which the umbilical
cord connects and is closely united; for the vessels which pass
through the cord run backwards and forwards between embryo
and uterus and split up into smaller vessels all over the uterus;
where they terminate, there are found the cotyledons). Their
convexity is turned towards the uterus, the concavity towards
the embryo. Between uterus and embryo are the chorion and
the membranes. As the embryo grows and approaches
perfection the cotyledons become smaller and finally disappear
when it is perfected. For Nature sends the sanguineous
nutriment for the embryo into this part of the uterus as she
sends milk into the breasts, and because the cotyledons are
gradually aggregated from many into a few the body of the
cotyledon becomes like an eruption or inflammation. So long as
the embryo is comparatively small, being unable to receive
much nutriment, they are plain and large, but when it has
increased in size they fall in together.
But most of the animals which have front teeth in both jaws
and no horns have no cotyledons in the uterus, but the
umbilical cord runs to meet one blood-vessel, which is large and
extends throughout the uterus. Of such animals some produce
one young at a time, some more than one, but the same
description applies to both these classes. (This should be
studied with the aid of the examples drawn in the Anatomy and
the Enquiries.) For the young, if numerous, are attached each to
its umbilical cord, and this to the blood-vessel of the mother;
they are arranged next to one another along the stream of the
2092
blood-vessel as along a canal; and each embryo is enclosed in
its membranes and chorion.
Those who say that children are nourished in the uterus by
sucking some lump of flesh or other are mistaken. If so, the
same would have been the case with other animals, but as it is
we do not find this (and this can easily be observed by
dissection). Secondly, all embryos alike, whether of creatures
that fly or swim or walk, are surrounded by fine membranes
separating them from the uterus and from the fluids which are
formed in it; but neither in these themselves is there anything
of the kind, nor is it possible for the embryo to take
nourishment by means of any of them. Thirdly, it is plain that
all creatures developed in eggs grow when separated from the
uterus.
Natural intercourse takes place between animals of the same
kind. However, those also unite whose nature is near akin and
whose form is not very different, if their size is much the same
and if the periods of gestation are equal. In other animals such
cases are rare, but they occur with dogs and foxes and wolves;
the Indian dogs also spring from the union of a dog with some
wild dog-like animal. A similar thing has been seen to take
place in those birds that are amative, as partridges and hens.
Among birds of prey hawks of different form are thought to
unite, and the same applies to some other birds. Nothing worth
mentioning has been observed in the inhabitants of the sea, but
the so-called 'rhinobates' especially is thought to spring from
the union of the 'rhini' and 'batus'. And the proverb about Libya,
that 'Libya is always producing something new', is said to have
originated from animals of different species uniting with one
another in that country, for it is said that because of the want of
water all meet at the few places where springs are to be found,
and that even different kinds unite in consequence.
2093
Of the animals that arise from such union all except mules are
found to copulate again with each other and to be able to
produce young of both sexes, but mules alone are sterile, for
they do not generate by union with one another or with other
animals. The problem why any individual, whether male or
female, is sterile is a general one, for some men and women are
sterile, and so are other animals in their several kinds, as horses
and sheep. But this kind, of mules, is universally so. The causes
of sterility in other animals are several. Both men and women
are sterile from birth when the parts useful for union are
imperfect, so that men never grow a beard but remain like
eunuchs, and women do not attain puberty; the same thing may
befall others as their years advance, sometimes on account of
the body being too well nourished (for men who are in too good
condition and women who are too fat the seminal secretion is
taken up into the body, and the former have no semen, the
latter no catamenia); at other times by reason of sickness men
emit the semen in a cold and liquid state, and the discharges of
women are bad and full of morbid secretions. Often, too, in both
sexes this state is caused by injuries in the parts and regions
contributory to copulation. Some such cases are curable, others
incurable, but the subjects especially remain sterile if anything
of the sort has happened in the first formation of the parts in
the embryo, for then are produced women of a masculine and
men of a feminine appearance, and in the former the catamenia
do not occur, in the latter the semen is thin and cold. Hence it is
with good reason that the semen of men is tested in water to
find out if it is infertile, for that which is thin and cold is quickly
spread out on the surface, but the fertile sinks to the bottom, for
that which is well concocted is hot indeed, but that which is
firm and thick is well concocted. They test women by pessaries
to see if the smells thereof permeate from below upwards to the
breath from the mouth and by colours smeared upon the eyes
to see if they colour the saliva. If these results do not follow it is
2094
a sign that the passages of the body, through which the
catamenia are secreted, are clogged and closed. For the region
about the eyes is, of all the head, that most nearly connected
with the generative secretions; a proof of this is that it alone is
visibly changed in sexual intercourse, and those who indulge
too much in this are seen to have their eyes sunken in. The
reason is that the nature of the semen is similar to that of the
brain, for the material of it is watery (the heat being acquired
later). And the seminal purgations are from the region of the
diaphragm, for the first principle of nature is there, so that the
movements from the pudenda are communicated to the chest,
and the smells from the chest are perceived through the
respiration.
8
In men, then, and in other kinds, as said before, such deficiency
occurs sporadically, but the whole of the mule kind is sterile.
The reason has not been rightly given by Empedocles and
Democritus, of whom the former expresses himself obscurely,
the latter more intelligibly. For they offer their demonstration in
the case of all these animals alike which unite against their
affinities. Democritus says that the genital passages of mules
are spoilt in the mother's uterus because the animals from the
first are not produced from parents of the same kind. But we
find that though this is so with other animals they are none the
less able to generate; yet, if this were the reason, all others that
unite in this manner ought to be barren. Empedocles assigns as
his reason that the mixture of the 'seeds' becomes dense, each
of the two seminal fluids out of which it is made being soft, for
the hollows in each fit into the densities of the other, and in
such cases a hard substance is formed out of soft ones, like
2095
bronze mingled with tin. Now he does not give the correct
reason in the case of bronze and tin - (we have spoken of them
in the Problems) - nor, to take general ground, does he take his
principles from the intelligible. How do the 'hollows' and 'solids'
fit into one another to make the mixing, e.g. in the case of wine
and water? This saying is quite beyond us; for how we are to
understand the 'hollows' of the wine and water is too far
beyond our perception. Again, when, as a matter of fact, horse is
born of horse, ass of ass, and mule of horse and ass in two ways
according as the parents are stallion and she-ass or jackass and
mare, why in the last case does there result something so
'dense' that the offspring is sterile, whereas the offspring of
male and female horse, male and female ass, is not sterile? And
yet the generative fluid of the male and female horse is soft. But
both sexes of the horse cross with both sexes of the ass, and the
offspring of both crosses are barren, according to Empedocles,
because from both is produced something 'dense', the 'seeds'
being 'soft'. If so, the offspring of stallion and mare ought also to
be sterile. If one of them alone united with the ass, it might be
said that the cause of the mule's being unable to generate was
the unlikeness of that one to the generative fluid of the ass; but,
as it is, whatever be the character of that generative fluid with
which it unites in the ass, such it is also in the animal of its own
kind. Then, again, the argument is intended to apply to both
male and female mules alike, but the male does generate at
seven years of age, it is said; it is the female alone that is
entirely sterile, and even she is so only because she does not
complete the development of the embryo, for a female mule has
been known to conceive.
Perhaps an abstract proof might appear to be more plausible
than those already given; I call it abstract because the more
general it is the further is it removed from the special principles
involved. It runs somewhat as follows. From male and female of
the same species there are born in course of nature male and
2096
female of the same species as the parents, e.g. male and female
puppies from male and female dog. From parents of different
species is born a young one different in species; thus if a dog is
different from a lion, the offspring of male dog and lioness or of
lion and bitch will be different from both parents. If this is so,
then since (1) mules are produced of both sexes and are not
different in species from one another, and (2) a mule is born of
horse and ass and these are different in species from mules, it
is impossible that anything should be produced from mules. For
(1) another kind cannot be, because the product of male and
female of the same species is also of the same species, and (2) a
mule cannot be, because that is the product of horse and ass
which are different in form, [and it was laid down that from
parents different in form is born a different animal]. Now this
theory is too general and empty. For all theories not based on
the special principles involved are empty; they only appear to
be connected with the facts without being so really. As
geometrical arguments must start from geometrical principles,
so it is with the others; that which is empty may seem to be
something, but is really nothing. Now the basis of this particular
theory is not true, for many animals of different species are
fertile with one another, as was said before. So we must not
inquire into questions of natural science in this fashion any
more than any other questions; we shall be more likely to find
the reason by considering the facts peculiar to the two kinds
concerned, horse and ass. In the first place, each of them, if
mated with its own kind, bears only one young one; secondly,
the females are not always able to conceive from the male
(wherefore breeders put the horse to the mare again at
intervals). Indeed, both the mare is deficient in catamenia,
discharging less than any other quadruped, and the she-ass
does not admit the impregnation, but ejects the semen with her
urine, wherefore men follow flogging her after intercourse.
Again the ass is an animal of cold nature, and so is not wont to
2097
be produced in wintry regions because it cannot bear cold, as in
Scythia and the neighbouring country and among the Celts
beyond Iberia, for this country also is cold. For this cause they
do not put the jackasses to the females at the equinox, as they
do with horses, but about the summer solstice, in order that the
ass-foals may be born in a warm season, for the mothers bear at
the same season as that in which they are impregnated, the
period of gestation in both horse and ass being one year. The
animal, then, being, as has been said of such a cold nature, its
semen also must be cold. A proof of this is that if a horse mount
a female already impregnated by an ass he does not destroy the
impregnation of the ass, but if the ass be the second to mount
her he does destroy that of the horse because of the coldness of
his own semen. When, therefore, they unite with each other, the
generative elements are preserved by the heat of the one of
them, that contributed by the horse being the hotter; for in the
ass both the semen of the male and the material contributed by
the female are cold, and those of the horse, in both sexes, are
hotter. Now when either hot is added to cold or cold to hot so as
to mix, the result is that the embryo itself arising from these is
preserved and thus these animals are fertile when crossed with
one another, but the animal produced by them is no longer
fertile but unable to produce perfect offspring.
And in general each of these animals naturally tends towards
sterility. The ass has all the disadvantages already mentioned,
and if it should not begin to generate after the first shedding of
teeth, it no longer generates at all; so near is the constitution of
the ass to being sterile. The horse is much the same; it tends
naturally towards sterility, and to make it entirely so it is only
necessary that its generative secretion should become colder;
now this is what happens to it when mixed with the
corresponding secretion of the ass. The ass in like manner
comes very near generating a sterile animal when mated with
its own species. Thus when the difficulty of a cross contrary to
2098
nature is added, (when too even in the other case when united
with their own species they with difficulty produce a single
young one), the result of the cross, being still more sterile and
contrary to nature, will need nothing further to make it sterile,
but will be so of necessity.
We find also that the bodies of female mules grow large because
the matter which is secreted in other animals to form the
catamenia is diverted to growth. But since the period of
gestation in such animals is a year, the mule must not only
conceive, if she is to be fertile, but must also nourish the
embryo till birth, and this is impossible if there are no
catamenia. But there are none in the mule; the useless part of
the nutriment is discharged with the excretion from the bladder
- this is why male mules do not smell to the pudenda of the
females, as do the other solid-hoofed ungulates, but only to the
evacuation itself - and the rest of the nutriment is used up to
increase the size of the body. Hence it is sometimes possible for
the female to conceive, as has been known to happen before
now, but it is impossible for her to complete the process of
nourishing the embryo and bringing it to birth.
The male, again, may sometimes generate, both because the
male sex is naturally hotter than the female and because it does
not contribute any material substance to the mixture. The result
in such cases is a 'ginnus', that is to say, a dwarf mule; for 'ginni'
are produced also from the crossing of horse and ass when the
embryo is diseased in the uterus. The ginnus is in fact like the
so-called 'metachoera' in swine, for a 'metachoerum' also is a
pig injured in the uterus; this may happen to any pig. The origin
of human dwarfs is similar, for these also have their parts and
their whole development injured during gestation, and
resemble ginni and metachoera.
2099
Book III
We have now spoken about the sterility of mules, and about
those animals which are viviparous both externally and within
themselves. The generation of the oviparous sanguinea is to a
certain extent similar to that of the animals that walk, and all
may be embraced in the same general statement; but in other
respects there are differences in them both as compared with
each other and with those that walk. All alike are generated
from sexual union, the male emitting semen into the female.
But among the ovipara (1) birds produce a perfect hard-shelled
egg, unless it be injured by disease, and the eggs of birds are all
two-coloured. (2) The cartilaginous fishes, as has been often
said already, are oviparous internally but produce the young
alive, the egg changing previously from one part of the uterus to
another; and their egg is soft-shelled and of one colour. One of
this class alone does not produce the young from the egg within
itself, the so-called 'frog'; the reason of which must be stated
later. (3) All other oviparous fishes produce an egg of one colour,
but this is imperfect, for its growth is completed outside the
mother's body by the same cause as are those eggs which are
perfected within.
Concerning the uterus of these classes of animals, what
differences there are among them and for what reasons, has
been stated previously. For in some of the viviparous creatures it
is high up near the hypozoma, in others low down by the
2100
pudenda; the former in the cartilaginous fishes, the latter in
animals both internally and externally viviparous, such as man
and horse and the rest; in the ovipara it is sometimes low, as in
the oviparous fish, and sometimes high, as in birds.
Some embryos are formed in birds spontaneously, which are
called wind-eggs and 'zephyria' by some; these occur in birds
which are not given to flight nor rapine but which produce
many young, for these birds have much residual matter,
whereas in the birds of prey all such secretion is diverted to the
wings and wing-feathers, while the body is small and dry and
hot. (The secretion corresponding in hen-birds to catamenia,
and the semen of the cock, are residues.) Since then both the
wings and the semen are made from residual matter, nature
cannot afford to spend much upon both. And for this same
reason the birds of prey are neither given to treading much nor
to laying many eggs, as are the heavy birds and those flying
birds whose bodies are bulky, as the pigeon and so forth. For
such residual matter is secreted largely in the heavy birds not
given to flying, such as fowls, partridges, and so on, wherefore
their males tread often and their females produce much
material. Of such birds some lay many eggs at a time and some
lay often; for instance, the fowl, the partridge, and the Libyan
ostrich lay many eggs, while the pigeon family do not lay many
but lay often. For these are between the birds of prey and the
heavy ones; they are flyers like the former, but have bulky
bodies like the latter; hence, because they are flyers and the
residue is diverted that, way, they lay few eggs, but they lay
often because of their having bulky bodies and their stomachs
being hot and very active in concoction, and because moreover
they can easily procure their food, whereas the birds of prey do
so with difficulty.
Small birds also tread often and are very fertile, as are
sometimes small plants, for what causes bodily growth in
2101
others turn in them to a seminal residuum. Hence the Adrianic
fowls lay most eggs, for because of the smallness of their bodies
the nutriment is used up in producing young. And other birds
are more fertile than game-fowl, for their bodies are more fluid
and bulkier, whereas those of game-fowl are leaner and drier,
since a passionate spirit is found rather in such bodies as the
latter. Moreover the thinness and weakness of the legs
contribute to making the former class of birds naturally inclined
to tread and to be fertile, as we find also in the human species;
for the nourishment which otherwise goes to the legs is turned
in such into a seminal secretion, what Nature takes from the
one place being added at the other. Birds of prey, on the
contrary, have a strong walk and their legs are thick owing to
their habits, so that for all these reasons they neither tread nor
lay much. The kestrel is the most fertile; for this is nearly the
only bird of prey which drinks, and its moisture, both innate
and acquired, along with its heat is favourable to generative
products. Even this bird does not lay very many eggs, but four at
the outside.
The cuckoo, though not a bird of prey, lays few eggs, because it
is of a cold nature, as is shown by the cowardice of the bird,
whereas a generative animal should be hot and moist. That it is
cowardly is plain, for it is pursued by all the birds and lays eggs
in the nests of others.
The pigeon family are in the habit of laying two for the most
part, for they neither lay one (no bird does except the cuckoo,
and even that sometimes lays two) nor yet many, but they
frequently produce two, or three at the most generally two, for
this number lies between one and many.
It is plain from the facts that with the birds that lay many eggs
the nutriment is diverted to the semen. For most trees, if they
bear too much fruit, wither away after the crop when nutriment
2102
is not reserved for themselves, and this seems to be what
happens to annuals, as leguminous plants, corn, and the like.
For they consume all their nutriment to make seed, their kind
being prolific. And some fowls after laying too much, so as even
to lay two eggs in a day, have died after this. For both the birds
the plants become exhausted, and this condition is an excess of
secretion of residual matter. A similar condition is the cause of
the later sterility of the lioness, for at the first birth she
produces five or six, then in the next year four, and again three
cubs, then the next number down to one, then none at all,
showing that the residue is being used up and the generative
secretion is failing along with the advance of years.
We have now stated in which birds wind-eggs are found, and
also what sort of birds lay many eggs or few, and for what
reasons. And wind-eggs, as said before, come into being because
while it is the material for generation that exists in the female
of all animals, birds have no discharge of catamenia like
viviparous sanguinea (for they occur in all these latter, more in
some, less in others, and in some only enough in quantity just
to mark the class). The same applies to fish as to birds, and so in
them as in birds is found an embryonic formation without
impregnation, but it is less obvious because their nature is
colder. The secretion corresponding to the catamenia of vivipara
is formed in birds at the appropriate season for the discharge of
superfluous matter, and, because the region near the hypozoma
is hot, it is perfected so far as size is concerned, but in birds and
fishes alike it is imperfect for generation without the seminal
fluid of the male; the cause of this has been previously given.
Wind-eggs are not formed in the flying birds, for the same
reason as prevents their laying many eggs; for the residual
matter in birds of prey is small, and they need the male to give
an impulse for the discharge of it. The wind-eggs are produced
in greater numbers than the impregnated but smaller in size for
one and the same reason; they are smaller in size because they
2103
are imperfect, and because they are smaller in size they are
more in number. They are less pleasant for food because they
are less concocted, for in all foods the concocted is more
agreeable. It has been sufficiently observed, then, that neither
birds' nor fishes' eggs are perfected for generation without the
males. As for embryos being formed in fish also (though in a
less degree) without the males, the fact has been observed
especially in river fish, for some are seen to have eggs from the
first, as has been written in the Enquiries concerning them. And
generally speaking in the case of birds even the impregnated
eggs are not wont for the most part to attain their full growth
unless the hen be trodden continually. The reason of this is that
just as with women intercourse with men draws down the
secretion of the catamenia (for the uterus being heated attracts
the moisture and the passages are opened), so this happens
also with birds; the residual matter corresponding to the
catamenia advances a little at a time, and is not discharged
externally, because its amount is small and the uterus is high
up by the hypozoma, but trickles together into the uterus itself.
For as the embryo of the vivipara grows by means of the
umbilical cord, so the egg grows through this matter flowing to
it through the uterus. For when once the hens have been
trodden, they all continue to have eggs almost without
intermission, though very small ones. Hence some are wont to
speak of wind-eggs as not coming into being independently but
as mere relics from a previous impregnation. But this is a false
view, for sufficient observations have been made of their arising
without impregnation in chickens and goslings. Also the female
partridges which are taken out to act as decoys, whether they
have ever been impregnated or not, immediately on smelling
the male and hearing his call, become filled with eggs in the
latter case and lay them in the former. The reason why this
happens is the same as in men and quadrupeds, for if their
bodies chance to be in rut they emit semen at the mere sight of
2104
the female or at a slight touch. And such birds are of a
lascivious and fertile nature, so that the impulse they need is
but small when they are in this excited condition, and the
secreting activity takes place quickly in them, wind-eggs
forming in the unimpregnated and the eggs in those which have
been impregnated growing and reaching perfection swiftly.
Among creatures that lay eggs externally birds produce their
egg perfect, fish imperfect, but the eggs of the latter complete
their growth outside as has been said before. The reason is that
the fish kind is very fertile; now it is impossible for many eggs
to reach completion within the mother and therefore they lay
them outside. They are quickly discharged, for the uterus of
externally oviparous fishes is near the generative passage.
While the eggs of birds are two-coloured, those of all fish are
one-coloured. The cause of the double colour may be seen from
considering the power of each of the two parts, the white and
the yolk. For the matter of the egg is secreted from the blood
[No bloodless animal lays eggs,] and that the blood is the
material of the body has been often said already. The one part,
then, of the egg is nearer the form of the animal coming into
being, that is the hot part; the more earthy part gives the
substance of the body and is further removed. Hence in all two-
coloured eggs the animal receives the first principle of
generation from the white (for the vital principle is in that
which is hot), but the nutriment from the yolk. Now in animals
of a hotter nature the part from which the first principle arises
is separated off from the part from which comes the nutriment,
the one being white and the other yellow, and the white and
pure is always more than the yellow and earthy; but in the
moister and less hot the yolk is more in quantity and more
fluid. This is what we find in lake birds, for they are of a moister
nature and are colder than the land birds, so that the so-called
'lecithus' or yolk in the eggs of such birds is large and less
yellow because the white is less separated off from it. But when
2105
we come to the ovipara which are both of a cold nature and also
moister (such is the fish kind) we find the white not separated
at all because of the small size of the eggs and the quantity of
the cold and earthy matter; therefore all fish eggs are of one
colour, and white compared with yellow, yellow compared with
white. Even the wind-eggs of birds have this distinction of
colour, for they contain that out of which will come each of the
two parts, alike that whence arises the principle of life and that
whence comes the nutriment; only both these are imperfect
and need the influence of the male in addition; for wind-eggs
become fertile if impregnated by the male within a certain
period. The difference in colour, however, is not due to any
difference of sex, as if the white came from the male, the yolk
from the female; both on the contrary come from the female,
but the one is cold, the other hot. In all cases then where the
hot part is considerable it is separated off, but where it is little it
cannot be so; hence the eggs of such animals, as has been said,
are of one colour. The semen of the male only puts them into
form; and therefore at first the egg in birds appears white and
small, but as it advances it is all yellow as more of the
sanguineous material is continually mixed with it; finally as the
hot part is separated the white takes up a position all round it
and equally distributed on all sides, as when a liquid boils; for
the white is naturally liquid and contains in itself the vital heat;
therefore it is separated off all round, but the yellow and earthy
part is inside. And if we enclose many eggs together in a bladder
or something of the kind and boil them over a fire so as not to
make the movement of the heat quicker than the separation of
the white and yolk in the eggs, then the same process takes
place in the whole mass of the eggs as in a single egg, all the
yellow part coming into the middle and the white surrounding
it.
We have thus stated why some eggs are of one colour and
others of two.
2106
The principle of the male is separated off in eggs at the point
where the egg is attached to the uterus, and the reason why the
shape of two-coloured eggs is unsymmetrical, and not perfectly
round but sharper at one end, is that the part of the white in
which is contained this principle must differ from the rest.
Therefore the egg is harder at this point than below, for it is
necessary to shelter and protect this principle. And this is why
the sharp end of the egg comes out of the hen later than the
blunt end; for the part attached to the uterus comes out later,
and the egg is attached at the point where is the said principle,
and the principle is in the sharp end. The same is the case also
in the seeds of plants; the principle of the seed is attached
sometimes to the twig, sometimes to the husk, sometimes to
the pericarp. This is plain in the leguminous plants, for where
the two cotyledons of beans and of similar seeds are united,
there is the seed attached to the parent plant, and there is the
principle of the seed.
A difficulty may be raised about the growth of the egg; how is it
derived from the uterus? For if animals derive their nutriment
through the umbilical cord, through what do eggs derive it?
They do not, like a scolex, acquire their growth by their own
means. If there is anything by which they are attached to the
uterus, what becomes of this when the egg is perfected? It does
not come out with the egg as the cord does with animals; for
when its egg is perfected the shell forms all round it. This
problem is rightly raised, but it is not observed that the shell is
at first only a soft membrane, and that it is only after the egg is
perfected that it becomes hard and brittle; this is so nicely
adjusted that it is still soft when it comes out (for otherwise it
2107
would cause pain in laying), but no sooner has it come out than
it is fixed hard by cooling, the moisture quickly evaporating
because there is but little of it, and the earthy part remaining.
Now at first a certain part of this membrane at the sharp end of
eggs resembles an umbilical cord, and projects like a pipe from
them while they are still small. It is plainly visible in small
aborted eggs, for if the bird be drenched with water or suddenly
chilled in any other way and cast out the egg too soon, it
appears still sanguineous and with a small tail like an umbilical
cord running through it. As the egg becomes larger this is more
twisted round and becomes smaller, and when the egg is
perfected this end is the sharp end. Under this is the inner
membrane which separates the white and the yolk from this.
When the egg is perfected, the whole of it is set free, and
naturally the umbilical cord does not appear, for it is now the
extreme end of the egg itself.
The egg is discharged in the opposite way from the young of
vivipara; the latter are born head-first, the part where is the first
principle leading, but the egg is discharged as it were feet first;
the reason of this being what has been stated, that the egg is
attached to the uterus at the point where is the first principle.
The young bird is produced out of the egg by the mother's
incubating and aiding the concoction, the creature developing
out of part of the egg, and receiving growth and completion
from the remaining part. For Nature not only places the
material of the creature in the egg but also the nourishment
sufficient for its growth; for since the mother bird cannot
perfect her young within herself she produces the nourishment
in the egg along with it. Whereas the nourishment, what is
called milk, is produced for the young of vivipara in another
part, in the breasts, Nature does this for birds in the egg. The
opposite, however, is the case to what people think and what is
asserted by Alcmaeon of Crotona. For it is not the white that is
2108
the milk, but the yolk, for it is this that is the nourishment of
the chick, whereas they think it is the white because of the
similarity of colour.
The chick then, as has been said, comes into being by the
incubation of the mother; yet if the temperature of the season is
favourable, or if the place in which the eggs happen to lie is
warm, the eggs are sufficiently concocted without incubation,
both those of birds and those of oviparous quadrupeds. For
these all lay their eggs upon the ground, where they are
concocted by the heat in the earth. Such oviparous quadrupeds
as do visit their eggs and incubate do so rather for the sake of
protecting them than of incubation.
The eggs of these quadrupeds are formed in the same way as
those of birds, for they are hard-shelled and two-coloured, and
they are formed near the hypozoma as are those of birds, and in
all other respects resemble them both internally and externally,
so that the inquiry into their causes is the same for all. But
whereas the eggs of quadrupeds are hatched out by the mere
heat of the weather owing to their strength, those of birds are
more exposed to destruction and need the mother-bird. Nature
seems to wish to implant in animals a special sense of care for
their young: in the inferior animals this lasts only to the
moment of giving birth to the incompletely developed animal;
in others it continues till they are perfect; in all that are more
intelligent, during the bringing up of the young also. In those
which have the greatest portion in intelligence we find
familiarity and love shown also towards the young when
perfected, as with men and some quadrupeds; with birds we
find it till they have produced and brought up their young, and
therefore if the hens do not incubate after laying they get into
worse condition, as if deprived of something natural to them.
2109
The young is perfected within the egg more quickly in sunshiny
weather, the season aiding in the work, for concoction is a kind
of heat. For the earth aids in the concoction by its heat, and the
brooding hen does the same, for she applies the heat that is
within her. And it is in the hot season, as we should expect, that
the eggs are more apt to be spoilt and the so-called 'uria' or
rotten eggs are produced; for just as wines turn sour in the
heats from the sediment rising (for this is the cause of their
being spoilt), so is it with the yolk in eggs, for the sediment and
yolk are the earthy part in each case, wherefore the wine
becomes turbid when the sediment mixes with it, and the like
applies to the eggs that are spoiling because of the yolk. It is
natural then that such should be the case with the birds that lay
many eggs, for it is not easy to give the fitting amount of heat to
all, but (while some have too little) others have too much and
this makes them turbid, as it were by putrefaction. But this
happens none the less with the birds of prey though they lay
few eggs, for often one of the two becomes rotten, and the third
practically always, for being of a hot nature they make the
moisture in the eggs to overboil so to say. For the nature of the
white is opposed to that of the yolk; the yolk congeals in frosts
but liquefies on heating, and therefore it liquefies on concoction
in the earth or by reason of incubation, and becoming liquid
serves as nutriment for the developing chick. If exposed to heat
and roasted it does not become hard, because though earthy in
nature it is only so in the same way as wax is; accordingly on
heating too much the eggs become watery and rotten, [if they be
not from a liquid residue]. The white on the contrary is not
congealed by frost but rather liquefies (the reason of which has
been stated before), but on exposure to heat becomes solid.
Therefore being concocted in the development of the chick it is
thickened. For it is from this that the young is formed (whereas
the yolk turns to nutriment) and it is from this that the parts
derive their growth as they are formed one after another. This is
2110
why the white and the yolk are separated by membranes, as
being different in nature. The precise details of the relation of
the parts to one another both at the beginning of generation
and as the animals are forming, and also the details of the
membranes and umbilical cords, must be learnt from what has
been written in the Enquiries; for the present investigation it is
sufficient to understand this much clearly, that, when the heart
has been first formed and the great blood-vessel has been
marked off from it, two umbilical cords run from the vessel, the
one to the membrane which encloses the yolk, the other to the
membrane resembling a chorion which surrounds the whole
embryo; this latter runs round on the inside of the membrane of
the shell. Through the one of these the embryo receives the
nutriment from the yolk, and the yolk becomes larger, for it
becomes more liquid by heating. This is because the
nourishment, being of a material character in its first form,
must become liquid before it can be absorbed, just as it is with
plants, and at first this embryo, whether in an egg or in the
mother's uterus, lives the life of a plant, for it receives its first
growth and nourishment by being attached to something else.
The second umbilical cord runs to the surrounding chorion. For
we must understand that, in the case of animals developed in
eggs, the chick has the same relation to the yolk as the embryo
of the vivipara has to the mother so long as it is within the
mother (for since the nourishment of the embryo of the ovipara
is not completed within the mother, the embryo takes part of it
away from her). So also the relation of the chick to the
outermost membrane, the sanguineous one, is like that of the
mammalian embryo to the uterus. At the same time the egg-
shell surrounds both the yolk and the membrane analogous to
the uterus, just as if it should be put round both the embryo
itself and the whole of the mother, in the vivipara. This is so
because the embryo must be in the uterus and attached to the
mother. Now in the vivipara the uterus is within the mother, but
2111
in the ovipara it is the other way about, as if one should say that
the mother was in the uterus, for that which comes from the
mother, the nutriment, is the yolk. The reason is that the
process of nourishment is not completed within the mother.
As the creature grows the umbilicus running the chorion
collapses first, because it is here that the young is to come out;
what is left of the yolk, and the umbilical cord running to the
yolk, collapse later. For the young must have nourishment as
soon as it is hatched; it is not nursed by the mother and cannot
immediately procure its nourishment for itself; therefore the
yolk enters within it along with its umbilicus and the flesh
grows round it.
This then is the manner in which animals produced from
perfect eggs are hatched in all those, whether birds or
quadrupeds, which lay the egg with a hard shell. These details
are plainer in the larger creatures; in the smaller they are
obscure because of the smallness of the masses concerned.
The class of fishes is also oviparous. Those among them which
have the uterus low down lay an imperfect egg for the reason
previously given, but the so-called 'selache' or cartilaginous
fishes produce a perfect egg within themselves but are
externally viviparous except one which they call the 'frog'; this
alone lays a perfect egg externally. The reason is the nature of
its body, for its head is many times as large as the rest of the
body and is spiny and very rough. This is also why it does not
receive its young again within itself nor produce them alive to
begin with, for as the size and roughness of the head prevents
their entering so it would prevent their exit. And while the egg
2112
of the cartilaginous fishes is soft-shelled (for they cannot
harden and dry its circumference, being colder than birds), the
egg of the frog-fish alone is solid and firm to protect it outside,
but those of the rest are of a moist and soft nature, for they are
sheltered within and by the body of the mother.
The young are produced from the egg in the same way both
with those externally perfected (the frog-fishes) and those
internally, and the process in these eggs is partly similar to,
partly different from that in birds' eggs. In the first place they
have not the second umbilicus which runs to the chorion under
the surrounding shell. The reason of this is that they have not
the surrounding shell, for it is no use to them since the mother
shelters them, and the shell is a protection to the eggs against
external injury between laying and hatching out. Secondly, the
process in these also begins on the surface of the egg but not
where it is attached to the uterus, as in birds, for the chick is
developed from the sharp end and that is where the egg was
attached. The reason is that the egg of birds is separated from
the uterus before it is perfected, but in most though not all
cartilaginous fishes the egg is still attached to the uterus when
perfect. While the young develops upon the surface the egg is
consumed by it just as in birds and the other animals detached
from the uterus, and at last the umbilicus of the now perfect
fish is left attached to the uterus. The like is the case with all
those whose eggs are detached from the uterus, for in some of
them the egg is so detached when it is perfect.
The question may be asked why the development of birds and
cartilaginous fishes differs in this respect. The reason is that in
birds the white and yolk are separate, but fish eggs are one-
coloured, the corresponding matter being completely mixed, so
that there is nothing to stop the first principle being at the
opposite end, for the egg is of the same nature both at the point
of attachment and at the opposite end, and it is easy to draw
2113
the nourishment from the uterus by passages running from this
principle. This is plain in the eggs which are not detached, for in
some of the cartilaginous fish the egg is not detached from the
uterus, but is still connected with it as it comes downwards
with a view to the production of the young alive; in these the
young fish when perfected is still connected by the umbilicus to
the uterus when the egg has been consumed. From this it is
clear that previously also, while the egg was still round the
young, the passages ran to the uterus. This happens as we have
said in the 'smooth hound'.
In these respects and for the reasons given the development of
cartilaginous fishes differs from that of birds, but otherwise it
takes place in the same way. For they have the one umbilicus in
like manner as that of birds connecting with the yolk, - only in
these fishes it connects with the whole egg (for it is not divided
into white and yolk but all one-coloured), - and get their
nourishment from this, and as it is being consumed the flesh in
like manner encroaches upon and grows round it.
Such is the process of development in those fish that produce a
perfect egg within themselves but are externally viviparous.
Most of the other fish are externally oviparous, all laying an
imperfect egg except the frog-fish; the reason of this exception
has been previously stated, and the reason also why the others
lay imperfect eggs. In these also the development from the egg
runs on the same lines as that of the cartilaginous and
internally oviparous fishes, except that the growth is quick and
from small beginnings and the outside of the egg is harder. The
growth of the egg is like that of a scolex, for those animals
2114
which produce a scolex give birth to a small thing at first and
this grows by itself and not through any attachment to the
parent. The reason is similar to that of the growth of yeast, for
yeast also grows great from a small beginning as the more solid
part liquefies and the liquid is aerated. This is effected in
animals by the nature of the vital heat, in yeasts by the heat of
the juice commingled with them. The eggs then grow of
necessity through this cause (for they have in them superfluous
yeasty matter), but also for the sake of a final cause, for it is
impossible for them to attain their whole growth in the uterus
because these animals have so many eggs. Therefore are they
very small when set free and grow quickly, small because the
uterus is narrow for the multitude of the eggs, and growing
quickly that the race may not perish, as it would if much of the
time required for the whole development were spent in this
growth; even as it is most of those laid are destroyed before
hatching. Hence the class of fish is prolific, for Nature makes up
for the destruction by numbers. Some fish actually burst
because of the size of the eggs, as the fish called 'belone', for its
eggs are large instead of numerous, what Nature has taken
away in number being added in size.
So much for the growth of such eggs and its reason.
A proof that these fish also are oviparous is the fact that even
viviparous fish, such as the cartilaginous, are first internally
oviparous, for hence it is plain that the whole class of fishes is
oviparous. Where, however, both sexes exist and the eggs are
produced in consequence of impregnation, the eggs do not
arrive at completion unless the male sprinkle his milt upon
2115
them. Some erroneously assert that all fish are female except in
the cartilaginous fishes, for they think that the females of fish
differ from what are supposed to be males only in the same way
as in those plants where the one bears fruit but the other is
fruitless, as olive and oleaster, fig and caprifig. They think the
like applies to fish except the cartilaginous, for they do not
dispute the sexes in these. And yet there is no difference in the
males of cartilaginous fishes and those belonging to the
oviparous class in respect of the organs for the milt, and it is
manifest that semen can be squeezed out of males of both
classes at the right season. The female also has a uterus. But if
the whole class were females and some of them unproductive
(as with mules in the class of bushy-tailed animals), then not
only should those which lay eggs have a uterus but also the
others, only the uterus of the latter should be different from
that of the former. But, as it is, some of them have organs for
milt and others have a uterus, and this distinction obtains in all
except two, the erythrinus and the channa, some of them
having the milt organs, others a uterus. The difficulty which
drives some thinkers to this conclusion is easily solved if we
look at the facts. They say quite correctly that no animal which
copulates produces many young, for of all those that generate
from themselves perfect animals or perfect eggs none is prolific
on the same scale as the oviparous fishes, for the number of
eggs in these is enormous. But they had overlooked the fact that
fish-eggs differ from those of birds in one circumstance. Birds
and all oviparous quadrupeds, and any of the cartilaginous fish
that are oviparous, produce a perfect egg, and it does not
increase outside of them, whereas the eggs of fish are imperfect
and do so complete their growth. Moreover the same thing
applies to cephalopods also and Crustacea, yet these animals
are actually seen copulating, for their union lasts a long time,
and it is plain in these cases that the one is male and the other
has a uterus. Finally, it would be strange if this distinction did
2116
not exist in the whole class, just as male and female in all the
vivipara. The cause of the ignorance of those who make this
statement is that the differences in the copulation and
generation of various animals are of all kinds and not obvious,
and so, speculating on a small induction, they think the same
must hold good in all cases.
So also those who assert that conception in female fishes is
caused by their swallowing the semen of the male have not
observed certain points when they say this. For the males have
their milt and the females their eggs at about the same time of
year, and the nearer the female is to laying the more abundant
and the more liquid is the milt formed in the male. And just as
the increase of the milt in the male and of the roe in the female
takes place at the same time, so is it also with their emission,
for neither do the females lay all their eggs together, but
gradually, nor do the males emit all the milt at once. All these
facts are in accordance with reason. For just as the class of birds
in some cases has eggs without impregnation, but few and
seldom, impregnation being generally required, so we find the
same thing, though to a less degree, in fish. But in both classes
these spontaneous eggs are infertile unless the male, in those
kinds where the male exists, shed his fluid upon them. Now in
birds this must take place while the eggs are still within the
mother, because they are perfect when discharged, but in fish,
because the eggs are imperfect and complete their growth
outside the mother in all cases, those outside are preserved by
the sprinkling of the milt over them, even if they come into
being by impregnation, and here it is that the milt of the males
is used up. Therefore it comes down the ducts and diminishes
in quantity at the same time as this happens to the eggs of the
females, for the males always attend them, shedding their milt
upon the eggs as they are laid. Thus then they are male and
female, and all of them copulate (unless in any kind the
2117
distinction of sex does not exist), and without the semen of the
male no such animal comes into being.
What helps in the deception is also the fact that the union of
such fishes is brief, so that it is not observed even by many of
the fishermen, for none of them ever watches anything of the
sort for the sake of knowledge. Nevertheless their copulation
has been seen, for fish [when the tail part does not prevent it]
copulate like the dolphins by throwing themselves alongside of
one another. But the dolphins take longer to get free again,
whereas such fishes do so quickly. Hence, not seeing this, but
seeing the swallowing of the milt and the eggs, even the
fishermen repeat the same simple tale, so much noised abroad,
as Herodotus the storyteller, as if fish were conceived by the
mother's swallowing the milt, - not considering that this is
impossible. For the passage which enters by way of the mouth
runs to the intestines, not to the uterus, and what goes into the
intestines must be turned into nutriment, for it is concocted;
the uterus, however, is plainly full of eggs, and from whence did
they enter it?
A similar story is told also of the generation of birds. For there
are some who say that the raven and the ibis unite at the
mouth, and among quadrupeds that the weasel brings forth its
young by the mouth; so say Anaxagoras and some of the other
physicists, speaking too superficially and without consideration.
Concerning the birds, they are deceived by a false reasoning,
because the copulation of ravens is seldom seen, but they are
often seen uniting with one another with their beaks, as do all
the birds of the raven family; this is plain with domesticated
2118
jackdaws. Birds of the pigeon kind do the same, but, because
they also plainly copulate, therefore they have not had the same
legend told of them. But the raven family is not amorous, for
they are birds that produce few young, though this bird also has
been seen copulating before now. It is a strange thing, however,
that these theorists do not ask themselves how the semen
enters the uterus through the intestine, which always concocts
whatever comes into it, as the nutriment; and these birds have
a uterus like others, and eggs are found them near the
hypozoma. And the weasel has a uterus in like manner to the
other quadrupeds; by what passage is the embryo to get from it
to the mouth? But this opinion has arisen because the young of
the weasel are very small like those of the other fissipeds, of
which we shall speak later, and because they often carry the
young about in their mouths.
Much deceived also are those who make a foolish statement
about the trochus and the hyena. Many say that the hyena, and
Herodorus the Heracleot says that the trochus, has two
pudenda, those of the male and of the female, and that the
trochus impregnates itself but the hyena mounts and is
mounted in alternate years. This is untrue, for the hyena has
been seen to have only one pudendum, there being no lack of
opportunity for observation in some districts, but hyenas have
under the tail a line like the pudendum of the female. Both
male and female have such a mark, but the males are taken
more frequently; this casual observation has given rise to this
opinion. But enough has been said of this.
2119
Touching the generation of fish, the question may be raised,
why it is that in the cartilaginous fish neither the females are
seen discharging their eggs nor the males their milt, whereas in
the non-viviparous fishes this is seen in both sexes. The reason
is that the whole cartilaginous class do not produce much
semen, and further the females have their uterus near
hypozoma. For the males and females of the one class of fish
differ from the males and females of the other class in like
manner, for the cartilaginous are less productive of semen. But
in the oviparous fish, as the females lay their eggs on account of
their number, so do the males shed their milt on account of its
abundance. For they have more milt than just what is required
for copulation, as Nature prefers to expend the milt in helping
to perfect the eggs, when the female has deposited them, rather
than in forming them at first. For as has been said both further
back and in our recent discussions, the eggs of birds are
perfected internally but those of fish externally. The latter,
indeed, resemble in a way those animals which produce a
scolex, for the product discharged by them is still more
imperfect than a fish's egg. It is the male that brings about the
perfection of the egg both of birds and of fishes, only in the
former internally, as they are perfected internally, and in the
latter externally, because the egg is imperfect when deposited;
but the result is the same in both cases.
In birds the wind-eggs become fertile, and those previously
impregnated by one kind of cock change their nature to that of
the later cock. And if the eggs be behindhand in growth, then, if
the same cock treads the hen again after leaving off treading for
a time, he causes them to increase quickly, not, however, at any
period whatever of their development, but if the treading take
place before the egg changes so far that the white begins to
separate from the yolk. But in the eggs of fishes no such limit of
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time has been laid down, but the males shed their milt quickly
upon them to preserve them. The reason is that these eggs are
not two-coloured, and hence there is no such limit of time fixed
with them as with those of birds. This fact is what we should
expect, for by the time that the white and yolk are separated off
from one another, the birds egg already contains the principle
that comes from the male parent.... for the male contributes to
this.
Wind-eggs, then, participate in generation so far as is possible
for them. That they should be perfected into an animal is
impossible, for an animal requires sense-perception; but the
nutritive faculty of the soul is possessed by females as well as
males, and indeed by all living things, as has been often said,
wherefore the egg itself is perfect only as the embryo of a plant,
but imperfect as that of an animal. If, then, there had been no
male sex in the class of birds, the egg would have been
produced as it is in some fishes, if indeed there is any kind of
fish of such a nature as to generate without a male; but it has
been said of them before that this has not yet been
satisfactorily observed. But as it is both sexes exist in all birds,
so that, considered as a plant, the egg is perfect, but in so far as
it is not a plant it is not perfect, nor does anything else result
from it; for neither has it come into being simply like a real
plant nor from copulation like an animal. Eggs, however,
produced from copulation but already separated into white and
yolk take after the first cock; for they already contain both
principles, which is why they do not change again after the
second impregnation.
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8
The young are produced in the same way also by the
cephalopoda, e.g. sepias and the like, and by the Crustacea, e.g.
carabi and their kindred, for these also lay eggs in consequence
of copulation, and the male has often been seen uniting with
the female. Therefore those who say that all fish are female and
lay eggs without copulation are plainly speaking unscientifically
from this point of view also. For it is a wonderful thing to
suppose that the former animals lay eggs in consequence of
copulation and that fish do not; if again they were unaware of
this, it is a sign of ignorance. The union of all these creatures
lasts a considerable time, as in insects, and naturally so, for they
are bloodless and therefore of a cold nature.
In the sepias and calamaries or squids the eggs appear to be
two, because the uterus is divided and appears double, but that
of the poulps appears to be single. The reason is that the shape
of the uterus in the poulp is round in form and spherical, the
cleavage being obscure when it is filled with eggs. The uterus of
the carabi is also bifid. All these animals also lay an imperfect
egg for the same reason as fishes. In the carabi and their like
the females produce their eggs so as to keep them attached to
themselves, which is why the side-flaps of the females are
larger than those of the males, to protect the eggs; the
cephalopoda lay them away from themselves. The males of the
cephalopoda sprinkle their milt over the females, as the male
fish do over the eggs, and it becomes a sticky and glutinous
mass, but in the carabi and their like nothing of the sort has
been seen or can be naturally expected, for the egg is under the
female and is hard-shelled. Both these eggs and those of the
cephalopoda grow after deposition like those of fishes.
The sepia while developing is attached to the egg by its front
part, for here alone is it possible, because this animal alone has
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its front and back pointing in the same direction. For the
position and attitude of the young while developing you must
look at the Enquiries.
We have now spoken of the generation of other animals, those
that walk, fly, and swim; it remains to speak of insects and
testacea according to the plan laid down. Let us begin with the
insects. It was observed previously that some of these are
generated by copulation, others spontaneously, and besides this
that they produce a scolex, and why this is so. For pretty much
all creatures seem in a certain way to produce a scolex first,
since the most imperfect embryo is of such a nature; and in all
animals, even the viviparous and those that lay a perfect egg,
the first embryo grows in size while still undifferentiated into
parts; now such is the nature of the scolex. After this stage
some of the ovipara produce the egg in a perfect condition,
others in an imperfect, but it is perfected outside as has been
often stated of fish. With animals internally viviparous the
embryo becomes egg-like in a certain sense after its original
formation, for the liquid is contained in a fine membrane, just
as if we should take away the shell of the egg, wherefore they
call the abortion of an embryo at that stage an 'efflux'.
Those insects which generate at all generate a scolex, and those
which come into being spontaneously and not from copulation
do so at first from a formation this nature. I say that the former
generate a scolex, for we must put down caterpillars also and
the product of spiders as a sort of scolex. And yet some even of
these and many of the others may be thought to resemble eggs
because of their round shape, but we must not judge by shapes
2123
nor yet by softness and hardness (for what is produced by some
is hard), but by the fact that the whole of them is changed into
the body of the creature and the animal is not developed from a
part of them. All these products that are of the nature of a
scolex, after progressing and acquiring their full size, become a
sort of egg, for the husk about them hardens and they are
motionless during this period. This is plain in the scolex of bees
and wasps and in caterpillars. The reason of this is that their
nature, because of its imperfection, oviposits as it were before
the right time, as if the scolex, while still growing in size, were a
soft egg. Similar to this is also what happens with all other
insects which come into being without copulation in wool and
other such materials and in water. For all of them after the
scolex stage become immovable and their integument dries
round them, and after this the latter bursts and there comes
forth as from an egg an animal perfected in its second
metamorphosis, most of those which are not aquatic being
winged.
Another point is quite natural, which may wondered at by
many. Caterpillars at first take nourishment, but after this stage
do so no longer, but what is called by some the chrysalis is
motionless. The same applies to the scolex of wasps and bees,
but after this comes into being the so-called nymph.... and have
nothing of the kind. For an egg is also of such a nature that
when it has reached perfection it grows no more in size, but at
first it grows and receives nourishment until it is differentiated
and becomes a perfect egg. Sometimes the scolex contains in
itself the material from which it is nourished and obtains such
an addition to its size, e.g. in bees and wasps; sometimes it gets
its nourishment from outside itself, as caterpillars and some
others.
It has thus been stated why such animals go through a double
development and for what reason they become immovable
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again after moving. And some of them come into being by
copulation, like birds and vivipara and most fishes, others
spontaneously, like some plants.
10
There is much difficulty about the generation of bees. If it is
really true that in the case of some fishes there is such a
method of generation that they produce eggs without
copulation, this may well happen also with bees, to judge from
appearances. For they must (1) either bring the young brood
from elsewhere, as some say, and if so the young must either be
spontaneously generated or produced by some other animal, or
(2) they must generate them themselves, or (3) they must bring
some and generate others, for this also is maintained by some,
who say that they bring the young of the drones only. Again, if
they generate them it must be either with or without
copulation; if the former, then either (1) each kind must
generate its own kind, or (2) some one kind must generate the
others, or (3) one kind must unite with another for the purpose
(I mean for instance (1) that bees may be generated from the
union of bees, drones from that of drones, and kings from that
of kings, or (2) that all the others may be generated from one, as
from what are called kings and leaders, or (3) from the union of
drones and bees, for some say that the former are male, the
latter female, while others say that the bees are male and the
drones female). But all these views are impossible if we reason
first upon the facts peculiar to bees and secondly upon those
which apply more generally to other animals also.
For if they do not generate the young but bring them from
elsewhere, then bees ought to come into being also, if the bees
2125
did not carry them off, in the places from which the old bees
carry the germs. For why, if new bees come into existence when
the germs are transported, should they not do so if the germs
are left there? They ought to do so just as much, whether the
germs are spontaneously generated in the flowers or whether
some animal generates them. And if the germs were of some
other animal, then that animal ought to be produced from them
instead of bees. Again, that they should collect honey is
reasonable, for it is their food, but it is strange that they should
collect the young if they are neither their own offspring nor
food. With what object should they do so? for all animals that
trouble themselves about the young labour for what appears to
be their own offspring.
But, again, it is also unreasonable to suppose that the bees are
female and the drones male, for Nature does not give weapons
for fighting to any female, and while the drones are stingless all
the bees have a sting. Nor is the opposite view reasonable, that
the bees are male and the drones female, for no males are in
the habit of working for their offspring, but as it is the bees do
this. And generally, since the brood of the drones is found
coming into being among them even if there is no mature drone
present, but that of the bees is not so found without the
presence of the kings (which is why some say that the young of
the drones alone is brought in from outside), it is plain that they
are not produced from copulation, either (1) of bee with bee or
drone with drone or (2) of bees with drones. (That they should
import the brood of the drones alone is impossible for the
reasons already given, and besides it is unreasonable that a
similar state of things should not prevail with all the three
kinds if it prevails with one.) Then, again, it is also impossible
that the bees themselves should be some of them male and
some female, for in all kinds of animals the two sexes differ.
Besides they would in that case generate their own kind, but as
it is their brood is not found to come into being if the leaders
2126
are not among them, as men say. And an argument against both
theories, that the young are generated by union of the bees with
one another or with the drones, separately or with one another,
is this: none of them has ever yet been seen copulating,
whereas this would have often happened if the sexes had
existed in them. It remains then, if they are generated by
copulation at all, that the kings shall unite to generate them.
But the drones are found to come into being even if no leaders
are present, and it is not possible that the bees should either
import their brood or themselves generate them by copulation.
It remains then, as appears to be the case in certain fishes, that
the bees should generate the drones without copulation, being
indeed female in respect of generative power, but containing in
themselves both sexes as plants do. Hence also they have the
instrument of offence, for we ought not to call that female in
which the male sex is not separated. But if this is found to be
the case with drones, if they come into being without
copulation, then as it is necessary that the same account should
be given of the bees and the kings and that they also should be
generated without copulation. Now if the brood of the bees had
been found to come into being among them without the
presence of the kings, it would necessarily follow that the bees
also are produced from bees themselves without copulation, but
as it is, since those occupied with the tendance of these
creatures deny this, it remains that the kings must generate
both their own kind and the bees.
As bees are a peculiar and extraordinary kind of animal so also
their generation appears to be peculiar. That bees should
generate without copulation is a thing which may be paralleled
in other animals, but that what they generate should not be of
the same kind is peculiar to them, for the erythrinus generates
an erythrinus and the channa a channa. The reason is that bees
themselves are not generated like flies and similar creatures,
but from a kind different indeed but akin to them, for they are
2127
produced from the leaders. Hence in a sort of way their
generation is analogous. For the leaders resemble the drones in
size and the bees in possessing a sting; so the bees are like
them in this respect, and the drones are like them in size. For
there must needs be some overlapping unless the same kind is
always to be produced from each; but this is impossible, for at
that rate the whole class would consist of leaders. The bees,
then, are assimilated to them their power of generation, the
drones in size; if the latter had had a sting also they would have
been leaders, but as it is this much of the difficulty has been
solved, for the leaders are like both kinds at once, like the bees
in possessing a sting, like the drones in size.
But the leaders also must be generated from something. Since it
is neither from the bees nor from the drones, it must be from
their own kind. The grubs of the kings are produced last and are
not many in number.
Thus what happens is this: the leaders generate their own kind
but also another kind, that of the bees; the bees again generate
another kind, the drones, but do not also generate their own
kind, but this has been denied them. And since what is
according to Nature is always in due order, therefore it is
necessary that it should be denied to the drones even to
generate another kind than themselves. This is just what we
find happening, for though the drones are themselves
generated, they generate nothing else, but the process reaches
its limit in the third stage. And so beautifully is this arranged by
Nature that the three kinds always continue in existence and
none of them fails, though they do not all generate.
Another fact is also natural, that in fine seasons much honey is
collected and many drones are produced but in rainy reasons a
large brood of ordinary bees. For the wet causes more residual
matter to be formed in the bodies of the leaders, the fine
2128
weather in that of the bees, for being smaller in size they need
the fine weather more than the kings do. It is right also that the
kings, being as it were made with a view to producing young,
should remain within, freed from the labour of procuring
necessaries, and also that they should be of a considerable size,
their bodies being, as it were, constituted with a view to bearing
young, and that the drones should be idle as having no weapon
to fight for the food and because of the slowness of their bodies.
But the bees are intermediate in size between the two other
kinds, for this is useful for their work, and they are workers as
having to support not only their young but also their fathers.
And it agrees with our views that the bees attend upon their
kings because they are their offspring (for if nothing of the sort
had been the case the facts about their leadership would be
unreasonable), and that, while they suffer the kings to do no
work as being their parents, they punish the drones as their
children, for it is nobler to punish one's children and those who
have no work to perform. The fact that the leaders, being few,
generate the bees in large numbers seems to be similar to what
obtains in the generation of lions, which at first produce five,
afterwards a smaller number each time at last one and
thereafter none. So the leaders at first produce a number of
workers, afterwards a few of their own kind; thus the brood of
the latter is smaller in number than that of the former, but
where Nature has taken away from them in number she has
made it up again in size.
Such appears to be the truth about the generation of bees,
judging from theory and from what are believed to be the facts
about them; the facts, however, have not yet been sufficiently
grasped; if ever they are, then credit must be given rather to
observation than to theories, and to theories only if what they
affirm agrees with the observed facts.
2129
A further indication that bees are produced without copulation
is the fact that the brood appears small in the cells of the comb,
whereas, whenever insects are generated by copulation, the
parents remain united for a long time but produce quickly
something of the nature of a scolex and of a considerable size.
Concerning the generation of animals akin to them, as hornets
and wasps, the facts in all cases are similar to a certain extent,
but are devoid of the extraordinary features which characterize
bees; this we should expect, for they have nothing divine about
them as the bees have. For the so-called 'mothers' generate the
young and mould the first part of the combs, but they generate
by copulation with one another, for their union has often been
observed. As for all the differences of each of these kind from
one another and from bees, they must be investigated with the
aid of the illustrations to the Enquiries.
11
Having spoken of the generation of all insects, we must now
speak of the testacea. Here also the facts of generation are
partly like and partly unlike those in the other classes. And this
is what might be expected. For compared with animals they
resemble plants, compared with plants they resemble animals,
so that in a sense they appear to come into being from semen,
but in another sense not so, and in one way they are
spontaneously generated but in another from their own kind, or
some of them in the latter way, others in the former. Because
their nature answers to that of plants, therefore few or no kinds
of testacea come into being on land, e.g. the snails and any
others, few as they are, that resemble them; but in the sea and
similar waters there are many of all kinds of forms. But the
2130
class of plants has but few and one may say practically no
representatives in the sea and such places, all such growing on
the land. For plants and testacea are analogous; and in
proportion as liquid has more quickening power than solid,
water than earth, so much does the nature of testacea differ
from that of plants, since the object of testacea is to be in such a
relation to water as plants are to earth, as if plants were, so to
say, land-oysters, oysters water-plants.
For such a reason also the testacea in the water vary more in
form than those on the land. For the nature of liquid is more
plastic than that of earth and yet not much less material, and
this is especially true of the inhabitants of the sea, for fresh
water, though sweet and nutritious, is cold and less material.
Wherefore animals having no blood and not of a hot nature are
not produced in lakes nor in the fresher among brackish waters,
but only exceptionally, but it is in estuaries and at the mouths
of rivers that they come into being, as testacea and cephalopoda
and Crustacea, all these being bloodless and of a cold nature. For
they seek at the same time the warmth of the sun and food;
now the sea is not only water but much more material than
fresh water and hot in its nature; it has a share in all the parts
of the universe, water and air and earth, so that it also has a
share in all living things which are produced in connexion with
each of these elements. Plants may be assigned to land, the
aquatic animals to water, the land animals to air, but variations
of quantity and distance make a great and wonderful difference.
The fourth class must not be sought in these regions, though
there certainly ought to be some animal corresponding to the
element of fire, for this is counted in as the fourth of the
elementary bodies. But the form which fire assumes never
appears to be peculiar to it, but it always exists in some other of
the elements, for that which is ignited appears to be either air
or smoke or earth. Such a kind of animal must be sought in the
moon, for this appears to participate in the element removed in
2131
the third degree from earth. The discussion of these things
however belongs to another subject.
To return to testacea, some of them are formed spontaneously,
some emit a sort of generative substance from themselves, but
these also often come into being from a spontaneous formation.
To understand this we must grasp the different methods of
generation in plants; some of these are produced from seed,
some from slips, planted out, some by budding off alongside, as
the class of onions. In the last way produced mussels, for
smaller ones are always growing off alongside the original, but
the whelks, the purple-fish, and those which are said to 'spawn'
emit masses of a liquid slime as if originated by something of a
seminal nature. We must not, however, consider that anything
of the sort is real semen, but that these creatures participate in
the resemblance to plants in the manner stated above. Hence
when once one such creature has been produced, then is
produced a number of them. For all these creatures are liable to
be even spontaneously generated, and so to be formed still
more plentifully in proportion if some are already existing. For it
is natural that each should have some superfluous residue
attached to it from the original, and from this buds off each of
the creatures growing alongside of it. Again, since the nutriment
and its residue possess a like power, it is likely that the product
of those testacea which 'spawn' should resemble the original
formation, and so it is natural that a new animal of the same
kind should come into being from this also.
All those which do not bud off or 'spawn' are spontaneously
generated. Now all things formed in this way, whether in earth
or water, manifestly come into being in connexion with
putrefaction and an admixture of rain-water. For as the sweet is
separated off into the matter which is forming, the residue of
the mixture takes such a form. Nothing comes into being by
putrefying, but by concocting; putrefaction and the thing
2132
putrefied is only a residue of that which is concocted. For
nothing comes into being out of the whole of anything, any
more than in the products of art; if it did art would have
nothing to do, but as it is in the one case art removes the
useless material, in the other Nature does so. Animals and
plants come into being in earth and in liquid because there is
water in earth, and air in water, and in all air is vital heat so
that in a sense all things are full of soul. Therefore living things
form quickly whenever this air and vital heat are enclosed in
anything. When they are so enclosed, the corporeal liquids
being heated, there arises as it were a frothy bubble. Whether
what is forming is to be more or less honourable in kind
depends on the embracing of the psychical principle; this again
depends on the medium in which the generation takes place
and the material which is included. Now in the sea the earthy
matter is present in large quantities, and consequently the
testaceous animals are formed from a concretion of this kind,
the earthy matter hardening round them and solidifying in the
same manner as bones and horns (for these cannot be melted
by fire), and the matter (or body) which contains the life being
included within it.
The class of snails is the only class of such creatures that has
been seen uniting, but it has never yet been sufficiently
observed whether their generation is the result of the union or
not.
It may be asked, if we wish to follow the right line of
investigation, what it is in such animals the formation of which
corresponds to the material principle. For in the females this is
a residual secretion of the animal, potentially such as that from
which it came, by imparting motion to which the principle
derived from the male perfects the animal. But here what must
be said to correspond to this, and whence comes or what is the
moving principle which corresponds to the male? We must
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understand that even in animals which generate it is from the
incoming nourishment that the heat in the animal makes the
residue, the beginning of the conception, by secretion and
concoction. The like is the case also in plants, except that in
these (and also in some animals) there is no further need of the
male principle, because they have it mingled with the female
principle within themselves, whereas the residual secretion in
most animals does need it. The nourishment again of some is
earth and water, of others the more complicated combinations
of these, so that what the heat in animals produces from their
nutriment, this does the heat of the warm season in the
environment put together and combine by concoction out of the
sea-water on the earth. And the portion of the psychical
principle which is either included along with it or separated off
in the air makes an embryo and puts motion into it. Now in
plants which are spontaneously generated the method of
formation is uniform; they arise from a part of something, and
while some of it is the starting-point of the plant, some is the
first nourishment of the young shoots.... Other animals are
produced in the form of a scolex, not only those bloodless
animals which are not generated from parents but even some
sanguinea, as a kind of mullet and some other river fishes and
also the eel kind. For all of these, though they have but little
blood by nature, are nevertheless sanguinea, and have a heart
with blood in it as the origin of the parts; and the so-called
'entrails of earth', in which comes into being the body of the eel,
have the nature of a scolex.
Hence one might suppose, in connexion with the origin of men
and quadrupeds, that, if ever they were really 'earth-born' as
some say, they came into being in one of two ways; that either it
was by the formation of a scolex at first or else it was out of
eggs. For either they must have had in themselves the
nutriment for growth (and such a conception is a scolex) or they
must have got it from elsewhere, and that either from the
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mother or from part of the conception. If then the former is
impossible (I mean that nourishment should flow to them from
the earth as it does in animals from the mother), then they
must have got it from some part of the conception, and such
generation we say is from an egg.
It is plain then that, if there really was any such beginning of
the generation of all animals, it is reasonable to suppose to have
been one of these two, scolex or egg. But it is less reasonable to
suppose that it was from eggs, for we do not see such
generation occurring with any animal, but we do see the other
both in the sanguinea above mentioned and in the bloodless
animals. Such are some of the insects and such are the testacea
which we are discussing; for they do not develop out of a part of
something (as do animals from eggs), and they grow like a
scolex. For the scolex grows towards the upper part and the first
principle, since in the lower part is the nourishment for the
upper. And this resembles the development of animals from
eggs, except that these latter consume the whole egg, whereas
in the scolex, when the upper part has grown by taking up into
itself part of the substance in the lower part, the lower part is
then differentiated out of the rest. The reason is that in later life
also the nourishment is absorbed by all animals in the part
below the hypozoma.
That the scolex grows in this way is plain in the case of bees
and the like, for at first the lower part is large in them and the
upper is smaller. The details of growth in the testacea are
similar. This is plain in the whorls of the turbinata, for always as
the animal grows the whorls become larger towards the front
and what is called the head of the creature.
We have now pretty well described the manner of the
development of these and the other spontaneously generated
animals. That all the testacea are formed spontaneously is clear
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from such facts as these. They come into being on the side of
boats when the frothy mud putrefies. In many places where
previously nothing of the kind existed, the so-called limnostrea,
a kind of oyster, have come into being when the spot turned
muddy through want of water; thus when a naval armament
cast anchor at Rhodes a number of clay vessels were thrown out
into the sea, and after some time, when mud had collected
round them, oysters used to be found in them. Here is another
proof that such animals do not emit any generative substance
from themselves; when certain Chians carried some live oysters
over from Pyrrha in Lesbos and placed them in narrow straits of
the sea where tides clash, they became no more numerous as
time passed, but increased greatly in size. The so-called eggs
contribute to generation but are only a condition, like fat in the
sanguinea, and therefore the oysters are savoury at these
periods. A proof that this substance is not really eggs is the fact
that such 'eggs' are always found in some testacea, as in pinnae,
whelks, and purple-fish; only they are sometimes larger and
sometimes smaller; in others as pectens, mussels, and the so-
called limnostrea, they are not always present but only in the
spring; as the season advances they dwindle and at last
disappear altogether; the reason being that the spring is
favourable to their being in good condition. In others again, as
the ascidians, nothing of the sort is visible. (The details
concerning these last, and the places in which they come into
being, must be learnt from the Enquiry.)
2136
Book IV
We have thus spoken of the generation of animals both
generally and separately in all the different classes. But, since
male and female are distinct in the most perfect of them, and
since we say that the sexes are first principles of all living
things whether animals or plants, only in some of them the
sexes are separated and in others not, therefore we must speak
first of the origin of the sexes in the latter. For while the animal
is still imperfect in its kind the distinction is already made
between male and female.
It is disputed, however, whether the embryo is male or female,
as the case may be, even before the distinction is plain to our
senses, and further whether it is thus differentiated within the
mother or even earlier. It is said by some, as by Anaxagoras and
other of the physicists, that this antithesis exists from the
beginning in the germs or seeds; for the germ, they say, comes
from the male while the female only provides the place in
which it is to be developed, and the male is from the right, the
female from the left testis, and so also that the male embryo is
in the right of the uterus, the female in the left. Others, as
Empedocles, say that the differentiation takes place in the
uterus; for he says that if the uterus is hot or cold what enters it
becomes male or female, the cause of the heat or cold being the
flow of the catamenia, according as it is colder or hotter, more
'antique' or more 'recent'. Democritus of Abdera also says that
the differentiation of sex takes place within the mother; that
however it is not because of heat and cold that one embryo
becomes female and another male, but that it depends on the
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question which parent it is whose semen prevails, - not the
whole of the semen, but that which has come from the part by
which male and female differ from one another. This is a better
theory, for certainly Empedocles has made a rather light-
hearted assumption in thinking that the difference between
them is due only to cold and heat, when he saw that there was
a great difference in the whole of the sexual parts, the
difference in fact between the male pudenda and the uterus. For
suppose two animals already moulded in embryo, the one
having all the parts of the female, the other those of the male;
suppose them then to be put into the uterus as into an oven,
the former when the oven is hot, the latter when it is cold; then
on the view of Empedocles that which has no uterus will be
female and that which has will be male. But this is impossible.
Thus the theory of Democritus would be the better of the two, at
least as far as this goes, for he seeks for the origin of this
difference and tries to set it forth; whether he does so well or
not is another question.
Again, if heat and cold were the cause of the difference of the
parts, this ought to have been stated by those who maintain the
view of Empedocles; for to explain the origin of male and
female is practically the same thing as to explain this, which is
the manifest difference between them. And it is no small
matter, starting from temperature as a principle, to collect the
cause of the origin of these parts, as if it were a necessary
consequence for this part which they call the uterus to be
formed in the embryo under the influence of cold but not under
that of heat. The same applies also to the parts which serve for
intercourse, since these also differ in the way stated previously.
Moreover male and female twins are often found together in
the same part of the uterus; this we have observed sufficiently
by dissection in all the vivipara, both land animals and fish.
Now if Empedocles had not seen this it was only natural for him
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to fall into error in assigning this cause of his; but if he had seen
it it is strange that he should still think the heat or cold of the
uterus to be the cause, since on his theory both these twins
would have become either male or female, but as it is we do not
see this to be the fact.
Again he says that the parts of the embryo are 'sundered', some
being in the male and some in the female parent, which is why
they desire intercourse with one another. If so it is necessary
that the sexual parts like the rest should be separated from one
another, already existing as masses of a certain size, and that
they should come into being in the embryo on account of
uniting with one another, not on account of cooling or heating
of the semen. But perhaps it would take too long to discuss
thoroughly such a cause as this which is stated by Empedocles,
for its whole character seems to be fanciful. If, however, the
facts about semen are such as we have actually stated, if it does
not come from the whole of the body of the male parent and if
the secretion of the male does not give any material at all to the
embryo, then we must make a stand against both Empedocles
and Democritus and any one else who argues on the same lines.
For then it is not possible that the body of the embryo should
exist 'sundered', part in the female parent and part in the male,
as Empedocles says in the words: 'But the nature of the limbs
hath been sundered, part in the man's...'; nor yet that a whole
embryo is drawn off from each parent and the combination of
the two becomes male or female according as one part prevails
over another.
And, to take a more general view, though it is better to say that
the one part makes the embryo female by prevailing through
some superiority than to assign nothing but heat as the cause
without any reflection, yet, as the form of the pudendum also
varies along with the uterus from that of the father, we need an
explanation of the fact that both these parts go along with each
2139
other. If it is because they are near each other, then each of the
other parts also ought to go with them, for one of the prevailing
parts is always near another part where the struggle is not yet
decided; thus the offspring would be not only female or male
but also like its mother or father respectively in all other details.
Besides, it is absurd to suppose that these parts should come
into being as something isolated, without the body as a whole
having changed along with them. Take first and foremost the
blood-vessels, round which the whole mass of the flesh lies as
round a framework. It is not reasonable that these should
become of a certain quality because of the uterus, but rather
that the uterus should do so on account of them. For though it
is true that each is a receptacle of blood of some kind, still the
system of the vessels is prior to the other; the moving principle
must needs always be prior to that which it moves, and it is
because it is itself of a certain quality that it is the cause of the
development. The difference, then, of these parts as compared
with each other in the two sexes is only a concomitant result;
not this but something else must be held to be the first
principle and the cause of the development of an embryo as
male or female; this is so even if no semen is secreted by either
male or female, but the embryo is formed in any way you
please.
The same argument as that with which we meet Empedocles
and Democritus will serve against those who say that the male
comes from the right and the female from the left. If the male
contributes no material to the embryo, there can be nothing in
this view. If, as they say, he does contribute something of the
sort, we must confront them in the same way as we did the
theory of Empedocles, which accounts for the difference
between male and female by the heat and cold of the uterus.
They make the same mistake as he does, when they account for
the difference by their 'right and left', though they see that the
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sexes differ actually by the whole of the sexual parts; for what
reason then is the body of the uterus to exist in those embryos
which come from the left and not in those from the right? For if
an embryo have come from the left but has not acquired this
part, it will be a female without a uterus, and so too there is
nothing to stop another from being a male with a uterus!
Besides as has been said before, a female embryo has been
observed in the right part of the uterus, a male in the left, or
again both at once in the same part, and this not only once but
several times.
Some again, persuaded of the truth of a view resembling that of
these philosophers, say that if a man copulates with the right or
left testis tied up the result is male or female offspring
respectively; so at least Leophanes asserted. And some say that
the same happens in the case of those who have one or other
testis excised, not speaking truth but vaticinating what will
happen from probabilities and jumping at the conclusion that it
is so before seeing that it proves to be so. Moreover, they know
not that these parts of animals contribute nothing to the
production of one sex rather than the other; a proof of this is
that many animals in which the distinction of sex exists, and
which produce both male and female offspring, nevertheless
have no testes, as the footless animals; I mean the classes of
fish and of serpents.
To suppose, then, either that heat and cold are the causes of
male and female, or that the different sexes come from the right
and left, is not altogether unreasonable in itself; for the right of
the body is hotter than the left, and the concocted semen is
hotter than the unconcocted; again, the thickened is concocted,
and the more thickened is more fertile. Yet to put it in this way
is to seek for the cause from too remote a starting-point; we
must draw near the immediate causes in so far as it is possible
for us.
2141
We have, then, previously spoken elsewhere of both the body as
a whole and its parts, explaining what each part is and for what
reason it exists. But (1) the male and female are distinguished
by a certain capacity and incapacity. (For the male is that which
can concoct the blood into semen and which can form and
secrete and discharge a semen carrying with it the principle of
form - by 'principle' I do not mean a material principle out of
which comes into being an offspring resembling the parent, but
I mean the first moving cause, whether it have power to act as
such in the thing itself or in something else - but the female is
that which receives semen, indeed, but cannot form it for itself
or secrete or discharge it.) And (2) all concoction works by
means of heat. Therefore the males of animals must needs be
hotter than the females. For it is by reason of cold and
incapacity that the female is more abundant in blood in certain
parts of her anatomy, and this abundance is an evidence of the
exact opposite of what some suppose, thinking that the female
is hotter than the male for this reason, i.e. the discharge of the
catamenia. It is true that blood is hot, and that which has more
of it is hotter than that which has less. But they assume that
this discharge occurs through excess of blood and of heat, as if
it could be taken for granted that all blood is equally blood if
only it be liquid and sanguineous in colour, and as if it might
not become less in quantity but purer in quality in those who
assimilate nourishment properly. In fact they look upon this
residual discharge in the same light as that of the intestines,
when they think that a greater amount of it is a sign of a hotter
nature, whereas the truth is just the opposite. For consider the
production of fruit; the nutriment in its first stage is abundant,
but the useful product derived from it is small, indeed the final
result is nothing at all compared to the quantity in the first
stage. So is it with the body; the various parts receive and work
up the nutriment, from the whole of which the final result is
quite small. This is blood in some animals, in some its analogue.
2142
Now since (1) the one sex is able and the other is unable to
reduce the residual secretion to a pure form, and (2) every
capacity or power in an organism has a certain corresponding
organ, whether the faculty produces the desired results in a
lower degree or in a higher degree, and the two sexes
correspond in this manner (the terms 'able' and 'unable' being
used in more senses than one) - therefore it is necessary that
both female and male should have organs. Accordingly the one
has the uterus, the other the male organs.
Again, Nature gives both the faculty and the organ to each
individual at the same time, for it is better so. Hence each
region comes into being along with the secretions and the
faculties, as e.g. the faculty of sight is not perfected without the
eye, nor the eye without the faculty of sight; and so too the
intestine and bladder come into being along with the faculty of
forming the excreta. And since that from which an organ comes
into being and that by which it is increased are the same (i.e.
the nutriment), each of the parts will be made out of such a
material and such residual matter as it is able to receive. In the
second place, again, it is formed, as we say, in a certain sense,
out of its opposite. Thirdly, we must understand besides this
that, if it is true that when a thing perishes it becomes the
opposite of what it was, it is necessary also that what is not
under the sway of that which made it must change into its
opposite. After these premisses it will perhaps be now clearer
for what reason one embryo becomes female and another male.
For when the first principle does not bear sway and cannot
concoct the nourishment through lack of heat nor bring it into
its proper form, but is defeated in this respect, then must needs
the material which it works on change into its opposite. Now
the female is opposite to the male, and that in so far as the one
is female and the other male. And since it differs in its faculty,
its organ also is different, so that the embryo changes into this
state. And as one part of first-rate importance changes, the
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whole system of the animal differs greatly in form along with it.
This may be seen in the case of eunuchs, who, though mutilated
in one part alone, depart so much from their original
appearance and approximate closely to the female form. The
reason of this is that some of the parts are principles, and when
a principle is moved or affected needs must many of the parts
that go along with it change with it.
If then (1) the male quality or essence is a principle and a cause,
and (2) the male is such in virtue of a certain capacity and the
female is such in virtue of an incapacity, and (3) the essence or
definition of the capacity and of the incapacity is ability or
inability to concoct the nourishment in its ultimate stage, this
being called blood in the sanguinea and the analogue of blood
in the other animals, and (4) the cause of this capacity is in the
first principle and in the part which contains the principle of
natural heat - therefore a heart must be formed in the
sanguinea (and the resulting animal will be either male or
female), and in the other kinds which possess the sexes must be
formed that which is analogous to the heart.
This, then, is the first principle and cause of male and female,
and this is the part of the body in which it resides. But the
animal becomes definitely female or male by the time when it
possesses also the parts by which the female differs from the
male, for it is not in virtue of any part you please that it is male
or female, any more than it is able to see or hear by possessing
any part you please.
To recapitulate, we say that the semen, which is the foundation
of the embryo, is the ultimate secretion of the nutriment. By
ultimate I mean that which is carried to every part of the body,
and this is also the reason why the offspring is like the parent.
For it makes no difference whether we say that the semen
comes from all the parts or goes to all of them, but the latter is
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the better. But the semen of the male differs from the
corresponding secretion of the female in that it contains a
principle within itself of such a kind as to set up movements
also in the embryo and to concoct thoroughly the ultimate
nourishment, whereas the secretion of the female contains
material alone. If, then, the male element prevails it draws the
female element into itself, but if it is prevailed over it changes
into the opposite or is destroyed. But the female is opposite to
the male, and is female because of its inability to concoct and of
the coldness of the sanguineous nutriment. And Nature assigns
to each of the secretions the part fitted to receive it. But the
semen is a secretion, and this in the hotter animals with blood,
i.e. the males, is moderate in quantity, wherefore the recipient
parts of this secretion in males are only passages. But the
females, owing to inability to concoct, have a great quantity of
blood, for it cannot be worked up into semen. Therefore they
must also have a part to receive this, and this part must be
unlike the passages of the male and of a considerable size. This
is why the uterus is of such a nature, this being the part by
which the female differs from the male.
We have thus stated for what reason the one becomes female
and the other male. Observed facts confirm what we have said.
For more females are produced by the young and by those
verging on old age than by those in the prime of life; in the
former the vital heat is not yet perfect, in the latter it is failing.
And those of a moister and more feminine state of body are
more wont to beget females, and a liquid semen causes this
more than a thicker; now all these characteristics come of
deficiency in natural heat.
2145
Again, more males are born if copulation takes place when
north than when south winds are blowing. For in the latter case
the animals produce more secretion, and too much secretion is
harder to concoct; hence the semen of the males is more liquid,
and so is the discharge of the catamenia.
Also the fact that the catamenia occur in the course of nature
rather when the month is waning is due to the same causes. For
this time of the month is colder and moister because of the
waning and failure of the moon; as the sun makes winter and
summer in the year as a whole, so does the moon in the month.
This is not due to the turning of the moon, but it grows warmer
as the light increases and colder as it wanes.
The shepherds also say that it not only makes a difference in
the production of males and females if copulation takes place
during northern or southerly winds, but even if the animals
while copulating look towards the south or north; so small a
thing will sometimes turn the scale and cause cold or heat, and
these again influence generation.
The male and female, then, are distinguished generally, as
compared with one another in connexion with the production
of male and female offspring, for the causes stated. However,
they also need a certain correspondence with one another to
produce at all, for all things that come into being as products of
art or of Nature exist in virtue of a certain ratio. Now if the hot
preponderates too much it dries up the liquid; if it is very
deficient it does not solidify it; for the artistic or natural product
we need the due mean between the extremes. Otherwise it will
be as in cooking; too much fire burns the meat, too little does
not cook it, and in either case the process is a failure. So also
there is need of due proportion in the mixture of the male and
female elements. And for this cause it often happens to many of
both sexes that they do not generate with one another, but if
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divorced and remarried to others do generate; and these
oppositions show themselves sometimes in youth, sometimes
in advanced age, alike as concerns fertility or infertility, and as
concerns generation of male or female offspring.
One country also differs from another in these respects, and
one water from another, for the same reasons. For the
nourishment and the medical condition of the body are of such
or such a kind because of the tempering of the surrounding air
and of the food entering the body, especially the water; for men
consume more of this than of anything else, and this enters as
nourishment into all food, even solids. Hence hard waters cause
infertility, and cold waters the birth of females.
The same causes must be held responsible for the following
groups of facts. (1) Some children resemble their parents, while
others do not; some being like the father and others like the
mother, both in the body as a whole and in each part, male and
female offspring resembling father and mother respectively
rather than the other way about. (2) They resemble their parents
more than remoter ancestors, and resemble those ancestors
more than any chance individual. (3) Some, though resembling
none of their relations, yet do at any rate resemble a human
being, but others are not even like a human being but a
monstrosity. For even he who does not resemble his parents is
already in a certain sense a monstrosity; for in these cases
Nature has in a way departed from the type. The first departure
indeed is that the offspring should become female instead of
male; this, however, is a natural necessity. (For the class of
animals divided into sexes must be preserved, and as it is
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possible for the male sometimes not to prevail over the female
in the mixture of the two elements, either through youth or age
or some other such cause, it is necessary that animals should
produce female young). And the monstrosity, though not
necessary in regard of a final cause and an end, yet is necessary
accidentally. As for the origin of it, we must look at it in this
way. If the generative secretion in the catamenia is properly
concocted, the movement imparted by the male will make the
form of the embryo in the likeness of itself. (Whether we say
that it is the semen or this movement that makes each of the
parts grow, makes no difference; nor again whether we say that
it 'makes them grow' or 'forms them from the beginning', for
the formula of the movement is the same in either case.) Thus if
this movement prevail, it will make the embryo male and not
female, like the father and not like the mother; if it prevail not,
the embryo is deficient in that faculty in which it has not
prevailed. By 'each faculty' I mean this. That which generates is
not only male but also a particular male, e.g. Coriscus or
Socrates, and it is not only Coriscus but also a man. In this way
some of the characteristics of the father are more near to him,
others more remote from him considered simply as a parent
and not in reference to his accidental qualities (as for instance
if the parent is a scholar or the neighbour of some particular
person). Now the peculiar and individual has always more force
in generation than the more general and wider characteristics.
Coriscus is both a man and an animal, but his manhood is
nearer to his individual existence than is his animalhood. In
generation both the individual and the class are operative, but
the individual is the more so of the two, for this is the only true
existence. And the offspring is produced indeed of a certain
quality, but also as an individual, and this latter is the true
existence. Therefore it is from the forces of all such existences
that the efficient movements come which exist in the semen;
potentially from remoter ancestors but in a higher degree and
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more nearly from the individual (and by the individual I mean
e.g. Coriscus or Socrates). Now since everything changes not
into anything haphazard but into its opposite, therefore also
that which is not prevailed over in generation must change and
become the opposite, in respect of that particular force in which
the paternal and efficient or moving element has not prevailed.
If then it has not prevailed in so far as it is male, the offspring
becomes female; if in so far as it is Coriscus or Socrates, the
offspring does not resemble the father but the mother. For as
'father' and 'mother' are opposed as general terms, so also the
individual father is opposed to the individual mother. The like
applies also to the forces that come next in order, for the
offspring always changes rather into the likeness of the nearer
ancestor than the more remote, both in the paternal and in the
maternal line.
Some of the movements exist in the semen actually, others
potentially; actually, those of the father and the general type, as
man and animal; potentially those of the female and the
remoter ancestors. Thus the male and efficient principle, if it
lose its own nature, changes to its opposites, but the
movements which form the embryo change into those nearly
connected with them; for instance, if the movement of the male
parent be resolved, it changes by a very slight difference into
that of his father, and in the next instance into that of his
grandfather; and in this way not only in the male but also in the
female line the movement of the female parent changes into
that of her mother, and, if not into this, then into that of her
grandmother; and similarly also with the more remote
ancestors.
Naturally then it is most likely that the characteristics of 'male'
and of the individual father will go together, whether they
prevail or are prevailed over. For the difference between them is
small so that there is no difficulty in both concurring, for
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Socrates is an individual man with certain characters. Hence for
the most part the male offspring resemble the father, and the
female the mother. For in the latter case the loss of both
characters takes place at once, and the change is into the two
opposites; now is opposed to male, and the individual mother to
the individual father.
But if the movement coming from the male principle prevails
while that coming from the individual Socrates does not, or vice
versa, then the result is that male children are produced
resembling the mother and female children resembling the
father.
If again the movements be resolved, if the male character
remain but the movement coming from the individual Socrates
be resolved into that of the father of Socrates, the result will be
a male child resembling its grandfather or some other of its
more remote ancestors in the male line on the same principle. If
the male principle be prevailed over, the child will be female
and resembling most probably its mother, but, if the movement
coming from the mother also be resolved, it will resemble its
mother's mother or the resemblance will be to some other of its
more remote ancestors in the female line on the same principle.
The same applies also to the separate parts, for often some of
these take after the father, and others after the mother, and yet
others after some of the remoter ancestors. For, as has been
often said already, some of the movements which form the
parts exist in the semen actually and others potentially. We
must grasp certain fundamental general principles, not only
that just mentioned (that some of the movements exist
potentially and others actually), but also two others, that if a
character be prevailed over it changes into its opposite, and, if it
be resolved, is resolved into the movement next allied to it - if
less, into that which is near, if more, into that which is further
2150
removed. Finally, the movements are so confused together that
there is no resemblance to any of the family or kindred, but the
only character that remains is that common to the race, i.e. it is
a human being. The reason of this is that this is closely knit up
with the individual characteristics; 'human being' is the general
term, while Socrates, the father, and the mother, whoever she
may be, are individuals.
The reason why the movements are resolved is this. The agent
is itself acted upon by that on which it acts; thus that which
cuts is blunted by that which is cut by it, that which heats is
cooled by that which is heated by it, and in general the moving
or efficient cause (except in the case of the first cause of all)
does itself receive some motion in return; e.g. what pushes is
itself in a way pushed again and what crushes is itself crushed
again. Sometimes it is altogether more acted upon than is the
thing on which it acts, so that what is heating or cooling
something else is itself cooled or heated; sometimes having
produced no effect, sometimes less than it has itself received.
(This question has been treated in the special discussion of
action and reaction, where it is laid down in what classes of
things action and reaction exist.) Now that which is acted on
escapes and is not mastered by the semen, either through
deficiency of power in the concocting and moving agent or
because what should be concocted and formed into distinct
parts is too cold and in too great quantity. Thus the moving
agent, mastering it in one part but not in another, makes the
embryo in formation to be multiform, as happens with athletes
because they eat so much. For owing to the quantity of their
food their nature is not able to master it all, so as to increase
and arrange their form symmetrically; therefore their limbs
develop irregularly, sometimes indeed almost so much that no
one of them resembles what it was before. Similar to this is also
the disease known as satyrism, in which the face appears like
2151
that of a satyr owing to a quantity of unconcocted humour or
wind being diverted into parts of the face.
We have thus discussed the cause of all these phenomena, (1)
female and male offspring are produced, (2) why some are
similar to their parents, female to female and male to male, and
others the other way about, females being similar to the father
and males to the mother, and in general why some are like their
ancestors while others are like none of them, and all this as
concerns both the body as a whole and each of the parts
separately. Different accounts, however, have been given of
these phenomena by some of the nature-philosophers; I mean
why children are like or unlike their parents. They give two
versions of the reason. Some say that the child is more like that
parent of the two from whom comes more semen, this applying
equally both to the body as a whole and to the separate parts,
on the assumption that semen comes from each part of both
parents; if an equal part comes from each, then, they say, the
child is like neither. But if this is false, if semen does not come
off from the whole body of the parents, it is clear that the
reason assigned cannot be the cause of likeness and unlikeness.
Moreover, they are hard put to it to explain how it is that a
female child can be like the father and a male like the mother.
For (1) those who assign the same cause of sex as Empedocles
or Democritus say what is on other grounds impossible, and (2)
those who say that it is determined by the greater or smaller
amount of semen coming the male or female parent, and that
this is why one child is male and another female, cannot show
how the female is to resemble the father and the male the
mother, for it is impossible that more should come from both at
once. Again, for what reason is a child generally like its
ancestors, even the more remote? None of the semen has come
from them at any rate.
2152
But those who account for the similarity in the manner which
remains to be discussed, explain this point better, as well as the
others. For there are some who say that the semen, though one,
is as it were a common mixture (panspermia) of many
elements; just as, if one should mix many juices in one liquid
and then take some from it, it would be possible to take, not an
equal quantity always from each juice, but sometimes more of
one and sometimes more of another, sometimes some of one
and none at all of another, so they say it is with the generative
fluid, which is a mixture of many elements, for the offspring
resembles that parent from which it has derived most. Though
this theory is obscure and in many ways fictitious, it aims at
what is better expressed by saying that what is called
'panspermia' exists potentially, not actually; it cannot exist
actually, but it can do so potentially. Also, if we assign only one
sort of cause, it is not easy to explain all the phenomena, (1) the
distinction of sex, (2) why the female is often like the father and
the male like the mother, and again (3) the resemblance to
remoter ancestors, and further (4) the reason why the offspring
is sometimes unlike any of these but still a human being, but
sometimes, (5) proceeding further on these lines, appears finally
to be not even a human being but only some kind of animal,
what is called a monstrosity.
For, following what has been said, it remains to give the reason
for such monsters. If the movements imparted by the semen are
resolved and the material contributed by the mother is not
controlled by them, at last there remains the most general
substratum, that is to say the animal. Then people say that the
child has the head of a ram or a bull, and so on with other
animals, as that a calf has the head of a child or a sheep that of
an ox. All these monsters result from the causes stated above,
but they are none of the things they are said to be; there is only
some similarity, such as may arise even where there is no defect
of growth. Hence often jesters compare some one who is not
2153
beautiful to a 'goat breathing fire', or again to a 'ram butting',
and a certain physiognomist reduced all faces to those of two or
three animals, and his arguments often prevailed on people.
That, however, it is impossible for such a monstrosity to come
into existence - I mean one animal in another - is shown by the
great difference in the period of gestation between man, sheep,
dog, and ox, it being impossible for each to be developed except
in its proper time.
This is the description of some of the monsters talked about;
others are such because certain parts of their form are
multiplied so that they are born with many feet or many heads.
The account of the cause of monstrosities is very close and
similar in a way to that of the cause of animals being born
defective in any part, for monstrosity is also a kind of deficiency.
Democritus said that monstrosities arose because two
emissions of seminal fluid met together, the one succeeding the
other at an interval of time; that the later entering into the
uterus reinforced the earlier so that the parts of the embryo
grow together and get confused with one another. But in birds,
he says, since copulation takes place quickly, both the eggs and
their colour always cross one another. But if it is the fact, as it
manifestly is, that several young are produced from one
emission of semen and a single act of intercourse, it is better
not to desert the short road to go a long way about, for in such
cases it is absolutely necessary that this should occur when the
semen is not separated but all enters the female at once.
2154
If, then, we must attribute the cause to the semen of the male,
this will be the way we shall have to state it, but we must rather
by all means suppose that the cause lies in the material
contributed by the female and in the embryo as it is forming.
Hence also such monstrosities appear very rarely in animals
producing only one young one, more frequently in those
producing many, most of all in birds and among birds in the
common fowl. For this bird produces many young, not only
because it lays often like the pigeon family, but also because it
has many embryos at once and copulates all the year round.
Therefore it produces many double eggs, for the embryos grow
together because they are near one another, as often happens
with many fruits. In such double eggs, when the yolks are
separated by the membrane, two separate chickens are
produced with nothing abnormal about them; when the yolks
are continuous, with no division between them, the chickens
produced are monstrous, having one body and head but four
legs and four wings; this is because the upper parts are formed
earlier from the white, their nourishment being drawn from the
yolk, whereas the lower part comes into being later and its
nourishment is one and indivisible.
A snake has also been observed with two heads for the same
reason, this class also being oviparous and producing many
young. Monstrosities, however, are rarer among them owing to
the shape of the uterus, for by reason of its length the
numerous eggs are set in a line.
Nothing of the kind occurs with bees and wasps, because their
brood is in separate cells. But in the fowl the opposite is the
case, whereby it is plain that we must hold the cause of such
phenomena to lie in the material. So, too, monstrosities are
commoner in other animals if they produce many young. Hence
they are less common in man, for he produces for the most part
only one young one and that perfect; even in man monstrosities
2155
occur more often in regions where the women give birth to
more than one at a time, as in Egypt. And they are commoner in
sheep and goats, since they produce more young. Still more
does this apply to the fissipeds, for such animals produce many
young and imperfect, as the dog, the young of these creatures
being generally blind. Why this happens and why they produce
many young must be stated later, but in them Nature has made
an advance towards the production of monstrosities in that
what they generate, being imperfect, is so far unlike the parent;
now monstrosities also belong to the class of things unlike the
parent. Therefore this accident also often invades animals of
such a nature. So, too, it is in these that the so-called
'metachoera' are most frequent, and the condition of these also
is in a way monstrous, since both deficiency and excess are
monstrous. For the monstrosity belongs to the class of things
contrary to Nature, not any and every kind of Nature, but Nature
in her usual operations; nothing can happen contrary to Nature
considered as eternal and necessary, but we speak of things
being contrary to her in those cases where things generally
happen in a certain way but may also happen in another way. In
fact, even in the case of monstrosities, whenever things occur
contrary indeed to the established order but still always in a
certain way and not at random, the result seems to be less of a
monstrosity because even that which is contrary to Nature is in
a certain sense according to Nature, whenever, that is, the
formal nature has not mastered the material nature. Therefore
they do not call such things monstrosities any more than in the
other cases where a phenomenon occurs habitually, as in fruits;
for instance, there is a vine which some call 'capneos'; if this
bear black grapes they do not judge it a monstrosity because it
is in the habit of doing this very often. The reason is that it is in
its nature intermediate between white and black; thus the
change is not a violent one nor, so to say, contrary to Nature; at
least, is it not a change into another nature. But in animals
2156
producing many young not only do the same phenomena occur,
but also the numerous embryos hinder one another from
becoming perfect and interfere with the generative motions
imparted by the semen.
A difficulty may be raised concerning (1) the production of
many young and the multiplication of the parts in a single
young one, and (2) the production of few young or only one and
the deficiency of the parts. Sometimes animals are born with
too many toes, sometimes with one alone, and so on with the
other parts, for they may be multiplied or they may be absent.
Again, they may have the generative parts doubled, the one
being male, the other female; this is known in men and
especially in goats. For what are called 'tragaenae' are such
because they have both male and female generative parts; there
is a case also of a goat being born with a horn upon its leg.
Changes and deficiencies are found also in the internal parts,
animals either not possessing some at all, or possessing them
in a rudimentary condition, or too numerous or in the wrong
place. No animal, indeed, has ever been born without a heart,
but they are born without a spleen or with two spleens or with
one kidney; there is no case again of total absence of the liver,
but there are cases of its being incomplete. And all these
phenomena have been seen in animals perfect and alive.
Animals also which naturally have a gall-bladder are found
without one; others are found to have more than one. Cases are
known, too, of the organs changing places, the liver being on the
left, the spleen on the right. These phenomena have been
observed, as stated above, in animals whose growth is
perfected; at the time of birth great confusion of every kind has
been found. Those deficiency which only depart a little from
Nature commonly live; not so those which depart further, when
the unnatural condition is in the parts which are sovereign over
life.
2157
The question then about all these cases is this. Are we to
suppose that a single cause is responsible for the production of
a single young one and for the deficiency of the parts, and
another but still a single cause for the production of many
young and the multiplication of parts, or not?
In the first place it seems only reasonable to wonder why some
animals produce many young, others only one. For it is the
largest animals that produce one, e.g. the elephant, camel,
horse, and the other solid-hoofed ungulates; of these some are
larger than all other animals, while the others are of a
remarkable size. But the dog, the wolf, and practically all the
fissipeds, produce many, even the small members of the class,
as the mouse family. The cloven-footed animals again produce
few, except the pig, which belongs to those that produce many.
This certainly seems surprising, for we should expect the large
animals to be able to generate more young and to secrete more
semen. But precisely what we wonder at is the reason for not
wondering; it is just because of their size that they do not
produce many young, for the nutriment is expended in such
animals upon increasing the body. But in the smaller animals
Nature takes away from the size and adds the excess so gained
to the seminal secretion. Moreover, more semen must needs be
used in generation by the larger animal, and little by the
smaller. Therefore many small ones may be produced together,
but it is hard for many large ones to be so, and to those
intermediate in size Nature has assigned the intermediate
number. We have formerly given the reason why some animals
are large, some smaller, and some between the two, and
speaking generally, with regard to the number of young
produced, the solid-hoofed produce one, the cloven-footed few,
the many-toed many. (The reason of this is that, generally
speaking, their sizes correspond to this difference.) It is not so,
however, in all cases; for it is the largeness and smallness of the
body that is cause of few or many young being born, not the fact
2158
that the kind of animal has one, two, or many toes. A proof of
this is that the elephant is the largest of animals and yet is
many-toed, and the camel, the next largest, is cloven-footed.
And not only in animals that walk but also in those that fly or
swim the large ones produce few, the small many, for the same
reason. In like manner also it is not the largest plants that bear
most fruit.
We have explained then why some animals naturally produce
many young, some but few, and some only one; in the difficulty
now stated we may rather be surprised with reason at those
which produce many, since such animals are often seen to
conceive from a single copulation. Whether the semen of the
male contributes to the material of the embryo by itself
becoming a part of it and mixing with the semen of the female,
or whether, as we say, it does not act in this way but brings
together and fashions the material within the female and the
generative secretion as the fig-juice does the liquid substance of
milk, what is the reason why it does not form a single animal of
considerable size? For certainly in the parallel case the fig-juice
is not separated if it has to curdle a large quantity of milk, but
the more the milk and the more the fig-juice put into it, so
much the greater is the curdled mass. Now it is no use to say
that the several regions of the uterus attract the semen and
therefore more young than one are formed, because the regions
are many and the cotyledons are more than one. For two
embryos are often formed in the same region of the uterus, and
they may be seen lying in a row in animals that produce many,
when the uterus is filled with the embryos. (This is plain from
the dissections.) Rather the truth is this. As animals complete
their growth there are certain limits to their size, both upwards
and downwards, beyond which they cannot go, but it is in the
space between these limits that they exceed or fall short of one
another in size, and it is within these limits that one man (or
any other animal) is larger or smaller than another. So also the
2159
generative material from which each animal is formed is not
without a quantitative limit in both directions, nor can it be
formed from any quantity you please. Whenever then an
animal, for the cause assigned, discharges more of the female
secretion than is needed for beginning the existence of a single
animal, it is not possible that only one should be formed out of
all this, but a number limited by the appropriate size in each
case; nor will the semen of the male, or the power residing in
the semen, form anything either more or less than what is
according to Nature. In like manner, if the male emits more
semen than is necessary, or more powers in different parts of
the semen as it is divided, however much it is it will not make
anything greater; on the contrary it will dry up the material of
the female and destroy it. So fire also does not continue to make
water hotter in proportion as it is itself increased, but there is a
fixed limit to the heat of which water is capable; if that is once
reached and the fire is then increased, the water no longer gets
hotter but rather evaporates and at last disappears and is dried
up. Now since it appears that the secretion of the female and
that from the male need to stand in some proportionate
relation to one another (I mean in animals of which the male
emits semen), what happens in those that produce many young
is this: from the very first the semen emitted by the male has
power, being divided, to form several embryos, and the material
contributed by the female is so much that several can be formed
out of it. (The parallel of curdling milk, which we spoke of
before, is no longer in point here, for what is formed by the heat
of the semen is not only of a certain quantity but also of a
certain quality, whereas with fig-juice and rennet quantity
alone is concerned.) This then is just the reason why in such
animals the embryos formed are numerous and do not all unite
into one whole; it is because an embryo is not formed out of any
quantity you please, but whether there is too much or too little,
in either case there will be no result, for there is a limit set alike
2160
to the power of the heat which acts on the material and to the
material so acted upon.
On the same principle many embryos are not formed, though
the secretion is much, in the large animals which produce only
one young one, for in them also both the material and that
which works upon it are of a certain quantity. So then they do
not secrete such material in too great quantity for the reason
previously stated, and what they do secrete is naturally just
enough for one embryo alone to be formed from it. If ever too
much is secreted, then twins are born. Hence such cases seem
to be more portentous, because they are contrary to the general
and customary rule.
Man belongs to all three classes, for he produces one only and
sometimes many or few, though naturally he almost always
produces one. Because of the moisture and heat of his body he
may produce many [for semen is naturally fluid and hot], but
because of his size he produces few or one. On account of this it
results that in man alone among animals the period of
gestation is irregular; whereas the period is fixed in the rest,
there are several periods in man, for children are born at seven
months and at ten months and at the times between, for even
those of eight months do live though less often than the rest.
The reason may be gathered from what has just been said, and
the question has been discussed in the Problems. Let this
explanation suffice for these points.
The cause why the parts may be multiplied contrary to Nature
is the same as the cause of the birth of twins. For the reason
exists already in the embryo, whenever it aggregates more
material at any point of itself than is required by the nature of
the part. The result is then that either one of its parts is larger
than the others, as a finger or hand or foot or any of the other
extremities or limbs; or again if the embryo is cleft there may
2161
come into being more than one such part, as eddies do in rivers;
as the water in these is carried along with a certain motion, if it
dash against anything two systems or eddies come into being
out of one, each retaining the same motion; the same thing
happens also with the embryos. The abnormal parts generally
are attached near those they resemble, but sometimes at a
distance because of the movement - taking place in the embryo,
and especially because of the excess of material returning to
that place whence it was taken away while retaining the form
of that part whence it arose as a superfluity.
In certain cases we find a double set of generative organs [one
male and the other female]. When such duplication occurs the
one is always functional but not the other, because it is always
insufficiently supplied with nourishment as being contrary to
Nature; it is attached like a growth (for such growths also
receive nourishment though they are a later development than
the body proper and contrary to Nature.) If the formative power
prevails, both are similar; if it is altogether vanquished, both are
similar; but if it prevail here and be vanquished there, then the
one is female and the other male. (For whether we consider the
reason why the whole animal is male or female, or why the
parts are so, makes no difference.)
When we meet with deficiency in such parts, e.g. an extremity
or one of the other members, we must assume the same cause
as when the embryo is altogether aborted (abortion of embryos
happens frequently).
Outgrowths differ from the production of many young in the
manner stated before; monsters differ from these in that most
of them are due to embryos growing together. Some however
are also of the following kind, when the monstrosity affects
greater and more sovereign parts, as for instance some
monsters have two spleens or more than two kidneys. Further,
2162
the parts may migrate, the movements which form the embryo
being diverted and the material changing its place. We must
decide whether the monstrous animal is one or is composed of
several grown together by considering the vital principle; thus, if
the heart is a part of such a kind then that which has one heart
will be one animal, the multiplied parts being mere outgrowths,
but those which have more than one heart will be two animals
grown together through their embryos having been confused.
It also often happens even in many animals that do not seem to
be defective and whose growth is now complete, that some of
their passages may have grown together or others may have
been diverted from the normal course. Thus in some women
before now the os uteri has remained closed, so that when the
time for the catamenia has arrived pain has attacked them, till
either the passage has burst open of its own accord or the
physicians have removed the impediment; some such cases
have ended in death if the rupture has been made too violently
or if it has been impossible to make it at all. In some boys on the
other hand the end of the penis has not coincided with the end
of the passage where the urine is voided, but the passage has
ended below, so that they crouch sitting to void it, and if the
testes are drawn up they appear from a distance to have both
male and female generative organs. The passage of the solid
food also has been closed before now in sheep and some other
animals; there was a cow in Perinthus which passed fine matter,
as if it were sifted, through the bladder, and when the anus was
cut open it quickly closed up again nor could they succeed in
keeping it open.
We have now spoken of the production of few and many young,
and of the outgrowth of superfluous parts or of their deficiency,
and also of monstrosities.
2163
Superfoetation does not occur at all in some animals but does
in others; of the former some are able to bring the later formed
embryo to birth, while others can only do so sometimes. The
reason why it does not occur in some is that they produce only
one young one, for it is not found in solid-hoofed animals and
those larger than these, as owing to their size the secretion of
the female is all used up for the one embryo. For all these have
large bodies, and when an animal is large its foetus is large in
proportion, e.g. the foetus of the elephant is as big as a calf. But
superfoetation occurs in those which produce many young
because the production of more than one at a birth is itself a
sort of superfoetation, one being added to another. Of these all
that are large, as man, bring to birth the later embryo, if the
second impregnation takes place soon after the first, for such
an event has been observed before now. The reason is that given
above, for even in a single act of intercourse the semen
discharged is more than enough for one embryo, and this being
divided causes more than one child to be born, the one of which
is later than the other. But when the embryo has already grown
to some size and it so happens that copulation occurs again,
superfoetation sometimes takes place, but rarely, since the
uterus generally closes in women during the period of gestation.
If this ever happens (for this also has occurred) the mother
cannot bring the second embryo to perfection, but it is cast out
in a state like what are called abortions. For just as, in those
animals that bear only one, all the secretion of the female is
converted to the first formed embryo because of its size, so it is
here also; the only difference is that in the former case this
happens at once, in the latter when the foetus has attained to
some size, for then they are in the same state as those that bear
only one. In like manner, since man naturally would produce
2164
many young, and since the size of the uterus and the quantity
of the female secretion are both greater than is necessary for
one embryo, only not so much so as to bring to birth a second,
therefore women and mares are the only animals which admit
the male during gestation, the former for the reason stated, and
mares both because of the barrenness of their nature and
because their uterus is of superfluous size, too large for one but
too small to allow a second embryo to be brought to perfection
by superfoetation. And the mare is naturally inclined to sexual
intercourse because she is in the same case as the barren
among women; these latter are barren because they have no
monthly discharge (which corresponds to the act of intercourse
in males) and mares have exceedingly little. And in all the
vivipara the barren females are so inclined, because they
resemble the males when the semen has collected in the testes
but is not being got rid of. For the discharge of the catamenia is
in females a sort of emission of semen, they being unconcocted
semen as has been said before. Hence it is that those women
also who are incontinent in regard to such intercourse cease
from their passion for it when they have borne many children,
for, the seminal secretion being then drained off, they no longer
desire this intercourse. And among birds the hens are less
disposed that way than the cocks, because the uterus of the
hen-bird is up near the hypozoma; but with the cock-birds it is
the other way, for their testes are drawn up within them, so
that, if any kind of such birds has much semen naturally, it is
always in need of this intercourse. In females then it
encourages copulation to have the uterus low down, but in
males to have the testes drawn up.
It has been now stated why superfoetation is not found in some
animals at all, why it is found in others which sometimes bring
the later embryos to birth and sometimes not, and why some
such animals are inclined to sexual intercourse while others are
not.
2165
Some of those animals in which superfoetation occurs can bring
the embryos to birth even if a long time elapses between the
two impregnations, if their kind is spermatic, if their body is not
of a large size, and if they bear many young. For because they
bear many their uterus is spacious, because they are spermatic
the generative discharge is copious, and because the body is not
large but the discharge is excessive and in greater measure than
is required for the nourishment wanted for the embryo,
therefore they can not only form animals but also bring them to
birth later on. Further, the uterus in such animals does not close
up during gestation because there is a quantity of the residual
discharge left over. This has happened before now even in
women, for in some of them the discharge continues during all
the time of pregnancy. In women, however, this is contrary to
Nature, so that the embryo suffers, but in such animals it is
according to Nature, for their body is so formed from the
beginning, as with hares. For superfoetation occurs in these
animals, since they are not large and they bear many young (for
they have many toes and the many-toed animals bear many),
and they are spermatic. This is shown by their hairiness, for the
quantity of their hair is excessive, these animals alone having
hair under the feet and within the jaws. Now hairiness is a sign
of abundance of residual matter, wherefore among men also the
hairy are given to sexual intercourse and have much semen
rather than the smooth. In the hare it often happens that some
of the embryos are imperfect while others of its young are
produced perfect.
Some of the vivipara produce their young imperfect, others
perfect; the one-hoofed and cloven-footed perfect, most of the
2166
many-toed imperfect. The reason of this is that the one-hoofed
produce one young one, and the cloven-footed either one or two
generally speaking; now it is easy to bring the few to perfection.
All the many-toed animals that bear their young imperfect give
birth to many. Hence, though they are able to nourish the
embryos while newly formed, their bodies are unable to
complete the process when the embryos have grown and
acquired some size. So they produce them imperfect, like those
animals which generate a scolex, for some of them when born
are scarcely brought into form at all, as the fox, bear, and lion,
and some of the rest in like manner; and nearly all of them are
blind, as not only the animals mentioned but also the dog, wolf,
and jackal. The pig alone produces both many and perfect
young, and thus here alone we find any overlapping; it produces
many as do the many-toed animals, but is cloven-footed or
solid-hoofed (for there certainly are solid-hoofed swine). They
bear, then, many young because the nutriment which would
otherwise go to increase their size is diverted to the generative
secretion (for considered as a solid-hoofed animal the pig is not
a large one), and also it is more often cloven-hoofed, striving as
it were with the nature of the solid-hoofed animals. For this
reason it produces sometimes only one, sometimes two, but
generally many, and brings them to perfection before birth
because of the good condition of its body, being like a rich soil -
which has sufficient and abundant nutriment for plants.
The young of some birds also are hatched imperfect, that is to
say blind; this applies to all small birds which lay many eggs, as
crows and rooks, jays, sparrows, swallows, and to all those
which lay few eggs without producing abundant nourishment
along with the young, as ring-doves, turtle-doves, and pigeons.
Hence if the eyes of swallows while still young be put out they
recover their sight again, for the birds are still developing, not
yet developed, when the injury is inflicted, so that the eyes grow
and sprout afresh. And in general the production of young
2167
before they are perfect is owing to inability to continue
nourishing them, and they are born imperfect because they are
born too soon. This is plain also with seven-months children,
for since they are not perfected it often happens that even the
passages, e.g. of the ears and nostrils, are not yet opened in
some of them at birth, but only open later as they are growing,
and many such infants survive.
In man males are more often born defective than females, but
in the other animals this is not the case. The reason is that in
man the male is much superior to the female in natural heat,
and so the male foetus moves about more than the female, and
on account of moving is more liable to injury, for what is young
is easily injured since it is weak. For this same reason also the
female foetus is not perfected equally with the male in man
(but they are so in the other animals, for in them the female is
not later in developing than the male). For while within the
mother the female takes longer in developing, but after birth
everything is perfected more quickly in females than in males; I
mean, for instance, puberty, the prime of life, and old age. For
females are weaker and colder in nature, and we must look
upon the female character as being a sort of natural deficiency.
Accordingly while it is within the mother it develops slowly
because of its coldness (for development is concoction, and it is
heat that concocts, and what is hotter is easily concocted); but
after birth it quickly arrives at maturity and old age on account
of its weakness, for all inferior things come sooner to their
perfection or end, and as this is true of works of art so it is of
what is formed by Nature. For the reason just given also twins
are less likely to survive in man if one be male and one female,
but this is not at all so in the other animals; for in man it is
contrary to Nature that they should run an equal course, as
their development does not take place in equal periods, but the
male must needs be too late or the female too early; in the other
animals, however, it is not contrary to Nature. A difference is
2168
also found between man and the other animals in respect of
gestation, for animals are in better bodily condition most of the
time, whereas in most women gestation is attended with
discomfort. Their way of life is partly responsible for this, for
being sedentary they are full of more residual matter; among
nations where the women live a laborious life gestation is not
equally conspicuous and those who are accustomed to work
bear children easily both there and elsewhere; for work
consumes the residual matter, but those who are sedentary
have a great deal of it in them because not only is there no
monthly discharge during pregnancy but also they do no work;
therefore their travail is painful. But work exercises them so
that they can hold their breath, upon which depends the ease or
difficulty of child-birth. These circumstances then, as we have
said, contribute to cause the difference between women and the
other animals in this state, but the most important thing is this:
in some animals the discharge corresponding to the catamenia
is but small, and in some not visible at all, but in women it is
greater than in any other animal, so that when this discharge
ceases owing to pregnancy they are troubled (for if they are not
pregnant they are afflicted with ailments whenever the
catamenia do not occur); and they are more troubled as a rule at
the beginning of pregnancy, for the embryo is able indeed to
stop the catamenia but is too small at first to consume any
quantity of the secretion; later on it takes up some of it and so
alleviates the mother. In the other animals, on the contrary, the
residual matter is but small and so corresponds with the growth
of the foetus, and as the secretions which hinder nourishment
are being consumed by the foetus the mother is in better bodily
condition than usual. The same holds good also with aquatic
animals and birds. If it ever happens that the body of the
mother is no longer in good condition when the foetus is now
becoming large, the reason is that its growth needs more
nourishment than the residual matter supplies. (In some few
2169
women it happens that the body is in a better state during
pregnancy; these are women in whose body the residual matter
is small so that it is all used up along with the nourishment that
goes to the foetus.)
We must also speak of what is known as mola uteri, which
occurs rarely in women but still is found sometimes during
pregnancy. For they produce what is called a mola; it has
happened before now to a woman, after she had had
intercourse with her husband and supposed she had conceived,
that at first the size of her belly increased and everything else
happened accordingly, but yet when the time for birth came on,
she neither bore a child nor was her size reduced, but she
continued thus for three or four years until dysentery came on,
endangering her life, and she produced a lump of flesh which is
called mola. Moreover this condition may continue till old age
and death. Such masses when expelled from the body become
so hard that they can hardly be cut through even by iron.
Concerning the cause of this phenomenon we have spoken in
the Problems; the same thing happens to the embryo in the
womb as to meats half cooked in roasting, and it is not due to
heat, as some say, but rather to the weakness of the maternal
heat. (For their nature seems to be incapable, and unable to
perfect or to put the last touches to the process of generation.
Hence it is that the mola remains in them till old age or at any
rate for a long time, for in its nature it is neither perfect nor
altogether a foreign body.) It is want of concoction that is the
reason of its hardness, as with half-cooked meat, for this half-
dressing of meat is also a sort of want of concoction.
2170
A difficulty is raised as to why this does not occur in other
animals, unless indeed it does occur and has entirely escaped
observation. We must suppose the reason to be that woman
alone among animals is subject to troubles of the uterus, and
alone has a superfluous amount of catamenia and is unable to
concoct them; when, then, the embryo has been formed of a
liquid hard to concoct, then comes the so-called mola into
being, and this happens naturally in women alone or at any rate
more than in other animals.
8
Milk is formed in the females of all internally viviparous
animals, becoming useful for the time of birth. For Nature has
made it for the sake of the nourishment of animals after birth,
so that it may neither fail at this time at all nor yet be at all
superfluous; this is just what we find happening, unless
anything chance contrary to Nature. In the other animals the
period of gestation does not vary, and so the milk is concocted
in time to suit this moment, but in man, since there are several
times of birth, it must be ready at the first of these; hence in
women the milk is useless before the seventh month and only
then becomes useful. That it is only concocted at the last stages
is what we should expect to happen also as being due to a
necessary cause. For at first such residual matter when secreted
is used up for the development of the embryo; now the
nutritious part in all things is the sweetest and the most
concocted, and thus when all such elements are removed what
remains must become of necessity bitter and ill-flavoured. As
the embryo is perfecting, the residual matter left over increases
in quantity because the part consumed by the embryo is less; it
is also sweeter since the easily concocted part is less drawn
2171
away from it. For it is no longer expended on moulding the
embryo but only on slightly increasing its growth, it being now
fixed because it has reached perfection (for in a sense there is a
perfection even of an embryo). Therefore it comes forth from
the mother and changes its mode of development, as now
possessing what belongs to it; and no longer takes that which
does not belong to it; and it is at this season that the milk
becomes useful.
The milk collects in the upper part of the body and the breasts
because of the original plan of the organism. For the part above
the hypozoma is the sovereign part of the animal, while that
below is concerned with nourishment and residual matter, in
order that all animals which move about may contain within
themselves nourishment enough to make them independent
when they move from one place to another. From this upper
part also is produced the generative secretion for the reason
mentioned in the opening of our discussion. But both the
secretion of the male and the catamenia of the female are of a
sanguineous nature, and the first principle of this blood and of
the blood-vessels is the heart, and the heart is in this part of the
body. Therefore it is here that the change of such a secretion
must first become plain. This is why the voice changes in both
sexes when they begin to bear seed (for the first principle of the
voice resides there, and is itself changed when its moving cause
changes). At the same time the parts about the breasts are
raised visibly even in males but still more in females, for the
region of the breasts becomes empty and spongy in them
because so much material is drained away below. This is so not
only in women but also in those animals which have the
mammae low down.
This change in the voice and the parts about the mammae is
plain even in other creatures to those who have experience of
each kind of animal, but is most remarkable in man. The reason
2172
is that in man the production of secretion is greatest in both
sexes in proportion to their size as compared with other
animals; I mean that of the catamenia in women and the
emission of semen in men. When, therefore, the embryo no
longer takes up the secretion in question but yet prevents its
being discharged from the mother, it is necessary that the
residual matter should collect in all those empty parts which
are set upon the same passages. And such is the position of the
mammae in each kind of animals for both causes; it is so both
for the sake of what is best and of necessity.
It is here, then, that the nourishment in animals is now formed
and becomes thoroughly concocted. As for the cause of
concoction, we may take that already given, or we may take the
opposite, for it is a reasonable view also that the embryo being
larger takes more nourishment, so that less is left over about
this time, and the less is concocted more quickly.
That milk has the same nature as the secretion from which
each animal is formed is plain, and has been stated previously.
For the material which nourishes is the same as that from
which Nature forms the animal in generation. Now this is the
sanguineous liquid in the sanguinea, and milk is blood
concocted (not corrupted; Empedocles either mistook the fact or
made a bad metaphor when he composed the line: 'On the
tenth day of the eighth month the milk comes into being, a
white pus', for putrefaction and concoction are opposite things,
and pus is a kind of putrefaction but milk is concocted). While
women are suckling children the catamenia do not occur
according to Nature, nor do they conceive; if they do conceive,
the milk dries up. This is because the nature of the milk and of
the catamenia is the same, and Nature cannot be so productive
as to supply both at once; if the secretion is diverted in the one
direction it must needs cease in the other, unless some violence
is done contrary to the general rule. But this is as much as to
2173
say that it is contrary to Nature, for in all cases where it is not
impossible for things to be otherwise than they generally are
but where they may so happen, still what is the general rule is
what is 'according to Nature'.
The time also at which the young animal is born has been well
arranged. For when the nourishment coming through the
umbilical cord is no longer sufficient for the foetus because of
its size, then at the same time the milk becomes useful for the
nourishment of the newly-born animal, and the blood-vessels
round which the so-called umbilical cord lies as a coat collapse
as the nourishment is no longer passing through it; for these
reasons it is at that time also that the young animal enters into
the world.
The natural birth of all animals is head-foremost, because the
parts above the umbilical cord are larger than those below. The
body then, being suspended from the cord as in a balance,
inclines towards the heavy end, and the larger parts are the
heavier.
10
The period of gestation is, as a matter of fact, determined
generally in each animal in proportion to the length of its life.
This we should expect, for it is reasonable that the development
of the long-lived animals should take a longer time. Yet this is
not the cause of it, but the periods only correspond accidentally
2174
for the most part; for though the larger and more perfect
sanguinea do live a long time, yet the larger are not all longer-
lived. Man lives a longer time than any animal of which we have
any credible experience except the elephant, and yet the human
kind is smaller than that of the bushy-tailed animals and many
others. The real cause of long life in any animal is its being
tempered in a manner resembling the environing air, along with
certain other circumstances of its nature, of which we will
speak later; but the cause of the time of gestation is the size of
the offspring. For it is not easy for large masses to arrive at their
perfection in a small time, whether they be animals or, one may
say, anything else whatever. That is why horses and animals
akin to them, though living a shorter time than man, yet carry
their young longer; for the time in the former is a year, but in
the latter ten months at the outside. For the same reason also
the time is long in elephants; they carry their young two years
on account of their excessive size.
We find, as we might expect, that in all animals the time of
gestation and development and the length of life aims at being
measured by naturally complete periods. By a natural period I
mean, e.g. a day and night, a month, a year, and the greater
times measured by these, and also the periods of the moon, that
is to say, the full moon and her disappearance and the halves of
the times between these, for it is by these that the moon's orbit
fits in with that of the sun [the month being a period common
to both].
The moon is a first principle because of her connexion with the
sun and her participation in his light, being as it were a second
smaller sun, and therefore she contributes to all generation and
development. For heat and cold varying within certain limits
make things to come into being and after this to perish, and it is
the motions of the sun and moon that fix the limit both of the
beginning and of the end of these processes. Just as we see the
2175
sea and all bodies of water settling and changing according to
the movement or rest of the winds, and the air and winds again
according to the course of the sun and moon, so also the things
which grow out of these or are in these must needs follow suit.
For it is reasonable that the periods of the less important should
follow those of the more important. For in a sense a wind, too,
has a life and birth and death.
As for the revolutions of the sun and moon, they may perhaps
depend on other principles. It is the aim, then, of Nature to
measure the coming into being and the end of animals by the
measure of these higher periods, but she does not bring this to
pass accurately because matter cannot be easily brought under
rule and because there are many principles which hinder
generation and decay from being according to Nature, and often
cause things to fall out contrary to Nature.
We have now spoken of the nourishment of animals within the
mother and of their birth into the world, both of each kind
separately and of all in common.
BookV
We must now investigate the qualities by which the parts of
animals differ. I mean such qualities of the parts as blueness
and blackness in the eyes, height and depth of pitch in the
2176
voice, and differences in colour whether of the skin or of hair
and feathers. Some such qualities are found to characterize the
whole of a kind of animals sometimes, while in other kinds they
occur at random, as is especially the case in man. Further, in
connexion with the changes in the time of life, all animals are
alike in some points, but are opposed in others as in the case of
the voice and the colour of the hair, for some do not grow grey
visibly in old age, while man is subject to this more than any
other animal. And some of these affections appear immediately
after birth, while others become plain as age advances or in old
age.
Now we must no longer suppose that the cause of these and all
such phenomena is the same. For whenever things are not the
product of Nature working upon the animal kingdom as a
whole, nor yet characteristic of each separate kind, then none of
these things is such as it is or is so developed for any final
cause. The eye for instance exists for a final cause, but it is not
blue for a final cause unless this condition be characteristic of
the kind of animal. In fact in some cases this condition has no
connexion with the essence of the animal's being, but we must
refer the causes to the material and the motive principle or
efficient cause, on the view that these things come into being by
Necessity. For, as was said originally in the outset of our
discussion, when we are dealing with definite and ordered
products of Nature, we must not say that each is of a certain
quality because it becomes so, but rather that they become so
and so because they are so and so, for the process of Becoming
or development attends upon Being and is for the sake of Being,
not vice versa.
The ancient Nature-philosophers however took the opposite
view. The reason of this is that they did not see that the causes
were numerous, but only saw the material and efficient and did
2177
not distinguish even these, while they made no inquiry at all
into the formal and final causes.
Everything then exists for a final cause, and all those things
which are included in the definition of each animal, or which
either are means to an end or are ends in themselves, come into
being both through this cause and the rest. But when we come
to those things which come into being without falling under the
heads just mentioned, their course must be sought in the
movement or process of coming into being, on the view that the
differences which mark them arise in the actual formation of
the animal. An eye, for instance, the animal must have of
necessity (for the fundamental idea of the animal is of such a
kind), but it will have an eye of a particular kind of necessity in
another sense, not the sense mentioned just above, because it is
its nature to act or be acted on in this or that way.
These distinctions being drawn let us speak of what comes next
in order. As soon then as the offspring of all animals are born,
especially those born imperfect, they are in the habit of
sleeping, because they continue sleeping also within the mother
when they first acquire sensation. But there is a difficulty about
the earliest period of development, whether the state of
wakefulness exists in animals first, or that of sleep. Since they
plainly wake up more as they grow older, it is reasonable to
suppose that the opposite state, that of sleep, exists in the first
stages of development. Moreover the change from not being to
being must pass through the intermediate condition, and sleep
seems to be in its nature such a condition, being as it were a
boundary between living and not living, and the sleeper being
neither altogether non-existent nor yet existent. For life most of
all appertains to wakefulness, on account of sensation. But on
the other hand, if it is necessary that the animal should have
sensation and if it is then first an animal when it has acquired
sensation, we ought to consider the original condition to be not
2178
sleep but only something resembling sleep, such a condition as
we find also in plants, for indeed at this time animals do
actually live the life of a plant. But it is impossible that plants
should sleep, for there is no sleep which cannot be broken, and
the condition in plants which is analogous to sleep cannot be
broken.
It is necessary then for the embryo animal to sleep most of the
time because the growth takes place in the upper part of the
body, which is consequently heavier (and we have stated
elsewhere that such is the cause of sleep). But nevertheless they
are found to wake even in the womb (this is clear in dissections
and in the ovipara), and then they immediately fall into a sleep
again. This is why after birth also they spend most of their time
in sleep.
When awake infants do not laugh, but while asleep they both
laugh and cry. For animals have sensations even while asleep,
not only what are called dreams but also others besides dreams,
as those persons who arise while sleeping and do many things
without dreaming. For there are some who get up while
sleeping and walk about seeing just like those who are awake;
these have perception of what is happening, and though they
are not awake, yet this perception is not like a dream. So infants
presumably have sense-perception and live in their sleep owing
to previous habit, being as it were without knowledge of the
waking state. As time goes on and their growth is transferred to
the lower part of the body, they now wake up more and spend
most of their time in that condition. Children continue asleep at
first more than other animals, for they are born in a more
imperfect condition than other animals that are produced in
anything like a perfect state, and their growth has taken place
more in the upper part of the body.
2179
The eyes of all children are bluish immediately after birth; later
on they change to the colour which is to be theirs permanently.
But in the case of other animals this is not visible. The reason of
this is that the eyes of other animals are more apt to have only
one colour for each kind of animal; e.g. cattle are dark-eyed, the
eye of all sheep is pale, of others again the whole kind is blue or
grey-eyed, and some are yellow (goat-eyed), as the majority of
goats themselves, whereas the eyes of men happen to be of
many colours, for they are blue or grey or dark in some cases
and yellow in others. Hence, as the individuals in other kinds of
animals do not differ from one another in the colour, so neither
do they differ from themselves, for they are not of a nature to
have more than one colour. Of the other animals the horse has
the greatest variety of colour in the eye, for some of them are
actually heteroglaucous; this phenomenon is not to be seen in
any of the other animals, but man is sometimes
heteroglaucous.
Why then is it that there is no visible change in the other
animals if we compare their condition when newly born with
their condition at a more advanced age, but that there is such a
change in children? We must consider just this to be a sufficient
cause, that the part concerned has only one colour in the
former but several colours in the latter. And the reason why the
eyes of infants are bluish and have no other colour is that the
parts are weaker in the newly born and blueness is a sort of
weakness.
We must also gain a general notion about the difference in eyes,
for what reason some are blue, some grey, some yellow, and
some dark. To suppose that the blue are fiery, as Empedocles
says, while the dark have more water than fire in them, and
that this is why the former, the blue, have not keen sight by day,
viz. owing to deficiency of water in their composition, and the
latter are in like condition by night, viz. owing to deficiency of
2180
fire - this is not well said if indeed we are to assume sight to be
connected with water, not fire, in all cases. Moreover it is
possible to render another account of the cause of the colours,
but if indeed the fact is as was stated before in the treatise on
the senses, and still earlier than that in the investigations
concerning soul - if this sense organ is composed of water and
if we were right in saying for what reason it is composed of
water and not of air or fire - then we must assume the water to
be the cause of the colours mentioned. For some eyes have too
much liquid to be adapted to the movement, others have too
little, others the due amount. Those eyes therefore in which
there is much liquid are dark because much liquid is not
transparent, those which have little are blue; (so we find in the
sea that the transparent part of it appears light blue, the less
transparent watery, and the unfathomable water is dark or
deep-blue on account of its depth). When we come to the eyes
between these, they differ only in degree.
We must suppose the same cause also to be responsible for the
fact that blue eyes are not keen-sighted by day nor dark eyes by
night. Blue eyes, because there is little liquid in them, are too
much moved by the light and by visible objects in respect of
their liquidity as well as their transparency, but sight is the
movement of this part in so far as it is transparent, not in so far
as it is liquid. Dark eyes are less moved because of the quantity
of liquid in them. And so they see less well in the dusk, for the
nocturnal light is weak; at the same time also liquid is in
general hard to move in the night. But if the eye is to see, it
must neither not be moved at all nor yet more than in so far as
it is transparent, for the stronger movement drives out the
weaker. Hence it is that on changing from strong colours, or on
going out of the sun into the dark, men cannot see, for the
motion already existing in the eye, being strong, stops that from
outside, and in general neither a strong nor a weak sight can
2181
see bright things because the liquid is acted upon and moved
too much.
The same thing is shown also by the morbid affections of each
kind of sight. Cataract attacks the blue-eyed more, but what is
called 'nyctalopia' the dark-eyed. Now cataract is a sort of
dryness of the eyes and therefore it is found more in the aged,
for this part also like the rest of the body gets dry towards old
age; but is an excess of liquidity and so is found more in the
younger, for their brain is more liquid.
The sight of the eye which is intermediate between too much
and too little liquid is the best, for it has neither too little so as
to be disturbed and hinder the movement of the colours, nor
too much so as to cause difficulty of movement.
Not only the above-mentioned facts are causes of seeing keenly
or the reverse, but also the nature of the skin upon what is
called the pupil. This ought to be transparent, and it is
necessary that the transparent should be thin and white and
even, thin that the movement coming from without may pass
straight through it, even that it may not cast a shade the liquid
behind it by wrinkling (for this also is a reason why old men
have not keen sight, the skin of the eye like the rest of the skin
wrinkling and becoming thicker in old age), and white because
black is not transparent, for that is just what is meant by 'black',
what is not shone through, and that is why lanterns cannot give
light if they be made of black skin. It is for these reasons then
that the sight is not keen in old age nor in the diseases in
question, but it is because of the small amount of liquid that the
eyes of children appear blue at first.
And the reason why men especially and horses occasionally are
heteroglaucous is the same as the reason why man alone grows
grey and the horse is the only other animal whose hairs whiten
visibly in old age. For greyness is a weakness of the fluid in the
2182
brain and an incapacity to concoct properly, and so is blueness
of the eyes; excess of thinness or of thickness produces the
same effect, according as this liquidity is too little or too much.
Whenever then Nature cannot make the eyes correspond
exactly, either by concocting or by not concocting the liquid in
both, but concocts the one and not the other, then the result is
heteroglaucia.
The cause of some animals being keen-sighted and others not
so is not simple but double. For the word 'keen' has pretty much
a double sense (and this is the case in like manner with hearing
and smelling). In one sense keen sight means the power of
seeing at a distance, in another it means the power of
distinguishing as accurately as possible the objects seen. These
two faculties are not necessarily combined in the same
individual. For the same person, if he shades his eyes with his
hand or look through a tube, does not distinguish the
differences of colour either more or less in any way, but he will
see further; in fact, men in pits or wells sometimes see the
stars. Therefore if any animal's brows project far over the eye,
but if the liquid in the pupil is not pure nor suited to the
movement coming from external objects and if the skin over
the surface is not thin, this animal will not distinguish
accurately the differences of the colours but it will be able to see
from a long distance (just as it can from a short one) better than
those in which the liquid and the covering membrane are pure
but which have no brows projecting over the eyes. For the cause
of seeing keenly in the sense of distinguishing the differences is
in the eye itself; as on a clean garment even small stains are
visible, so also in a pure sight even small movements are plain
and cause sensation. But it is the position of the eyes that is the
cause of seeing things far off and of the movements in the
transparent medium coming to the eyes from distant objects. A
proof of this is that animals with prominent eyes do not see
well at a distance, whereas those which have their eyes lying
2183
deep in the head can see things at a distance because the
movement is not dispersed in space but comes straight to the
eye. For it makes no difference whether we say, as some do, that
seeing is caused by the sight going forth from the eye - on that
view, if there is nothing projecting over the eyes, the sight must
be scattered and so less of it will fall on the objects of vision
and things at a distance will not be seen so well - or whether
we say that seeing is due to the movement coming from the
objects; for the sight also must see, in a manner resembling the
movement. Things at a distance, then, would be seen best if
there were, so to say, a continuous tube straight from the sight
to its object, for the movement from the object would not then
be dissipated; but, if that is impossible, still the further the tube
extends the more accurately must distant objects be seen.
Let these, then, be given as the causes of the difference in eyes.
It is the same also with hearing and smell; to hear and smell
accurately mean in one sense to perceive as precisely as
possible all the distinctions of the objects of perception, in
another sense to hear and smell far off. As with sight, so here
the sense-organ is the cause of judging well the distinctions, if
both that organ itself and the membrane round it be pure. For
the passages of all the sense-organs, as has been said in the
treatise on sensation, run to the heart, or to its analogue in
creatures that have no heart. The passage of the hearing, then,
since this sense-organ is of air, ends at the place where the
innate spiritus causes in some animals the pulsation of the
heart and in others respiration; wherefore also it is that we are
able to understand what is said and repeat what we have heard,
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for as was the movement which entered through the sense-
organ, such again is the movement which is caused by means of
the voice, being as it were of one and the same stamp, so that a
man can say what he has heard. And we hear less well during a
yawn or expiration than during inspiration, because the
starting-point of the sense-organ of hearing is set upon the part
concerned with breathing and is shaken and moved as the
organ moves the breath, for while setting the breath in motion
it is moved itself. The same thing happens in wet weather or a
damp atmosphere.... And the ears seemed to be filled with air
because their starting-point is near the region of breathing.
Accuracy then in judging the differences of sounds and smells
depends on the purity of the sense-organ and of the membrane
lying upon its surface, for then all the movements become clear
in such cases, as in the case of sight. Perception and non-
perception at a distance also depend on the same things with
hearing and smell as with sight. For those animals can perceive
at a distance which have channels, so to say, running through
the parts concerned and projecting far in front of the sense-
organs. Therefore all animals whose nostrils are long, as the
Laconian hounds, are keen-scented, for the sense-organ being
above them, the movements from a distance are not dissipated
but go straight to the mark, just as the movements which cause
sight do with those who shadow the eyes with the hand.
Similar is the case of animals whose ears are long and project
far like the eaves of a house, as in some quadrupeds, with the
internal spiral passage long; these also catch the movement
from afar and pass it on to the sense-organ.
In respect of sense-perception at a distance, man is, one may
say, the worst of all animals in proportion to his size, but in
respect of judging the differences of quality in the objects he is
the best of all. The reason is that the sense-organ in man is pure
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and least earthy and material, and he is by nature the thinnest-
skinned of all animals for his size.
The workmanship of Nature is admirable also in the seal, for
though a viviparous quadruped it has no ears but only passages
for hearing. This is because its life is passed in the water; now
the ear is a part added to the passages to preserve the
movement of the air at a distance; therefore an ear is no use to
it but would even bring about the contrary result by receiving a
mass of water into itself.
We have thus spoken of sight, hearing, and smell.
As for hair, men differ in this themselves at different ages, and
also from all other kinds of animals that have hair. These are
almost all which are internally viviparous, for even when the
covering of such animals is spiny it must be considered as a
kind of hair, as in the land hedgehog and any other such animal
among the vivipara. Hairs differ in respect of hardness and
softness, length and shortness, straightness and curliness,
quantity and scantiness, and in addition to these qualities, in
their colours, whiteness and blackness and the intermediate
shades. They differ also in some of these respects according to
age, as they are young or growing old. This is especially plain in
man; the hair gets coarser as time goes on, and some go bald on
the front of the head; children indeed do not go bald, nor do
women, but men do so by the time their age is advancing.
Human beings also go grey on the head as they grow old, but
this is not visible in practically any other animal, though more
so in the horse than others. Men go bald on the front of the
head, but turn grey first on the temples; no one goes bald first
2186
on these or on the back of the head. Some such affections occur
in a corresponding manner also in all animals which have not
hair but something analogous to it, as the feathers of birds and
scales in the class of fish.
For what purpose Nature has made hair in general for animals
has been previously stated in the work dealing with the causes
of the parts of animals; it is the business of the present inquiry
to show under what circumstances and for what necessary
causes each particular kind of hair occurs. The principal cause
then of thickness and thinness is the skin, for this is thick in
some animals and thin in others, rare in some and dense in
others. The different quality of the included moisture is also a
helping cause, for in some animals this is greasy and in others
watery. For generally speaking the substratum of the skin is of
an earthy nature; being on the surface of the body it becomes
solid and earthy as the moisture evaporates. Now the hairs or
their analogue are not formed out of the flesh but out of the
skin moisture evaporating and exhaling in them, and therefore
thick hairs arise from a thick skin and thin from thin. If then the
skin is rarer and thicker, the hairs are thick because of the
quantity of earthy matter and the size of the pores, but if it is
denser they are thin because of the narrowness of the pores.
Further, if the moisture be watery it dries up quickly and the
hairs do not gain in size, but if it be greasy the opposite
happens, for the greasy is not easily dried up. Therefore the
thicker-skinned animals are as a general rule thicker-haired for
the causes mentioned; however, the thickest-skinned are not
more so than other thick-skinned ones, as is shown by the class
of swine compared to that of oxen and to the elephant and
many others. And for the same reason also the hairs of the head
in man are thickest, for this part of his skin is thickest and lies
over most moisture and besides is very porous.
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The cause of the hairs being long or short depends on the
evaporating moisture not being easily dried. Of this there are
two causes, quantity and quality; if the liquid is much it does
not dry up easily nor if it is greasy. And for this reason the hairs
of the head are longest in man, for the brain, being fluid and
cold, supplies great abundance of moisture.
The hairs become straight or curly on account of the vapour
arising in them. If it be smoke-like, it is hot and dry and so
makes the hair curly, for it is twisted as being carried with a
double motion, the earthy part tending downwards and the hot
upwards. Thus, being easily bent, it is twisted owing to its
weakness, and this is what is meant by curliness in hair. It is
possible then that this is the cause, but it is also possible that,
owing to its having but little moisture and much earthy matter
in it, it is dried by the surrounding air and so coiled up together.
For what is straight becomes bent, if the moisture in it is
evaporated, and runs together as a hair does when burning
upon the fire; curliness will then be a contraction owing to
deficiency of moisture caused by the heat of the environment. A
sign of this is the fact that curly hair is harder than straight, for
the dry is hard. And animals with much moisture are straight-
haired; for in these hairs the moisture advances as a stream,
not in drops. For this reason the Scythians on the Black Sea and
the Thracians are straight-haired, for both they themselves and
the environing air are moist, whereas the Aethiopians and men
in hot countries are curly-haired, for their brains and the
surrounding air are dry.
Some, however, of the thick-skinned animals are fine-haired for
the cause previously stated, for the finer the pores are the finer
must the hairs be. Hence the class of sheep have such hairs (for
wool is only a multitude of hairs).
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There are some animals whose hair is soft and yet less fine, as
is the case with the class of hares compared with that of sheep;
in such animals the hair is on the surface of the skin, not deeply
rooted in it, and so is not long but in much the same state as
the scrapings from linen, for these also are not long but are soft
and do not admit of weaving.
The condition of sheep in cold climates is opposite to that of
man; the hair of the Scythians is soft but that of the Sauromatic
sheep is hard. The reason of this is the same as it is also all wild
animals. The cold hardens and solidifies them by drying them,
for as the heat is pressed out the moisture evaporates, and both
hair and skin become earthy and hard. In wild animals then the
exposure to the cold is the cause of hardness in the hair, in the
others the nature of the climate is the cause. A proof of this is
also what happens in the sea-urchins which are used as a
remedy in stranguries. For these, too, though small themselves,
have large and hard spines because the sea in which they live is
cold on account of its depth (for they are found in sixty fathoms
and even more). The spines are large because the growth of the
body is diverted to them, since having little heat in them they
do not concoct their nutriment and so have much residual
matter and it is from this that spines, hairs, and such things are
formed; they are hard and petrified through the congealing
effect of the cold. In the same way also plants are found to be
harder, more earthy, and stony, if the region in which they grow
looks to the north than if it looks to the south, and those in
windy places than those in sheltered, for they are all more
chilled and their moisture evaporates.
Hardening, then, comes of both heat and cold, for both cause
the moisture to evaporate, heat per se and cold per accidens
(since the moisture goes out of things along with the heat, there
being no moisture without heat), but whereas cold not only
hardens but also condenses, heat makes a substance rarer.
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For the same reason, as animals grow older, the hairs become
harder in those which have hairs, and the feathers and scales in
the feathered and scaly kinds. For their skins become harder
and thicker as they get older, for they are dried up, and old age,
as the word denotes, is earthy because the heat fails and the
moisture along with it.
Men go bald visibly more than any other animal, but still such a
state is something general, for among plants also some are
evergreens while others are deciduous, and birds which
hibernate shed their feathers. Similar to this is the condition of
baldness in those human beings to whom it is incident. For
leaves are shed by all plants, from one part of the plant at a
time, and so are feathers and hairs by those animals that have
them; it is when they are all shed together that the condition is
described by the terms mentioned, for it is called 'going bald'
and 'the fall of the leaf and 'moulting'. The cause of the
condition is deficiency of hot moisture, such moisture being
especially the unctuous, and hence unctuous plants are more
evergreen. (However we must elsewhere state the cause of this
phenomena in plants, for other causes also contribute to it.) It is
in winter that this happens to plants (for the change from
summer to winter is more important to them than the time of
life), and to those animals which hibernate (for these, too, are by
nature less hot and moist than man); in the latter it is the
seasons of life that correspond to summer and winter. Hence no
one goes bald before the time of sexual intercourse, and at that
time it is in those naturally inclined to such intercourse that
baldness appears, for the brain is naturally the coldest part of
the body and sexual intercourse makes men cold, being a loss of
pure natural heat. Thus we should expect the brain to feel the
effect of it first, for a little cause turns the scale where the thing
concerned is weak and in poor condition. Thus if we reckon up
these points, that the brain itself has but little heat, and further
that the skin round it must needs have still less, and again that
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the hair must have still less than the skin inasmuch as it is
furthest removed from the brain, we should reasonably expect
baldness to come about this age upon those who have much
semen. And it is for the same reason that the front part of the
head alone goes bald in man and that he is the only animal to
do so; the front part goes bald because the brain is there, and
man is the only animal to go bald because his brain is much the
largest and the moistest. Women do not go bald because their
nature is like that of children, both alike being incapable of
producing seminal secretion. Eunuchs do not become bald,
because they change into the female condition. And as to the
hair that comes later in life, eunuchs either do not grow it at all,
or lose it if they happen to have it, with the exception of the
pubic hair; for women also grow that though they have not the
other, and this mutilation is a change from the male to the
female condition.
The reason why the hair does not grow again in cases of
baldness, although both hibernating animals recover their
feathers or hair and trees that have shed their leaves grow
leaves again, is this. The seasons of the year are the turning-
points of their lives, rather than their age, so that when these
seasons change they change with them by growing and losing
feathers, hairs, or leaves respectively. But the winter and
summer, spring and autumn of man are defined by his age, so
that, since his ages do not return, neither do the conditions
caused by them return, although the cause of the change of
condition is similar in man to what it is in the animals and
plants in question.
We have now spoken pretty much of all the other conditions of
hair.
2191
But as to their colour, it is the nature of the skin that is the
cause of this in other animals and also of their being uni-
coloured or vari-coloured); but in man it is not the cause, except
of the hair going grey through disease (not through old age), for
in what is called leprosy the hairs become white; on the
contrary, if the hairs are white the whiteness does not invade
the skin. The reason is that the hairs grow out of skin; if, then,
the skin is diseased and white the hair becomes diseased with
it, and the disease of hair is greyness. But the greyness of hair
which is due to age results from weakness and deficiency of
heat. For as the body declines in vigour we tend to cold at every
time of life, and especially in old age, this age being cold and
dry. We must remember that the nutriment coming to each part
of the body is concocted by the heat appropriate to the part; if
the heat is inadequate the part loses its efficiency, and
destruction or disease results. (We shall speak more in detail of
causes in the treatise on growth and nutrition.) Whenever, then,
the hair in man has naturally little heat and too much moisture
enters it, its own proper heat is unable to concoct the moisture
and so it is decayed by the heat in the environing air. All decay
is caused by heat, not the innate heat but external heat, as has
been stated elsewhere. And as there is a decay of water, of earth,
and all such material bodies, so there is also of the earthy
vapour, for instance what is called mould (for mould is a decay
of earthy vapour). Thus also the liquid nutriment in the hair
decays because it is not concocted, and what is called greyness
results. It is white because mould also, practically alone among
decayed things, is white. The reason of this is that it has much
air in it, all earthy vapour being equivalent to thick air. For
mould is, as it were, the antithesis of hoar-frost; if the ascending
vapour be frozen it becomes hoar-frost, if it be decayed, mould.
Hence both are on the surface of things, for vapour is
superficial. And so the comic poets make a good metaphor in
2192
jest when they call grey hairs 'mould of old age' and For the one
is generically the same as greyness, the other specifically; hoar-
frost generically (for both are a vapour), mould specifically (for
both are a form of decay). A proof that this is so is this: grey
hairs have often grown on men in consequence of disease, and
later on dark hairs instead of them after restoration to health.
The reason is that in sickness the whole body is deficient in
natural heat and so the parts besides, even the very small ones,
participate in this weakness; and again, much residual matter is
formed in the body and all its parts in illness, wherefore the
incapacity in the flesh to concoct the nutriment causes the grey
hairs. But when men have recovered health and strength again
they change, becoming as it were young again instead of old; in
consequence the states change also. Indeed, we may rightly call
disease an acquired old age, old age a natural disease; at any
rate, some diseases produce the same effects as old age.
Men go grey on the temples first, because the back of the head
is empty of moisture owing to its containing no brain, and the
'bregma' has a great deal of moisture, a large quantity not being
liable to decay; the hair on the temples however has neither so
little that it can concoct it nor so much that it cannot decay, for
this region of the head being between the two extremes is
exempt from both states. The cause of greyness in man has now
been stated.
The reason why this change does not take place visibly on
account of age in other animals is the same as that already
given in the case of baldness; their brain is small and less fluid
than in man, so that the heat required for concoction does not
2193
altogether fail. Among them it is most clear in horses of all
animals that we know, because the bone about the brain is
thinner in them than in others in proportion to their size. A sign
of this is that a blow to this spot is fatal to them, wherefore
Homer also has said: 'where the first hairs grow on the skull of
horses, and a wound is most fatal.' As then the moisture easily
flows to these hairs because of the thinness of the bone, whilst
the heat fails on account of age, they go grey. The reddish hairs
go grey sooner than the black, redness also being a sort of
weakness of hair and all weak things ageing sooner. It is said,
however, that cranes become darker as they grow old. The
reason of this would be, if it should prove true, that their
feathers are naturally moister than others and as they grow old
the moisture in the feathers is too much to decay easily.
Greyness comes about by some sort of decay, and is not, as
some think, a withering. (1) A proof of the former statement is
the fact that hair protected by hats or other coverings goes grey
sooner (for the winds prevent decay and the protection keeps
off the winds), and the fact that it is aided by anointing with a
mixture of oil and water. For, though water cools things, the oil
mingled with it prevents the hair from drying quickly, water
being easily dried up. (2) That the process is not a withering,
that the hair does not whiten as grass does by withering, is
shown by the fact that some hairs grow grey from the first,
whereas nothing springs up in a withered state. Many hairs also
whiten at the tip, for there is least heat in the extremities and
thinnest parts.
When the hairs of other animals are white, this is caused by
nature, not by any affection. The cause of the colours in other
animals is the skin; if they are white, the skin is white, if they
are dark it is dark, if they are piebald in consequence of a
mixture of the hairs, it is found to be white in the one part and
dark in the other. But in man the skin is in no way the cause, for
2194
even white-skinned men have very dark hair. The reason is that
man has the thinnest skin of all animals in proportion to his
size and therefore it has not strength to change the hairs; on
the contrary the skin itself changes its colour through its
weakness and is darkened by sun and wind, while the hairs do
not change along with it at all. But in the other animals the
skin, owing to its thickness, has the influence belonging to the
soil in which a thing grows, therefore the hairs change
according to the skin but the skin does not change at all in
consequence of the winds and the sun.
Of animals some are uni-coloured (I mean by this term those of
which the kind as a whole has one colour, as all lions are tawny;
and this condition exists also in birds, fish, and the other
classes of animals alike); others though many-coloured are yet
whole-coloured (I mean those whose body as a whole has the
same colour, as a bull is white as a whole or dark as a whole);
others are vari-coloured. This last term is used in both ways;
sometimes the whole kind is vari-coloured, as leopards and
peacocks, and some fish, e.g. the so-called 'thrattai'; sometimes
the kind as a whole is not so, but such individuals are found in
it, as with cattle and goats and, among birds, pigeons; the same
applies also to other kinds of birds. The whole-coloured change
much more than the uniformly coloured, both into the simple
colour of another individual of the same kind (as dark changing
into white and vice versa) and into both colours mingled. This is
because it is a natural characteristic of the kind as a whole not
to have one colour only, the kind being easily moved in both
directions so that the colours both change more into one
another and are more varied. The opposite holds with the
2195
uniformly coloured; they do not change except by an affection
of the colour, and that rarely; but still they do so change, for
before now white individuals have been observed among
partridges, ravens, sparrows, and bears. This happens when the
course of development is perverted, for what is small is easily
spoilt and easily moved, and what is developing is small, the
beginning of all such things being on a small scale.
Change is especially found in those animals of which by nature
the individual is whole-coloured but the kind many-coloured.
This is owing to the water which they drink, for hot waters
make the hair white, cold makes it dark, an effect found also in
plants. The reason is that the hot have more air than water in
them, and the air shining through causes whiteness, as also in
froth. As, then, skins which are white by reason of some
affection differ from those white by nature, so also in the hair
the whiteness due to disease or age differs from that due to
nature in that the cause is different; the latter are whitened by
the natural heat, the former by the external heat. Whiteness is
caused in all things by the vaporous air imprisoned in them.
Hence also in all animals not uniformly coloured all the part
under the belly is whiter. For practically all white animals are
both hotter and better flavoured for the same reason; the
concoction of their nutriment makes them well-flavoured, and
heat causes the concoction. The same cause holds for those
animals which are uniformly-coloured, but either dark or white;
heat and cold are the causes of the nature of the skin and hair,
each of the parts having its own special heat.
The tongue also varies in colour in the simply coloured as
compared with the vari-coloured animals, and again in the
simply coloured which differ from one another, as white and
dark. The reason is that assigned before, that the skins of the
vari-coloured are vari-coloured, and the skins of the white-
haired and dark-haired are white and dark in each case. Now
2196
we must conceive of the tongue as one of the external parts, not
taking into account the fact that it is covered by the mouth but
looking on it as we do on the hand or foot; thus since the skin of
the vari-coloured animals is not uniformly coloured, this is the
cause of the skin on the tongue being also vari-coloured.
Some birds and some wild quadrupeds change their colour
according to the seasons of the year. The reason is that, as men
change according to their age, so the same thing happens to
them according to the season; for this makes a greater
difference to them than the change of age.
The more omnivorous animals are more vari-coloured to speak
generally, and this is what might be expected; thus bees are
more uniformly coloured than hornets and wasps. For if the
food is responsible for the change we should expect varied food
to increase the variety in the movements which cause the
development and so in the residual matter of the food, from
which come into being hairs and feathers and skins.
So much for colours and hairs.
As to the voice, it is deep in some animals, high in others, in
others again well-pitched and in due proportion between both
extremes. Again, in some it is loud, in others small, and it differs
in smoothness and roughness, flexibility and inflexibility. We
must inquire then into the causes of each of these distinctions.
We must suppose then that the same cause is responsible for
high and deep voices as for the change which they undergo in
passing from youth to age. The voice is higher in all other
2197
animals when younger, but in cattle that of calves is deeper. We
find the same thing also in the male and female sexes; in the
other kinds of animals the voice of the female is higher than
that of the male (this being especially plain in man, for Nature
has given this faculty to him in the highest degree because he
alone of animals makes use of speech and the voice is the
material of speech), but in cattle the opposite obtains, for the
voice of cows is deeper than that of bulls.
Now the purpose for which animals have a voice, and what is
meant by 'voice' and by 'sound' generally, has been stated partly
in the treatise on sensation, partly in that on the soul. But since
lowness of voice depends on the movement of the air being
slow and its highness on its being quick, there is a difficulty in
knowing whether it is that which moves or that which is moved
that is the cause of the slowness or quickness. For some say
that what is much is moved slowly, what is little quickly, and
that the quantity of the air is the cause of some animals having
a deep and others a high voice. Up to a certain point this is well
said (for it seems to be rightly said in a general way that the
depth depends on a certain amount of the air put in motion),
but not altogether, for if this were true it would not be easy to
speak both soft and deep at once, nor again both loud and high.
Again, the depth seems to belong to the nobler nature, and in
songs the deep note is better than the high-pitched ones, the
better lying in superiority, and depth of tone being a sort of
superiority. But then depth and height in the voice are different
from loudness and softness, and some high-voiced animals are
loud-voiced, and in like manner some soft-voiced ones are
deep-voiced, and the same applies to the tones lying between
these extremes. And by what else can we define these (I mean
loudness and softness of voice) except by the large and small
amount of the air put in motion? If then height and depth are to
be decided in accordance with the distinction postulated, the
result will be that the same animals will be deep-and loud-
2198
voiced, and the same will be high - and not loud - voiced; but
this is false.
The reason of the difficulty is that the words 'great' and 'small',
'much' and 'little' are used sometimes absolutely, sometimes
relatively to one another. Whether an animal has a great (or
loud) voice depends on the air which is moved being much
absolutely, whether it has a small voice depends on its being
little absolutely; but whether they have a deep or high voice
depends on their being thus differentiated in relation to one
another. For if that which is moved surpass the strength of that
which moves it, the air that is sent forth must go slowly; if the
opposite, quickly. The strong, then, on account of their strength,
sometimes move much air and make the movement slow,
sometimes, having complete command over it, make the
movement swift. On the same principle the weak either move
too much air for their strength and so make the movement
slow, or if they make it swift move but little because of their
weakness.
These, then, are the reasons of these contrarieties, that neither
are all young animals high-voiced nor all deep-voiced, nor are
all the older, nor yet are the two sexes thus opposed, and again
that not only the sick speak in a high voice but also those in
good bodily condition, and, further, that as men verge on old
age they become higher-voiced, though this age is opposite to
that of youth.
Most young animals, then, and most females set but little air in
motion because of their want of power, and are consequently
high-voiced, for a little air is carried along quickly, and in the
voice what is quick is high. But in calves and cows, in the one
case because of their age, in the other because of their female
nature, the part by which they set the air in motion is not
strong; at the same time they set a great quantity in motion and
2199
so are deep-voiced; for that which is borne along slowly is
heavy, and much air is borne along slowly. And these animals
set much in movement whereas the others set but little,
because the vessel through which the breath is first borne has
in them a large opening and necessarily sets much air in
motion, whereas in the rest the air is better dispensed. As their
age advances this part which moves the air gains more strength
in each animal, so that they change into the opposite condition,
the high-voiced becoming deeper-voiced than they were, and
the deep-voiced higher-voiced, which is why bulls have a higher
voice than calves and cows. Now the strength of all animals is
in their sinews, and so those in the prime of life are stronger,
the young being weaker in the joints and sinews; moreover, in
the young they are not yet tense, and in those now growing old
the tension relaxes, wherefore both these ages are weak and
powerless for movement. And bulls are particularly sinewy,
even their hearts, and therefore that part by which they set the
air in motion is in a tense state, like a sinewy string stretched
tight. (That the heart of bulls is of such a nature is shown by the
fact that a bone is actually found in some of them, and bones
are naturally connected with sinew.)
All animals when castrated change to the female character, and
utter a voice like that of the females because the sinewy
strength in the principle of the voice is relaxed. This relaxation
is just as if one should stretch a string and make it taut by
hanging some weight on to it, as women do who weave at the
loom, for they stretch the warp by attaching to it what are called
'laiai'. For in this way are the testes attached to the seminal
passages, and these again to the blood-vessel which takes its
origin in the heart near the organ which sets the voice in
motion. Hence as the seminal passages change towards the age
at which they are now able to secrete the semen, this part also
changes along with them. As this changes, the voice again
changes, more indeed in males, but the same thing happens in
2200
females too, only not so plainly, the result being what some call
'bleating' when the voice is uneven. After this it settles into the
deep or high voice of the succeeding time of life. If the testes are
removed the tension of the passages relaxes, as when the
weight is taken off the string or the warp; as this relaxes, the
organ which moves the voice is loosened in the same
proportion. This, then, is the reason why the voice and the form
generally changes to the female character in castrated animals;
it is because the principle is relaxed upon which depends the
tension of the body; not that, as some suppose, the testes are
themselves a ganglion of many principles, but small changes
are the causes of great ones, not per se but when it happens
that a principle changes with them. For the principles, though
small in size, are great in potency; this, indeed, is what is meant
by a principle, that it is itself the cause of many things without
anything else being higher than it for it to depend upon.
The heat or cold also of their habitat contributes to make some
animals of such a character as to be deep-voiced, and others
high-voiced. For hot breath being thick causes depth, cold
breath being thin the opposite. This is clear also in pipe-playing,
for if the breath of the performer is hotter, that is to say if it is
expelled as by a groan, the note is deeper.
The cause of roughness and smoothness in the voice, and of all
similar inequality, is that the part or organ through which the
voice is conveyed is rough or smooth or generally even or
uneven. This is plain when there is any moisture about the
trachea or when it is roughened by any affection, for then the
voice also becomes uneven.
Flexibility depends on the softness or hardness of the organ, for
what is soft can be regulated and assume any form, while what
is hard cannot; thus the soft organ can utter a loud or a small
note, and accordingly a high or a deep one, since it easily
2201
regulates the breath, becoming itself easily great or small. But
hardness cannot be regulated.
Let this be enough on all those points concerning the voice
which have not been previously discussed in the treatise on
sensation and in that on the soul.
8
With regard to the teeth it has been stated previously that they
do not exist for a single purpose nor for the same purpose in all
animals, but in some for nutrition only, in others also for
fighting and for vocal speech. We must, however, consider it not
alien to the discussion of generation and development to
inquire into the reason why the front teeth are formed first and
the grinders later, and why the latter are not shed but the
former are shed and grow again.
Democritus has spoken of these questions but not well, for he
assigns the cause too generally without investigating the facts
in all cases. He says that the early teeth are shed because they
are formed in animals too early, for it is when animals are
practically in their prime that they grow according to Nature,
and suckling is the cause he assigns for their being found too
early. Yet the pig also suckles but does not shed its teeth, and,
further, all the animals with carnivorous dentition suckle, but
some of them do not shed any teeth except the canines, e.g.
lions. This mistake, then, was due to his speaking generally
without examining what happens in all cases; but this is what
we to do, for any one who makes any general statement must
speak of all the particular cases.
2202
Now we assume, basing our assumption upon what we see, that
Nature never fails nor does anything in vain so far as is possible
in each case. And it is necessary, if an animal is to obtain food
after the time of taking milk is over, that it should have
instruments for the treatment of the food. If, then, as
Democritus says, this happened about the time of reaching
maturity, Nature would fail in something possible for her to do.
And, besides, the operation of Nature would be contrary to
Nature, for what is done by violence is contrary to Nature, and it
is by violence that he says the formation of the first teeth is
brought about. That this view then is not true is plain from
these and other similar considerations.
Now these teeth are developed before the flat teeth, in the first
place because their function is earlier (for dividing comes before
crushing, and the flat teeth are for crushing, the others for
dividing), in the second place because the smaller is naturally
developed quicker than the larger, even if both start together,
and these teeth are smaller in size than the grinders, because
the bone of the jaw is flat in that part but narrow towards the
mouth. From the greater part, therefore, must flow more
nutriment to form the teeth, and from the narrower part less.
The act of sucking in itself contributes nothing to the formation
of the teeth, but the heat of the milk makes them appear more
quickly. A proof of this is that even in suckling animals those
young which enjoy hotter milk grow their teeth quicker, heat
being conducive to growth.
They are shed, after they have been formed, partly because it is
better so (for what is sharp is soon blunted, so that a fresh relay
is needed for the work, whereas the flat teeth cannot be blunted
but are only smoothed in time by wearing down), partly from
necessity because, while the roots of the grinders are fixed
where the jaw is flat and the bone strong, those of the front
2203
teeth are in a thin part, so that they are weak and easily moved.
They grow again because they are shed while the bone is still
growing and the animal is still young enough to grow teeth. A
proof of this is that even the flat teeth grow for a long time, the
last of them cutting the gum at about twenty years of age;
indeed in some cases the last teeth have been grown in quite
old age. This is because there is much nutriment in the broad
part of the bones, whereas the front part being thin soon
reaches perfection and no residual matter is found in it, the
nutriment being consumed in its own growth.
Democritus, however, neglecting the final cause, reduces to
necessity all the operations of Nature. Now they are necessary,
it is true, but yet they are for a final cause and for the sake of
what is best in each case. Thus nothing prevents the teeth from
being formed and being shed in this way; but it is not on
account of these causes but on account of the end (or final
cause); these are causes only in the sense of being the moving
and efficient instruments and the material. So it is reasonable
that Nature should perform most of her operations using breath
as an instrument, for as some instruments serve many uses in
the arts, e.g. the hammer and anvil in the smith's art, so does
breath in the living things formed by Nature. But to say that
necessity is the only cause is much as if we should think that
the water has been drawn off from a dropsical patient on
account of the lancet, not on account of health, for the sake of
which the lancet made the incision.
We have thus spoken of the teeth, saying why some are shed
and grow again, and others not, and generally for what cause
they are formed. And we have spoken of the other affections of
the parts which are found to occur not for any final end but of
necessity and on account of the motive or efficient cause.
2204
Aristotle - Metaphysics
[Translated by W. D. Ross]
Book A
All men by nature desire to know. An indication of this is the
delight we take in our senses; for even apart from their
usefulness they are loved for themselves; and above all others
the sense of sight. For not only with a view to action, but even
when we are not going to do anything, we prefer seeing (one
might say) to everything else. The reason is that this, most of all
the senses, makes us know and brings to light many differences
between things.
By nature animals are born with the faculty of sensation, and
from sensation memory is produced in some of them, though
not in others. And therefore the former are more intelligent and
apt at learning than those which cannot remember; those
which are incapable of hearing sounds are intelligent though
they cannot be taught, e.g. the bee, and any other race of
animals that may be like it; and those which besides memory
have this sense of hearing can be taught.
The animals other than man live by appearances and
memories, and have but little of connected experience; but the
human race lives also by art and reasonings. Now from memory
experience is produced in men; for the several memories of the
same thing produce finally the capacity for a single experience.
And experience seems pretty much like science and art, but
2205
really science and art come to men through experience; for
'experience made art', as Polus says, 'but inexperience luck.'
Now art arises when from many notions gained by experience
one universal judgement about a class of objects is produced.
For to have a judgement that when Callias was ill of this disease
this did him good, and similarly in the case of Socrates and in
many individual cases, is a matter of experience; but to judge
that it has done good to all persons of a certain constitution,
marked off in one class, when they were ill of this disease, e.g.
to phlegmatic or bilious people when burning with fevers - this
is a matter of art.
With a view to action experience seems in no respect inferior to
art, and men of experience succeed even better than those who
have theory without experience. (The reason is that experience
is knowledge of individuals, art of universals, and actions and
productions are all concerned with the individual; for the
physician does not cure man, except in an incidental way, but
Callias or Socrates or some other called by some such individual
name, who happens to be a man. If, then, a man has the theory
without the experience, and recognizes the universal but does
not know the individual included in this, he will often fail to
cure; for it is the individual that is to be cured.) But yet we think
that knowledge and understanding belong to art rather than to
experience, and we suppose artists to be wiser than men of
experience (which implies that Wisdom depends in all cases
rather on knowledge); and this because the former know the
cause, but the latter do not. For men of experience know that
the thing is so, but do not know why, while the others know the
'why' and the cause. Hence we think also that the
masterworkers in each craft are more honourable and know in a
truer sense and are wiser than the manual workers, because
they know the causes of the things that are done (we think the
manual workers are like certain lifeless things which act
indeed, but act without knowing what they do, as fire burns, -
2206
but while the lifeless things perform each of their functions by a
natural tendency, the labourers perform them through habit);
thus we view them as being wiser not in virtue of being able to
act, but of having the theory for themselves and knowing the
causes. And in general it is a sign of the man who knows and of
the man who does not know, that the former can teach, and
therefore we think art more truly knowledge than experience is;
for artists can teach, and men of mere experience cannot.
Again, we do not regard any of the senses as Wisdom; yet surely
these give the most authoritative knowledge of particulars. But
they do not tell us the 'why' of anything - e.g. why fire is hot;
they only say that it is hot.
At first he who invented any art whatever that went beyond the
common perceptions of man was naturally admired by men,
not only because there was something useful in the inventions,
but because he was thought wise and superior to the rest. But
as more arts were invented, and some were directed to the
necessities of life, others to recreation, the inventors of the
latter were naturally always regarded as wiser than the
inventors of the former, because their branches of knowledge
did not aim at utility. Hence when all such inventions were
already established, the sciences which do not aim at giving
pleasure or at the necessities of life were discovered, and first in
the places where men first began to have leisure. This is why
the mathematical arts were founded in Egypt; for there the
priestly caste was allowed to be at leisure.
We have said in the Ethics what the difference is between art
and science and the other kindred faculties; but the point of our
present discussion is this, that all men suppose what is called
Wisdom to deal with the first causes and the principles of
things; so that, as has been said before, the man of experience is
thought to be wiser than the possessors of any sense-
2207
perception whatever, the artist wiser than the men of
experience, the masterworker than the mechanic, and the
theoretical kinds of knowledge to be more of the nature of
Wisdom than the productive. Clearly then Wisdom is knowledge
about certain principles and causes.
Since we are seeking this knowledge, we must inquire of what
kind are the causes and the principles, the knowledge of which
is Wisdom. If one were to take the notions we have about the
wise man, this might perhaps make the answer more evident.
We suppose first, then, that the wise man knows all things, as
far as possible, although he has not knowledge of each of them
in detail; secondly, that he who can learn things that are
difficult, and not easy for man to know, is wise (sense-
perception is common to all, and therefore easy and no mark of
Wisdom); again, that he who is more exact and more capable of
teaching the causes is wiser, in every branch of knowledge; and
that of the sciences, also, that which is desirable on its own
account and for the sake of knowing it is more of the nature of
Wisdom than that which is desirable on account of its results,
and the superior science is more of the nature of Wisdom than
the ancillary; for the wise man must not be ordered but must
order, and he must not obey another, but the less wise must
obey him.
Such and so many are the notions, then, which we have about
Wisdom and the wise. Now of these characteristics that of
knowing all things must belong to him who has in the highest
degree universal knowledge; for he knows in a sense all the
instances that fall under the universal. And these things, the
2208
most universal, are on the whole the hardest for men to know;
for they are farthest from the senses. And the most exact of the
sciences are those which deal most with first principles; for
those which involve fewer principles are more exact than those
which involve additional principles, e.g. arithmetic than
geometry. But the science which investigates causes is also
instructive, in a higher degree, for the people who instruct us
are those who tell the causes of each thing. And understanding
and knowledge pursued for their own sake are found most in
the knowledge of that which is most knowable (for he who
chooses to know for the sake of knowing will choose most
readily that which is most truly knowledge, and such is the
knowledge of that which is most knowable); and the first
principles and the causes are most knowable; for by reason of
these, and from these, all other things come to be known, and
not these by means of the things subordinate to them. And the
science which knows to what end each thing must be done is
the most authoritative of the sciences, and more authoritative
than any ancillary science; and this end is the good of that
thing, and in general the supreme good in the whole of nature.
Judged by all the tests we have mentioned, then, the name in
question falls to the same science; this must be a science that
investigates the first principles and causes; for the good, i.e. the
end, is one of the causes.
That it is not a science of production is clear even from the
history of the earliest philosophers. For it is owing to their
wonder that men both now begin and at first began to
philosophize; they wondered originally at the obvious
difficulties, then advanced little by little and stated difficulties
about the greater matters, e.g. about the phenomena of the
moon and those of the sun and of the stars, and about the
genesis of the universe. And a man who is puzzled and wonders
thinks himself ignorant (whence even the lover of myth is in a
sense a lover of Wisdom, for the myth is composed of wonders);
2209
therefore since they philosophized order to escape from
ignorance, evidently they were pursuing science in order to
know, and not for any utilitarian end. And this is confirmed by
the facts; for it was when almost all the necessities of life and
the things that make for comfort and recreation had been
secured, that such knowledge began to be sought. Evidently
then we do not seek it for the sake of any other advantage; but
as the man is free, we say, who exists for his own sake and not
for another's, so we pursue this as the only free science, for it
alone exists for its own sake.
Hence also the possession of it might be justly regarded as
beyond human power; for in many ways human nature is in
bondage, so that according to Simonides 'God alone can have
this privilege', and it is unfitting that man should not be content
to seek the knowledge that is suited to him. If, then, there is
something in what the poets say, and jealousy is natural to the
divine power, it would probably occur in this case above all, and
all who excelled in this knowledge would be unfortunate. But
the divine power cannot be jealous (nay, according to the
proverb, 'bards tell a lie'), nor should any other science be
thought more honourable than one of this sort. For the most
divine science is also most honourable; and this science alone
must be, in two ways, most divine. For the science which it
would be most meet for God to have is a divine science, and so
is any science that deals with divine objects; and this science
alone has both these qualities; for (1) God is thought to be
among the causes of all things and to be a first principle, and (2)
such a science either God alone can have, or God above all
others. All the sciences, indeed, are more necessary than this,
but none is better.
Yet the acquisition of it must in a sense end in something
which is the opposite of our original inquiries. For all men begin,
as we said, by wondering that things are as they are, as they do
2210
about self-moving marionettes, or about the solstices or the
incommensurability of the diagonal of a square with the side;
for it seems wonderful to all who have not yet seen the reason,
that there is a thing which cannot be measured even by the
smallest unit. But we must end in the contrary and, according to
the proverb, the better state, as is the case in these instances
too when men learn the cause; for there is nothing which would
surprise a geometer so much as if the diagonal turned out to be
commensurable.
We have stated, then, what is the nature of the science we are
searching for, and what is the mark which our search and our
whole investigation must reach.
Evidently we have to acquire knowledge of the original causes
(for we say we know each thing only when we think we
recognize its first cause), and causes are spoken of in four
senses. In one of these we mean the substance, i.e. the essence
(for the 'why' is reducible finally to the definition, and the
ultimate 'why' is a cause and principle); in another the matter
or substratum, in a third the source of the change, and in a
fourth the cause opposed to this, the purpose and the good (for
this is the end of all generation and change). We have studied
these causes sufficiently in our work on nature, but yet let us
call to our aid those who have attacked the investigation of
being and philosophized about reality before us. For obviously
they too speak of certain principles and causes; to go over their
views, then, will be of profit to the present inquiry, for we shall
either find another kind of cause, or be more convinced of the
correctness of those which we now maintain.
2211
Of the first philosophers, then, most thought the principles
which were of the nature of matter were the only principles of
all things. That of which all things that are consist, the first
from which they come to be, the last into which they are
resolved (the substance remaining, but changing in its
modifications), this they say is the element and this the
principle of things, and therefore they think nothing is either
generated or destroyed, since this sort of entity is always
conserved, as we say Socrates neither comes to be absolutely
when he comes to be beautiful or musical, nor ceases to be
when loses these characteristics, because the substratum,
Socrates himself remains, just so they say nothing else comes to
be or ceases to be; for there must be some entity - either one or
more than one - from which all other things come to be, it being
conserved.
Yet they do not all agree as to the number and the nature of
these principles. Thales, the founder of this type of philosophy,
says the principle is water (for which reason he declared that
the earth rests on water), getting the notion perhaps from
seeing that the nutriment of all things is moist, and that heat
itself is generated from the moist and kept alive by it (and that
from which they come to be is a principle of all things). He got
his notion from this fact, and from the fact that the seeds of all
things have a moist nature, and that water is the origin of the
nature of moist things.
Some think that even the ancients who lived long before the
present generation, and first framed accounts of the gods, had a
similar view of nature; for they made Ocean and Tethys the
parents of creation, and described the oath of the gods as being
by water, to which they give the name of Styx; for what is oldest
is most honourable, and the most honourable thing is that by
which one swears. It may perhaps be uncertain whether this
opinion about nature is primitive and ancient, but Thales at any
2212
rate is said to have declared himself thus about the first cause.
Hippo no one would think fit to include among these thinkers,
because of the paltriness of his thought.
Anaximenes and Diogenes make air prior to water, and the
most primary of the simple bodies, while Hippasus of
Metapontium and Heraclitus of Ephesus say this of fire, and
Empedocles says it of the four elements (adding a fourth-earth
to those which have been named); for these, he says, always
remain and do not come to be, except that they come to be
more or fewer, being aggregated into one and segregated out of
one.
Anaxagoras of Clazomenae, who, though older than
Empedocles, was later in his philosophical activity, says the
principles are infinite in number; for he says almost all the
things that are made of parts like themselves, in the manner of
water or fire, are generated and destroyed in this way, only by
aggregation and segregation, and are not in any other sense
generated or destroyed, but remain eternally.
From these facts one might think that the only cause is the so-
called material cause; but as men thus advanced, the very facts
opened the way for them and joined in forcing them to
investigate the subject. However true it may be that all
generation and destruction proceed from some one or (for that
matter) from more elements, why does this happen and what is
the cause? For at least the substratum itself does not make
itself change; e.g. neither the wood nor the bronze causes the
change of either of them, nor does the wood manufacture a bed
and the bronze a statue, but something else is the cause of the
change. And to seek this is to seek the second cause, as we
should say, - that from which comes the beginning of the
movement. Now those who at the very beginning set
themselves to this kind of inquiry, and said the substratum was
2213
one, were not at all dissatisfied with themselves; but some at
least of those who maintain it to be one - as though defeated by
this search for the second cause - say the one and nature as a
whole is unchangeable not only in respect of generation and
destruction (for this is a primitive belief, and all agreed in it), but
also of all other change; and this view is peculiar to them. Of
those who said the universe was one, then none succeeded in
discovering a cause of this sort, except perhaps Parmenides, and
he only inasmuch as he supposes that there is not only one but
also in some sense two causes. But for those who make more
elements it is more possible to state the second cause, e.g. for
those who make hot and cold, or fire and earth, the elements;
for they treat fire as having a nature which fits it to move
things, and water and earth and such things they treat in the
contrary way.
When these men and the principles of this kind had had their
day, as the latter were found inadequate to generate the nature
of things men were again forced by the truth itself, as we said,
to inquire into the next kind of cause. For it is not likely either
that fire or earth or any such element should be the reason why
things manifest goodness and, beauty both in their being and in
their coming to be, or that those thinkers should have supposed
it was; nor again could it be right to entrust so great a matter to
spontaneity and chance. When one man said, then, that reason
was present - as in animals, so throughout nature - as the
cause of order and of all arrangement, he seemed like a sober
man in contrast with the random talk of his predecessors. We
know that Anaxagoras certainly adopted these views, but
Hermotimus of Clazomenae is credited with expressing them
earlier. Those who thought thus stated that there is a principle
of things which is at the same time the cause of beauty, and
that sort of cause from which things acquire movement.
2214
One might suspect that Hesiod was the first to look for such a
thing - or some one else who put love or desire among existing
things as a principle, as Parmenides, too, does; for he, in
constructing the genesis of the universe, says: -
Love first of all the Gods she planned.
And Hesiod says: -
First of all things was chaos made, and then
Broad-breasted earth...
And love, mid all the gods pre-eminent,
which implies that among existing things there must be from
the first a cause which will move things and bring them
together. How these thinkers should be arranged with regard to
priority of discovery let us be allowed to decide later; but since
the contraries of the various forms of good were also perceived
to be present in nature - not only order and the beautiful, but
also disorder and the ugly, and bad things in greater number
than good, and ignoble things than beautiful - therefore another
thinker introduced friendship and strife, each of the two the
cause of one of these two sets of qualities. For if we were to
follow out the view of Empedocles, and interpret it according to
its meaning and not to its lisping expression, we should find
that friendship is the cause of good things, and strife of bad.
Therefore, if we said that Empedocles in a sense both mentions,
and is the first to mention, the bad and the good as principles,
we should perhaps be right, since the cause of all goods is the
good itself.
2215
These thinkers, as we say, evidently grasped, and to this extent,
two of the causes which we distinguished in our work on nature
- the matter and the source of the movement - vaguely,
however, and with no clearness, but as untrained men behave
in fights; for they go round their opponents and often strike fine
blows, but they do not fight on scientific principles, and so too
these thinkers do not seem to know what they say; for it is
evident that, as a rule, they make no use of their causes except
to a small extent. For Anaxagoras uses reason as a deus ex
machina for the making of the world, and when he is at a loss
to tell from what cause something necessarily is, then he drags
reason in, but in all other cases ascribes events to anything
rather than to reason. And Empedocles, though he uses the
causes to a greater extent than this, neither does so sufficiently
nor attains consistency in their use. At least, in many cases he
makes love segregate things, and strife aggregate them. For
whenever the universe is dissolved into its elements by strife,
fire is aggregated into one, and so is each of the other elements;
but whenever again under the influence of love they come
together into one, the parts must again be segregated out of
each element.
Empedocles, then, in contrast with his precessors, was the first
to introduce the dividing of this cause, not positing one source
of movement, but different and contrary sources. Again, he was
the first to speak of four material elements; yet he does not use
four, but treats them as two only; he treats fire by itself, and its
opposite - earth, air, and water - as one kind of thing. We may
learn this by study of his verses.
This philosopher then, as we say, has spoken of the principles in
this way, and made them of this number. Leucippus and his
associate Democritus say that the full and the empty are the
elements, calling the one being and the other non-being - the
full and solid being being, the empty non-being (whence they
2216
say being no more is than non-being, because the solid no more
is than the empty); and they make these the material causes of
things. And as those who make the underlying substance one
generate all other things by its modifications, supposing the
rare and the dense to be the sources of the modifications, in the
same way these philosophers say the differences in the
elements are the causes of all other qualities. These differences,
they say, are three-shape and order and position. For they say
the real is differentiated only by 'rhythm and 'inter-contact' and
'turning'; and of these rhythm is shape, inter-contact is order,
and turning is position; for A differs from N in shape, AN from
NA in order, M from W in position. The question of movement -
whence or how it is to belong to things - these thinkers, like the
others, lazily neglected.
Regarding the two causes, then, as we say, the inquiry seems to
have been pushed thus far by the early philosophers.
Contemporaneously with these philosophers and before them,
the so-called Pythagoreans, who were the first to take up
mathematics, not only advanced this study, but also having
been brought up in it they thought its principles were the
principles of all things. Since of these principles numbers are by
nature the first, and in numbers they seemed to see many
resemblances to the things that exist and come into being -
more than in fire and earth and water (such and such a
modification of numbers being justice, another being soul and
reason, another being opportunity - and similarly almost all
other things being numerically expressible); since, again, they
saw that the modifications and the ratios of the musical scales
2217
were expressible in numbers; - since, then, all other things
seemed in their whole nature to be modelled on numbers, and
numbers seemed to be the first things in the whole of nature,
they supposed the elements of numbers to be the elements of
all things, and the whole heaven to be a musical scale and a
number. And all the properties of numbers and scales which
they could show to agree with the attributes and parts and the
whole arrangement of the heavens, they collected and fitted
into their scheme; and if there was a gap anywhere, they readily
made additions so as to make their whole theory coherent. E.g.
as the number 10 is thought to be perfect and to comprise the
whole nature of numbers, they say that the bodies which move
through the heavens are ten, but as the visible bodies are only
nine, to meet this they invent a tenth - the 'counter-earth'. We
have discussed these matters more exactly elsewhere.
But the object of our review is that we may learn from these
philosophers also what they suppose to be the principles and
how these fall under the causes we have named. Evidently,
then, these thinkers also consider that number is the principle
both as matter for things and as forming both their
modifications and their permanent states, and hold that the
elements of number are the even and the odd, and that of these
the latter is limited, and the former unlimited; and that the One
proceeds from both of these (for it is both even and odd), and
number from the One; and that the whole heaven, as has been
said, is numbers.
Other members of this same school say there are ten principles,
which they arrange in two columns of cognates - limit and
unlimited, odd and even, one and plurality, right and left, male
and female, resting and moving, straight and curved, light and
darkness, good and bad, square and oblong. In this way
Alcmaeon of Croton seems also to have conceived the matter,
and either he got this view from them or they got it from him;
2218
for he expressed himself similarly to them. For he says most
human affairs go in pairs, meaning not definite contrarieties
such as the Pythagoreans speak of, but any chance contrarieties,
e.g. white and black, sweet and bitter, good and bad, great and
small. He threw out indefinite suggestions about the other
contrarieties, but the Pythagoreans declared both how many
and which their contrarieties are.
From both these schools, then, we can learn this much, that the
contraries are the principles of things; and how many these
principles are and which they are, we can learn from one of the
two schools. But how these principles can be brought together
under the causes we have named has not been clearly and
articulately stated by them; they seem, however, to range the
elements under the head of matter; for out of these as
immanent parts they say substance is composed and moulded.
From these facts we may sufficiently perceive the meaning of
the ancients who said the elements of nature were more than
one; but there are some who spoke of the universe as if it were
one entity, though they were not all alike either in the
excellence of their statement or in its conformity to the facts of
nature. The discussion of them is in no way appropriate to our
present investigation of causes, for. they do not, like some of the
natural philosophers, assume being to be one and yet generate
it out of the one as out of matter, but they speak in another way;
those others add change, since they generate the universe, but
these thinkers say the universe is unchangeable. Yet this much
is germane to the present inquiry: Parmenides seems to fasten
on that which is one in definition, Melissus on that which is one
in matter, for which reason the former says that it is limited, the
latter that it is unlimited; while Xenophanes, the first of these
partisans of the One (for Parmenides is said to have been his
pupil), gave no clear statement, nor does he seem to have
grasped the nature of either of these causes, but with reference
2219
to the whole material universe he says the One is God. Now
these thinkers, as we said, must be neglected for the purposes
of the present inquiry - two of them entirely, as being a little too
naive, viz. Xenophanes and Melissus; but Parmenides seems in
places to speak with more insight. For, claiming that, besides
the existent, nothing non-existent exists, he thinks that of
necessity one thing exists, viz. the existent and nothing else (on
this we have spoken more clearly in our work on nature), but
being forced to follow the observed facts, and supposing the
existence of that which is one in definition, but more than one
according to our sensations, he now posits two causes and two
principles, calling them hot and cold, i.e. fire and earth; and of
these he ranges the hot with the existent, and the other with
the non-existent.
From what has been said, then, and from the wise men who
have now sat in council with us, we have got thus much - on
the one hand from the earliest philosophers, who regard the
first principle as corporeal (for water and fire and such things
are bodies), and of whom some suppose that there is one
corporeal principle, others that there are more than one, but
both put these under the head of matter; and on the other hand
from some who posit both this cause and besides this the
source of movement, which we have got from some as single
and from others as twofold.
Down to the Italian school, then, and apart from it, philosophers
have treated these subjects rather obscurely, except that, as we
said, they have in fact used two kinds of cause, and one of these
- the source of movement - some treat as one and others as
two. But the Pythagoreans have said in the same way that there
are two principles, but added this much, which is peculiar to
them, that they thought that finitude and infinity were not
attributes of certain other things, e.g. of fire or earth or anything
else of this kind, but that infinity itself and unity itself were the
2220
substance of the things of which they are predicated. This is
why number was the substance of all things. On this subject,
then, they expressed themselves thus; and regarding the
question of essence they began to make statements and
definitions, but treated the matter too simply. For they both
defined superficially and thought that the first subject of which
a given definition was predicable was the substance of the thing
defined, as if one supposed that 'double' and '2' were the same,
because 2 is the first thing of which 'double' is predicable. But
surely to be double and to be 2 are not the same; if they are, one
thing will be many - a consequence which they actually drew.
From the earlier philosophers, then, and from their successors
we can learn thus much.
After the systems we have named came the philosophy of Plato,
which in most respects followed these thinkers, but had
peculiarities that distinguished it from the philosophy of the
Italians. For, having in his youth first become familiar with
Cratylus and with the Heraclitean doctrines (that all sensible
things are ever in a state of flux and there is no knowledge
about them), these views he held even in later years. Socrates,
however, was busying himself about ethical matters and
neglecting the world of nature as a whole but seeking the
universal in these ethical matters, and fixed thought for the
first time on definitions; Plato accepted his teaching, but held
that the problem applied not to sensible things but to entities of
another kind - for this reason, that the common definition
could not be a definition of any sensible thing, as they were
always changing. Things of this other sort, then, he called Ideas,
and sensible things, he said, were all named after these, and in
2221
virtue of a relation to these; for the many existed by
participation in the Ideas that have the same name as they.
Only the name 'participation' was new; for the Pythagoreans
say that things exist by 'imitation' of numbers, and Plato says
they exist by participation, changing the name. But what the
participation or the imitation of the Forms could be they left an
open question.
Further, besides sensible things and Forms he says there are the
objects of mathematics, which occupy an intermediate position,
differing from sensible things in being eternal and
unchangeable, from Forms in that there are many alike, while
the Form itself is in each case unique.
Since the Forms were the causes of all other things, he thought
their elements were the elements of all things. As matter, the
great and the small were principles; as essential reality, the One;
for from the great and the small, by participation in the One,
come the Numbers.
But he agreed with the Pythagoreans in saying that the One is
substance and not a predicate of something else; and in saying
that the Numbers are the causes of the reality of other things he
agreed with them; but positing a dyad and constructing the
infinite out of great and small, instead of treating the infinite as
one, is peculiar to him; and so is his view that the Numbers
exist apart from sensible things, while they say that the things
themselves are Numbers, and do not place the objects of
mathematics between Forms and sensible things. His
divergence from the Pythagoreans in making the One and the
Numbers separate from things, and his introduction of the
Forms, were due to his inquiries in the region of definitions (for
the earlier thinkers had no tincture of dialectic), and his making
the other entity besides the One a dyad was due to the belief
that the numbers, except those which were prime, could be
2222
neatly produced out of the dyad as out of some plastic material.
Yet what happens is the contrary; the theory is not a reasonable
one. For they make many things out of the matter, and the form
generates only once, but what we observe is that one table is
made from one matter, while the man who applies the form,
though he is one, makes many tables. And the relation of the
male to the female is similar; for the latter is impregnated by
one copulation, but the male impregnates many females; yet
these are analogues of those first principles.
Plato, then, declared himself thus on the points in question; it is
evident from what has been said that he has used only two
causes, that of the essence and the material cause (for the
Forms are the causes of the essence of all other things, and the
One is the cause of the essence of the Forms); and it is evident
what the underlying matter is, of which the Forms are
predicated in the case of sensible things, and the One in the
case of Forms, viz. that this is a dyad, the great and the small.
Further, he has assigned the cause of good and that of evil to
the elements, one to each of the two, as we say some of his
predecessors sought to do, e.g. Empedocles and Anaxagoras.
Our review of those who have spoken about first principles and
reality and of the way in which they have spoken, has been
concise and summary; but yet we have learnt this much from
them, that of those who speak about 'principle' and 'cause' no
one has mentioned any principle except those which have been
distinguished in our work on nature, but all evidently have
some inkling of them, though only vaguely. For some speak of
the first principle as matter, whether they suppose one or more
2223
first principles, and whether they suppose this to be a body or
to be incorporeal; e.g. Plato spoke of the great and the small, the
Italians of the infinite, Empedocles of fire, earth, water, and air,
Anaxagoras of the infinity of things composed of similar parts.
These, then, have all had a notion of this kind of cause, and so
have all who speak of air or fire or water, or something denser
than fire and rarer than air; for some have said the prime
element is of this kind.
These thinkers grasped this cause only; but certain others have
mentioned the source of movement, e.g. those who make
friendship and strife, or reason, or love, a principle.
The essence, i.e. the substantial reality, no one has expressed
distinctly. It is hinted at chiefly by those who believe in the
Forms; for they do not suppose either that the Forms are the
matter of sensible things, and the One the matter of the Forms,
or that they are the source of movement (for they say these are
causes rather of immobility and of being at rest), but they
furnish the Forms as the essence of every other thing, and the
One as the essence of the Forms.
That for whose sake actions and changes and movements take
place, they assert to be a cause in a way, but not in this way, i.e.
not in the way in which it is its nature to be a cause. For those
who speak of reason or friendship class these causes as goods;
they do not speak, however, as if anything that exists either
existed or came into being for the sake of these, but as if
movements started from these. In the same way those who say
the One or the existent is the good, say that it is the cause of
substance, but not that substance either is or comes to be for
the sake of this. Therefore it turns out that in a sense they both
say and do not say the good is a cause; for they do not call it a
cause qua good but only incidentally.
2224
All these thinkers then, as they cannot pitch on another cause,
seem to testify that we have determined rightly both how many
and of what sort the causes are. Besides this it is plain that
when the causes are being looked for, either all four must be
sought thus or they must be sought in one of these four ways.
Let us next discuss the possible difficulties with regard to the
way in which each of these thinkers has spoken, and with
regard to his situation relatively to the first principles.
8
Those, then, who say the universe is one and posit one kind of
thing as matter, and as corporeal matter which has spatial
magnitude, evidently go astray in many ways. For they posit the
elements of bodies only, not of incorporeal things, though there
are also incorporeal things. And in trying to state the causes of
generation and destruction, and in giving a physical account of
all things, they do away with the cause of movement. Further,
they err in not positing the substance, i.e. the essence, as the
cause of anything, and besides this in lightly calling any of the
simple bodies except earth the first principle, without inquiring
how they are produced out of one anothers - I mean fire, water,
earth, and air. For some things are produced out of each other
by combination, others by separation, and this makes the
greatest difference to their priority and posteriority. For (1) in a
way the property of being most elementary of all would seem to
belong to the first thing from which they are produced by
combination, and this property would belong to the most fine-
grained and subtle of bodies. For this reason those who make
fire the principle would be most in agreement with this
argument. But each of the other thinkers agrees that the
element of corporeal things is of this sort. At least none of those
2225
who named one element claimed that earth was the element,
evidently because of the coarseness of its grain. (Of the other
three elements each has found some judge on its side; for some
maintain that fire, others that water, others that air is the
element. Yet why, after all, do they not name earth also, as most
men do? For people say all things are earth Hesiod says earth
was produced first of corporeal things; so primitive and popular
has the opinion been.) According to this argument, then, no one
would be right who either says the first principle is any of the
elements other than fire, or supposes it to be denser than air
but rarer than water. But (2) if that which is later in generation
is prior in nature, and that which is concocted and compounded
is later in generation, the contrary of what we have been saying
must be true, - water must be prior to air, and earth to water.
So much, then, for those who posit one cause such as we
mentioned; but the same is true if one supposes more of these,
as Empedocles says matter of things is four bodies. For he too is
confronted by consequences some of which are the same as
have been mentioned, while others are peculiar to him. For we
see these bodies produced from one another, which implies that
the same body does not always remain fire or earth (we have
spoken about this in our works on nature); and regarding the
cause of movement and the question whether we must posit
one or two, he must be thought to have spoken neither correctly
nor altogether plausibly. And in general, change of quality is
necessarily done away with for those who speak thus, for on
their view cold will not come from hot nor hot from cold. For if
it did there would be something that accepted the contraries
themselves, and there would be some one entity that became
fire and water, which Empedocles denies.
As regards Anaxagoras, if one were to suppose that he said
there were two elements, the supposition would accord
thoroughly with an argument which Anaxagoras himself did
2226
not state articulately, but which he must have accepted if any-
one had led him on to it. True, to say that in the beginning all
things were mixed is absurd both on other grounds and because
it follows that they must have existed before in an unmixed
form, and because nature does not allow any chance thing to be
mixed with any chance thing, and also because on this view
modifications and accidents could be separated from
substances (for the same things which are mixed can be
separated); yet if one were to follow him up, piecing together
what he means, he would perhaps be seen to be somewhat
modern in his views. For when nothing was separated out,
evidently nothing could be truly asserted of the substance that
then existed. I mean, e.g. that it was neither white nor black,
nor grey nor any other colour, but of necessity colourless; for if
it had been coloured, it would have had one of these colours.
And similarly, by this same argument, it was flavourless, nor
had it any similar attribute; for it could not be either of any
quality or of any size, nor could it be any definite kind of thing.
For if it were, one of the particular forms would have belonged
to it, and this is impossible, since all were mixed together; for
the particular form would necessarily have been already
separated out, but he all were mixed except reason, and this
alone was unmixed and pure. From this it follows, then, that he
must say the principles are the One (for this is simple and
unmixed) and the Other, which is of such a nature as we
suppose the indefinite to be before it is defined and partakes of
some form. Therefore, while expressing himself neither rightly
nor clearly, he means something like what the later thinkers say
and what is now more clearly seen to be the case.
But these thinkers are, after all, at home only in arguments
about generation and destruction and movement; for it is
practically only of this sort of substance that they seek the
principles and the causes. But those who extend their vision to
all things that exist, and of existing things suppose some to be
2227
perceptible and others not perceptible, evidently study both
classes, which is all the more reason why one should devote
some time to seeing what is good in their views and what bad
from the standpoint of the inquiry we have now before us.
The 'Pythagoreans' treat of principles and elements stranger
than those of the physical philosophers (the reason is that they
got the principles from non-sensible things, for the objects of
mathematics, except those of astronomy, are of the class of
things without movement); yet their discussions and
investigations are all about nature; for they generate the
heavens, and with regard to their parts and attributes and
functions they observe the phenomena, and use up the
principles and the causes in explaining these, which implies
that they agree with the others, the physical philosophers, that
the real is just all that which is perceptible and contained by the
so-called 'heavens'. But the causes and the principles which
they mention are, as we said, sufficient to act as steps even up
to the higher realms of reality, and are more suited to these
than to theories about nature. They do not tell us at all, however,
how there can be movement if limit and unlimited and odd and
even are the only things assumed, or how without movement
and change there can be generation and destruction, or the
bodies that move through the heavens can do what they do.
Further, if one either granted them that spatial magnitude
consists of these elements, or this were proved, still how would
some bodies be light and others have weight? To judge from
what they assume and maintain they are speaking no more of
mathematical bodies than of perceptible; hence they have said
nothing whatever about fire or earth or the other bodies of this
sort, I suppose because they have nothing to say which applies
peculiarly to perceptible things.
2228
Further, how are we to combine the beliefs that the attributes of
number, and number itself, are causes of what exists and
happens in the heavens both from the beginning and now, and
that there is no other number than this number out of which
the world is composed? When in one particular region they
place opinion and opportunity, and, a little above or below,
injustice and decision or mixture, and allege, as proof, that each
of these is a number, and that there happens to be already in
this place a plurality of the extended bodies composed of
numbers, because these attributes of number attach to the
various places, - this being so, is this number, which we must
suppose each of these abstractions to be, the same number
which is exhibited in the material universe, or is it another than
this? Plato says it is different; yet even he thinks that both these
bodies and their causes are numbers, but that the intelligible
numbers are causes, while the others are sensible.
Let us leave the Pythagoreans for the present; for it is enough to
have touched on them as much as we have done. But as for
those who posit the Ideas as causes, firstly, in seeking to grasp
the causes of the things around us, they introduced others
equal in number to these, as if a man who wanted to count
things thought he would not be able to do it while they were
few, but tried to count them when he had added to their
number. For the Forms are practically equal to - or not fewer
than - the things, in trying to explain which these thinkers
proceeded from them to the Forms. For to each thing there
answers an entity which has the same name and exists apart
from the substances, and so also in the case of all other groups
2229
there is a one over many, whether the many are in this world or
are eternal.
Further, of the ways in which we prove that the Forms exist,
none is convincing; for from some no inference necessarily
follows, and from some arise Forms even of things of which we
think there are no Forms. For according to the arguments from
the existence of the sciences there will be Forms of all things of
which there are sciences and according to the 'one over many'
argument there will be Forms even of negations, and according
to the argument that there is an object for thought even when
the thing has perished, there will be Forms of perishable things;
for we have an image of these. Further, of the more accurate
arguments, some lead to Ideas of relations, of which we say
there is no independent class, and others introduce the 'third
man'.
And in general the arguments for the Forms destroy the things
for whose existence we are more zealous than for the existence
of the Ideas; for it follows that not the dyad but number is first,
i.e. that the relative is prior to the absolute, - besides all the
other points on which certain people by following out the
opinions held about the Ideas have come into conflict with the
principles of the theory.
Further, according to the assumption on which our belief in the
Ideas rests, there will be Forms not only of substances but also
of many other things (for the concept is single not only in the
case of substances but also in the other cases, and there are
sciences not only of substance but also of other things, and a
thousand other such difficulties confront them). But according
to the necessities of the case and the opinions held about the
Forms, if Forms can be shared in there must be Ideas of
substances only. For they are not shared in incidentally, but a
thing must share in its Form as in something not predicated of
2230
a subject (by 'being shared in incidentally' I mean that e.g. if a
thing shares in 'double itself, it shares also in 'eternal', but
incidentally; for 'eternal' happens to be predicable of the
'double'). Therefore the Forms will be substance; but the same
terms indicate substance in this and in the ideal world (or what
will be the meaning of saying that there is something apart
from the particulars - the one over many?). And if the Ideas and
the particulars that share in them have the same form, there
will be something common to these; for why should '2' be one
and the same in the perishable 2's or in those which are many
but eternal, and not the same in the '2' itself as in the
particular 2? But if they have not the same form, they must
have only the name in common, and it is as if one were to call
both Callias and a wooden image a 'man', without observing
any community between them.
Above all one might discuss the question what on earth the
Forms contribute to sensible things, either to those that are
eternal or to those that come into being and cease to be. For
they cause neither movement nor any change in them. But
again they help in no wise either towards the knowledge of the
other things (for they are not even the substance of these, else
they would have been in them), or towards their being, if they
are not in the particulars which share in them; though if they
were, they might be thought to be causes, as white causes
whiteness in a white object by entering into its composition. But
this argument, which first Anaxagoras and later Eudoxus and
certain others used, is very easily upset; for it is not difficult to
collect many insuperable objections to such a view.
But, further, all other things cannot come from the Forms in any
of the usual senses of 'from'. And to say that they are patterns
and the other things share in them is to use empty words and
poetical metaphors. For what is it that works, looking to the
Ideas? And anything can either be, or become, like another
2231
without being copied from it, so that whether Socrates or not a
man Socrates like might come to be; and evidently this might be
so even if Socrates were eternal. And there will be several
patterns of the same thing, and therefore several Forms; e.g.
'animal' and 'two-footed' and also 'man himself will be Forms
of man. Again, the Forms are patterns not only sensible things,
but of Forms themselves also; i.e. the genus, as genus of various
species, will be so; therefore the same thing will be pattern and
copy.
Again, it would seem impossible that the substance and that of
which it is the substance should exist apart; how, therefore,
could the Ideas, being the substances of things, exist apart? In
the Phaedo' the case is stated in this way - that the Forms are
causes both of being and of becoming; yet when the Forms
exist, still the things that share in them do not come into being,
unless there is something to originate movement; and many
other things come into being (e.g. a house or a ring) of which we
say there are no Forms. Clearly, therefore, even the other things
can both be and come into being owing to such causes as
produce the things just mentioned.
Again, if the Forms are numbers, how can they be causes? Is it
because existing things are other numbers, e.g. one number is
man, another is Socrates, another Callias? Why then are the one
set of numbers causes of the other set? It will not make any
difference even if the former are eternal and the latter are not.
But if it is because things in this sensible world (e.g. harmony)
are ratios of numbers, evidently the things between which they
are ratios are some one class of things. If, then, this - the matter
- is some definite thing, evidently the numbers themselves too
will be ratios of something to something else. E.g. if Callias is a
numerical ratio between fire and earth and water and air, his
Idea also will be a number of certain other underlying things;
and man himself, whether it is a number in a sense or not, will
2232
still be a numerical ratio of certain things and not a number
proper, nor will it be a of number merely because it is a
numerical ratio.
Again, from many numbers one number is produced, but how
can one Form come from many Forms? And if the number
comes not from the many numbers themselves but from the
units in them, e.g. in 10,000, how is it with the units? If they are
specifically alike, numerous absurdities will follow, and also if
they are not alike (neither the units in one number being
themselves like one another nor those in other numbers being
all like to all); for in what will they differ, as they are without
quality? This is not a plausible view, nor is it consistent with our
thought on the matter.
Further, they must set up a second kind of number (with which
arithmetic deals), and all the objects which are called
'intermediate' by some thinkers; and how do these exist or from
what principles do they proceed? Or why must they be
intermediate between the things in this sensible world and the
things-themselves?
Further, the units in must each come from a prior but this is
impossible.
Further, why is a number, when taken all together, one?
Again, besides what has been said, if the units are diverse the
Platonists should have spoken like those who say there are four,
or two, elements; for each of these thinkers gives the name of
element not to that which is common, e.g. to body, but to fire
and earth, whether there is something common to them, viz.
body, or not. But in fact the Platonists speak as if the One were
homogeneous like fire or water; and if this is so, the numbers
will not be substances. Evidently, if there is a One itself and this
2233
is a first principle, 'one' is being used in more than one sense;
for otherwise the theory is impossible.
When we wish to reduce substances to their principles, we state
that lines come from the short and long (i.e. from a kind of
small and great), and the plane from the broad and narrow, and
body from the deep and shallow. Yet how then can either the
plane contain a line, or the solid a line or a plane? For the broad
and narrow is a different class from the deep and shallow.
Therefore, just as number is not present in these, because the
many and few are different from these, evidently no other of the
higher classes will be present in the lower. But again the broad
is not a genus which includes the deep, for then the solid would
have been a species of plane. Further, from what principle will
the presence of the points in the line be derived? Plato even
used to object to this class of things as being a geometrical
fiction. He gave the name of principle of the line - and this he
often posited - to the indivisible lines. Yet these must have a
limit; therefore the argument from which the existence of the
line follows proves also the existence of the point.
In general, though philosophy seeks the cause of perceptible
things, we have given this up (for we say nothing of the cause
from which change takes its start), but while we fancy we are
stating the substance of perceptible things, we assert the
existence of a second class of substances, while our account of
the way in which they are the substances of perceptible things
is empty talk; for 'sharing', as we said before, means nothing.
Nor have the Forms any connexion with what we see to be the
cause in the case of the arts, that for whose sake both all mind
and the whole of nature are operative, - with this cause which
we assert to be one of the first principles; but mathematics has
come to be identical with philosophy for modern thinkers,
though they say that it should be studied for the sake of other
2234
things. Further, one might suppose that the substance which
according to them underlies as matter is too mathematical, and
is a predicate and differentia of the substance, ie. of the matter,
rather than matter itself; i.e. the great and the small are like the
rare and the dense which the physical philosophers speak of,
calling these the primary differentiae of the substratum; for
these are a kind of excess and defect. And regarding movement,
if the great and the small are to he movement, evidently the
Forms will be moved; but if they are not to be movement,
whence did movement come? The whole study of nature has
been annihilated.
And what is thought to be easy - to show that all things are one
- is not done; for what is proved by the method of setting out
instances is not that all things are one but that there is a One
itself, - if we grant all the assumptions. And not even this
follows, if we do not grant that the universal is a genus; and this
in some cases it cannot be.
Nor can it be explained either how the lines and planes and
solids that come after the numbers exist or can exist, or what
significance they have; for these can neither be Forms (for they
are not numbers), nor the intermediates (for those are the
objects of mathematics), nor the perishable things. This is
evidently a distinct fourth class.
In general, if we search for the elements of existing things
without distinguishing the many senses in which things are
said to exist, we cannot find them, especially if the search for
the elements of which things are made is conducted in this
manner. For it is surely impossible to discover what 'acting' or
'being acted on', or 'the straight', is made of, but if elements can
be discovered at all, it is only the elements of substances;
therefore either to seek the elements of all existing things or to
think one has them is incorrect.
2235
And how could we learn the elements of all things? Evidently
we cannot start by knowing anything before. For as he who is
learning geometry, though he may know other things before,
knows none of the things with which the science deals and
about which he is to learn, so is it in all other cases. Therefore if
there is a science of all things, such as some assert to exist, he
who is learning this will know nothing before. Yet all learning is
by means of premisses which are (either all or some of them)
known before, - whether the learning be by demonstration or by
definitions; for the elements of the definition must be known
before and be familiar; and learning by induction proceeds
similarly. But again, if the science were actually innate, it were
strange that we are unaware of our possession of the greatest of
sciences.
Again, how is one to come to know what all things are made of,
and how is this to be made evident? This also affords a
difficulty; for there might be a conflict of opinion, as there is
about certain syllables; some say za is made out of s and d and
a, while others say it is a distinct sound and none of those that
are familiar.
Further, how could we know the objects of sense without having
the sense in question? Yet we ought to, if the elements of which
all things consist, as complex sounds consist of the elements
proper to sound, are the same.
10
It is evident, then, even from what we have said before, that all
men seem to seek the causes named in the Physics, and that we
cannot name any beyond these; but they seek these vaguely;
and though in a sense they have all been described before, in a
2236
sense they have not been described at all. For the earliest
philosophy is, on all subjects, like one who lisps, since it is
young and in its beginnings. For even Empedocles says bone
exists by virtue of the ratio in it. Now this is the essence and the
substance of the thing. But it is similarly necessary that flesh
and each of the other tissues should be the ratio of its elements,
or that not one of them should; for it is on account of this that
both flesh and bone and everything else will exist, and not on
account of the matter, which he names, - fire and earth and
water and air. But while he would necessarily have agreed if
another had said this, he has not said it clearly.
On these questions our views have been expressed before; but
let us return to enumerate the difficulties that might be raised
on these same points; for perhaps we may get from them some
help towards our later difficulties.
Book a
The investigation of the truth is in one way hard, in another
easy. An indication of this is found in the fact that no one is able
to attain the truth adequately, while, on the other hand, we do
not collectively fail, but every one says something true about
the nature of things, and while individually we contribute little
or nothing to the truth, by the union of all a considerable
amount is amassed. Therefore, since the truth seems to be like
2237
the proverbial door, which no one can fail to hit, in this respect
it must be easy, but the fact that we can have a whole truth and
not the particular part we aim at shows the difficulty of it.
Perhaps, too, as difficulties are of two kinds, the cause of the
present difficulty is not in the facts but in us. For as the eyes of
bats are to the blaze of day, so is the reason in our soul to the
things which are by nature most evident of all.
It is just that we should be grateful, not only to those with
whose views we may agree, but also to those who have
expressed more superficial views; for these also contributed
something, by developing before us the powers of thought. It is
true that if there had been no Timotheus we should have been
without much of our lyric poetry; but if there had been no
Phrynis there would have been no Timotheus. The same holds
good of those who have expressed views about the truth; for
from some thinkers we have inherited certain opinions, while
the others have been responsible for the appearance of the
former.
It is right also that philosophy should be called knowledge of
the truth. For the end of theoretical knowledge is truth, while
that of practical knowledge is action (for even if they consider
how things are, practical men do not study the eternal, but what
is relative and in the present). Now we do not know a truth
without its cause; and a thing has a quality in a higher degree
than other things if in virtue of it the similar quality belongs to
the other things as well (e.g. fire is the hottest of things; for it is
the cause of the heat of all other things); so that that causes
derivative truths to be true is most true. Hence the principles of
eternal things must be always most true (for they are not
merely sometimes true, nor is there any cause of their being,
but they themselves are the cause of the being of other things),
2238
so that as each thing is in respect of being, so is it in respect of
truth.
But evidently there is a first principle, and the causes of things
are neither an infinite series nor infinitely various in kind. For
neither can one thing proceed from another, as from matter, ad
infinitum (e.g. flesh from earth, earth from air, air from fire, and
so on without stopping), nor can the sources of movement form
an endless series (man for instance being acted on by air, air by
the sun, the sun by Strife, and so on without limit). Similarly the
final causes cannot go on ad infinitum, - walking being for the
sake of health, this for the sake of happiness, happiness for the
sake of something else, and so one thing always for the sake of
another. And the case of the essence is similar. For in the case of
intermediates, which have a last term and a term prior to them,
the prior must be the cause of the later terms. For if we had to
say which of the three is the cause, we should say the first;
surely not the last, for the final term is the cause of none; nor
even the intermediate, for it is the cause only of one. (It makes
no difference whether there is one intermediate or more, nor
whether they are infinite or finite in number.) But of series
which are infinite in this way, and of the infinite in general, all
the parts down to that now present are alike intermediates; so
that if there is no first there is no cause at all.
Nor can there be an infinite process downwards, with a
beginning in the upward direction, so that water should proceed
from fire, earth from water, and so always some other kind
should be produced. For one thing comes from another in two
ways - not in the sense in which 'from' means 'after' (as we say
2239
'from the Isthmian games come the Olympian'), but either (i) as
the man comes from the boy, by the boy's changing, or (ii) as air
comes from water. By 'as the man comes from the boy' we
mean 'as that which has come to be from that which is coming
to be' or 'as that which is finished from that which is being
achieved' (for as becoming is between being and not being, so
that which is becoming is always between that which is and
that which is not; for the learner is a man of science in the
making, and this is what is meant when we say that from a
learner a man of science is being made); on the other hand,
coming from another thing as water comes from air implies the
destruction of the other thing. This is why changes of the
former kind are not reversible, and the boy does not come from
the man (for it is not that which comes to be something that
comes to be as a result of coming to be, but that which exists
after the coming to be; for it is thus that the day, too, comes
from the morning - in the sense that it comes after the
morning; which is the reason why the morning cannot come
from the day); but changes of the other kind are reversible. But
in both cases it is impossible that the number of terms should
be infinite. For terms of the former kind, being intermediates,
must have an end, and terms of the latter kind change back into
one another, for the destruction of either is the generation of
the other.
At the same time it is impossible that the first cause, being
eternal, should be destroyed; for since the process of becoming
is not infinite in the upward direction, that which is the first
thing by whose destruction something came to be must be non-
eternal.
Further, the final cause is an end, and that sort of end which is
not for the sake of something else, but for whose sake
everything else is; so that if there is to be a last term of this sort,
the process will not be infinite; but if there is no such term,
2240
there will be no final cause, but those who maintain the infinite
series eliminate the Good without knowing it (yet no one would
try to do anything if he were not going to come to a limit); nor
would there be reason in the world; the reasonable man, at
least, always acts for a purpose, and this is a limit; for the end is
a limit.
But the essence, also, cannot be reduced to another definition
which is fuller in expression. For the original definition is
always more of a definition, and not the later one; and in a
series in which the first term has not the required character, the
next has not it either. Further, those who speak thus destroy
science; for it is not possible to have this till one comes to the
unanalysable terms. And knowledge becomes impossible; for
how can one apprehend things that are infinite in this way? For
this is not like the case of the line, to whose divisibility there is
no stop, but which we cannot think if we do not make a stop
(for which reason one who is tracing the infinitely divisible line
cannot be counting the possibilities of section), but the whole
line also must be apprehended by something in us that does not
move from part to part. - Again, nothing infinite can exist; and
if it could, at least the notion of infinity is not infinite.
But if the kinds of causes had been infinite in number, then also
knowledge would have been impossible; for we think we know,
only when we have ascertained the causes, that but that which
is infinite by addition cannot be gone through in a finite time.
The effect which lectures produce on a hearer depends on his
habits; for we demand the language we are accustomed to, and
that which is different from this seems not in keeping but
2241
somewhat unintelligible and foreign because of its
unwontedness. For it is the customary that is intelligible. The
force of habit is shown by the laws, in which the legendary and
childish elements prevail over our knowledge about them,
owing to habit. Thus some people do not listen to a speaker
unless he speaks mathematically, others unless he gives
instances, while others expect him to cite a poet as witness.
And some want to have everything done accurately, while
others are annoyed by accuracy, either because they cannot
follow the connexion of thought or because they regard it as
pettifoggery. For accuracy has something of this character, so
that as in trade so in argument some people think it mean.
Hence one must be already trained to know how to take each
sort of argument, since it is absurd to seek at the same time
knowledge and the way of attaining knowledge; and it is not
easy to get even one of the two.
The minute accuracy of mathematics is not to be demanded in
all cases, but only in the case of things which have no matter.
Hence method is not that of natural science; for presumably the
whole of nature has matter. Hence we must inquire first what
nature is: for thus we shall also see what natural science treats
of (and whether it belongs to one science or to more to
investigate the causes and the principles of things).
2242
BookB
We must, with a view to the science which we are seeking, first
recount the subjects that should be first discussed. These
include both the other opinions that some have held on the first
principles, and any point besides these that happens to have
been overlooked. For those who wish to get clear of difficulties
it is advantageous to discuss the difficulties well; for the
subsequent free play of thought implies the solution of the
previous difficulties, and it is not possible to untie a knot of
which one does not know. But the difficulty of our thinking
points to a 'knot' in the object; for in so far as our thought is in
difficulties, it is in like case with those who are bound; for in
either case it is impossible to go forward. Hence one should
have surveyed all the difficulties beforehand, both for the
purposes we have stated and because people who inquire
without first stating the difficulties are like those who do not
know where they have to go; besides, a man does not otherwise
know even whether he has at any given time found what he is
looking for or not; for the end is not clear to such a man, while
to him who has first discussed the difficulties it is clear. Further,
he who has heard all the contending arguments, as if they were
the parties to a case, must be in a better position forjudging.
The first problem concerns the subject which we discussed in
our prefatory remarks. It is this - (1) whether the investigation
of the causes belongs to one or to more sciences, and (2)
whether such a science should survey only the first principles
of substance, or also the principles on which all men base their
proofs, e.g. whether it is possible at the same time to assert and
2243
deny one and the same thing or not, and all other such
questions; and (3) if the science in question deals with
substance, whether one science deals with all substances, or
more than one, and if more, whether all are akin, or some of
them must be called forms of Wisdom and the others
something else. And (4) this itself is also one of the things that
must be discussed - whether sensible substances alone should
be said to exist or others also besides them, and whether these
others are of one kind or there are several classes of substances,
as is supposed by those who believe both in Forms and in
mathematical objects intermediate between these and sensible
things. Into these questions, then, as we say, we must inquire,
and also (5) whether our investigation is concerned only with
substances or also with the essential attributes of substances.
Further, with regard to the same and other and like and unlike
and contrariety, and with regard to prior and posterior and all
other such terms about which the dialecticians try to inquire,
starting their investigation from probable premises only, -
whose business is it to inquire into all these? Further, we must
discuss the essential attributes of these themselves; and we
must ask not only what each of these is, but also whether one
thing always has one contrary. Again (6), are the principles and
elements of things the genera, or the parts present in each
thing, into which it is divided; and (7) if they are the genera, are
they the genera that are predicated proximately of the
individuals, or the highest genera, e.g. is animal or man the first
principle and the more independent of the individual instance?
And (8) we must inquire and discuss especially whether there is,
besides the matter, any thing that is a cause in itself or not, and
whether this can exist apart or not, and whether it is one or
more in number, and whether there is something apart from
the concrete thing (by the concrete thing I mean the matter
with something already predicated of it), or there is nothing
apart, or there is something in some cases though not in others,
2244
and what sort of cases these are. Again (9) we ask whether the
principles are limited in number or in kind, both those in the
definitions and those in the substratum; and (10) whether the
principles of perishable and of imperishable things are the same
or different; and whether they are all imperishable or those of
perishable things are perishable. Further (11) there is the
question which is hardest of all and most perplexing, whether
unity and being, as the Pythagoreans and Plato said, are not
attributes of something else but the substance of existing
things, or this is not the case, but the substratum is something
else, - as Empedocles says, love; as some one else says, fire;
while another says water or air. Again (12) we ask whether the
principles are universal or like individual things, and (13)
whether they exist potentially or actually, and further, whether
they are potential or actual in any other sense than in reference
to movement; for these questions also would present much
difficulty. Further (14), are numbers and lines and figures and
points a kind of substance or not, and if they are substances are
they separate from sensible things or present in them? With
regard to all these matters not only is it hard to get possession
of the truth, but it is not easy even to think out the difficulties
well.
(1) First then with regard to what we mentioned first, does it
belong to one or to more sciences to investigate all the kinds of
causes? How could it belong to one science to recognize the
principles if these are not contrary?
Further, there are many things to which not all the principles
pertain. For how can a principle of change or the nature of the
2245
good exist for unchangeable things, since everything that in
itself and by its own nature is good is an end, and a cause in the
sense that for its sake the other things both come to be and are,
and since an end or purpose is the end of some action, and all
actions imply change? So in the case of unchangeable things
this principle could not exist, nor could there be a good itself.
This is why in mathematics nothing is proved by means of this
kind of cause, nor is there any demonstration of this kind -
'because it is better, or worse'; indeed no one even mentions
anything of the kind. And so for this reason some of the
Sophists, e.g. Aristippus, used to ridicule mathematics; for in
the arts (he maintained), even in the industrial arts, e.g. in
carpentry and cobbling, the reason always given is 'because it is
better, or worse,' but the mathematical sciences take no account
of goods and evils.
But if there are several sciences of the causes, and a different
science for each different principle, which of these sciences
should be said to be that which we seek, or which of the people
who possess them has the most scientific knowledge of the
object in question? The same thing may have all the kinds of
causes, e.g. the moving cause of a house is the art or the builder,
the final cause is the function it fulfils, the matter is earth and
stones, and the form is the definition. To judge from our
previous discussion of the question which of the sciences
should be called Wisdom, there is reason for applying the name
to each of them. For inasmuch as it is most architectonic and
authoritative and the other sciences, like slavewomen, may not
even contradict it, the science of the end and of the good is of
the nature of Wisdom (for the other things are for the sake of
the end). But inasmuch as it was described' as dealing with the
first causes and that which is in the highest sense object of
knowledge, the science of substance must be of the nature of
Wisdom. For since men may know the same thing in many
ways, we say that he who recognizes what a thing is by its being
2246
so and so knows more fully than he who recognizes it by its not
being so and so, and in the former class itself one knows more
fully than another, and he knows most fully who knows what a
thing is, not he who knows its quantity or quality or what it can
by nature do or have done to it. And further in all cases also we
think that the knowledge of each even of the things of which
demonstration is possible is present only when we know what
the thing is, e.g. what squaring a rectangle is, viz. that it is the
finding of a mean; and similarly in all other cases. And we know
about becomings and actions and about every change when we
know the source of the movement; and this is other than and
opposed to the end. Therefore it would seem to belong to
different sciences to investigate these causes severally.
But (2), taking the starting-points of demonstration as well as
the causes, it is a disputable question whether they are the
object of one science or of more (by the starting-points of
demonstration I mean the common beliefs, on which all men
base their proofs); e.g. that everything must be either affirmed
or denied, and that a thing cannot at the same time be and not
be, and all other such premisses: - the question is whether the
same science deals with them as with substance, or a different
science, and if it is not one science, which of the two must be
identified with that which we now seek. - It is not reasonable
that these topics should be the object of one science; for why
should it be peculiarly appropriate to geometry or to any other
science to understand these matters? If then it belongs to every
science alike, and cannot belong to all, it is not peculiar to the
science which investigates substances, any more than to any
other science, to know about these topics. - And, at the same
time, in what way can there be a science of the first principles?
For we are aware even now what each of them in fact is (at least
even other sciences use them as familiar); but if there is a
demonstrative science which deals with them, there will have
to be an underlying kind, and some of them must be
2247
demonstrable attributes and others must be axioms (for it is
impossible that there should be demonstration about all of
them); for the demonstration must start from certain premisses
and be about a certain subject and prove certain attributes.
Therefore it follows that all attributes that are proved must
belong to a single class; for all demonstrative sciences use the
axioms.
But if the science of substance and the science which deals with
the axioms are different, which of them is by nature more
authoritative and prior? The axioms are most universal and are
principles of all things. And if it is not the business of the
philosopher, to whom else will it belong to inquire what is true
and what is untrue about them?
(3) In general, do all substances fall under one science or under
more than one? If the latter, to what sort of substance is the
present science to be assigned? - On the other hand, it is not
reasonable that one science should deal with all. For then there
would be one demonstrative science dealing with all attributes.
For ever demonstrative science investigates with regard to some
subject its essential attributes, starting from the common
beliefs. Therefore to investigate the essential attributes of one
class of things, starting from one set of beliefs, is the business
of one science. For the subject belongs to one science, and the
premisses belong to one, whether to the same or to another; so
that the attributes do so too, whether they are investigated by
these sciences or by one compounded out of them.
(5) Further, does our investigation deal with substances alone or
also with their attributes? I mean for instance, if the solid is a
substance and so are lines and planes, is it the business of the
same science to know these and to know the attributes of each
of these classes (the attributes about which the mathematical
sciences offer proofs), or of a different science? If of the same,
2248
the science of substance also must be a demonstrative science,
but it is thought that there is no demonstration of the essence
of things. And if of another, what will be the science that
investigates the attributes of substance? This is a very difficult
question.
(4) Further, must we say that sensible substances alone exist, or
that there are others besides these? And are substances of one
kind or are there in fact several kinds of substances, as those
say who assert the existence both of the Forms and of the
intermediates, with which they say the mathematical sciences
deal? - The sense in which we say the Forms are both causes
and self-dependent substances has been explained in our first
remarks about them; while the theory presents difficulties in
many ways, the most paradoxical thing of all is the statement
that there are certain things besides those in the material
universe, and that these are the same as sensible things except
that they are eternal while the latter are perishable. For they say
there is a man-himself and a horse-itself and health-itself, with
no further qualification, - a procedure like that of the people
who said there are gods, but in human form. For they were
positing nothing but eternal men, nor are the Platonists making
the Forms anything other than eternal sensible things.
Further, if we are to posit besides the Forms and the sensibles
the intermediates between them, we shall have many
difficulties. For clearly on the same principle there will be lines
besides the lines-themselves and the sensible lines, and so with
each of the other classes of things; so that since astronomy is
one of these mathematical sciences there will also be a heaven
besides the sensible heaven, and a sun and a moon (and so with
the other heavenly bodies) besides the sensible. Yet how are we
to believe in these things? It is not reasonable even to suppose
such a body immovable, but to suppose it moving is quite
impossible. - And similarly with the things of which optics and
2249
mathematical harmonics treat; for these also cannot exist apart
from the sensible things, for the same reasons. For if there are
sensible things and sensations intermediate between Form and
individual, evidently there will also be animals intermediate
between animals-themselves and the perishable animals. - We
might also raise the question, with reference to which kind of
existing things we must look for these sciences of
intermediates. If geometry is to differ from mensuration only in
this, that the latter deals with things that we perceive, and the
former with things that are not perceptible, evidently there will
also be a science other than medicine, intermediate between
medical-science-itself and this individual medical science, and
so with each of the other sciences. Yet how is this possible?
There would have to be also healthy things besides the
perceptible healthy things and the healthy-itself. - And at the
same time not even this is true, that mensuration deals with
perceptible and perishable magnitudes; for then it would have
perished when they perished.
But on the other hand astronomy cannot be dealing with
perceptible magnitudes nor with this heaven above us. For
neither are perceptible lines such lines as the geometer speaks
of (for no perceptible thing is straight or round in the way in
which he defines 'straight' and 'round'; for a hoop touches a
straight edge not at a point, but as Protagoras used to say it did,
in his refutation of the geometers), nor are the movements and
spiral orbits in the heavens like those of which astronomy
treats, nor have geometrical points the same nature as the
actual stars. - Now there are some who say that these so-called
intermediates between the Forms and the perceptible things
exist, not apart from the perceptible things, however, but in
these; the impossible results of this view would take too long to
enumerate, but it is enough to consider even such points as the
following: - It is not reasonable that this should be so only in
the case of these intermediates, but clearly the Forms also
2250
might be in the perceptible things; for both statements are parts
of the same theory. Further, it follows from this theory that
there are two solids in the same place, and that the
intermediates are not immovable, since they are in the moving
perceptible things. And in general to what purpose would one
suppose them to exist indeed, but to exist in perceptible things?
For the same paradoxical results will follow which we have
already mentioned; there will be a heaven besides the heaven,
only it will be not apart but in the same place; which is still
more impossible.
(6) Apart from the great difficulty of stating the case truly with
regard to these matters, it is very hard to say, with regard to the
first principles, whether it is the genera that should be taken as
elements and principles, or rather the primary constituents of a
thing; e.g. it is the primary parts of which articulate sounds
consist that are thought to be elements and principles of
articulate sound, not the common genus-articulate sound; and
we give the name of 'elements' to those geometrical
propositions, the proofs of which are implied in the proofs of
the others, either of all or of most. Further, both those who say
there are several elements of corporeal things and those who
say there is one, say the parts of which bodies are compounded
and consist are principles; e.g. Empedocles says fire and water
and the rest are the constituent elements of things, but does
not describe these as genera of existing things. Besides this, if
we want to examine the nature of anything else, we examine
the parts of which, e.g. a bed consists and how they are put
together, and then we know its nature.
2251
To judge from these arguments, then, the principles of things
would not be the genera; but if we know each thing by its
definition, and the genera are the principles or starting-points
of definitions, the genera must also be the principles of
definable things. And if to get the knowledge of the species
according to which things are named is to get the knowledge of
things, the genera are at least starting-points of the species.
And some also of those who say unity or being, or the great and
the small, are elements of things, seem to treat them as genera.
But, again, it is not possible to describe the principles in both
ways. For the formula of the essence is one; but definition by
genera will be different from that which states the constituent
parts of a thing.
(7) Besides this, even if the genera are in the highest degree
principles, should one regard the first of the genera as
principles, or those which are predicated directly of the
individuals? This also admits of dispute. For if the universals are
always more of the nature of principles, evidently the
uppermost of the genera are the principles; for these are
predicated of all things. There will, then, be as many principles
of things as there are primary genera, so that both being and
unity will be principles and substances; for these are most of all
predicated of all existing things. But it is not possible that either
unity or being should be a single genus of things; for the
differentiae of any genus must each of them both have being
and be one, but it is not possible for the genus taken apart from
its species (any more than for the species of the genus) to be
predicated of its proper differentiae; so that if unity or being is a
genus, no differentia will either have being or be one. But if
unity and being are not genera, neither will they be principles, if
the genera are the principles. Again, the intermediate kinds, in
whose nature the differentiae are included, will on this theory
be genera, down to the indivisible species; but as it is, some are
2252
thought to be genera and others are not thought to be so.
Besides this, the differentiae are principles even more than the
genera; and if these also are principles, there comes to be
practically an infinite number of principles, especially if we
suppose the highest genus to be a principle. - But again, if unity
is more of the nature of a principle, and the indivisible is one,
and everything indivisible is so either in quantity or in species,
and that which is so in species is the prior, and genera are
divisible into species for man is not the genus of individual
men), that which is predicated directly of the individuals will
have more unity. - Further, in the case of things in which the
distinction of prior and posterior is present, that which is
predicable of these things cannot be something apart from
them (e.g. if two is the first of numbers, there will not be a
Number apart from the kinds of numbers; and similarly there
will not be a Figure apart from the kinds of figures; and if the
genera of these things do not exist apart from the species, the
genera of other things will scarcely do so; for genera of these
things are thought to exist if any do). But among the individuals
one is not prior and another posterior. Further, where one thing
is better and another worse, the better is always prior; so that of
these also no genus can exist. From these considerations, then,
the species predicated of individuals seem to be principles
rather than the genera. But again, it is not easy to say in what
sense these are to be taken as principles. For the principle or
cause must exist alongside of the things of which it is the
principle, and must be capable of existing in separation from
them; but for what reason should we suppose any such thing to
exist alongside of the individual, except that it is predicated
universally and of all? But if this is the reason, the things that
are more universal must be supposed to be more of the nature
of principles; so that the highest genera would be the principles.
2253
(8) There is a difficulty connected with these, the hardest of all
and the most necessary to examine, and of this the discussion
now awaits us. If, on the one hand, there is nothing apart from
individual things, and the individuals are infinite in number,
how then is it possible to get knowledge of the infinite
individuals? For all things that we come to know, we come to
know in so far as they have some unity and identity, and in so
far as some attribute belongs to them universally.
But if this is necessary, and there must be something apart from
the individuals, it will be necessary that the genera exist apart
from the individuals, either the lowest or the highest genera;
but we found by discussion just now that this is impossible.
Further, if we admit in the fullest sense that something exists
apart from the concrete thing, whenever something is
predicated of the matter, must there, if there is something
apart, be something apart from each set of individuals, or from
some and not from others, or from none? (A) If there is nothing
apart from individuals, there will be no object of thought, but all
things will be objects of sense, and there will not be knowledge
of anything, unless we say that sensation is knowledge. Further,
nothing will be eternal or unmovable; for all perceptible things
perish and are in movement. But if there is nothing eternal,
neither can there be a process of coming to be; for there must
be something that comes to be, i.e. from which something
comes to be, and the ultimate term in this series cannot have
come to be, since the series has a limit and since nothing can
come to be out of that which is not. Further, if generation and
movement exist there must also be a limit; for no movement is
infinite, but every movement has an end, and that which is
incapable of completing its coming to be cannot be in process of
2254
coming to be; and that which has completed its coming to be
must he as soon as it has come to be. Further, since the matter
exists, because it is ungenerated, it is a fortiori reasonable that
the substance or essence, that which the matter is at any time
coming to be, should exist; for if neither essence nor matter is
to be, nothing will be at all, and since this is impossible there
must be something besides the concrete thing, viz. the shape or
form.
But again (B) if we are to suppose this, it is hard to say in which
cases we are to suppose it and in which not. For evidently it is
not possible to suppose it in all cases; we could not suppose
that there is a house besides the particular houses. - Besides
this, will the substance of all the individuals, e.g. of all men, be
one? This is paradoxical, for all the things whose substance is
one are one. But are the substances many and different? This
also is unreasonable. - At the same time, how does the matter
become each of the individuals, and how is the concrete thing
these two elements?
(9) Again, one might ask the following question also about the
first principles. If they are one in kind only, nothing will be
numerically one, not even unity-itself and being-itself; and how
will knowing exist, if there is not to be something common to a
whole set of individuals?
But if there is a common element which is numerically one, and
each of the principles is one, and the principles are not as in the
case of perceptible things different for different things (e.g.
since this particular syllable is the same in kind whenever it
occurs, the elements it are also the same in kind; only in kind,
for these also, like the syllable, are numerically different in
different contexts), - if it is not like this but the principles of
things are numerically one, there will be nothing else besides
the elements (for there is no difference of meaning between
2255
'numerically one' and 'individual'; for this is just what we mean
by the individual - the numerically one, and by the universal we
mean that which is predicable of the individuals). Therefore it
will be just as if the elements of articulate sound were limited
in number; all the language in the world would be confined to
the ABC, since there could not be two or more letters of the
same kind.
(10) One difficulty which is as great as any has been neglected
both by modern philosophers and by their predecessors -
whether the principles of perishable and those of imperishable
things are the same or different. If they are the same, how are
some things perishable and others imperishable, and for what
reason? The school of Hesiod and all the theologians thought
only of what was plausible to themselves, and had no regard to
us. For, asserting the first principles to be gods and born of gods,
they say that the beings which did not taste of nectar and
ambrosia became mortal; and clearly they are using words
which are familiar to themselves, yet what they have said about
the very application of these causes is above our
comprehension. For if the gods taste of nectar and ambrosia for
their pleasure, these are in no wise the causes of their
existence; and if they taste them to maintain their existence,
how can gods who need food be eternal? - But into the
subtleties of the mythologists it is not worth our while to
inquire seriously; those, however, who use the language of proof
we must cross-examine and ask why, after all, things which
consist of the same elements are, some of them, eternal in
nature, while others perish. Since these philosophers mention
no cause, and it is unreasonable that things should be as they
say, evidently the principles or causes of things cannot be the
same. Even the man whom one might suppose to speak most
consistently - Empedocles, even he has made the same mistake;
for he maintains that strife is a principle that causes
destruction, but even strife would seem no less to produce
2256
everything, except the One; for all things excepting God proceed
from strife. At least he says: -
From which all that was and is and will be hereafter -
Trees, and men and women, took their growth,
And beasts and birds and water-nourished fish,
And long-aged gods.
The implication is evident even apart from these words; for if
strife had not been present in things, all things would have been
one, according to him; for when they have come together, 'then
strife stood outermost.' Hence it also follows on his theory that
God most blessed is less wise than all others; for he does not
know all the elements; for he has in him no strife, and
knowledge is of the like by the like. 'For by earth,' he says,
We see earth, by water water,
By ether godlike ether, by fire wasting fire,
Love by love, and strife by gloomy strife.
But - and this is the point we started from this at least is
evident, that on his theory it follows that strife is as much the
cause of existence as of destruction. And similarly love is not
specially the cause of existence; for in collecting things into the
One it destroys all other things. And at the same time
Empedocles mentions no cause of the change itself, except that
things are so by nature.
But when strife at last waxed great in the limbs of the Sphere,
And sprang to assert its rights as the time was fulfilled
Which is fixed for them in turn by a mighty oath.
2257
This implies that change was necessary; but he shows no cause
of the necessity. But yet so far at least he alone speaks
consistently; for he does not make some things perishable and
others imperishable, but makes all perishable except the
elements. The difficulty we are speaking of now is, why some
things are perishable and others are not, if they consist of the
same principles.
Let this suffice as proof of the fact that the principles cannot be
the same. But if there are different principles, one difficulty is
whether these also will be imperishable or perishable. For if
they are perishable, evidently these also must consist of certain
elements (for all things that perish, perish by being resolved
into the elements of which they consist); so that it follows that
prior to the principles there are other principles. But this is
impossible, whether the process has a limit or proceeds to
infinity. Further, how will perishable things exist, if their
principles are to be annulled? But if the principles are
imperishable, why will things composed of some imperishable
principles be perishable, while those composed of the others are
imperishable? This is not probable, but is either impossible or
needs much proof. Further, no one has even tried to maintain
different principles; they maintain the same principles for all
things. But they swallow the difficulty we stated first as if they
took it to be something trifling.
(11) The inquiry that is both the hardest of all and the most
necessary for knowledge of the truth is whether being and unity
are the substances of things, and whether each of them,
without being anything else, is being or unity respectively, or we
must inquire what being and unity are, with the implication
that they have some other underlying nature. For some people
think they are of the former, others think they are of the latter
character. Plato and the Pythagoreans thought being and unity
were nothing else, but this was their nature, their essence being
2258
just unity and being. But the natural philosophers take a
different line; e.g. Empedocles - as though reducing to
something more intelligible - says what unity is; for he would
seem to say it is love: at least, this is for all things the cause of
their being one. Others say this unity and being, of which things
consist and have been made, is fire, and others say it is air. A
similar view is expressed by those who make the elements
more than one; for these also must say that unity and being are
precisely all the things which they say are principles.
(A) If we do not suppose unity and being to be substances, it
follows that none of the other universals is a substance; for
these are most universal of all, and if there is no unity-itself or
being-itself, there will scarcely be in any other case anything
apart from what are called the individuals. Further, if unity is
not a substance, evidently number also will not exist as an
entity separate from the individual things; for number is units,
and the unit is precisely a certain kind of one.
But (B) if there is a unity-itself and a being-itself, unity and
being must be their substance; for it is not something else that
is predicated universally of the things that are and are one, but
just unity and being. But if there is to be a being-itself and a
unity-itself, there is much difficulty in seeing how there will be
anything else besides these, - I mean, how things will be more
than one in number. For what is different from being does not
exist, so that it necessarily follows, according to the argument of
Parmenides, that all things that are are one and this is being.
There are objections to both views. For whether unity is not a
substance or there is a unity-itself, number cannot be a
substance. We have already said why this result follows if unity
is not a substance; and if it is, the same difficulty arises as arose
with regard to being. For whence is there to be another one
2259
besides unity-itself? It must be not-one; but all things are either
one or many, and of the many each is one.
Further, if unity-itself is indivisible, according to Zeno's
postulate it will be nothing. For that which neither when added
makes a thing greater nor when subtracted makes it less, he
asserts to have no being, evidently assuming that whatever has
being is a spatial magnitude. And if it is a magnitude, it is
corporeal; for the corporeal has being in every dimension, while
the other objects of mathematics, e.g. a plane or a line, added in
one way will increase what they are added to, but in another
way will not do so, and a point or a unit does so in no way. But,
since his theory is of a low order, and an indivisible thing can
exist in such a way as to have a defence even against him (for
the indivisible when added will make the number, though not
the size, greater), - yet how can a magnitude proceed from one
such indivisible or from many? It is like saying that the line is
made out of points.
But even if ore supposes the case to be such that, as some say,
number proceeds from unity-itself and something else which is
not one, none the less we must inquire why and how the
product will be sometimes a number and sometimes a
magnitude, if the not-one was inequality and was the same
principle in either case. For it is not evident how magnitudes
could proceed either from the one and this principle, or from
some number and this principle.
(14) A question connected with these is whether numbers and
bodies and planes and points are substances of a kind, or not. If
they are not, it baffles us to say what being is and what the
2260
substances of things are. For modifications and movements and
relations and dispositions and ratios do not seem to indicate
the substance of anything; for all are predicated of a subject,
and none is a 'this'. And as to the things which might seem
most of all to indicate substance, water and earth and fire and
air, of which composite bodies consist, heat and cold and the
like are modifications of these, not substances, and the body
which is thus modified alone persists as something real and as
a substance. But, on the other hand, the body is surely less of a
substance than the surface, and the surface than the line, and
the line than the unit and the point. For the body is bounded by
these; and they are thought to be capable of existing without
body, but body incapable of existing without these. This is why,
while most of the philosophers and the earlier among them
thought that substance and being were identical with body, and
that all other things were modifications of this, so that the first
principles of the bodies were the first principles of being, the
more recent and those who were held to be wiser thought
numbers were the first principles. As we said, then, if these are
not substance, there is no substance and no being at all; for the
accidents of these it cannot be right to call beings.
But if this is admitted, that lines and points are substance more
than bodies, but we do not see to what sort of bodies these
could belong (for they cannot be in perceptible bodies), there
can be no substance. - Further, these are all evidently divisions
of body, - one in breadth, another in depth, another in length.
Besides this, no sort of shape is present in the solid more than
any other; so that if the Hermes is not in the stone, neither is
the half of the cube in the cube as something determinate;
therefore the surface is not in it either; for if any sort of surface
were in it, the surface which marks off the half of the cube
would be in it too. And the same account applies to the line and
to the point and the unit. Therefore, if on the one hand body is
in the highest degree substance, and on the other hand these
2261
things are so more than body, but these are not even instances
of substance, it baffles us to say what being is and what the
substance of things is. - For besides what has been said, the
questions of generation and instruction confront us with
further paradoxes. For if substance, not having existed before,
now exists, or having existed before, afterwards does not exist,
this change is thought to be accompanied by a process of
becoming or perishing; but points and lines and surfaces cannot
be in process either of becoming or of perishing, when they at
one time exist and at another do not. For when bodies come
into contact or are divided, their boundaries simultaneously
become one in the one case when they touch, and two in the
other - when they are divided; so that when they have been put
together one boundary does not exist but has perished, and
when they have been divided the boundaries exist which before
did not exist (for it cannot be said that the point, which is
indivisible, was divided into two). And if the boundaries come
into being and cease to be, from what do they come into being?
A similar account may also be given of the 'now' in time; for
this also cannot be in process of coming into being or of ceasing
to be, but yet seems to be always different, which shows that it
is not a substance. And evidently the same is true of points and
lines and planes; for the same argument applies, since they are
all alike either limits or divisions.
In general one might raise the question why after all, besides
perceptible things and the intermediates, we have to look for
another class of things, i.e. the Forms which we posit. If it is for
this reason, because the objects of mathematics, while they
differ from the things in this world in some other respect, differ
2262
not at all in that there are many of the same kind, so that their
first principles cannot be limited in number (just as the
elements of all the language in this sensible world are not
limited in number, but in kind, unless one takes the elements of
this individual syllable or of this individual articulate sound -
whose elements will be limited even in number; so is it also in
the case of the intermediates; for there also the members of the
same kind are infinite in number), so that if there are not -
besides perceptible and mathematical objects - others such as
some maintain the Forms to be, there will be no substance
which is one in number, but only in kind, nor will the first
principles of things be determinate in number, but only in kind:
- if then this must be so, the Forms also must therefore be held
to exist. Even if those who support this view do not express it
articulately, still this is what they mean, and they must be
maintaining the Forms just because each of the Forms is a
substance and none is by accident.
But if we are to suppose both that the Forms exist and that the
principles are one in number, not in kind, we have mentioned
the impossible results that necessarily follow.
(13) Closely connected with this is the question whether the
elements exist potentially or in some other manner. If in some
other way, there will be something else prior to the first
principles; for the potency is prior to the actual cause, and it is
not necessary for everything potential to be actual. - But if the
elements exist potentially, it is possible that everything that is
should not be. For even that which is not yet is capable of being;
for that which is not comes to be, but nothing that is incapable
of being comes to be.
(12) We must not only raise these questions about the first
principles, but also ask whether they are universal or what we
call individuals. If they are universal, they will not be
2263
substances; for everything that is common indicates not a 'this'
but a 'such', but substance is a 'this'. And if we are to be allowed
to lay it down that a common predicate is a 'this' and a single
thing, Socrates will be several animals - himself and 'man' and
'animal', if each of these indicates a 'this' and a single thing.
If, then, the principles are universals, these universal. Therefore
if there is to be results follow; if they are not universals but of
knowledge of the principles there must be the nature of
individuals, they will not be other principles prior to them,
namely those knowable; for the knowledge of anything is that
are universally predicated of them.
Bookr
There is a science which investigates being as being and the
attributes which belong to this in virtue of its own nature. Now
this is not the same as any of the so-called special sciences; for
none of these others treats universally of being as being. They
cut off a part of being and investigate the attribute of this part;
this is what the mathematical sciences for instance do. Now
since we are seeking the first principles and the highest causes,
clearly there must be some thing to which these belong in
virtue of its own nature. If then those who sought the elements
of existing things were seeking these same principles, it is
necessary that the elements must be elements of being not by
2264
accident but just because it is being. Therefore it is of being as
being that we also must grasp the first causes.
There are many senses in which a thing may be said to 'be', but
all that 'is' is related to one central point, one definite kind of
thing, and is not said to 'be' by a mere ambiguity. Everything
which is healthy is related to health, one thing in the sense that
it preserves health, another in the sense that it produces it,
another in the sense that it is a symptom of health, another
because it is capable of it. And that which is medical is relative
to the medical art, one thing being called medical because it
possesses it, another because it is naturally adapted to it,
another because it is a function of the medical art. And we shall
find other words used similarly to these. So, too, there are many
senses in which a thing is said to be, but all refer to one
starting-point; some things are said to be because they are
substances, others because they are affections of substance,
others because they are a process towards substance, or
destructions or privations or qualities of substance, or
productive or generative of substance, or of things which are
relative to substance, or negations of one of these thing of
substance itself. It is for this reason that we say even of non-
being that it is nonbeing. As, then, there is one science which
deals with all healthy things, the same applies in the other
cases also. For not only in the case of things which have one
common notion does the investigation belong to one science,
but also in the case of things which are related to one common
nature; for even these in a sense have one common notion. It is
clear then that it is the work of one science also to study the
things that are, qua being. - But everywhere science deals
2265
chiefly with that which is primary, and on which the other
things depend, and in virtue of which they get their names. If,
then, this is substance, it will be of substances that the
philosopher must grasp the principles and the causes.
Now for each one class of things, as there is one perception, so
there is one science, as for instance grammar, being one
science, investigates all articulate sounds. Hence to investigate
all the species of being qua being is the work of a science which
is generically one, and to investigate the several species is the
work of the specific parts of the science.
If, now, being and unity are the same and are one thing in the
sense that they are implied in one another as principle and
cause are, not in the sense that they are explained by the same
definition (though it makes no difference even if we suppose
them to be like that - in fact this would even strengthen our
case); for 'one man' and 'man' are the same thing, and so are
'existent man' and 'man', and the doubling of the words in 'one
man and one existent man' does not express anything different
(it is clear that the two things are not separated either in
coming to be or in ceasing to be); and similarly 'one existent
man' adds nothing to 'existent man', and that it is obvious that
the addition in these cases means the same thing, and unity is
nothing apart from being; and if, further, the substance of each
thing is one in no merely accidental way, and similarly is from
its very nature something that is: - all this being so, there must
be exactly as many species of being as of unity. And to
investigate the essence of these is the work of a science which
is generically one - I mean, for instance, the discussion of the
same and the similar and the other concepts of this sort; and
nearly all contraries may be referred to this origin; let us take
them as having been investigated in the 'Selection of
Contraries'.
2266
And there are as many parts of philosophy as there are kinds of
substance, so that there must necessarily be among them a first
philosophy and one which follows this. For being falls
immediately into genera; for which reason the sciences too will
correspond to these genera. For the philosopher is like the
mathematician, as that word is used; for mathematics also has
parts, and there is a first and a second science and other
successive ones within the sphere of mathematics.
Now since it is the work of one science to investigate opposites,
and plurality is opposed to unity - and it belongs to one science
to investigate the negation and the privation because in both
cases we are really investigating the one thing of which the
negation or the privation is a negation or privation (for we
either say simply that that thing is not present, or that it is not
present in some particular class; in the latter case difference is
present over and above what is implied in negation; for
negation means just the absence of the thing in question, while
in privation there is also employed an underlying nature of
which the privation is asserted): - in view of all these facts, the
contraries of the concepts we named above, the other and the
dissimilar and the unequal, and everything else which is
derived either from these or from plurality and unity, must fall
within the province of the science above named. And
contrariety is one of these concepts; for contrariety is a kind of
difference, and difference is a kind of otherness. Therefore,
since there are many senses in which a thing is said to be one,
these terms also will have many senses, but yet it belongs to
one science to know them all; for a term belongs to different
sciences not if it has different senses, but if it has not one
meaning and its definitions cannot be referred to one central
meaning. And since all things are referred to that which is
primary, as for instance all things which are called one are
referred to the primary one, we must say that this holds good
also of the same and the other and of contraries in general; so
2267
that after distinguishing the various senses of each, we must
then explain by reference to what is primary in the case of each
of the predicates in question, saying how they are related to it;
for some will be called what they are called because they
possess it, others because they produce it, and others in other
such ways.
It is evident, then, that it belongs to one science to be able to
give an account of these concepts as well as of substance (this
was one of the questions in our book of problems), and that it is
the function of the philosopher to be able to investigate all
things. For if it is not the function of the philosopher, who is it
who will inquire whether Socrates and Socrates seated are the
same thing, or whether one thing has one contrary, or what
contrariety is, or how many meanings it has? And similarly with
all other such questions. Since, then, these are essential
modifications of unity qua unity and of being qua being, not
qua numbers or lines or fire, it is clear that it belongs to this
science to investigate both the essence of these concepts and
their properties. And those who study these properties err not
by leaving the sphere of philosophy, but by forgetting that
substance, of which they have no correct idea, is prior to these
other things. For number qua number has peculiar attributes,
such as oddness and evenness, commensurability and equality,
excess and defect, and these belong to numbers either in
themselves or in relation to one another. And similarly the solid
and the motionless and that which is in motion and the
weightless and that which has weight have other peculiar
properties. So too there are certain properties peculiar to being
as such, and it is about these that the philosopher has to
investigate the truth. - An indication of this may be mentioned:
dialecticians and sophists assume the same guise as the
philosopher, for sophistic is Wisdom which exists only in
semblance, and dialecticians embrace all things in their
dialectic, and being is common to all things; but evidently their
2268
dialectic embraces these subjects because these are proper to
philosophy. - For sophistic and dialectic turn on the same class
of things as philosophy, but this differs from dialectic in the
nature of the faculty required and from sophistic in respect of
the purpose of the philosophic life. Dialectic is merely critical
where philosophy claims to know, and sophistic is what
appears to be philosophy but is not.
Again, in the list of contraries one of the two columns is
privative, and all contraries are reducible to being and non-
being, and to unity and plurality, as for instance rest belongs to
unity and movement to plurality. And nearly all thinkers agree
that being and substance are composed of contraries; at least all
name contraries as their first principles - some name odd and
even, some hot and cold, some limit and the unlimited, some
love and strife. And all the others as well are evidently reducible
to unity and plurality (this reduction we must take for granted),
and the principles stated by other thinkers fall entirely under
these as their genera. It is obvious then from these
considerations too that it belongs to one science to examine
being qua being. For all things are either contraries or composed
of contraries, and unity and plurality are the starting-points of
all contraries. And these belong to one science, whether they
have or have not one single meaning. Probably the truth is that
they have not; yet even if 'one' has several meanings, the other
meanings will be related to the primary meaning (and similarly
in the case of the contraries), even if being or unity is not a
universal and the same in every instance or is not separable
from the particular instances (as in fact it probably is not; the
unity is in some cases that of common reference, in some cases
that of serial succession). And for this reason it does not belong
to the geometer to inquire what is contrariety or completeness
or unity or being or the same or the other, but only to
presuppose these concepts and reason from this starting-point.
- Obviously then it is the work of one science to examine being
2269
qua being, and the attributes which belong to it qua being, and
the same science will examine not only substances but also
their attributes, both those above named and the concepts
'prior' and 'posterior', 'genus' and 'species', 'whole' and 'part',
and the others of this sort.
We must state whether it belongs to one or to different sciences
to inquire into the truths which are in mathematics called
axioms, and into substance. Evidently, the inquiry into these
also belongs to one science, and that the science of the
philosopher; for these truths hold good for everything that is,
and not for some special genus apart from others. And all men
use them, because they are true of being qua being and each
genus has being. But men use them just so far as to satisfy their
purposes; that is, as far as the genus to which their
demonstrations refer extends. Therefore since these truths
clearly hold good for all things qua being (for this is what is
common to them), to him who studies being qua being belongs
the inquiry into these as well. And for this reason no one who is
conducting a special inquiry tries to say anything about their
truth or falsity, - neither the geometer nor the arithmetician.
Some natural philosophers indeed have done so, and their
procedure was intelligible enough; for they thought that they
alone were inquiring about the whole of nature and about
being. But since there is one kind of thinker who is above even
the natural philosopher (for nature is only one particular genus
of being), the discussion of these truths also will belong to him
whose inquiry is universal and deals with primary substance.
Physics also is a kind of Wisdom, but it is not the first kind. -
And the attempts of some of those who discuss the terms on
2270
which truth should be accepted, are due to a want of training in
logic; for they should know these things already when they
come to a special study, and not be inquiring into them while
they are listening to lectures on it.
Evidently then it belongs to the philosopher, i.e. to him who is
studying the nature of all substance, to inquire also into the
principles of syllogism. But he who knows best about each
genus must be able to state the most certain principles of his
subject, so that he whose subject is existing things qua existing
must be able to state the most certain principles of all things.
This is the philosopher, and the most certain principle of all is
that regarding which it is impossible to be mistaken; for such a
principle must be both the best known (for all men may be
mistaken about things which they do not know), and non-
hypothetical. For a principle which every one must have who
understands anything that is, is not a hypothesis; and that
which every one must know who knows anything, he must
already have when he comes to a special study. Evidently then
such a principle is the most certain of all; which principle this
is, let us proceed to say. It is, that the same attribute cannot at
the same time belong and not belong to the same subject and in
the same respect; we must presuppose, to guard against
dialectical objections, any further qualifications which might be
added. This, then, is the most certain of all principles, since it
answers to the definition given above. For it is impossible for
any one to believe the same thing to be and not to be, as some
think Heraclitus says. For what a man says, he does not
necessarily believe; and if it is impossible that contrary
attributes should belong at the same time to the same subject
(the usual qualifications must be presupposed in this premiss
too), and if an opinion which contradicts another is contrary to
it, obviously it is impossible for the same man at the same time
to believe the same thing to be and not to be; for if a man were
mistaken on this point he would have contrary opinions at the
2271
same time. It is for this reason that all who are carrying out a
demonstration reduce it to this as an ultimate belief; for this is
naturally the starting-point even for all the other axioms.
There are some who, as we said, both themselves assert that it
is possible for the same thing to be and not to be, and say that
people can judge this to be the case. And among others many
writers about nature use this language. But we have now
posited that it is impossible for anything at the same time to be
and not to be, and by this means have shown that this is the
most indisputable of all principles. - Some indeed demand that
even this shall be demonstrated, but this they do through want
of education, for not to know of what things one should
demand demonstration, and of what one should not, argues
want of education. For it is impossible that there should be
demonstration of absolutely everything (there would be an
infinite regress, so that there would still be no demonstration);
but if there are things of which one should not demand
demonstration, these persons could not say what principle they
maintain to be more self-evident than the present one.
We can, however, demonstrate negatively even that this view is
impossible, if our opponent will only say something; and if he
says nothing, it is absurd to seek to give an account of our views
to one who cannot give an account of anything, in so far as he
cannot do so. For such a man, as such, is from the start no
better than a vegetable. Now negative demonstration I
distinguish from demonstration proper, because in a
demonstration one might be thought to be begging the
question, but if another person is responsible for the
2272
assumption we shall have negative proof, not demonstration.
The starting-point for all such arguments is not the demand
that our opponent shall say that something either is or is not
(for this one might perhaps take to be a begging of the
question), but that he shall say something which is significant
both for himself and for another; for this is necessary, if he
really is to say anything. For, if he means nothing, such a man
will not be capable of reasoning, either with himself or with
another. But if any one grants this, demonstration will be
possible; for we shall already have something definite. The
person responsible for the proof, however, is not he who
demonstrates but he who listens; for while disowning reason he
listens to reason. And again he who admits this has admitted
that something is true apart from demonstration (so that not
everything will be 'so and not so').
First then this at least is obviously true, that the word 'be' or
'not be' has a definite meaning, so that not everything will be
'so and not so'. Again, if 'man' has one meaning, let this be 'two-
footed animal'; by having one meaning I understand this: - if
'man' means 'X', then if A is a man 'X' will be what 'being a
man' means for him. (It makes no difference even if one were to
say a word has several meanings, if only they are limited in
number; for to each definition there might be assigned a
different word. For instance, we might say that 'man' has not
one meaning but several, one of which would have one
definition, viz. 'two-footed animal', while there might be also
several other definitions if only they were limited in number; for
a peculiar name might be assigned to each of the definitions. If,
however, they were not limited but one were to say that the
word has an infinite number of meanings, obviously reasoning
would be impossible; for not to have one meaning is to have no
meaning, and if words have no meaning our reasoning with one
another, and indeed with ourselves, has been annihilated; for it
is impossible to think of anything if we do not think of one
2273
thing; but if this is possible, one name might be assigned to this
thing.)
Let it be assumed then, as was said at the beginning, that the
name has a meaning and has one meaning; it is impossible,
then, that 'being a man' should mean precisely 'not being a
man', if 'man' not only signifies something about one subject
but also has one significance (for we do not identify 'having one
significance' with 'signifying something about one subject',
since on that assumption even 'musical' and 'white' and 'man'
would have had one significance, so that all things would have
been one; for they would all have had the same significance).
And it will not be possible to be and not to be the same thing,
except in virtue of an ambiguity, just as if one whom we call
'man', others were to call 'not-man'; but the point in question is
not this, whether the same thing can at the same time be and
not be a man in name, but whether it can in fact. Now if 'man'
and 'not-man' mean nothing different, obviously 'not being a
man' will mean nothing different from 'being a man'; so that
'being a man' will be 'not being a man'; for they will be one. For
being one means this - being related as 'raiment' and 'dress'
are, if their definition is one. And if 'being a man' and 'being a
not-man' are to be one, they must mean one thing. But it was
shown earlier that they mean different things. - Therefore, if it
is true to say of anything that it is a man, it must be a two-
footed animal (for this was what 'man' meant); and if this is
necessary, it is impossible that the same thing should not at
that time be a two-footed animal; for this is what 'being
necessary' means - that it is impossible for the thing not to be.
It is, then, impossible that it should be at the same time true to
say the same thing is a man and is not a man.
The same account holds good with regard to 'not being a man',
for 'being a man' and 'being a not-man' mean different things,
2274
since even 'being white' and 'being a man' are different; for the
former terms are much more different so that they must a
fortiori mean different things. And if any one says that 'white'
means one and the same thing as 'man', again we shall say the
same as what was said before, that it would follow that all
things are one, and not only opposites. But if this is impossible,
then what we have maintained will follow, if our opponent will
only answer our question.
And if, when one asks the question simply, he adds the
contradictories, he is not answering the question. For there is
nothing to prevent the same thing from being both a man and
white and countless other things: but still, if one asks whether
it is or is not true to say that this is a man, our opponent must
give an answer which means one thing, and not add that 'it is
also white and large'. For, besides other reasons, it is impossible
to enumerate its accidental attributes, which are infinite in
number; let him, then, enumerate either all or none. Similarly,
therefore, even if the same thing is a thousand times a man and
a not-man, he must not, in answering the question whether this
is a man, add that it is also at the same time a not-man, unless
he is bound to add also all the other accidents, all that the
subject is or is not; and if he does this, he is not observing the
rules of argument.
And in general those who say this do away with substance and
essence. For they must say that all attributes are accidents, and
that there is no such thing as 'being essentially a man' or 'an
animal'. For if there is to be any such thing as 'being essentially
a man' this will not be 'being a not-man' or 'not being a man'
(yet these are negations of it); for there was one thing which it
meant, and this was the substance of something. And denoting
the substance of a thing means that the essence of the thing is
nothing else. But if its being essentially a man is to be the same
as either being essentially a not-man or essentially not being a
2275
man, then its essence will be something else. Therefore our
opponents must say that there cannot be such a definition of
anything, but that all attributes are accidental; for this is the
distinction between substance and accident - 'white' is
accidental to man, because though he is white, whiteness is not
his essence. But if all statements are accidental, there will be
nothing primary about which they are made, if the accidental
always implies predication about a subject. The predication,
then, must go on ad infinitum. But this is impossible; for not
even more than two terms can be combined in accidental
predication. For (1) an accident is not an accident of an accident,
unless it be because both are accidents of the same subject. I
mean, for instance, that the white is musical and the latter is
white, only because both are accidental to man. But (2) Socrates
is musical, not in this sense, that both terms are accidental to
something else. Since then some predicates are accidental in
this and some in that sense, (a) those which are accidental in
the latter sense, in which white is accidental to Socrates, cannot
form an infinite series in the upward direction; e.g. Socrates the
white has not yet another accident; for no unity can be got out
of such a sum. Nor again (b) will 'white' have another term
accidental to it, e.g. 'musical'. For this is no more accidental to
that than that is to this; and at the same time we have drawn
the distinction, that while some predicates are accidental in
this sense, others are so in the sense in which 'musical' is
accidental to Socrates; and the accident is an accident of an
accident not in cases of the latter kind, but only in cases of the
other kind, so that not all terms will be accidental. There must,
then, even so be something which denotes substance. And if
this is so, it has been shown that contradictories cannot be
predicated at the same time.
Again, if all contradictory statements are true of the same
subject at the same time, evidently all things will be one. For the
same thing will be a trireme, a wall, and a man, if of everything
2276
it is possible either to affirm or to deny anything (and this
premiss must be accepted by those who share the views of
Protagoras). For if any one thinks that the man is not a trireme,
evidently he is not a trireme; so that he also is a trireme, if, as
they say, contradictory statements are both true. And we thus
get the doctrine of Anaxagoras, that all things are mixed
together; so that nothing really exists. They seem, then, to be
speaking of the indeterminate, and, while fancying themselves
to be speaking of being, they are speaking about non-being; for
it is that which exists potentially and not in complete reality
that is indeterminate. But they must predicate of every subject
the affirmation or the negation of every attribute. For it is
absurd if of each subject its own negation is to be predicable,
while the negation of something else which cannot be
predicated of it is not to be predicable of it; for instance, if it is
true to say of a man that he is not a man, evidently it is also
true to say that he is either a trireme or not a trireme. If, then,
the affirmative can be predicated, the negative must be
predicable too; and if the affirmative is not predicable, the
negative, at least, will be more predicable than the negative of
the subject itself. If, then, even the latter negative is predicable,
the negative of 'trireme' will be also predicable; and, if this is
predicable, the affirmative will be so too.
Those, then, who maintain this view are driven to this
conclusion, and to the further conclusion that it is not
necessary either to assert or to deny. For if it is true that a thing
is a man and a not-man, evidently also it will be neither a man
nor a not-man. For to the two assertions there answer two
negations, and if the former is treated as a single proposition
compounded out of two, the latter also is a single proposition
opposite to the former.
Again, either the theory is true in all cases, and a thing is both
white and not-white, and existent and non-existent, and all
2277
other assertions and negations are similarly compatible or the
theory is true of some statements and not of others. And if not
of all, the exceptions will be contradictories of which admittedly
only one is true; but if of all, again either the negation will be
true wherever the assertion is, and the assertion true wherever
the negation is, or the negation will be true where the assertion
is, but the assertion not always true where the negation is. And
(a) in the latter case there will be something which fixedly is
not, and this will be an indisputable belief; and if non-being is
something indisputable and knowable, the opposite assertion
will be more knowable. But (b) if it is equally possible also to
assert all that it is possible to deny, one must either be saying
what is true when one separates the predicates (and says, for
instance, that a thing is white, and again that it is not- white), or
not. And if (i) it is not true to apply the predicates separately,
our opponent is not saying what he professes to say, and also
nothing at all exists; but how could non-existent things speak
or walk, as he does? Also all things would on this view be one,
as has been already said, and man and God and trireme and
their contradictories will be the same. For if contradictories can
be predicated alike of each subject, one thing will in no wise
differ from another; for if it differ, this difference will be
something true and peculiar to it. And (ii) if one may with truth
apply the predicates separately, the above-mentioned result
follows none the less, and, further, it follows that all would then
be right and all would be in error, and our opponent himself
confesses himself to be in error. - And at the same time our
discussion with him is evidently about nothing at all; for he
says nothing. For he says neither 'yes' nor 'no', but 'yes and no';
and again he denies both of these and says 'neither yes nor no';
for otherwise there would already be something definite.
Again if when the assertion is true, the negation is false, and
when this is true, the affirmation is false, it will not be possible
2278
to assert and deny the same thing truly at the same time. But
perhaps they might say this was the very question at issue.
Again, is he in error who judges either that the thing is so or
that it is not so, and is he right who judges both? If he is right,
what can they mean by saying that the nature of existing things
is of this kind? And if he is not right, but more right than he
who judges in the other way, being will already be of a definite
nature, and this will be true, and not at the same time also not
true. But if all are alike both wrong and right, one who is in this
condition will not be able either to speak or to say anything
intelligible; for he says at the same time both 'yes' and 'no.' And
if he makes no judgement but 'thinks' and 'does not think',
indifferently, what difference will there be between him and a
vegetable? - Thus, then, it is in the highest degree evident that
neither any one of those who maintain this view nor any one
else is really in this position. For why does a man walk to
Megara and not stay at home, when he thinks he ought to be
walking there? Why does he not walk early some morning into
a well or over a precipice, if one happens to be in his way? Why
do we observe him guarding against this, evidently because he
does not think that falling in is alike good and not good?
Evidently, then, he judges one thing to be better and another
worse. And if this is so, he must also judge one thing to be a
man and another to be not-a-man, one thing to be sweet and
another to be not-sweet. For he does not aim at and judge all
things alike, when, thinking it desirable to drink water or to see
a man, he proceeds to aim at these things; yet he ought, if the
same thing were alike a man and not-a-man. But, as was said,
there is no one who does not obviously avoid some things and
not others. Therefore, as it seems, all men make unqualified
judgements, if not about all things, still about what is better and
worse. And if this is not knowledge but opinion, they should be
all the more anxious about the truth, as a sick man should be
more anxious about his health than one who is healthy; for he
2279
who has opinions is, in comparison with the man who knows,
not in a healthy state as far as the truth is concerned.
Again, however much all things may be 'so and not so', still
there is a more and a less in the nature of things; for we should
not say that two and three are equally even, nor is he who
thinks four things are five equally wrong with him who thinks
they are a thousand. If then they are not equally wrong,
obviously one is less wrong and therefore more right. If then
that which has more of any quality is nearer the norm, there
must be some truth to which the more true is nearer. And even
if there is not, still there is already something better founded
and liker the truth, and we shall have got rid of the unqualified
doctrine which would prevent us from determining anything in
our thought.
From the same opinion proceeds the doctrine of Protagoras, and
both doctrines must be alike true or alike untrue. For on the one
hand, if all opinions and appearances are true, all statements
must be at the same time true and false. For many men hold
beliefs in which they conflict with one another, and think those
mistaken who have not the same opinions as themselves; so
that the same thing must both be and not be. And on the other
hand, if this is so, all opinions must be true; for those who are
mistaken and those who are right are opposed to one another in
their opinions; if, then, reality is such as the view in question
supposes, all will be right in their beliefs.
Evidently, then, both doctrines proceed from the same way of
thinking. But the same method of discussion must not be used
with all opponents; for some need persuasion, and others
2280
compulsion. Those who have been driven to this position by
difficulties in their thinking can easily be cured of their
ignorance; for it is not their expressed argument but their
thought that one has to meet. But those who argue for the sake
of argument can be cured only by refuting the argument as
expressed in speech and in words.
Those who really feel the difficulties have been led to this
opinion by observation of the sensible world. (1) They think that
contradictories or contraries are true at the same time, because
they see contraries coming into existence out of the same thing.
If, then, that which is not cannot come to be, the thing must
have existed before as both contraries alike, as Anaxagoras says
all is mixed in all, and Democritus too; for he says the void and
the full exist alike in every part, and yet one of these is being,
and the other non-being. To those, then, whose belief rests on
these grounds, we shall say that in a sense they speak rightly
and in a sense they err. For 'that which is' has two meanings, so
that in some sense a thing can come to be out of that which is
not, while in some sense it cannot, and the same thing can at
the same time be in being and not in being - but not in the
same respect. For the same thing can be potentially at the same
time two contraries, but it cannot actually. And again we shall
ask them to believe that among existing things there is also
another kind of substance to which neither movement nor
destruction nor generation at all belongs.
And (2) similarly some have inferred from observation of the
sensible world the truth of appearances. For they think that the
truth should not be determined by the large or small number of
those who hold a belief, and that the same thing is thought
sweet by some when they taste it, and bitter by others, so that if
all were ill or all were mad, and only two or three were well or
sane, these would be thought ill and mad, and not the others.
2281
And again, they say that many of the other animals receive
impressions contrary to ours; and that even to the senses of
each individual, things do not always seem the same. Which,
then, of these impressions are true and which are false is not
obvious; for the one set is no more true than the other, but both
are alike. And this is why Democritus, at any rate, says that
either there is no truth or to us at least it is not evident.
And in general it is because these thinkers suppose knowledge
to be sensation, and this to be a physical alteration, that they
say that what appears to our senses must be true; for it is for
these reasons that both Empedocles and Democritus and, one
may almost say, all the others have fallen victims to opinions of
this sort. For Empedocles says that when men change their
condition they change their knowledge;
For wisdom increases in men according to what is before them.
And elsewhere he says that: -
So far as their nature changed, so far to them always
Came changed thoughts into mind.
And Parmenides also expresses himself in the same way:
For as at each time the much-bent limbs are composed,
So is the mind of men; for in each and all men
'Tis one thing thinks - the substance of their limbs:
For that of which there is more is thought.
A saying of Anaxagoras to some of his friends is also related, -
that things would be for them such as they supposed them to
be. And they say that Homer also evidently had this opinion,
because he made Hector, when he was unconscious from the
2282
blow, lie 'thinking other thoughts', - which implies that even
those who are bereft of thought have thoughts, though not the
same thoughts. Evidently, then, if both are forms of knowledge,
the real things also are at the same time 'both so and not so'.
And it is in this direction that the consequences are most
difficult. For if those who have seen most of such truth as is
possible for us (and these are those who seek and love it most) -
if these have such opinions and express these views about the
truth, is it not natural that beginners in philosophy should lose
heart? For to seek the truth would be to follow flying game.
But the reason why these thinkers held this opinion is that
while they were inquiring into the truth of that which is, they
thought, 'that which is' was identical with the sensible world; in
this, however, there is largely present the nature of the
indeterminate - of that which exists in the peculiar sense which
we have explained; and therefore, while they speak plausibly,
they do not say what is true (for it is fitting to put the matter so
rather than as Epicharmus put it against Xenophanes). And
again, because they saw that all this world of nature is in
movement and that about that which changes no true
statement can be made, they said that of course, regarding that
which everywhere in every respect is changing, nothing could
truly be affirmed. It was this belief that blossomed into the
most extreme of the views above mentioned, that of the
professed Heracliteans, such as was held by Cratylus, who
finally did not think it right to say anything but only moved his
finger, and criticized Heraclitus for saying that it is impossible
to step twice into the same river; for he thought one could not
do it even once.
But we shall say in answer to this argument also that while
there is some justification for their thinking that the changing,
when it is changing, does not exist, yet it is after all disputable;
for that which is losing a quality has something of that which is
2283
being lost, and of that which is coming to be, something must
already be. And in general if a thing is perishing, will be present
something that exists; and if a thing is coming to be, there must
be something from which it comes to be and something by
which it is generated, and this process cannot go on ad
infinitum. - But, leaving these arguments, let us insist on this,
that it is not the same thing to change in quantity and in
quality. Grant that in quantity a thing is not constant; still it is
in respect of its form that we know each thing. - And again, it
would be fair to criticize those who hold this view for asserting
about the whole material universe what they saw only in a
minority even of sensible things. For only that region of the
sensible world which immediately surrounds us is always in
process of destruction and generation; but this is - so to speak -
not even a fraction of the whole, so that it would have been
juster to acquit this part of the world because of the other part,
than to condemn the other because of this. - And again,
obviously we shall make to them also the same reply that we
made long ago; we must show them and persuade them that
there is something whose nature is changeless. Indeed, those
who say that things at the same time are and are not, should in
consequence say that all things are at rest rather than that they
are in movement; for there is nothing into which they can
change, since all attributes belong already to all subjects.
Regarding the nature of truth, we must maintain that not
everything which appears is true; firstly, because even if
sensation - at least of the object peculiar to the sense in
question - is not false, still appearance is not the same as
sensation. - Again, it is fair to express surprise at our
opponents' raising the question whether magnitudes are as
great, and colours are of such a nature, as they appear to people
at a distance, or as they appear to those close at hand, and
whether they are such as they appear to the healthy or to the
sick, and whether those things are heavy which appear so to the
2284
weak or those which appear so to the strong, and those things
true which appear to the slee ing or to the waking. For obviously
they do not think these to be open questions; no one, at least, if
when he is in Libya he has fancied one night that he is in
Athens, starts for the concert hall. - And again with regard to
the future, as Plato says, surely the opinion of the physician and
that of the ignorant man are not equally weighty, for instance,
on the question whether a man will get well or not. - And again,
among sensations themselves the sensation of a foreign object
and that of the appropriate object, or that of a kindred object
and that of the object of the sense in question, are not equally
authoritative, but in the case of colour sight, not taste, has the
authority, and in the case of flavour taste, not sight; each of
which senses never says at the same time of the same object
that it simultaneously is 'so and not so'. - But not even at
different times does one sense disagree about the quality, but
only about that to which the quality belongs. I mean, for
instance, that the same wine might seem, if either it or one's
body changed, at one time sweet and at another time not sweet;
but at least the sweet, such as it is when it exists, has never yet
changed, but one is always right about it, and that which is to be
sweet is of necessity of such and such a nature. Yet all these
views destroy this necessity, leaving nothing to be of necessity,
as they leave no essence of anything; for the necessary cannot
be in this way and also in that, so that if anything is of
necessity, it will not be 'both so and not so'.
And, in general, if only the sensible exists, there would be
nothing if animate things were not; for there would be no
faculty of sense. Now the view that neither the sensible
qualities nor the sensations would exist is doubtless true (for
they are affections of the perceiver), but that the substrata
which cause the sensation should not exist even apart from
sensation is impossible. For sensation is surely not the
sensation of itself, but there is something beyond the sensation,
2285
which must be prior to the sensation; for that which moves is
prior in nature to that which is moved, and if they are
correlative terms, this is no less the case.
There are, both among those who have these convictions and
among those who merely profess these views, some who raise a
difficulty by asking, who is to be the judge of the healthy man,
and in general who is likely to judge rightly on each class of
questions. But such inquiries are like puzzling over the question
whether we are now asleep or awake. And all such questions
have the same meaning. These people demand that a reason
shall be given for everything; for they seek a starting-point, and
they seek to get this by demonstration, while it is obvious from
their actions that they have no conviction. But their mistake is
what we have stated it to be; they seek a reason for things for
which no reason can be given; for the starting-point of
demonstration is not demonstration.
These, then, might be easily persuaded of this truth, for it is not
difficult to grasp; but those who seek merely compulsion in
argument seek what is impossible; for they demand to be
allowed to contradict themselves - a claim which contradicts
itself from the very first. - But if not all things are relative, but
some are self-existent, not everything that appears will be true;
for that which appears is apparent to some one; so that he who
says all things that appear are true, makes all things relative.
And, therefore, those who ask for an irresistible argument, and
at the same time demand to be called to account for their views,
must guard themselves by saying that the truth is not that what
appears exists, but that what appears exists for him to whom it
2286
appears, and when, and to the sense to which, and under the
conditions under which it appears. And if they give an account
of their view, but do not give it in this way, they will soon find
themselves contradicting themselves. For it is possible that the
same thing may appear to be honey to the sight, but not to the
taste, and that, since we have two eyes, things may not appear
the same to each, if their sight is unlike. For to those who for
the reasons named some time ago say that what appears is
true, and therefore that all things are alike false and true, for
things do not appear either the same to all men or always the
same to the same man, but often have contrary appearances at
the same time (for touch says there are two objects when we
cross our fingers, while sight says there is one) - to these we
shall say 'yes, but not to the same sense and in the same part of
it and under the same conditions and at the same time', so that
what appears will be with these qualifications true. But perhaps
for this reason those who argue thus not because they feel a
difficulty but for the sake of argument, should say that this is
not true, but true for this man. And as has been said before, they
must make everything relative - relative to opinion and
perception, so that nothing either has come to be or will be
without some one's first thinking so. But if things have come to
be or will be, evidently not all things will be relative to opinion. -
Again, if a thing is one, it is in relation to one thing or to a
definite number of things; and if the same thing is both half
and equal, it is not to the double that the equal is correlative. If,
then, in relation to that which thinks, man and that which is
thought are the same, man will not be that which thinks, but
only that which is thought. And if each thing is to be relative to
that which thinks, that which thinks will be relative to an
infinity of specifically different things.
Let this, then, suffice to show (1) that the most indisputable of
all beliefs is that contradictory statements are not at the same
time true, and (2) what consequences follow from the assertion
2287
that they are, and (3) why people do assert this. Now since it is
impossible that contradictories should be at the same time true
of the same thing, obviously contraries also cannot belong at
the same time to the same thing. For of contraries, one is a
privation no less than it is a contrary - and a privation of the
essential nature; and privation is the denial of a predicate to a
determinate genus. If, then, it is impossible to affirm and deny
truly at the same time, it is also impossible that contraries
should belong to a subject at the same time, unless both belong
to it in particular relations, or one in a particular relation and
one without qualification.
But on the other hand there cannot be an intermediate between
contradictories, but of one subject we must either affirm or
deny any one predicate. This is clear, in the first place, if we
define what the true and the false are. To say of what is that it is
not, or of what is not that it is, is false, while to say of what is
that it is, and of what is not that it is not, is true; so that he who
says of anything that it is, or that it is not, will say either what is
true or what is false; but neither what is nor what is not is said
to be or not to be. - Again, the intermediate between the
contradictories will be so either in the way in which grey is
between black and white, or as that which is neither man nor
horse is between man and horse, (a) If it were of the latter kind,
it could not change into the extremes (for change is from not-
good to good, or from good to not-good), but as a matter of fact
when there is an intermediate it is always observed to change
into the extremes. For there is no change except to opposites
and to their intermediates, (b) But if it is really intermediate, in
this way too there would have to be a change to white, which
2288
was not from not-white; but as it is, this is never seen. - Again,
every object of understanding or reason the understanding
either affirms or denies - this is obvious from the definition -
whenever it says what is true or false. When it connects in one
way by assertion or negation, it says what is true, and when it
does so in another way, what is false. - Again, there must be an
intermediate between all contradictories, if one is not arguing
merely for the sake of argument; so that it will be possible for a
man to say what is neither true nor untrue, and there will be a
middle between that which is and that which is not, so that
there will also be a kind of change intermediate between
generation and destruction. - Again, in all classes in which the
negation of an attribute involves the assertion of its contrary,
even in these there will be an intermediate; for instance, in the
sphere of numbers there will be number which is neither odd
nor not-odd. But this is impossible, as is obvious from the
definition. - Again, the process will go on ad infinitum, and the
number of realities will be not only half as great again, but even
greater. For again it will be possible to deny this intermediate
with reference both to its assertion and to its negation, and this
new term will be some definite thing; for its essence is
something different. - Again, when a man, on being asked
whether a thing is white, says 'no', he has denied nothing
except that it is; and its not being is a negation.
Some people have acquired this opinion as other paradoxical
opinions have been acquired; when men cannot refute eristical
arguments, they give in to the argument and agree that the
conclusion is true. This, then, is why some express this view;
others do so because they demand a reason for everything. And
the starting-point in dealing with all such people is definition.
Now the definition rests on the necessity of their meaning
something; for the form of words of which the word is a sign
will be its definition. - While the doctrine of Heraclitus, that all
things are and are not, seems to make everything true, that of
2289
Anaxagoras, that there is an intermediate between the terms of
a contradiction, seems to make everything false; for when
things are mixed, the mixture is neither good nor not-good, so
that one cannot say anything that is true.
8
In view of these distinctions it is obvious that the one-sided
theories which some people express about all things cannot be
valid - on the one hand the theory that nothing is true (for, say
they, there is nothing to prevent every statement from being like
the statement 'the diagonal of a square is commensurate with
the side'), on the other hand the theory that everything is true.
These views are practically the same as that of Heraclitus; for
he who says that all things are true and all are false also makes
each of these statements separately, so that since they are
impossible, the double statement must be impossible too. -
Again, there are obviously contradictories which cannot be at
the same time true - nor on the other hand can all statements
be false; yet this would seem more possible in the light of what
has been said. - But against all such views we must postulate, as
we said above,' not that something is or is not, but that
something has a meaning, so that we must argue from a
definition, viz. by assuming what falsity or truth means. If that
which it is true to affirm is nothing other than that which it is
false to deny, it is impossible that all statements should be false;
for one side of the contradiction must be true. Again, if it is
necessary with regard to everything either to assert or to deny
it, it is impossible that both should be false; for it is one side of
the contradiction that is false. - Therefore all such views are
also exposed to the often expressed objection, that they destroy
themselves. For he who says that everything is true makes even
2290
the statement contrary to his own true, and therefore his own
not true (for the contrary statement denies that it is true), while
he who says everything is false makes himself also false. - And
if the former person excepts the contrary statement, saying it
alone is not true, while the latter excepts his own as being not
false, none the less they are driven to postulate the truth or
falsity of an infinite number of statements; for that which says
the true statement is true is true, and this process will go on to
infinity
Evidently, again, those who say all things are at rest are not
right, nor are those who say all things are in movement. For if
all things are at rest, the same statements will always be true
and the same always false, - but this obviously changes; for he
who makes a statement, himself at one time was not and again
will not be. And if all things are in motion, nothing will be true;
everything therefore will be false. But it has been shown that
this is impossible. Again, it must be that which is that changes;
for change is from something to something. But again it is not
the case that all things are at rest or in motion sometimes, and
nothing for ever; for there is something which always moves
the things that are in motion, and the first mover is itself
unmoved.
2291
Book A
'Beginning' means (1) that part of a thing from which one would
start first, e.g a line or a road has a beginning in either of the
contrary directions. (2) That from which each thing would best
be originated, e.g. even in learning we must sometimes begin
not from the first point and the beginning of the subject, but
from the point from which we should learn most easily. (4) That
from which, as an immanent part, a thing first comes to be, e,g,
as the keel of a ship and the foundation of a house, while in
animals some suppose the heart, others the brain, others some
other part, to be of this nature. (4) That from which, not as an
immanent part, a thing first comes to be, and from which the
movement or the change naturally first begins, as a child comes
from its father and its mother, and a fight from abusive
language. (5) That at whose will that which is moved is moved
and that which changes changes, e.g. the magistracies in cities,
and oligarchies and monarchies and tyrannies, are called
arhchai, and so are the arts, and of these especially the
architectonic arts. (6) That from which a thing can first be
known, - this also is called the beginning of the thing, e.g. the
hypotheses are the beginnings of demonstrations. (Causes are
spoken of in an equal number of senses; for all causes are
beginnings.) It is common, then, to all beginnings to be the first
point from which a thing either is or comes to be or is known;
but of these some are immanent in the thing and others are
outside. Hence the nature of a thing is a beginning, and so is the
element of a thing, and thought and will, and essence, and the
final cause - for the good and the beautiful are the beginning
both of the knowledge and of the movement of many things.
2292
'Cause' means (1) that from which, as immanent material, a
thing comes into being, e.g. the bronze is the cause of the statue
and the silver of the saucer, and so are the classes which
include these. (2) The form or pattern, i.e. the definition of the
essence, and the classes which include this (e.g. the ratio 2:1
and number in general are causes of the octave), and the parts
included in the definition. (3) That from which the change or the
resting from change first begins; e.g. the adviser is a cause of
the action, and the father a cause of the child, and in general
the maker a cause of the thing made and the change-producing
of the changing. (4) The end, i.e. that for the sake of which a
thing is; e.g. health is the cause of walking. For 'Why does one
walk?' we say; 'that one may be healthy'; and in speaking thus
we think we have given the cause. The same is true of all the
means that intervene before the end, when something else has
put the process in motion, as e.g. thinning or purging or drugs
or instruments intervene before health is reached; for all these
are for the sake of the end, though they differ from one another
in that some are instruments and others are actions.
These, then, are practically all the senses in which causes are
spoken of, and as they are spoken of in several senses it follows
both that there are several causes of the same thing, and in no
accidental sense (e.g. both the art of sculpture and the bronze
are causes of the statue not in respect of anything else but qua
statue; not, however, in the same way, but the one as matter
and the other as source of the movement), and that things can
be causes of one another (e.g. exercise of good condition, and
the latter of exercise; not, however, in the same way, but the one
as end and the other as source of movement). - Again, the same
2293
thing is the cause of contraries; for that which when present
causes a particular thing, we sometimes charge, when absent,
with the contrary, e.g. we impute the shipwreck to the absence
of the steersman, whose presence was the cause of safety; and
both - the presence and the privation - are causes as sources of
movement.
All the causes now mentioned fall under four senses which are
the most obvious. For the letters are the cause of syllables, and
the material is the cause of manufactured things, and fire and
earth and all such things are the causes of bodies, and the parts
are causes of the whole, and the hypotheses are causes of the
conclusion, in the sense that they are that out of which these
respectively are made; but of these some are cause as the
substratum (e.g. the parts), others as the essence (the whole, the
synthesis, and the form). The semen, the physician, the adviser,
and in general the agent, are all sources of change or of rest.
The remainder are causes as the end and the good of the other
things; for that for the sake of which other things are tends to
be the best and the end of the other things; let us take it as
making no difference whether we call it good or apparent good.
These, then, are the causes, and this is the number of their
kinds, but the varieties of causes are many in number, though
when summarized these also are comparatively few. Causes are
spoken of in many senses, and even of those which are of the
same kind some are causes in a prior and others in a posterior
sense, e.g. both 'the physician' and 'the professional man' are
causes of health, and both 'the ratio 2:1' and 'number' are
causes of the octave, and the classes that include any particular
cause are always causes of the particular effect. Again, there are
accidental causes and the classes which include these; e.g.
while in one sense 'the sculptor' causes the statue, in another
sense 'Polyclitus' causes it, because the sculptor happens to be
Polyclitus; and the classes that include the accidental cause are
2294
also causes, e.g. 'man' - or in general 'animal' - is the cause of
the statue, because Polyclitus is a man, and man is an animal.
Of accidental causes also some are more remote or nearer than
others, as, for instance, if 'the white' and 'the musical' were
called causes of the statue, and not only 'Polyclitus' or 'man'.
But besides all these varieties of causes, whether proper or
accidental, some are called causes as being able to act, others as
acting; e.g. the cause of the house's being built is a builder, or a
builder who is building. - The same variety of language will be
found with regard to the effects of causes; e.g. a thing may be
called the cause of this statue or of a statue or in general of an
image, and of this bronze or of bronze or of matter in general;
and similarly in the case of accidental effects. Again, both
accidental and proper causes may be spoken of in combination;
e.g. we may say not 'Polyclitus' nor 'the sculptor' but 'Polyclitus
the sculptor'. Yet all these are but six in number, while each is
spoken of in two ways; for (A) they are causes either as the
individual, or as the genus, or as the accidental, or as the genus
that includes the accidental, and these either as combined, or
as taken simply; and (B) all may be taken as acting or as having
a capacity. But they differ inasmuch as the acting causes, i.e. the
individuals, exist, or do not exist, simultaneously with the
things of which they are causes, e.g. this particular man who is
healing, with this particular man who is recovering health, and
this particular builder with this particular thing that is being
built; but the potential causes are not always in this case; for
the house does not perish at the same time as the builder.
'Element' means (1) the primary component immanent in a
thing, and indivisible in kind into other kinds; e.g. the elements
2295
of speech are the parts of which speech consists and into which
it is ultimately divided, while they are no longer divided into
other forms of speech different in kind from them. If they are
divided, their parts are of the same kind, as a part of water is
water (while a part of the syllable is not a syllable). Similarly
those who speak of the elements of bodies mean the things into
which bodies are ultimately divided, while they are no longer
divided into other things differing in kind; and whether the
things of this sort are one or more, they call these elements. The
so-called elements of geometrical proofs, and in general the
elements of demonstrations, have a similar character; for the
primary demonstrations, each of which is implied in many
demonstrations, are called elements of demonstrations; and the
primary syllogisms, which have three terms and proceed by
means of one middle, are of this nature.
(2) People also transfer the word 'element' from this meaning
and apply it to that which, being one and small, is useful for
many purposes; for which reason what is small and simple and
indivisible is called an element. Hence come the facts that the
most universal things are elements (because each of them being
one and simple is present in a plurality of things, either in all or
in as many as possible), and that unity and the point are
thought by some to be first principles. Now, since the so-called
genera are universal and indivisible (for there is no definition of
them), some say the genera are elements, and more so than the
differentia, because the genus is more universal; for where the
differentia is present, the genus accompanies it, but where the
genus is present, the differentia is not always so. It is common
to all the meanings that the element of each thing is the first
component immanent in each.
2296
'Nature' means (1) the genesis of growing things - the meaning
which would be suggested if one were to pronounce the 'u' in
phusis long. - (2) That immanent part of a growing thing, from
which its growth first proceeds. - (3) The source from which the
primary movement in each natural object is present in it in
virtue of its own essence. Those things are said to grow which
derive increase from something else by contact and either by
organic unity, or by organic adhesion as in the case of embryos.
Organic unity differs from contact; for in the latter case there
need not be anything besides the contact, but in organic unities
there is something identical in both parts, which makes them
grow together instead of merely touching, and be one in respect
of continuity and quantity, though not of quality. - (4) 'Nature'
means the primary material of which any natural object
consists or out of which it is made, which is relatively unshaped
and cannot be changed from its own potency, as e.g. bronze is
said to be the nature of a statue and of bronze utensils, and
wood the nature of wooden things; and so in all other cases; for
when a product is made out of these materials, the first matter
is preserved throughout. For it is in this way that people call the
elements of natural objects also their nature, some naming fire,
others earth, others air, others water, others something else of
the sort, and some naming more than one of these, and others
all of them. - (5) 'Nature' means the essence of natural objects,
as with those who say the nature is the primary mode of
composition, or as Empedocles says: -
Nothing that is has a nature,
But only mixing and parting of the mixed,
And nature is but a name given them by men.
2297
Hence as regards the things that are or come to be by nature,
though that from which they naturally come to be or are is
already present, we say they have not their nature yet, unless
they have their form or shape. That which comprises both of
these exists by nature, e.g. the animals and their parts; and not
only is the first matter nature (and this in two senses, either the
first, counting from the thing, or the first in general; e.g. in the
case of works in bronze, bronze is first with reference to them,
but in general perhaps water is first, if all things that can be
melted are water), but also the form or essence, which is the
end of the process of becoming. - (6) By an extension of
meaning from this sense of 'nature' every essence in general
has come to be called a 'nature', because the nature of a thing is
one kind of essence.
From what has been said, then, it is plain that nature in the
primary and strict sense is the essence of things which have in
themselves, as such, a source of movement; for the matter is
called the nature because it is qualified to receive this, and
processes of becoming and growing are called nature because
they are movements proceeding from this. And nature in this
sense is the source of the movement of natural objects, being
present in them somehow, either potentially or in complete
reality.
We call 'necessary' (1) (a) that without which, as a condition, a
thing cannot live; e.g. breathing and food are necessary for an
animal; for it is incapable of existing without these; (b) the
conditions without which good cannot be or come to be, or
without which we cannot get rid or be freed of evil; e.g. drinking
2298
the medicine is necessary in order that we may be cured of
disease, and a man's sailing to Aegina is necessary in order that
he may get his money - (2) The compulsory and compulsion, i.e.
that which impedes and tends to hinder, contrary to impulse
and purpose. For the compulsory is called necessary (whence
the necessary is painful, as Evenus says: 'For every necessary
thing is ever irksome'), and compulsion is a form of necessity, as
Sophocles says: 'But force necessitates me to this act'. And
necessity is held to be something that cannot be persuaded -
and rightly, for it is contrary to the movement which accords
with purpose and with reasoning. - (3) We say that that which
cannot be otherwise is necessarily as it is. And from this sense
of 'necessary' all the others are somehow derived; for a thing is
said to do or suffer what is necessary in the sense of
compulsory, only when it cannot act according to its impulse
because of the compelling forces - which implies that necessity
is that because of which a thing cannot be otherwise; and
similarly as regards the conditions of life and of good; for when
in the one case good, in the other life and being, are not possible
without certain conditions, these are necessary, and this kind of
cause is a sort of necessity. Again, demonstration is a necessary
thing because the conclusion cannot be otherwise, if there has
been demonstration in the unqualified sense; and the causes of
this necessity are the first premisses, i.e. the fact that the
propositions from which the syllogism proceeds cannot be
otherwise.
Now some things owe their necessity to something other than
themselves; others do not, but are themselves the source of
necessity in other things. Therefore the necessary in the
primary and strict sense is the simple; for this does not admit of
more states than one, so that it cannot even be in one state and
also in another; for if it did it would already be in more than
one. If, then, there are any things that are eternal and
2299
unmovable, nothing compulsory or against their nature
attaches to them.
'One' means (1) that which is one by accident, (2) that which is
one by its own nature. (1) Instances of the accidentally one are
'Coriscus and what is musical', and 'musical Coriscus' (for it is
the same thing to say 'Coriscus and what is musical', and
'musical Coriscus'), and 'what is musical and what is just', and
'musical Coriscus and just Coriscus'. For all of these are called
one by virtue of an accident, 'what is just and what is musical'
because they are accidents of one substance, 'what is musical
and Coriscus' because the one is an accident of the other; and
similarly in a sense 'musical Coriscus' is one with 'Coriscus'
because one of the parts of the phrase is an accident of the
other, i.e. 'musical' is an accident of Coriscus; and 'musical
Coriscus' is one with 'just Coriscus' because one part of each is
an accident of one and the same subject. The case is similar if
the accident is predicated of a genus or of any universal name,
e.g. if one says that man is the same as 'musical man'; for this is
either because 'musical' is an accident of man, which is one
substance, or because both are accidents of some individual, e.g.
Coriscus. Both, however, do not belong to him in the same way,
but one presumably as genus and included in his substance, the
other as a state or affection of the substance.
The things, then, that are called one in virtue of an accident, are
called so in this way. (2) Of things that are called one in virtue of
their own nature some (a) are so called because they are
continuous, e.g. a bundle is made one by a band, and pieces of
wood are made one by glue; and a line, even if it is bent, is
2300
called one if it is continuous, as each part of the body is, e.g. the
leg or the arm. Of these themselves, the continuous by nature
are more one than the continuous by art. A thing is called
continuous which has by its own nature one movement and
cannot have any other; and the movement is one when it is
indivisible, and it is indivisible in respect of time. Those things
are continuous by their own nature which are one not merely by
contact; for if you put pieces of wood touching one another, you
will not say these are one piece of wood or one body or one
continuum of any other sort. Things, then, that are continuous
in any way called one, even if they admit of being bent, and still
more those which cannot be bent; e.g. the shin or the thigh is
more one than the leg, because the movement of the leg need
not be one. And the straight line is more one than the bent; but
that which is bent and has an angle we call both one and not
one, because its movement may be either simultaneous or not
simultaneous; but that of the straight line is always
simultaneous, and no part of it which has magnitude rests
while another moves, as in the bent line.
(b)(i) Things are called one in another sense because their
substratum does not differ in kind; it does not differ in the case
of things whose kind is indivisible to sense. The substratum
meant is either the nearest to, or the farthest from, the final
state. For, one the one hand, wine is said to be one and water is
said to be one, qua indivisible in kind; and, on the other hand,
all juices, e.g. oil and wine, are said to be one, and so are all
things that can be melted, because the ultimate substratum of
all is the same; for all of these are water or air.
(ii) Those things also are called one whose genus is one though
distinguished by opposite differentiae - these too are all called
one because the genus which underlies the differentiae is one
(e.g. horse, man, and dog form a unity, because all are animals),
and indeed in a way similar to that in which the matter is one.
2301
These are sometimes called one in this way, but sometimes it is
the higher genus that is said to be the same (if they are infimae
species of their genus) - the genus above the proximate genera;
e.g. the isosceles and the equilateral are one and the same
figure because both are triangles; but they are not the same
triangles.
(c) Two things are called one, when the definition which states
the essence of one is indivisible from another definition which
shows us the other (though in itself every definition is divisible).
Thus even that which has increased or is diminishing is one,
because its definition is one, as, in the case of plane figures, is
the definition of their form. In general those things the thought
of whose essence is indivisible, and cannot separate them
either in time or in place or in definition, are most of all one,
and of these especially those which are substances. For in
general those things that do not admit of division are called one
in so far as they do not admit of it; e.g. if two things are
indistinguishable qua man, they are one kind of man; if qua
animal, one kind of animal; if qua magnitude, one kind of
magnitude. - Now most things are called one because they
either do or have or suffer or are related to something else that
is one, but the things that are primarily called one are those
whose substance is one, - and one either in continuity or in
form or in definition; for we count as more than one either
things that are not continuous, or those whose form is not one,
or those whose definition is not one.
While in a sense we call anything one if it is a quantity and
continuous, in a sense we do not unless it is a whole, i.e. unless
it has unity of form; e.g. if we saw the parts of a shoe put
together anyhow we should not call them one all the same
(unless because of their continuity); we do this only if they are
put together so as to be a shoe and to have already a certain
2302
single form. This is why the circle is of all lines most truly one,
because it is whole and complete.
(3) The essence of what is one is to be some kind of beginning of
number; for the first measure is the beginning, since that by
which we first know each class is the first measure of the class;
the one, then, is the beginning of the knowable regarding each
class. But the one is not the same in all classes. For here it is a
quarter-tone, and there it is the vowel or the consonant; and
there is another unit of weight and another of movement. But
everywhere the one is indivisible either in quantity or in kind.
Now that which is indivisible in quantity is called a unit if it is
not divisible in any dimension and is without position, a point if
it is not divisible in any dimension and has position, a line if it
is divisible in one dimension, a plane if in two, a body if divisible
in quantity in all - i.e. in three - dimensions. And, reversing the
order, that which is divisible in two dimensions is a plane, that
which is divisible in one a line, that which is in no way divisible
in quantity is a point or a unit, - that which has not position a
unit, that which has position a point.
Again, some things are one in number, others in species, others
in genus, others by analogy; in number those whose matter is
one, in species those whose definition is one, in genus those to
which the same figure of predication applies, by analogy those
which are related as a third thing is to a fourth. The latter kinds
of unity are always found when the former are; e.g. things that
are one in number are also one in species, while things that are
one in species are not all one in number; but things that are one
in species are all one in genus, while things that are so in genus
are not all one in species but are all one by analogy; while
things that are one by analogy are not all one in genus.
Evidently 'many' will have meanings opposite to those of 'one';
some things are many because they are not continuous, others
2303
because their matter - either the proximate matter or the
ultimate - is divisible in kind, others because the definitions
which state their essence are more than one.
Things are said to 'be' (1) in an accidental sense, (2) by their own
nature.
(1) In an accidental sense, e.g. we say 'the righteous doer is
musical', and 'the man is musical', and 'the musician is a man',
just as we say 'the musician builds', because the builder
happens to be musical or the musician to be a builder; for here
'one thing is another' means 'one is an accident of another'. So
in the cases we have mentioned; for when we say 'the man is
musical' and 'the musician is a man', or 'he who is pale is
musical' or 'the musician is pale', the last two mean that both
attributes are accidents of the same thing; the first that the
attribute is an accident of that which is, while 'the musical is a
man' means that 'musical' is an accident of a man. (In this
sense, too, the not-pale is said to be, because that of which it is
an accident is.) Thus when one thing is said in an accidental
sense to be another, this is either because both belong to the
same thing, and this is, or because that to which the attribute
belongs is, or because the subject which has as an attribute that
of which it is itself predicated, itself is.
(2) The kinds of essential being are precisely those that are
indicated by the figures of predication; for the senses of 'being'
are just as many as these figures. Since, then, some predicates
indicate what the subject is, others its quality, others quantity,
others relation, others activity or passivity, others its 'where',
others its 'when', 'being' has a meaning answering to each of
2304
these. For there is no difference between 'the man is recovering'
and 'the man recovers', nor between 'the man is walking or
cutting' and 'the man walks' or 'cuts'; and similarly in all other
cases.
(3) Again, 'being' and 'is' mean that a statement is true, 'not
being' that it is not true but false - and this alike in the case of
affirmation and of negation; e.g. 'Socrates is musical' means
that this is true, or 'Socrates is not-pale' means that this is true;
but 'the diagonal of the square is not commensurate with the
side' means that it is false to say it is.
(4) Again, 'being' and 'that which is' mean that some of the
things we have mentioned 'are' potentially, others in complete
reality. For we say both of that which sees potentially and of
that which sees actually, that it is 'seeing', and both of that
which can actualize its knowledge and of that which is
actualizing it, that it knows, and both of that to which rest is
already present and of that which can rest, that it rests. And
similarly in the case of substances; we say the Hermes is in the
stone, and the half of the line is in the line, and we say of that
which is not yet ripe that it is corn. When a thing is potential
and when it is not yet potential must be explained elsewhere.
8
We call 'substance' (1) the simple bodies, i.e. earth and fire and
water and everything of the sort, and in general bodies and the
things composed of them, both animals and divine beings, and
the parts of these. All these are called substance because they
are not predicated of a subject but everything else is predicated
of them. - (2) That which, being present in such things as are
not predicated of a subject, is the cause of their being, as the
2305
soul is of the being of an animal. - (3) The parts which are
present in such things, limiting them and marking them as
individuals, and by whose destruction the whole is destroyed,
as the body is by the destruction of the plane, as some say, and
the plane by the destruction of the line; and in general number
is thought by some to be of this nature; for if it is destroyed,
they say, nothing exists, and it limits all things. - (4) The
essence, the formula of which is a definition, is also called the
substance of each thing.
It follows, then, that 'substance' has two senses, (A) ultimate
substratum, which is no longer predicated of anything else, and
(B) that which, being a 'this', is also separable and of this nature
is the shape or form of each thing.
'The same' means (1) that which is the same in an accidental
sense, e.g. 'the pale' and 'the musical' are the same because
they are accidents of the same thing, and 'a man' and 'musical'
because the one is an accident of the other; and 'the musical' is
'a man' because it is an accident of the man. (The complex
entity is the same as either of the simple ones and each of these
is the same as it; for both 'the man' and 'the musical' are said to
be the same as 'the musical man', and this the same as they.)
This is why all of these statements are made not universally; for
it is not true to say that every man is the same as 'the musical'
(for universal attributes belong to things in virtue of their own
nature, but accidents do not belong to them in virtue of their
own nature); but of the individuals the statements are made
without qualification. For 'Socrates' and 'musical Socrates' are
thought to be the same; but 'Socrates' is not predicable of more
2306
than one subject, and therefore we do not say 'every Socrates'
as we say 'every man'.
Some things are said to be the same in this sense, others (2) are
the same by their own nature, in as many senses as that which
is one by its own nature is so; for both the things whose matter
is one either in kind or in number, and those whose essence is
one, are said to be the same. Clearly, therefore, sameness is a
unity of the being either of more than one thing or of one thing
when it is treated as more than one, ie. when we say a thing is
the same as itself; for we treat it as two.
Things are called 'other' if either their kinds or their matters or
the definitions of their essence are more than one; and in
general 'other' has meanings opposite to those of 'the same'.
'Different' is applied (1) to those things which though other are
the same in some respect, only not in number but either in
species or in genus or by analogy; (2) to those whose genus is
other, and to contraries, and to an things that have their
otherness in their essence.
Those things are called 'like' which have the same attributes in
every respect, and those which have more attributes the same
than different, and those whose quality is one; and that which
shares with another thing the greater number or the more
important of the attributes (each of them one of two contraries)
in respect of which things are capable of altering, is like that
other thing. The senses of 'unlike' are opposite to those of 'like'.
2307
10
The term 'opposite' is applied to contradictories, and to
contraries, and to relative terms, and to privation and
possession, and to the extremes from which and into which
generation and dissolution take place; and the attributes that
cannot be present at the same time in that which is receptive of
both, are said to be opposed, - either themselves of their
constituents. Grey and white colour do not belong at the same
time to the same thing; hence their constituents are opposed.
The term 'contrary' is applied (1) to those attributes differing in
genus which cannot belong at the same time to the same
subject, (2) to the most different of the things in the same
genus, (3) to the most different of the attributes in the same
recipient subject, (4) to the most different of the things that fall
under the same faculty, (5) to the things whose difference is
greatest either absolutely or in genus or in species. The other
things that are called contrary are so called, some because they
possess contraries of the above kind, some because they are
receptive of such, some because they are productive of or
susceptible to such, or are producing or suffering them, or are
losses or acquisitions, or possessions or privations, of such.
Since 'one' and 'being' have many senses, the other terms
which are derived from these, and therefore 'same', 'other', and
'contrary', must correspond, so that they must be different for
each category.
The term 'other in species' is applied to things which being of
the same genus are not subordinate the one to the other, or
which being in the same genus have a difference, or which have
a contrariety in their substance; and contraries are other than
one another in species (either all contraries or those which are
so called in the primary sense), and so are those things whose
definitions differ in the infima species of the genus (e.g. man
2308
and horse are indivisible in genus, but their definitions are
different), and those which being in the same substance have a
difference. 'The same in species' has the various meanings
opposite to these.
11
The words 'prior' and 'posterior' are applied (1) to some things
(on the assumption that there is a first, i.e. a beginning, in each
class) because they are nearer some beginning determined
either absolutely and by nature, or by reference to something or
in some place or by certain people; e.g. things are prior in place
because they are nearer either to some place determined by
nature (e.g. the middle or the last place), or to some chance
object; and that which is farther is posterior. - Other things are
prior in time; some by being farther from the present, i.e. in the
case of past events (for the Trojan war is prior to the Persian,
because it is farther from the present), others by being nearer
the present, i.e. in the case of future events (for the Nemean
games are prior to the Pythian, if we treat the present as
beginning and first point, because they are nearer the present).
- Other things are prior in movement; for that which is nearer
the first mover is prior (e.g. the boy is prior to the man); and the
prime mover also is a beginning absolutely. - Others are prior in
power; for that which exceeds in power, i.e. the more powerful,
is prior; and such is that according to whose will the other - i.e.
the posterior - must follow, so that if the prior does not set it in
motion the other does not move, and if it sets it in motion it
does move; and here will is a beginning. - Others are prior in
arrangement; these are the things that are placed at intervals in
reference to some one definite thing according to some rule, e.g.
in the chorus the second man is prior to the third, and in the
2309
lyre the second lowest string is prior to the lowest; for in the
one case the leader and in the other the middle string is the
beginning.
These, then, are called prior in this sense, but (2) in another
sense that which is prior for knowledge is treated as also
absolutely prior; of these, the things that are prior in definition
do not coincide with those that are prior in relation to
perception. For in definition universals are prior, in relation to
perception individuals. And in definition also the accident is
prior to the whole, e.g. 'musical' to 'musical man', for the
definition cannot exist as a whole without the part; yet
musicalness cannot exist unless there is some one who is
musical.
(3) The attributes of prior things are called prior, e.g.
straightness is prior to smoothness; for one is an attribute of a
line as such, and the other of a surface.
Some things then are called prior and posterior in this sense,
others (4) in respect of nature and substance, i.e. those which
can be without other things, while the others cannot be without
them, - a distinction which Plato used. (If we consider the
various senses of 'being', firstly the subject is prior, so that
substance is prior; secondly, according as potency or complete
reality is taken into account, different things are prior, for some
things are prior in respect of potency, others in respect of
complete reality, e.g. in potency the half line is prior to the
whole line, and the part to the whole, and the matter to the
concrete substance, but in complete reality these are posterior;
for it is only when the whole has been dissolved that they will
exist in complete reality.) In a sense, therefore, all things that
are called prior and posterior are so called with reference to this
fourth sense; for some things can exist without others in
respect of generation, e.g. the whole without the parts, and
2310
others in respect of dissolution, e.g. the part without the whole.
And the same is true in all other cases.
12
'Potency' means (1) a source of movement or change, which is in
another thing than the thing moved or in the same thing qua
other; e.g. the art of building is a potency which is not in the
thing built, while the art of healing, which is a potency, may be
in the man healed, but not in him qua healed. 'Potency' then
means the source, in general, of change or movement in
another thing or in the same thing qua other, and also (2) the
source of a thing's being moved by another thing or by itself qua
other. For in virtue of that principle, in virtue of which a patient
suffers anything, we call it 'capable' of suffering; and this we do
sometimes if it suffers anything at all, sometimes not in respect
of everything it suffers, but only if it suffers a change for the
better - (3) The capacity of performing this well or according to
intention; for sometimes we say of those who merely can walk
or speak but not well or not as they intend, that they cannot
speak or walk. So too (4) in the case of passivity. - (5) The states
in virtue of which things are absolutely impassive or
unchangeable, or not easily changed for the worse, are called
potencies; for things are broken and crushed and bent and in
general destroyed not by having a potency but by not having
one and by lacking something, and things are impassive with
respect to such processes if they are scarcely and slightly
affected by them, because of a 'potency' and because they 'can'
do something and are in some positive state.
'Potency' having this variety of meanings, so too the 'potent' or
'capable' in one sense will mean that which can begin a
2311
movement (or a change in general, for even that which can
bring things to rest is a 'potent' thing) in another thing or in
itself qua other; and in one sense that over which something
else has such a potency; and in one sense that which has a
potency of changing into something, whether for the worse or
for the better (for even that which perishes is thought to be
'capable' of perishing, for it would not have perished if it had
not been capable of it; but, as a matter of fact, it has a certain
disposition and cause and principle which fits it to suffer this;
sometimes it is thought to be of this sort because it has
something, sometimes because it is deprived of something; but
if privation is in a sense 'having' or 'habit', everything will be
capable by having something, so that things are capable both by
having a positive habit and principle, and by having the
privation of this, if it is possible to have a privation; and if
privation is not in a sense 'habit', 'capable' is used in two
distinct senses); and a thing is capable in another sense because
neither any other thing, nor itself qua other, has a potency or
principle which can destroy it. Again, all of these are capable
either merely because the thing might chance to happen or not
to happen, or because it might do so well. This sort of potency is
found even in lifeless things, e.g. in instruments; for we say one
lyre can speak, and another cannot speak at all, if it has not a
good tone.
Incapacity is privation of capacity - i.e. of such a principle as
has been described either in general or in the case of something
that would naturally have the capacity, or even at the time
when it would naturally already have it; for the senses in which
we should call a boy and a man and a eunuch 'incapable of
begetting' are distinct. - Again, to either kind of capacity there is
an opposite incapacity - both to that which only can produce
movement and to that which can produce it well.
2312
Some things, then, are called adunata in virtue of this kind of
incapacity, while others are so in another sense; i.e. both
dunaton and adunaton are used as follows. The impossible is
that of which the contrary is of necessity true, e.g. that the
diagonal of a square is commensurate with the side is
impossible, because such a statement is a falsity of which the
contrary is not only true but also necessary; that it is
commensurate, then, is not only false but also of necessity false.
The contrary of this, the possible, is found when it is not
necessary that the contrary is false, e.g. that a man should be
seated is possible; for that he is not seated is not of necessity
false. The possible, then, in one sense, as has been said, means
that which is not of necessity false; in one, that which is true; in
one, that which may be true. - A 'potency' or 'power' in
geometry is so called by a change of meaning. -These senses of
'capable' or 'possible' involve no reference to potency. But the
senses which involve a reference to potency all refer to the
primary kind of potency; and this is a source of change in
another thing or in the same thing qua other. For other things
are called 'capable', some because something else has such a
potency over them, some because it has not, some because it
has it in a particular way. The same is true of the things that are
incapable. Therefore the proper definition of the primary kind of
potency will be 'a source of change in another thing or in the
same thing qua other'.
13
'Quantum' means that which is divisible into two or more
constituent parts of which each is by nature a 'one' and a 'this'.
A quantum is a plurality if it is numerable, a magnitude if it is a
measurable. 'Plurality' means that which is divisible potentially
2313
into non-continuous parts, 'magnitude' that which is divisible
into continuous parts; of magnitude, that which is continuous
in one dimension is length; in two breadth, in three depth. Of
these, limited plurality is number, limited length is a line,
breadth a surface, depth a solid.
Again, some things are called quanta in virtue of their own
nature, others incidentally; e.g. the line is a quantum by its own
nature, the musical is one incidentally. Of the things that are
quanta by their own nature some are so as substances, e.g. the
line is a quantum (for 'a certain kind of quantum' is present in
the definition which states what it is), and others are
modifications and states of this kind of substance, e.g. much
and little, long and short, broad and narrow, deep and shallow,
heavy and light, and all other such attributes. And also great
and small, and greater and smaller, both in themselves and
when taken relatively to each other, are by their own nature
attributes of what is quantitative; but these names are
transferred to other things also. Of things that are quanta
incidentally, some are so called in the sense in which it was said
that the musical and the white were quanta, viz. because that to
which musicalness and whiteness belong is a quantum, and
some are quanta in the way in which movement and time are
so; for these also are called quanta of a sort and continuous
because the things of which these are attributes are divisible. I
mean not that which is moved, but the space through which it
is moved; for because that is a quantum movement also is a
quantum, and because this is a quantum time is one.
2314
14
'Quality' means (1) the differentia of the essence, e.g. man is an
animal of a certain quality because he is two-footed, and the
horse is so because it is four-footed; and a circle is a figure of
particular quality because it is without angles, - which shows
that the essential differentia is a quality. - This, then, is one
meaning of quality - the differentia of the essence, but (2) there
is another sense in which it applies to the unmovable objects of
mathematics, the sense in which the numbers have a certain
quality, e.g. the composite numbers which are not in one
dimension only, but of which the plane and the solid are copies
(these are those which have two or three factors); and in general
that which exists in the essence of numbers besides quantity is
quality; for the essence of each is what it is once, e.g. that of is
not what it is twice or thrice, but what it is once; for 6 is once 6.
(3) All the modifications of substances that move (e.g. heat and
cold, whiteness and blackness, heaviness and lightness, and the
others of the sort) in virtue of which, when they change, bodies
are said to alter. (4) Quality in respect of virtue and vice, and in
general, of evil and good.
Quality, then, seems to have practically two meanings, and one
of these is the more proper. The primary quality is the
differentia of the essence, and of this the quality in numbers is
a part; for it is a differentia of essences, but either not of things
that move or not of them qua moving. Secondly, there are the
modifications of things that move, qua moving, and the
differentiae of movements. Virtue and vice fall among these
modifications; for they indicate differentiae of the movement or
activity, according to which the things in motion act or are
acted on well or badly; for that which can be moved or act in
one way is good, and that which can do so in another - the
contrary - way is vicious. Good and evil indicate quality
2315
especially in living things, and among these especially in those
which have purpose.
15
Things are 'relative' (1) as double to half, and treble to a third,
and in general that which contains something else many times
to that which is contained many times in something else, and
that which exceeds to that which is exceeded; (2) as that which
can heat to that which can be heated, and that which can cut to
that which can be cut, and in general the active to the passive;
(3) as the measurable to the measure, and the knowable to
knowledge, and the perceptible to perception.
(1) Relative terms of the first kind are numerically related either
indefinitely or definitely, to numbers themselves or to 1. E.g. the
double is in a definite numerical relation to 1, and that which is
'many times as great' is in a numerical, but not a definite,
relation to 1, i.e. not in this or in that numerical relation to it;
the relation of that which is half as big again as something else
to that something is a definite numerical relation to a number;
that which is n+I/n times something else is in an indefinite
relation to that something, as that which is 'many times as
great' is in an indefinite relation to 1; the relation of that which
exceeds to that which is exceeded is numerically quite
indefinite; for number is always commensurate, and 'number' is
not predicated of that which is not commensurate, but that
which exceeds is, in relation to that which is exceeded, so much
and something more; and this something is indefinite; for it
can, indifferently, be either equal or not equal to that which is
exceeded. - All these relations, then, are numerically expressed
and are determinations of number, and so in another way are
2316
the equal and the like and the same. For all refer to unity. Those
things are the same whose substance is one; those are like
whose quality is one; those are equal whose quantity is one;
and 1 is the beginning and measure of number, so that all these
relations imply number, though not in the same way.
(2) Things that are active or passive imply an active or a passive
potency and the actualizations of the potencies; e.g. that which
is capable of heating is related to that which is capable of being
heated, because it can heat it, and, again, that which heats is
related to that which is heated and that which cuts to that
which is cut, in the sense that they actually do these things. But
numerical relations are not actualized except in the sense
which has been elsewhere stated; actualizations in the sense of
movement they have not. Of relations which imply potency
some further imply particular periods of time, e.g. that which
has made is relative to that which has been made, and that
which will make to that which will be made. For it is in this way
that a father is called the father of his son; for the one has acted
and the other has been acted on in a certain way. Further, some
relative terms imply privation of potency, i.e. 'incapable' and
terms of this sort, e.g. 'invisible'.
Relative terms which imply number or potency, therefore, are all
relative because their very essence includes in its nature a
reference to something else, not because something else
involves a reference to it; but (3) that which is measurable or
knowable or thinkable is called relative because something else
involves a reference to it. For 'that which is thinkable' implies
that the thought of it is possible, but the thought is not relative
to 'that of which it is the thought'; for we should then have said
the same thing twice. Similarly sight is the sight of something,
not 'of that of which it is the sight' (though of course it is true to
say this); in fact it is relative to colour or to something else of
2317
the sort. But according to the other way of speaking the same
thing would be said twice, - 'the sight is of that of which it is.'
Things that are by their own nature called relative are called so
sometimes in these senses, sometimes if the classes that
include them are of this sort; e.g. medicine is a relative term
because its genus, science, is thought to be a relative term.
Further, there are the properties in virtue of which the things
that have them are called relative, e.g. equality is relative
because the equal is, and likeness because the like is. Other
things are relative by accident; e.g. a man is relative because he
happens to be double of something and double is a relative
term; or the white is relative, if the same thing happens to be
double and white.
16
What is called 'complete' is (1) that outside which it is not
possible to find any, even one, of its parts; e.g. the complete
time of each thing is that outside which it is not possible to find
any time which is a part proper to it. - (2) That which in respect
of excellence and goodness cannot be excelled in its kind; e.g.
we have a complete doctor or a complete flute-player, when
they lack nothing in respect of the form of their proper
excellence. And thus, transferring the word to bad things, we
speak of a complete scandal-monger and a complete thief;
indeed we even call them good, i.e. a good thief and a good
scandal-monger. And excellence is a completion; for each thing
is complete and every substance is complete, when in respect of
the form of its proper excellence it lacks no part of its natural
magnitude. - (3) The things which have attained their end, this
being good, are called complete; for things are complete in
2318
virtue of having attained their end. Therefore, since the end is
something ultimate, we transfer the word to bad things and say
a thing has been completely spoilt, and completely destroyed,
when it in no wise falls short of destruction and badness, but is
at its last point. This is why death, too, is by a figure of speech
called the end, because both are last things. But the ultimate
purpose is also an end. - Things, then, that are called complete
in virtue of their own nature are so called in all these senses,
some because in respect of goodness they lack nothing and
cannot be excelled and no part proper to them can be found
outside them, others in general because they cannot be
exceeded in their several classes and no part proper to them is
outside them; the others presuppose these first two kinds, and
are called complete because they either make or have
something of the sort or are adapted to it or in some way or
other involve a reference to the things that are called complete
in the primary sense.
17
'Limit' means (1) the last point of each thing, i.e. the first point
beyond which it is not possible to find any part, and the first
point within which every part is; (2) the form, whatever it may
be, of a spatial magnitude or of a thing that has magnitude; (3)
the end of each thing (and of this nature is that towards which
the movement and the action are, not that from which they are
- though sometimes it is both, that from which and that to
which the movement is, i.e. the final cause); (4) the substance of
each thing, and the essence of each; for this is the limit of
knowledge; and if of knowledge, of the object also. Evidently,
therefore, 'limit' has as many senses as 'beginning', and yet
2319
more; for the beginning is a limit, but not every limit is a
beginning.
18
'That in virtue of which' has several meanings: - (1) the form or
substance of each thing, e.g. that in virtue of which a man is
good is the good itself, (2) the proximate subject in which it is
the nature of an attribute to be found, e.g. colour in a surface.
'That in virtue of which', then, in the primary sense is the form,
and in a secondary sense the matter of each thing and the
proximate substratum of each. - In general 'that in virtue of
which' will found in the same number of senses as 'cause'; for
we say indifferently (3) in virtue of what has he come?' or 'for
what end has he come?'; and (4) in virtue of what has he
inferred wrongly, or inferred?' or 'what is the cause of the
inference, or of the wrong inference?' - Further (5) Kath' d is
used in reference to position, e.g. 'at which he stands' or 'along
which he walks; for all such phrases indicate place and
position.
Therefore 'in virtue of itself must likewise have several
meanings. The following belong to a thing in virtue of itself: - (1)
the essence of each thing, e.g. Callias is in virtue of himself
Callias and what it was to be Callias; - (2) whatever is present in
the 'what', e.g. Callias is in virtue of himself an animal. For
'animal' is present in his definition; Callias is a particular
animal. - (3) Whatever attribute a thing receives in itself directly
or in one of its parts; e.g. a surface is white in virtue of itself,
and a man is alive in virtue of himself; for the soul, in which life
directly resides, is a part of the man. - (4) That which has no
cause other than itself; man has more than one cause - animal,
2320
two-footed - but yet man is man in virtue of himself. - (5)
Whatever attributes belong to a thing alone, and in so far as
they belong to it merely by virtue of itself considered apart by
itself.
19
'Disposition' means the arrangement of that which has parts, in
respect either of place or of potency or of kind; for there must
be a certain position, as even the word 'disposition' shows.
20
'Having' means (1) a kind of activity of the haver and of what he
has - something like an action or movement. For when one
thing makes and one is made, between them there is a making;
so too between him who has a garment and the garment which
he has there is a having. This sort of having, then, evidently we
cannot have; for the process will go on to infinity, if it is to be
possible to have the having of what we have. - (2) 'Having' or
'habit' means a disposition according to which that which is
disposed is either well or ill disposed, and either in itself or with
reference to something else; e.g. health is a 'habit'; for it is such
a disposition. - (3) We speak of a 'habit' if there is a portion of
such a disposition; and so even the excellence of the parts is a
'habit' of the whole thing.
2321
21
'Affection' means (1) a quality in respect of which a thing can be
altered, e.g. white and black, sweet and bitter, heaviness and
lightness, and all others of the kind. - (2) The actualization of
these - the already accomplished alterations. - (3) Especially,
injurious alterations and movements, and, above all painful
injuries. - (4) Misfortunes and painful experiences when on a
large scale are called affections.
22
We speak of 'privation' (1) if something has not one of the
attributes which a thing might naturally have, even if this thing
itself would not naturally have it; e.g. a plant is said to be
'deprived' of eyes. - (2) If, though either the thing itself or its
genus would naturally have an attribute, it has it not; e.g. a blind
man and a mole are in different senses 'deprived' of sight; the
latter in contrast with its genus, the former in contrast with his
own normal nature. - (3) If, though it would naturally have the
attribute, and when it would naturally have it, it has it not; for
blindness is a privation, but one is not 'blind' at any and every
age, but only if one has not sight at the age at which one would
naturally have it. Similarly a thing is called blind if it has not
sight in the medium in which, and in respect of the organ in
respect of which, and with reference to the object with
reference to which, and in the circumstances in which, it would
naturally have it. - (4) The violent taking away of anything is
called privation.
Indeed there are just as many kinds of privations as there are of
words with negative prefixes; for a thing is called unequal
because it has not equality though it would naturally have it,
2322
and invisible either because it has no colour at all or because it
has a poor colour, and apodous either because it has no feet at
all or because it has imperfect feet. Again, a privative term may
be used because the thing has little of the attribute (and this
means having it in a sense imperfectly), e.g. 'kernel-less'; or
because it has it not easily or not well (e.g. we call a thing
uncuttable not only if it cannot be cut but also if it cannot be cut
easily or well); or because it has not the attribute at all; for it is
not the one-eyed man but he who is sightless in both eyes that
is called blind. This is why not every man is 'good' or 'bad', 'just'
or 'unjust', but there is also an intermediate state.
23
To 'have' or 'hold' means many things: - (1) to treat a thing
according to one's own nature or according to one's own
impulse; so that fever is said to have a man, and tyrants to have
their cities, and people to have the clothes they wear. - (2) That
in which a thing is present as in something receptive of it is
said to have the thing; e.g. the bronze has the form of the
statue, and the body has the disease. - (3) As that which
contains holds the things contained; for a thing is said to be
held by that in which it is as in a container; e.g. we say that the
vessel holds the liquid and the city holds men and the ship
sailors; and so too that the whole holds the parts. - (4) That
which hinders a thing from moving or acting according to its
own impulse is said to hold it, as pillars hold the incumbent
weights, and as the poets make Atlas hold the heavens,
implying that otherwise they would collapse on the earth, as
some of the natural philosophers also say. In this way also that
which holds things together is said to hold the things it holds
2323
together, since they would otherwise separate, each according
to its own impulse.
'Being in something' has similar and corresponding meanings
to 'holding' or 'having'.
24
'To come from something' means (1) to come from something
as from matter, and this in two senses, either in respect of the
highest genus or in respect of the lowest species; e.g. in a sense
all things that can be melted come from water, but in a sense
the statue comes from bronze. - (2) As from the first moving
principle; e.g. 'what did the fight come from?' From abusive
language, because this was the origin of the fight. - (3) From the
compound of matter and shape, as the parts come from the
whole, and the verse from the Iliad, and the stones from the
house; (in every such case the whole is a compound of matter
and shape,) for the shape is the end, and only that which
attains an end is complete. - (4) As the form from its part, e.g.
man from 'two-footed'and syllable from 'letter'; for this is a
different sense from that in which the statue comes from
bronze; for the composite substance comes from the sensible
matter, but the form also comes from the matter of the form. -
Some things, then, are said to come from something else in
these senses; but (5) others are so described if one of these
senses is applicable to a part of that other thing; e.g. the child
comes from its father and mother, and plants come from the
earth, because they come from a part of those things. - (6) It
means coming after a thing in time, e.g. night comes from day
and storm from fine weather, because the one comes after the
other. Of these things some are so described because they admit
2324
of change into one another, as in the cases now mentioned;
some merely because they are successive in time, e.g. the
voyage took place 'from' the equinox, because it took place after
the equinox, and the festival of the Thargelia comes 'from' the
Dionysia, because after the Dionysia.
25
'Part' means (1) (a) that into which a quantum can in any way
be divided; for that which is taken from a quantum qua
quantum is always called a part of it, e.g. two is called in a sense
a part of three. It means (b), of the parts in the first sense, only
those which measure the whole; this is why two, though in one
sense it is, in another is not, called a part of three. - (2) The
elements into which a kind might be divided apart from the
quantity are also called parts of it; for which reason we say the
species are parts of the genus. - (3) The elements into which a
whole is divided, or of which it consists - the 'whole' meaning
either the form or that which has the form; e.g. of the bronze
sphere or of the bronze cube both the bronze - i.e. the matter in
which the form is - and the characteristic angle are parts. - (4)
The elements in the definition which explains a thing are also
parts of the whole; this is why the genus is called a part of the
species, though in another sense the species is part of the
genus.
2325
26
'A whole' means (1) that from which is absent none of the parts
of which it is said to be naturally a whole, and (2) that which so
contains the things it contains that they form a unity; and this
in two senses - either as being each severally one single thing,
or as making up the unity between them. For (a) that which is
true of a whole class and is said to hold good as a whole (which
implies that it is a kind whole) is true of a whole in the sense
that it contains many things by being predicated of each, and by
all of them, e.g. man, horse, god, being severally one single
thing, because all are living things. But (b) the continuous and
limited is a whole, when it is a unity consisting of several parts,
especially if they are present only potentially, but, failing this,
even if they are present actually. Of these things themselves,
those which are so by nature are wholes in a higher degree than
those which are so by art, as we said in the case of unity also,
wholeness being in fact a sort of oneness.
Again (3) of quanta that have a beginning and a middle and an
end, those to which the position does not make a difference are
called totals, and those to which it does, wholes. Those which
admit of both descriptions are both wholes and totals. These are
the things whose nature remains the same after transposition,
but whose form does not, e.g. wax or a coat; they are called both
wholes and totals; for they have both characteristics. Water and
all liquids and number are called totals, but 'the whole number'
or 'the whole water' one does not speak of, except by an
extension of meaning. To things, to which qua one the term
'total' is applied, the term 'all' is applied when they are treated
as separate; 'this total number,' 'all these units.'
2326
27
It is not any chance quantitative thing that can be said to be
'mutilated'; it must be a whole as well as divisible. For not only
is two not 'mutilated' if one of the two ones is taken away (for
the part removed by mutilation is never equal to the
remainder), but in general no number is thus mutilated; for it is
also necessary that the essence remain; if a cup is mutilated, it
must still be a cup; but the number is no longer the same.
Further, even if things consist of unlike parts, not even these
things can all be said to be mutilated, for in a sense a number
has unlike parts (e.g. two and three) as well as like; but in
general of the things to which their position makes no
difference, e.g. water or fire, none can be mutilated; to be
mutilated, things must be such as in virtue of their essence
have a certain position. Again, they must be continuous; for a
musical scale consists of unlike parts and has position, but
cannot become mutilated. Besides, not even the things that are
wholes are mutilated by the privation of any part. For the parts
removed must be neither those which determine the essence
nor any chance parts, irrespective of their position; e.g. a cup is
not mutilated if it is bored through, but only if the handle or a
projecting part is removed, and a man is mutilated not if the
flesh or the spleen is removed, but if an extremity is, and that
not every extremity but one which when completely removed
cannot grow again. Therefore baldness is not a mutilation.
28
The term 'race' or 'genus' is used (1) if generation of things
which have the same form is continuous, e.g. 'while the race of
men lasts' means 'while the generation of them goes on
2327
continuously'. - (2) It is used with reference to that which first
brought things into existence; for it is thus that some are called
Hellenes by race and others Ionians, because the former
proceed from Hellen and the latter from Ion as their first
begetter. And the word is used in reference to the begetter more
than to the matter, though people also get a race-name from
the female, e.g. 'the descendants of Pyrrha'. - (3) There is genus
in the sense in which 'plane' is the genus of plane figures and
solid' of solids; for each of the figures is in the one case a plane
of such and such a kind, and in the other a solid of such and
such a kind; and this is what underlies the differentiae. Again
(4) in definitions the first constituent element, which is
included in the 'what', is the genus, whose differentiae the
qualities are said to be 'Genus' then is used in all these ways, (1)
in reference to continuous generation of the same kind, (2) in
reference to the first mover which is of the same kind as the
things it moves, (3) as matter; for that to which the differentia
or quality belongs is the substratum, which we call matter.
Those things are said to be 'other in genus' whose proximate
substratum is different, and which are not analysed the one
into the other nor both into the same thing (e.g. form and
matter are different in genus); and things which belong to
different categories of being (for some of the things that are said
to 'be' signify essence, others a quality, others the other
categories we have before distinguished); these also are not
analysed either into one another or into some one thing.
29
'The false' means (1) that which is false as a thing, and that (a)
because it is not put together or cannot be put together, e.g.
2328
'that the diagonal of a square is commensurate with the side' or
'that you are sitting'; for one of these is false always, and the
other sometimes; it is in these two senses that they are non-
existent, (b) There are things which exist, but whose nature it is
to appear either not to be such as they are or to be things that
do not exist, e.g. a sketch or a dream; for these are something,
but are not the things the appearance of which they produce in
us. We call things false in this way, then, - either because they
themselves do not exist, or because the appearance which
results from them is that of something that does not exist.
(2) A false account is the account of non-existent objects, in so
far as it is false. Hence every account is false when applied to
something other than that of which it is true; e.g. the account of
a circle is false when applied to a triangle. In a sense there is
one account of each thing, i.e. the account of its essence, but in
a sense there are many, since the thing itself and the thing itself
with an attribute are in a sense the same, e.g. Socrates and
musical Socrates (a false account is not the account of anything,
except in a qualified sense). Hence Antisthenes was too simple-
minded when he claimed that nothing could be described
except by the account proper to it, - one predicate to one
subject; from which the conclusion used to be drawn that there
could be no contradiction, and almost that there could be no
error. But it is possible to describe each thing not only by the
account of itself, but also by that of something else. This may be
done altogether falsely indeed, but there is also a way in which
it may be done truly; e.g. eight may be described as a double
number by the use of the definition of two.
These things, then, are called false in these senses, but (3) a
false man is one who is ready at and fond of such accounts, not
for any other reason but for their own sake, and one who is
good at impressing such accounts on other people, just as we
say things are which produce a false appearance. This is why
2329
the proof in the Hippias that the same man is false and true is
misleading. For it assumes that he is false who can deceive (i.e.
the man who knows and is wise); and further that he who is
willingly bad is better. This is a false result of induction - for a
man who limps willingly is better than one who does so
unwillingly - by 'limping' Plato means 'mimicking a limp', for if
the man were lame willingly, he would presumably be worse in
this case as in the corresponding case of moral character.
30
'Accident' means (1) that which attaches to something and can
be truly asserted, but neither of necessity nor usually, e.g. if
some one in digging a hole for a plant has found treasure. This -
the finding of treasure - is for the man who dug the hole an
accident; for neither does the one come of necessity from the
other or after the other, nor, if a man plants, does he usually
find treasure. And a musical man might be pale; but since this
does not happen of necessity nor usually, we call it an accident.
Therefore since there are attributes and they attach to subjects,
and some of them attach to these only in a particular place and
at a particular time, whatever attaches to a subject, but not
because it was this subject, or the time this time, or the place
this place, will be an accident. Therefore, too, there is no definite
cause for an accident, but a chance cause, i.e. an indefinite one.
Going to Aegina was an accident for a man, if he went not in
order to get there, but because he was carried out of his way by
a storm or captured by pirates. The accident has happened or
exists, - not in virtue of the subject's nature, however, but of
something else; for the storm was the cause of his coming to a
place for which he was not sailing, and this was Aegina.
2330
'Accident' has also (2) another meaning, i.e. all that attaches to
each thing in virtue of itself but is not in its essence, as having
its angles equal to two right angles attaches to the triangle. And
accidents of this sort may be eternal, but no accident of the
other sort is. This is explained elsewhere.
BookE
We are seeking the principles and the causes of the things that
are, and obviously of them qua being. For, while there is a cause
of health and of good condition, and the objects of mathematics
have first principles and elements and causes, and in general
every science which is ratiocinative or at all involves reasoning
deals with causes and principles, more or less precise, all these
sciences mark off some particular being - some genus, and
inquire into this, but not into being simply nor qua being, nor
do they offer any discussion of the essence of the things of
which they treat; but starting from the essence - some making
it plain to the senses, others assuming it as a hypothesis - they
then demonstrate, more or less cogently, the essential attributes
of the genus with which they deal. It is obvious, therefore, that
such an induction yields no demonstration of substance or of
the essence, but some other way of exhibiting it. And similarly
the sciences omit the question whether the genus with which
2331
they deal exists or does not exist, because it belongs to the
same kind of thinking to show what it is and that it is.
And since natural science, like other sciences, is in fact about
one class of being, i.e. to that sort of substance which has the
principle of its movement and rest present in itself, evidently it
is neither practical nor productive. For in the case of things
made the principle is in the maker - it is either reason or art or
some faculty, while in the case of things done it is in the doer -
viz. will, for that which is done and that which is willed are the
same. Therefore, if all thought is either practical or productive
or theoretical, physics must be a theoretical science, but it will
theorize about such being as admits of being moved, and about
substance - as defined for the most part only as not separable
from matter. Now, we must not fail to notice the mode of being
of the essence and of its definition, for, without this, inquiry is
but idle. Of things defined, i.e. of 'whats', some are like 'snub',
and some like 'concave'. And these differ because 'snub' is
bound up with matter (for what is snub is a concave nose),
while concavity is independent of perceptible matter. If then all
natural things are a analogous to the snub in their nature; e.g.
nose, eye, face, flesh, bone, and, in general, animal; leaf, root,
bark, and, in general, plant (for none of these can be defined
without reference to movement - they always have matter), it is
clear how we must seek and define the 'what' in the case of
natural objects, and also that it belongs to the student of nature
to study even soul in a certain sense, i.e. so much of it as is not
independent of matter.
That physics, then, is a theoretical science, is plain from these
considerations. Mathematics also, however, is theoretical; but
whether its objects are immovable and separable from matter, is
not at present clear; still, it is clear that some mathematical
theorems consider them qua immovable and qua separable
from matter. But if there is something which is eternal and
2332
immovable and separable, clearly the knowledge of it belongs to
a theoretical science, - not, however, to physics (for physics
deals with certain movable things) nor to mathematics, but to a
science prior to both. For physics deals with things which exist
separately but are not immovable, and some parts of
mathematics deal with things which are immovable but
presumably do not exist separately, but as embodied in matter;
while the first science deals with things which both exist
separately and are immovable. Now all causes must be eternal,
but especially these; for they are the causes that operate on so
much of the divine as appears to us. There must, then, be three
theoretical philosophies, mathematics, physics, and what we
may call theology, since it is obvious that if the divine is present
anywhere, it is present in things of this sort. And the highest
science must deal with the highest genus. Thus, while the
theoretical sciences are more to be desired than the other
sciences, this is more to be desired than the other theoretical
sciences. For one might raise the question whether first
philosophy is universal, or deals with one genus, i.e. some one
kind of being; for not even the mathematical sciences are all
alike in this respect, - geometry and astronomy deal with a
certain particular kind of thing, while universal mathematics
applies alike to all. We answer that if there is no substance
other than those which are formed by nature, natural science
will be the first science; but if there is an immovable substance,
the science of this must be prior and must be first philosophy,
and universal in this way, because it is first. And it will belong to
this to consider being qua being - both what it is and the
attributes which belong to it qua being.
2333
But since the unqualified term 'being' has several meanings, of
which one was seen' to be the accidental, and another the true
('non-being' being the false), while besides these there are the
figures of predication (e.g. the 'what', quality, quantity, place,
time, and any similar meanings which 'being' may have), and
again besides all these there is that which 'is' potentially or
actually: - since 'being' has many meanings, we must say
regarding the accidental, that there can be no scientific
treatment of it. This is confirmed by the fact that no science
practical, productive, or theoretical troubles itself about it. For
on the one hand he who produces a house does not produce all
the attributes that come into being along with the house; for
these are innumerable; the house that has been made may
quite well be pleasant for some people, hurtful for some, and
useful to others, and different - to put it shortly from all things
that are; and the science of building does not aim at producing
any of these attributes. And in the same way the geometer does
not consider the attributes which attach thus to figures, nor
whether 'triangle' is different from 'triangle whose angles are
equal to two right angles'. -And this happens naturally enough;
for the accidental is practically a mere name. And so Plato was
in a sense not wrong in ranking sophistic as dealing with that
which is not. For the arguments of the sophists deal, we may
say, above all with the accidental; e.g. the question whether
'musical' and 'lettered' are different or the same, and whether
'musical Coriscus' and 'Coriscus' are the same, and whether
'everything which is, but is not eternal, has come to be', with
the paradoxical conclusion that if one who was musical has
come to be lettered, he must also have been lettered and have
come to be musical, and all the other arguments of this sort; the
accidental is obviously akin to non-being. And this is clear also
from arguments such as the following: things which are in
another sense come into being and pass out of being by a
2334
process, but things which are accidentally do not. But still we
must, as far as we can, say further, regarding the accidental,
what its nature is and from what cause it proceeds; for it will
perhaps at the same time become clear why there is no science
of it.
Since, among things which are, some are always in the same
state and are of necessity (not necessity in the sense of
compulsion but that which we assert of things because they
cannot be otherwise), and some are not of necessity nor always,
but for the most part, this is the principle and this the cause of
the existence of the accidental; for that which is neither always
nor for the most part, we call accidental. For instance, if in the
dog-days there is wintry and cold weather, we say this is an
accident, but not if there is sultry heat, because the latter is
always or for the most part so, but not the former. And it is an
accident that a man is pale (for this is neither always nor for the
most part so), but it is not by accident that he is an animal. And
that the builder produces health is an accident, because it is the
nature not of the builder but of the doctor to do this, - but the
builder happened to be a doctor. Again, a confectioner, aiming
at giving pleasure, may make something wholesome, but not in
virtue of the confectioner's art; and therefore we say 'it was an
accident', and while there is a sense in which he makes it, in
the unqualified sense he does not. For to other things answer
faculties productive of them, but to accidental results there
corresponds no determinate art nor faculty; for of things which
are or come to be by accident, the cause also is accidental.
Therefore, since not all things either are or come to be of
necessity and always, but, the majority of things are for the
most part, the accidental must exist; for instance a pale man is
not always nor for the most part musical, but since this
sometimes happens, it must be accidental (if not, everything
will be of necessity). The matter, therefore, which is capable of
being otherwise than as it usually is, must be the cause of the
2335
accidental. And we must take as our starting-point the question
whether there is nothing that is neither always nor for the most
part. Surely this is impossible. There is, then, besides these
something which is fortuitous and accidental. But while the
usual exists, can nothing be said to be always, or are there
eternal things? This must be considered later,' but that there is
no science of the accidental is obvious; for all science is either
of that which is always or of that which is for the most part. (For
how else is one to learn or to teach another? The thing must be
determined as occurring either always or for the most part, e.g.
that honey-water is useful for a patient in a fever is true for the
most part.) But that which is contrary to the usual law science
will be unable to state, i.e. when the thing does not happen,
e.g.'on the day of new moon'; for even that which happens on
the day of new moon happens then either always or for the
most part; but the accidental is contrary to such laws. We have
stated, then, what the accidental is, and from what cause it
arises, and that there is no science which deals with it.
That there are principles and causes which are generable and
destructible without ever being in course of being generated or
destroyed, is obvious. For otherwise all things will be of
necessity, since that which is being generated or destroyed
must have a cause which is not accidentally its cause. Will A
exist or not? It will if B happens; and if not, not. And B will exist
if C happens. And thus if time is constantly subtracted from a
limited extent of time, one will obviously come to the present.
This man, then, will die by violence, if he goes out; and he will
do this if he gets thirsty; and he will get thirsty if something
else happens; and thus we shall come to that which is now
2336
present, or to some past event. For instance, he will go out if he
gets thirsty; and he will get thirsty if he is eating pungent food;
and this is either the case or not; so that he will of necessity die,
or of necessity not die. And similarly if one jumps over to past
events, the same account will hold good; for this - I mean the
past condition - is already present in something. Everything,
therefore, that will be, will be of necessity; e.g. it is necessary
that he who lives shall one day die; for already some condition
has come into existence, e.g. the presence of contraries in the
same body. But whether he is to die by disease or by violence is
not yet determined, but depends on the happening of
something else. Clearly then the process goes back to a certain
starting-point, but this no longer points to something further.
This then will be the starting-point for the fortuitous, and will
have nothing else as cause of its coming to be. But to what sort
of starting-point and what sort of cause we thus refer the
fortuitous - whether to matter or to the purpose or to the
motive power, must be carefully considered.
Let us dismiss accidental being; for we have sufficiently
determined its nature. But since that which is in the sense of
being true, or is not in the sense of being false, depends on
combination and separation, and truth and falsity together
depend on the allocation of a pair of contradictory judgements
(for the true judgement affirms where the subject and predicate
really are combined, and denies where they are separated, while
the false judgement has the opposite of this allocation; it is
another question, how it happens that we think things together
or apart; by 'together' and 'apart' I mean thinking them so that
there is no succession in the thoughts but they become a unity);
2337
for falsity and truth are not in things - it is not as if the good
were true, and the bad were in itself false - but in thought;
while with regard to simple concepts and 'whats' falsity and
truth do not exist even in thought - this being so, we must
consider later what has to be discussed with regard to that
which is or is not in this sense. But since the combination and
the separation are in thought and not in the things, and that
which is in this sense is a different sort of 'being' from the
things that are in the full sense (for the thought attaches or
removes either the subject's 'what' or its having a certain
quality or quantity or something else), that which is
accidentally and that which is in the sense of being true must
be dismissed. For the cause of the former is indeterminate, and
that of the latter is some affection of the thought, and both are
related to the remaining genus of being, and do not indicate the
existence of any separate class of being. Therefore let these be
dismissed, and let us consider the causes and the principles of
being itself, qua being. (It was clear in our discussion of the
various meanings of terms, that 'being' has several meanings.)
BookZ
There are several senses in which a thing may be said to 'be', as
we pointed out previously in our book on the various senses of
words;' for in one sense the 'being' meant is 'what a thing is' or
2338
a 'this', and in another sense it means a quality or quantity or
one of the other things that are predicated as these are. While
'being' has all these senses, obviously that which 'is' primarily is
the 'what', which indicates the substance of the thing. For when
we say of what quality a thing is, we say that it is good or bad,
not that it is three cubits long or that it is a man; but when we
say what it is, we do not say 'white' or 'hot' or 'three cubits
long', but 'a man' or 'a 'god'. And all other things are said to be
because they are, some of them, quantities of that which is in
this primary sense, others qualities of it, others affections of it,
and others some other determination of it. And so one might
even raise the question whether the words 'to walk', 'to be
healthy', 'to sit' imply that each of these things is existent, and
similarly in any other case of this sort; for none of them is
either self-subsistent or capable of being separated from
substance, but rather, if anything, it is that which walks or sits
or is healthy that is an existent thing. Now these are seen to be
more real because there is something definite which underlies
them (i.e. the substance or individual), which is implied in such
a predicate; for we never use the word 'good' or 'sitting' without
implying this. Clearly then it is in virtue of this category that
each of the others also is. Therefore that which is primarily, i.e.
not in a qualified sense but without qualification, must be
substance.
Now there are several senses in which a thing is said to be first;
yet substance is first in every sense - (1) in definition, (2) in
order of knowledge, (3) in time. For (3) of the other categories
none can exist independently, but only substance. And (1) in
definition also this is first; for in the definition of each term the
definition of its substance must be present. And (2) we think we
know each thing most fully, when we know what it is, e.g. what
man is or what fire is, rather than when we know its quality, its
quantity, or its place; since we know each of these predicates
also, only when we know what the quantity or the quality is.
2339
And indeed the question which was raised of old and is raised
now and always, and is always the subject of doubt, viz. what
being is, is just the question, what is substance? For it is this
that some assert to be one, others more than one, and that
some assert to be limited in number, others unlimited. And so
we also must consider chiefly and primarily and almost
exclusively what that is which is in this sense.
Substance is thought to belong most obviously to bodies; and so
we say that not only animals and plants and their parts are
substances, but also natural bodies such as fire and water and
earth and everything of the sort, and all things that are either
parts of these or composed of these (either of parts or of the
whole bodies), e.g. the physical universe and its parts, stars and
moon and sun. But whether these alone are substances, or there
are also others, or only some of these, or others as well, or none
of these but only some other things, are substances, must be
considered. Some think the limits of body, i.e. surface, line,
point, and unit, are substances, and more so than body or the
solid.
Further, some do not think there is anything substantial besides
sensible things, but others think there are eternal substances
which are more in number and more real; e.g. Plato posited two
kinds of substance - the Forms and objects of mathematics - as
well as a third kind, viz. the substance of sensible bodies. And
Speusippus made still more kinds of substance, beginning with
the One, and assuming principles for each kind of substance,
one for numbers, another for spatial magnitudes, and then
another for the soul; and by going on in this way he multiplies
2340
the kinds of substance. And some say Forms and numbers have
the same nature, and the other things come after them - lines
and planes - until we come to the substance of the material
universe and to sensible bodies.
Regarding these matters, then, we must inquire which of the
common statements are right and which are not right, and
what substances there are, and whether there are or are not any
besides sensible substances, and how sensible substances exist,
and whether there is a substance capable of separate existence
(and if so why and how) or no such substance, apart from
sensible substances; and we must first sketch the nature of
substance.
The word 'substance' is applied, if not in more senses, still at
least to four main objects; for both the essence and the
universal and the genus, are thought to be the substance of
each thing, and fourthly the substratum. Now the substratum is
that of which everything else is predicated, while it is itself not
predicated of anything else. And so we must first determine the
nature of this; for that which underlies a thing primarily is
thought to be in the truest sense its substance. And in one
sense matter is said to be of the nature of substratum, in
another, shape, and in a third, the compound of these. (By the
matter I mean, for instance, the bronze, by the shape the
pattern of its form, and by the compound of these the statue,
the concrete whole.) Therefore if the form is prior to the matter
and more real, it will be prior also to the compound of both, for
the same reason.
2341
We have now outlined the nature of substance, showing that it
is that which is not predicated of a stratum, but of which all
else is predicated. But we must not merely state the matter
thus; for this is not enough. The statement itself is obscure, and
further, on this view, matter becomes substance. For if this is
not substance, it baffles us to say what else is. When all else is
stripped off evidently nothing but matter remains. For while the
rest are affections, products, and potencies of bodies, length,
breadth, and depth are quantities and not substances (for a
quantity is not a substance), but the substance is rather that to
which these belong primarily. But when length and breadth and
depth are taken away we see nothing left unless there is
something that is bounded by these; so that to those who
consider the question thus matter alone must seem to be
substance. By matter I mean that which in itself is neither a
particular thing nor of a certain quantity nor assigned to any
other of the categories by which being is determined. For there
is something of which each of these is predicated, whose being
is different from that of each of the predicates (for the
predicates other than substance are predicated of substance,
while substance is predicated of matter). Therefore the ultimate
substratum is of itself neither a particular thing nor of a
particular quantity nor otherwise positively characterized; nor
yet is it the negations of these, for negations also will belong to
it only by accident.
If we adopt this point of view, then, it follows that matter is
substance. But this is impossible; for both separability and
'thisness' are thought to belong chiefly to substance. And so
form and the compound of form and matter would be thought
to be substance, rather than matter. The substance
compounded of both, i.e. of matter and shape, may be
dismissed; for it is posterior and its nature is obvious. And
matter also is in a sense manifest. But we must inquire into the
third kind of substance; for this is the most perplexing.
2342
Some of the sensible substances are generally admitted to be
substances, so that we must look first among these. For it is an
advantage to advance to that which is more knowable. For
learning proceeds for all in this way - through that which is less
knowable by nature to that which is more knowable; and just as
in conduct our task is to start from what is good for each and
make what is without qualification good good for each, so it is
our task to start from what is more knowable to oneself and
make what is knowable by nature knowable to oneself. Now
what is knowable and primary for particular sets of people is
often knowable to a very small extent, and has little or nothing
of reality. But yet one must start from that which is barely
knowable but knowable to oneself, and try to know what is
knowable without qualification, passing, as has been said, by
way of those very things which one does know.
Since at the start we distinguished the various marks by which
we determine substance, and one of these was thought to be
the essence, we must investigate this. And first let us make
some linguistic remarks about it. The essence of each thing is
what it is said to be propter se. For being you is not being
musical, since you are not by your very nature musical. What,
then, you are by your very nature is your essence.
Nor yet is the whole of this the essence of a thing; not that
which is propter se as white is to a surface, because being a
surface is not identical with being white. But again the
combination of both - 'being a white surface' - is not the
essence of surface, because 'surface' itself is added. The
formula, therefore, in which the term itself is not present but its
2343
meaning is expressed, this is the formula of the essence of each
thing. Therefore if to be a white surface is to be a smooth
surface, to be white and to be smooth are one and the same.
But since there are also compounds answering to the other
categories (for there is a substratum for each category, e.g. for
quality, quantity, time, place, and motion), we must inquire
whether there is a formula of the essence of each of them, i.e.
whether to these compounds also there belongs an essence, e.g.
'white man'. Let the compound be denoted by 'cloak'. What is
the essence of cloak? But, it may be said, this also is not a
propter se expression. We reply that there are just two ways in
which a predicate may fail to be true of a subject propter se, and
one of these results from the addition, and the other from the
omission, of a determinant. One kind of predicate is not propter
se because the term that is being defined is combined with
another determinant, e.g. if in defining the essence of white one
were to state the formula of white man; the other because in
the subject another determinant is combined with that which is
expressed in the formula, e.g. if 'cloak' meant 'white man', and
one were to define cloak as white; white man is white indeed,
but its essence is not to be white.
But is being-a-cloak an essence at all? Probably not. For the
essence is precisely what something is; but when an attribute is
asserted of a subject other than itself, the complex is not
precisely what some 'this' is, e.g. white man is not precisely
what some 'this' is, since thisness belongs only to substances.
Therefore there is an essence only of those things whose
formula is a definition. But we have a definition not where we
have a word and a formula identical in meaning (for in that case
all formulae or sets of words would be definitions; for there will
be some name for any set of words whatever, so that even the
Iliad will be a definition), but where there is a formula of
something primary; and primary things are those which do not
2344
imply the predication of one element in them of another
element. Nothing, then, which is not a species of a genus will
have an essence - only species will have it, for these are thought
to imply not merely that the subject participates in the attribute
and has it as an affection, or has it by accident; but for ever
thing else as well, if it has a name, there be a formula of its
meaning - viz. that this attribute belongs to this subject; or
instead of a simple formula we shall be able to give a more
accurate one; but there will be no definition nor essence.
Or has 'definition', like 'what a thing is', several meanings?
'What a thing is' in one sense means substance and the 'this', in
another one or other of the predicates, quantity, quality, and the
like. For as 'is' belongs to all things, not however in the same
sense, but to one sort of thing primarily and to others in a
secondary way, so too 'what a thing is' belongs in the simple
sense to substance, but in a limited sense to the other
categories. For even of a quality we might ask what it is, so that
quality also is a 'what a thing is', - not in the simple sense,
however, but just as, in the case of that which is not, some say,
emphasizing the linguistic form, that that is which is not is-not
is simply, but is non-existent; so too with quality.
We must no doubt inquire how we should express ourselves on
each point, but certainly not more than how the facts actually
stand. And so now also, since it is evident what language we
use, essence will belong, just as 'what a thing is' does, primarily
and in the simple sense to substance, and in a secondary way to
the other categories also, - not essence in the simple sense, but
the essence of a quality or of a quantity. For it must be either by
an equivocation that we say these are, or by adding to and
taking from the meaning of 'are' (in the way in which that
which is not known may be said to be known), - the truth being
that we use the word neither ambiguously nor in the same
sense, but just as we apply the word 'medical' by virtue of a
2345
reference to one and the same thing, not meaning one and the
same thing, nor yet speaking ambiguously; for a patient and an
operation and an instrument are called medical neither by an
ambiguity nor with a single meaning, but with reference to a
common end. But it does not matter at all in which of the two
ways one likes to describe the facts; this is evident, that
definition and essence in the primary and simple sense belong
to substances. Still they belong to other things as well, only not
in the primary sense. For if we suppose this it does not follow
that there is a definition of every word which means the same
as any formula; it must mean the same as a particular kind of
formula; and this condition is satisfied if it is a formula of
something which is one, not by continuity like the Iliad or the
things that are one by being bound together, but in one of the
main senses of 'one', which answer to the senses of 'is'; now
'that which is' in one sense denotes a 'this', in another a
quantity, in another a quality. And so there can be a formula or
definition even of white man, but not in the sense in which
there is a definition either of white or of a substance.
It is a difficult question, if one denies that a formula with an
added determinant is a definition, whether any of the terms
that are not simple but coupled will be definable. For we must
explain them by adding a determinant. E.g. there is the nose,
and concavity, and snubness, which is compounded out of the
two by the presence of the one in the other, and it is not by
accident that the nose has the attribute either of concavity or of
snubness, but in virtue of its nature; nor do they attach to it as
whiteness does to Callias, or to man (because Callias, who
happens to be a man, is white), but as 'male' attaches to animal
2346
and 'equal' to quantity, and as all so-called 'attributes propter
se' attach to their subjects. And such attributes are those in
which is involved either the formula or the name of the subject
of the particular attribute, and which cannot be explained
without this; e.g. white can be explained apart from man, but
not female apart from animal. Therefore there is either no
essence and definition of any of these things, or if there is, it is
in another sense, as we have said.
But there is also a second difficulty about them. For if snub nose
and concave nose are the same thing, snub and concave will be
the thing; but if snub and concave are not the same (because it
is impossible to speak of snubness apart from the thing of
which it is an attribute propter se, for snubness is concavity-in-
a-nose), either it is impossible to say 'snub nose' or the same
thing will have been said twice, concave-nose nose; for snub
nose will be concave-nose nose. And so it is absurd that such
things should have an essence; if they have, there will be an
infinite regress; for in snub-nose nose yet another 'nose' will be
involved.
Clearly, then, only substance is definable. For if the other
categories also are definable, it must be by addition of a
determinant, e.g. the qualitative is defined thus, and so is the
odd, for it cannot be defined apart from number; nor can female
be defined apart from animal. (When I say 'by addition' I mean
the expressions in which it turns out that we are saying the
same thing twice, as in these instances.) And if this is true,
coupled terms also, like 'odd number', will not be definable (but
this escapes our notice because our formulae are not accurate.).
But if these also are definable, either it is in some other way or,
as we definition and essence must be said to have more than
one sense. Therefore in one sense nothing will have a definition
and nothing will have an essence, except substances, but in
another sense other things will have them. Clearly, then,
2347
definition is the formula of the essence, and essence belongs to
substances either alone or chiefly and primarily and in the
unqualified sense.
We must inquire whether each thing and its essence are the
same or different. This is of some use for the inquiry concerning
substance; for each thing is thought to be not different from its
substance, and the essence is said to be the substance of each
thing.
Now in the case of accidental unities the two would be
generally thought to be different, e.g. white man would be
thought to be different from the essence of white man. For if
they are the same, the essence of man and that of white man
are also the same; for a man and a white man are the same
thing, as people say, so that the essence of white man and that
of man would be also the same. But perhaps it does not follow
that the essence of accidental unities should be the same as
that of the simple terms. For the extreme terms are not in the
same way identical with the middle term. But perhaps this
might be thought to follow, that the extreme terms, the
accidents, should turn out to be the same, e.g. the essence of
white and that of musical; but this is not actually thought to be
the case.
But in the case of so-called self-subsistent things, is a thing
necessarily the same as its essence? E.g. if there are some
substances which have no other substances nor entities prior to
them - substances such as some assert the Ideas to be? - If the
essence of good is to be different from good-itself, and the
essence of animal from animal-itself, and the essence of being
2348
from being-itself, there will, firstly, be other substances and
entities and Ideas besides those which are asserted, and,
secondly, these others will be prior substances, if essence is
substance. And if the posterior substances and the prior are
severed from each other, (a) there will be no knowledge of the
former, and (b) the latter will have no being. (By 'severed' I
mean, if the good-itself has not the essence of good, and the
latter has not the property of being good.) For (a) there is
knowledge of each thing only when we know its essence. And
(b) the case is the same for other things as for the good; so that
if the essence of good is not good, neither is the essence of
reality real, nor the essence of unity one. And all essences alike
exist or none of them does; so that if the essence of reality is
not real, neither is any of the others. Again, that to which the
essence of good does not belong is not good. - The good, then,
must be one with the essence of good, and the beautiful with
the essence of beauty, and so with all things which do not
depend on something else but are self-subsistent and primary.
For it is enough if they are this, even if they are not Forms; or
rather, perhaps, even if they are Forms. (At the same time it is
clear that if there are Ideas such as some people say there are, it
will not be substratum that is substance; for these must be
substances, but not predicable of a substratum; for if they were
they would exist only by being participated in.)
Each thing itself, then, and its essence are one and the same in
no merely accidental way, as is evident both from the preceding
arguments and because to know each thing, at least, is just to
know its essence, so that even by the exhibition of instances it
becomes clear that both must be one.
(But of an accidental term, e.g.'the musical' or 'the white', since
it has two meanings, it is not true to say that it itself is identical
with its essence; for both that to which the accidental quality
belongs, and the accidental quality, are white, so that in a sense
2349
the accident and its essence are the same, and in a sense they
are not; for the essence of white is not the same as the man or
the white man, but it is the same as the attribute white.)
The absurdity of the separation would appear also if one were
to assign a name to each of the essences; for there would be yet
another essence besides the original one, e.g. to the essence of
horse there will belong a second essence. Yet why should not
some things be their essences from the start, since essence is
substance? But indeed not only are a thing and its essence one,
but the formula of them is also the same, as is clear even from
what has been said; for it is not by accident that the essence of
one, and the one, are one. Further, if they are to be different, the
process will go on to infinity; for we shall have (1) the essence of
one, and (2) the one, so that to terms of the former kind the
same argument will be applicable.
Clearly, then, each primary and self-subsistent thing is one and
the same as its essence. The sophistical objections to this
position, and the question whether Socrates and to be Socrates
are the same thing, are obviously answered by the same
solution; for there is no difference either in the standpoint from
which the question would be asked, or in that from which one
could answer it successfully. We have explained, then, in what
sense each thing is the same as its essence and in what sense it
is not.
Of things that come to be, some come to be by nature, some by
art, some spontaneously. Now everything that comes to be
comes to be by the agency of something and from something
and comes to be something. And the something which I say it
2350
comes to be may be found in any category; it may come to be
either a 'this' or of some size or of some quality or somewhere.
Now natural comings to be are the comings to be of those
things which come to be by nature; and that out of which they
come to be is what we call matter; and that by which they come
to be is something which exists naturally; and the something
which they come to be is a man or a plant or one of the things
of this kind, which we say are substances if anything is - all
things produced either by nature or by art have matter; for each
of them is capable both of being and of not being, and this
capacity is the matter in each - and, in general, both that from
which they are produced is nature, and the type according to
which they are produced is nature (for that which is produced,
e.g. a plant or an animal, has a nature), and so is that by which
they are produced - the so-called 'formal' nature, which is
specifically the same (though this is in another individual); for
man begets man.
Thus, then, are natural products produced; all other productions
are called 'makings'. And all makings proceed either from art or
from a faculty or from thought. Some of them happen also
spontaneously or by luck just as natural products sometimes
do; for there also the same things sometimes are produced
without seed as well as from seed. Concerning these cases,
then, we must inquire later, but from art proceed the things of
which the form is in the soul of the artist. (By form I mean the
essence of each thing and its primary substance.) For even
contraries have in a sense the same form; for the substance of a
privation is the opposite substance, e.g. health is the substance
of disease (for disease is the absence of health); and health is
the formula in the soul or the knowledge of it. The healthy
subject is produced as the result of the following train of
thought: - since this is health, if the subject is to be healthy this
must first be present, e.g. a uniform state of body, and if this is
2351
to be present, there must be heat; and the physician goes on
thinking thus until he reduces the matter to a final something
which he himself can produce. Then the process from this point
onward, i.e. the process towards health, is called a 'making'.
Therefore it follows that in a sense health comes from health
and house from house, that with matter from that without
matter; for the medical art and the building art are the form of
health and of the house, and when I speak of substance without
matter I mean the essence.
Of the productions or processes one part is called thinking and
the other making, - that which proceeds from the starting-point
and the form is thinking, and that which proceeds from the
final step of the thinking is making. And each of the other,
intermediate, things is produced in the same way. I mean, for
instance, if the subject is to be healthy his bodily state must be
made uniform. What then does being made uniform imply?
This or that. And this depends on his being made warm. What
does this imply? Something else. And this something is present
potentially; and what is present potentially is already in the
physician's power.
The active principle then and the starting point for the process
of becoming healthy is, if it happens by art, the form in the soul,
and if spontaneously, it is that, whatever it is, which starts the
making, for the man who makes by art, as in healing the
starting-point is perhaps the production of warmth (and this
the physician produces by rubbing). Warmth in the body, then, is
either a part of health or is followed (either directly or through
several intermediate steps) by something similar which is a part
of health; and this, viz. that which produces the part of health,
is the limiting-point - and so too with a house (the stones are
the limiting-point here) and in all other cases. Therefore, as the
saying goes, it is impossible that anything should be produced if
there were nothing existing before. Obviously then some part of
2352
the result will pre-exist of necessity; for the matter is a part; for
this is present in the process and it is this that becomes
something. But is the matter an element even in the formula?
We certainly describe in both ways what brazen circles are; we
describe both the matter by saying it is brass, and the form by
saying that it is such and such a figure; and figure is the
proximate genus in which it is placed. The brazen circle, then,
has its matter in its formula.
As for that out of which as matter they are produced, some
things are said, when they have been produced, to be not that
but 'thaten'; e.g. the statue is not gold but golden. And a healthy
man is not said to be that from which he has come. The reason
is that though a thing comes both from its privation and from
its substratum, which we call its matter (e.g. what becomes
healthy is both a man and an invalid), it is said to come rather
from its privation (e.g. it is from an invalid rather than from a
man that a healthy subject is produced). And so the healthy
subject is not said to he an invalid, but to be a man, and the
man is said to be healthy. But as for the things whose privation
is obscure and nameless, e.g. in brass the privation of a
particular shape or in bricks and timber the privation of
arrangement as a house, the thing is thought to be produced
from these materials, as in the former case the healthy man is
produced from an invalid. And so, as there also a thing is not
said to be that from which it comes, here the statue is not said
to be wood but is said by a verbal change to be wooden, not
brass but brazen, not gold but golden, and the house is said to
be not bricks but bricken (though we should not say without
qualification, if we looked at the matter carefully, even that a
statue is produced from wood or a house from bricks, because
coming to be implies change in that from which a thing comes
to be, and not permanence). It is for this reason, then, that we
use this way of speaking.
2353
8
Since anything which is produced is produced by something
(and this I call the starting-point of the production), and from
something (and let this be taken to be not the privation but the
matter; for the meaning we attach to this has already been
explained), and since something is produced (and this is either
a sphere or a circle or whatever else it may chance to be), just as
we do not make the substratum (the brass), so we do not make
the sphere, except incidentally, because the brazen sphere is a
sphere and we make the forme. For to make a 'this' is to make a
'this' out of the substratum in the full sense of the word. (I
mean that to make the brass round is not to make the round or
the sphere, but something else, i.e. to produce this form in
something different from itself. For if we make the form, we
must make it out of something else; for this was assumed. E.g.
we make a brazen sphere; and that in the sense that out of this,
which is brass, we make this other, which is a sphere.) If, then,
we also make the substratum itself, clearly we shall make it in
the same way, and the processes of making will regress to
infinity. Obviously then the form also, or whatever we ought to
call the shape present in the sensible thing, is not produced, nor
is there any production of it, nor is the essence produced; for
this is that which is made to be in something else either by art
or by nature or by some faculty. But that there is a brazen
sphere, this we make. For we make it out of brass and the
sphere; we bring the form into this particular matter, and the
result is a brazen sphere. But if the essence of sphere in general
is to be produced, something must be produced out of
something. For the product will always have to be divisible, and
one part must be this and another that; I mean the one must be
2354
matter and the other form. If, then, a sphere is 'the figure whose
circumference is at all points equidistant from the centre', part
of this will be the medium in which the thing made will be, and
part will be in that medium, and the whole will be the thing
produced, which corresponds to the brazen sphere. It is obvious,
then, from what has been said, that that which is spoken of as
form or substance is not produced, but the concrete thing which
gets its name from this is produced, and that in everything
which is generated matter is present, and one part of the thing
is matter and the other form.
Is there, then, a sphere apart from the individual spheres or a
house apart from the bricks? Rather we may say that no 'this'
would ever have been coming to be, if this had been so, but that
the 'form' means the 'such', and is not a 'this' - a definite thing;
but the artist makes, or the father begets, a 'such' out of a 'this';
and when it has been begotten, it is a 'this such'. And the whole
'this', Callias or Socrates, is analogous to 'this brazen sphere',
but man and animal to 'brazen sphere' in general. Obviously,
then, the cause which consists of the Forms (taken in the sense
in which some maintain the existence of the Forms, i.e. if they
are something apart from the individuals) is useless, at least
with regard to comings-to-be and to substances; and the Forms
need not, for this reason at least, be self-subsistent substances.
In some cases indeed it is even obvious that the begetter is of
the same kind as the begotten (not, however, the same nor one
in number, but in form), i.e. in the case of natural products (for
man begets man), unless something happens contrary to
nature, e.g. the production of a mule by a horse. (And even these
cases are similar; for that which would be found to be common
to horse and ass, the genus next above them, has not received a
name, but it would doubtless be both in fact something like a
mule.) Obviously, therefore, it is quite unnecessary to set up a
Form as a pattern (for we should have looked for Forms in these
cases if in any; for these are substances if anything is so); the
2355
begetter is adequate to the making of the product and to the
causing of the form in the matter. And when we have the whole,
such and such a form in this flesh and in these bones, this is
Callias or Socrates; and they are different in virtue of their
matter (for that is different), but the same in form; for their
form is indivisible.
The question might be raised, why some things are produced
spontaneously as well as by art, e.g. health, while others are not,
e.g. a house. The reason is that in some cases the matter which
governs the production in the making and producing of any
work of art, and in which a part of the product is present, -
some matter is such as to be set in motion by itself and some is
not of this nature, and of the former kind some can move itself
in the particular way required, while other matter is incapable
of this; for many things can be set in motion by themselves but
not in some particular way, e.g. that of dancing. The things,
then, whose matter is of this sort, e.g. stones, cannot be moved
in the particular way required, except by something else, but in
another way they can move themselves - and so it is with fire.
Therefore some things will not exist apart from some one who
has the art of making them, while others will; for motion will be
started by these things which have not the art but can
themselves be moved by other things which have not the art or
with a motion starting from a part of the product.
And it is clear also from what has been said that in a sense
every product of art is produced from a thing which shares its
name (as natural products are produced), or from a part of itself
which shares its name (e.g. the house is produced from a house,
2356
qua produced by reason; for the art of building is the form of
the house), or from something which contains a art of it, - if we
exclude things produced by accident; for the cause of the thing's
producing the product directly per se is a part of the product.
The heat in the movement caused heat in the body, and this is
either health, or a part of health, or is followed by a part of
health or by health itself. And so it is said to cause health,
because it causes that to which health attaches as a
consequence.
Therefore, as in syllogisms, substance is the starting-point of
everything. It is from 'what a thing is' that syllogisms start; and
from it also we now find processes of production to start.
Things which are formed by nature are in the same case as
these products of art. For the seed is productive in the same
way as the things that work by art; for it has the form
potentially, and that from which the seed comes has in a sense
the same name as the offspring only in a sense, for we must not
expect parent and offspring always to have exactly the same
name, as in the production of 'human being' from 'human' for a
'woman' also can be produced by a 'man' - unless the offspring
be an imperfect form; which is the reason why the parent of a
mule is not a mule. The natural things which (like the artificial
objects previously considered) can be produced spontaneously
are those whose matter can be moved even by itself in the way
in which the seed usually moves it; those things which have not
such matter cannot be produced except from the parent
animals themselves.
But not only regarding substance does our argument prove that
its form does not come to be, but the argument applies to all the
primary classes alike, i.e. quantity, quality, and the other
categories. For as the brazen sphere comes to be, but not the
sphere nor the brass, and so too in the case of brass itself, if it
2357
comes to be, it is its concrete unity that comes to be (for the
matter and the form must always exist before), so is it both in
the case of substance and in that of quality and quantity and
the other categories likewise; for the quality does not come to
be, but the wood of that quality, and the quantity does not come
to be, but the wood or the animal of that size. But we may learn
from these instances a peculiarity of substance, that there must
exist beforehand in complete reality another substance which
produces it, e.g. an animal if an animal is produced; but it is not
necessary that a quality or quantity should pre-exist otherwise
than potentially.
10
Since a definition is a formula, and every formula has parts, and
as the formula is to the thing, so is the part of the formula to
the part of the thing, the question is already being asked
whether the formula of the parts must be present in the
formula of the whole or not. For in some cases the formulae of
the parts are seen to be present, and in some not. The formula
of the circle does not include that of the segments, but that of
the syllable includes that of the letters; yet the circle is divided
into segments as the syllable is into letters. - And further if the
parts are prior to the whole, and the acute angle is a part of the
right angle and the finger a part of the animal, the acute angle
will be prior to the right angle and finger to the man. But the
latter are thought to be prior; for in formula the parts are
explained by reference to them, and in respect also of the power
of existing apart from each other the wholes are prior to the
parts.
2358
Perhaps we should rather say that 'part' is used in several
senses. One of these is 'that which measures another thing in
respect of quantity'. But let this sense be set aside; let us inquire
about the parts of which substance consists. If then matter is
one thing, form another, the compound of these a third, and
both the matter and the form and the compound are substance
even the matter is in a sense called part of a thing, while in a
sense it is not, but only the elements of which the formula of
the form consists. E.g. of concavity flesh (for this is the matter
in which it is produced) is not a part, but of snubness it is a part;
and the bronze is a part of the concrete statue, but not of the
statue when this is spoken of in the sense of the form. (For the
form, or the thing as having form, should be said to be the
thing, but the material element by itself must never be said to
be so.) And so the formula of the circle does not include that of
the segments, but the formula of the syllable includes that of
the letters; for the letters are parts of the formula of the form,
and not matter, but the segments are parts in the sense of
matter on which the form supervenes; yet they are nearer the
form than the bronze is when roundness is produced in bronze.
But in a sense not even every kind of letter will be present in the
formula of the syllable, e.g. particular waxen letters or the
letters as movements in the air; for in these also we have
already something that is part of the syllable only in the sense
that it is its perceptible matter. For even if the line when divided
passes away into its halves, or the man into bones and muscles
and flesh, it does not follow that they are composed of these as
parts of their essence, but rather as matter; and these are parts
of the concrete thing, but not also of the form, i.e. of that to
which the formula refers; wherefore also they are not present in
the formulae. In one kind of formula, then, the formula of such
parts will be present, but in another it must not be present,
where the formula does not refer to the concrete object. For it is
for this reason that some things have as their constituent
2359
principles parts into which they pass away, while some have
not. Those things which are the form and the matter taken
together, e.g. the snub, or the bronze circle, pass away into these
materials, and the matter is a part of them; but those things
which do not involve matter but are without matter, and whose
formulae are formulae of the form only, do not pass away, -
either not at all or at any rate not in this way. Therefore these
materials are principles and parts of the concrete things, while
of the form they are neither parts nor principles. And therefore
the clay statue is resolved into clay and the ball into bronze and
Callias into flesh and bones, and again the circle into its
segments; for there is a sense of 'circle' in which involves
matter. For 'circle' is used ambiguously, meaning both the circle,
unqualified, and the individual circle, because there is no name
peculiar to the individuals.
The truth has indeed now been stated, but still let us state it yet
more clearly, taking up the question again. The parts of the
formula, into which the formula is divided, are prior to it, either
all or some of them. The formula of the right angle, however,
does not include the formula of the acute, but the formula of
the acute includes that of the right angle; for he who defines
the acute uses the right angle; for the acute is 'less than a right
angle'. The circle and the semicircle also are in a like relation;
for the semicircle is defined by the circle; and so is the finger by
the whole body, for a finger is 'such and such a part of a man'.
Therefore the parts which are of the nature of matter, and into
which as its matter a thing is divided, are posterior; but those
which are of the nature of parts of the formula, and of the
substance according to its formula, are prior, either all or some
of them. And since the soul of animals (for this is the substance
of a living being) is their substance according to the formula, i.e.
the form and the essence of a body of a certain kind (at least we
shall define each part, if we define it well, not without reference
to its function, and this cannot belong to it without perception),
2360
so that the parts of soul are prior, either all or some of them, to
the concrete 'animal', and so too with each individual animal;
and the body and parts are posterior to this, the essential
substance, and it is not the substance but the concrete thing
that is divided into these parts as its matter: - this being so, to
the concrete thing these are in a sense prior, but in a sense they
are not. For they cannot even exist if severed from the whole;
for it is not a finger in any and every state that is the finger of a
living thing, but a dead finger is a finger only in name. Some
parts are neither prior nor posterior to the whole, i.e. those
which are dominant and in which the formula, i.e. the essential
substance, is immediately present, e.g. perhaps the heart or the
brain; for it does not matter in the least which of the two has
this quality. But man and horse and terms which are thus
applied to individuals, but universally, are not substance but
something composed of this particular formula and this
particular matter treated as universal; and as regards the
individual, Socrates already includes in him ultimate individual
matter; and similarly in all other cases. 'A part' may be a part
either of the form (i.e. of the essence), or of the compound of
the form and the matter, or of the matter itself. But only the
parts of the form are parts of the formula, and the formula is of
the universal; for 'being a circle' is the same as the circle, and
'being a soul' the same as the soul. But when we come to the
concrete thing, e.g. this circle, i.e. one of the individual circles,
whether perceptible or intelligible (I mean by intelligible circles
the mathematical, and by perceptible circles those of bronze
and of wood), - of these there is no definition, but they are
known by the aid of intuitive thinking or of perception; and
when they pass out of this complete realization it is not clear
whether they exist or not; but they are always stated and
recognized by means of the universal formula. But matter is
unknowable in itself. And some matter is perceptible and some
intelligible, perceptible matter being for instance bronze and
2361
wood and all matter that is changeable, and intelligible matter
being that which is present in perceptible things not qua
perceptible, i.e. the objects of mathematics.
We have stated, then, how matters stand with regard to whole
and part, and their priority and posteriority. But when any one
asks whether the right angle and the circle and the animal are
prior, or the things into which they are divided and of which
they consist, i.e. the parts, we must meet the inquiry by saying
that the question cannot be answered simply. For if even bare
soul is the animal or the living thing, or the soul of each
individual is the individual itself, and 'being a circle' is the
circle, and 'being a right angle' and the essence of the right
angle is the right angle, then the whole in one sense must be
called posterior to the art in one sense, i.e. to the parts included
in the formula and to the parts of the individual right angle (for
both the material right angle which is made of bronze, and that
which is formed by individual lines, are posterior to their parts);
while the immaterial right angle is posterior to the parts
included in the formula, but prior to those included in the
particular instance, and the question must not be answered
simply. If, however, the soul is something different and is not
identical with the animal, even so some parts must, as we have
maintained, be called prior and others must not.
11
Another question is naturally raised, viz. what sort of parts
belong to the form and what sort not to the form, but to the
concrete thing. Yet if this is not plain it is not possible to define
any thing; for definition is of the universal and of the form. If
then it is not evident what sort of parts are of the nature of
2362
matter and what sort are not, neither will the formula of the
thing be evident. In the case of things which are found to occur
in specifically different materials, as a circle may exist in bronze
or stone or wood, it seems plain that these, the bronze or the
stone, are no part of the essence of the circle, since it is found
apart from them. Of things which are not seen to exist apart,
there is no reason why the same may not be true, just as if all
circles that had ever been seen were of bronze; for none the less
the bronze would be no part of the form; but it is hard to
eliminate it in thought. E.g. the form of man is always found in
flesh and bones and parts of this kind; are these then also parts
of the form and the formula? No, they are matter; but because
man is not found also in other matters we are unable to
perform the abstraction.
Since this is thought to be possible, but it is not clear when it is
the case, some people already raise the question even in the
case of the circle and the triangle, thinking that it is not right to
define these by reference to lines and to the continuous, but
that all these are to the circle or the triangle as flesh and bones
are to man, and bronze or stone to the statue; and they reduce
all things to numbers, and they say the formula of 'line' is that
of 'two'. And of those who assert the Ideas some make 'two' the
line-itself, and others make it the Form of the line; for in some
cases they say the Form and that of which it is the Form are the
same, e.g. 'two' and the Form of two; but in the case of 'line'
they say this is no longer so.
It follows then that there is one Form for many things whose
form is evidently different (a conclusion which confronted the
Pythagoreans also); and it is possible to make one thing the
Form-itself of all, and to hold that the others are not Forms; but
thus all things will be one.
2363
We have pointed out, then, that the question of definitions
contains some difficulty, and why this is so. And so to reduce all
things thus to Forms and to eliminate the matter is useless
labour; for some things surely are a particular form in a
particular matter, or particular things in a particular state. And
the comparison which Socrates the younger used to make in
the case of 'animal' is not sound; for it leads away from the
truth, and makes one suppose that man can possibly exist
without his parts, as the circle can without the bronze. But the
case is not similar; for an animal is something perceptible, and
it is not possible to define it without reference to movement -
nor, therefore, without reference to the parts' being in a certain
state. For it is not a hand in any and every state that is a part of
man, but only when it can fulfil its work, and therefore only
when it is alive; if it is not alive it is not a part.
Regarding the objects of mathematics, why are the formulae of
the parts not parts of the formulae of the wholes; e.g. why are
not the semicircles included in the formula of the circle? It
cannot be said, 'because these parts are perceptible things'; for
they are not. But perhaps this makes no difference; for even
some things which are not perceptible must have matter;
indeed there is some matter in everything which is not an
essence and a bare form but a 'this'. The semicircles, then, will
not be parts of the universal circle, but will be parts of the
individual circles, as has been said before; for while one kind of
matter is perceptible, there is another which is intelligible.
It is clear also that the soul is the primary substance and the
body is matter, and man or animal is the compound of both
taken universally; and 'Socrates' or 'Coriscus', if even the soul of
Socrates may be called Socrates, has two meanings (for some
mean by such a term the soul, and others mean the concrete
thing), but if 'Socrates' or 'Coriscus' means simply this
2364
particular soul and this particular body, the individual is
analogous to the universal in its composition.
Whether there is, apart from the matter of such substances,
another kind of matter, and one should look for some substance
other than these, e.g. numbers or something of the sort, must be
considered later. For it is for the sake of this that we are trying
to determine the nature of perceptible substances as well, since
in a sense the inquiry about perceptible substances is the work
of physics, i.e. of second philosophy; for the physicist must
come to know not only about the matter, but also about the
substance expressed in the formula, and even more than about
the other. And in the case of definitions, how the elements in
the formula are parts of the definition, and why the definition is
one formula (for clearly the thing is one, but in virtue of what is
the thing one, although it has parts?), - this must be considered
later.
What the essence is and in what sense it is independent, has
been stated universally in a way which is true of every case, and
also why the formula of the essence of some things contains
the parts of the thing defined, while that of others does not.
And we have stated that in the formula of the substance the
material parts will not be present (for they are not even parts of
the substance in that sense, but of the concrete substance; but
of this there is in a sense a formula, and in a sense there is not;
for there is no formula of it with its matter, for this is indefinite,
but there is a formula of it with reference to its primary
substance - e.g. in the case of man the formula of the soul - , for
the substance is the indwelling form, from which and the
matter the so-called concrete substance is derived; e.g.
concavity is a form of this sort, for from this and the nose arise
'snub nose' and 'snubness'); but in the concrete substance, e.g. a
snub nose or Callias, the matter also will be present. And we
have stated that the essence and the thing itself are in some
2365
cases the same; ie. in the case of primary substances, e.g.
curvature and the essence of curvature if this is primary. (By a
'primary' substance I mean one which does not imply the
presence of something in something else, i.e. in something that
underlies it which acts as matter.) But things which are of the
nature of matter, or of wholes that include matter, are not the
same as their essences, nor are accidental unities like that of
'Socrates' and 'musical'; for these are the same only by accident.
12
Now let us treat first of definition, in so far as we have not
treated of it in the Analytics; for the problem stated in them is
useful for our inquiries concerning substance. I mean this
problem: - wherein can consist the unity of that, the formula of
which we call a definition, as for instance, in the case of man,
'two-footed animal'; for let this be the formula of man. Why,
then, is this one, and not many, viz. 'animal' and 'two-footed?
For in the case of 'man' and 'pale' there is a plurality when one
term does not belong to the other, but a unity when it does
belong and the subject, man, has a certain attribute; for then a
unity is produced and we have 'the pale man'. In the present
case, on the other hand, one does not share in the other; the
genus is not thought to share in its differentiae (for then the
same thing would share in contraries; for the differentiae by
which the genus is divided are contrary). And even if the genus
does share in them, the same argument applies, since the
differentiae present in man are many, e.g. endowed with feet,
two-footed, featherless. Why are these one and not many? Not
because they are present in one thing; for on this principle a
unity can be made out of all the attributes of a thing. But surely
all the attributes in the definition must be one; for the
2366
definition is a single formula and a formula of substance, so
that it must be a formula of some one thing; for substance
means a 'one' and a 'this', as we maintain.
We must first inquire about definitions reached by the method
of divisions. There is nothing in the definition except the first-
named and the differentiae. The other genera are the first genus
and along with this the differentiae that are taken with it, e.g.
the first may be 'animal', the next 'animal which is two-footed',
and again 'animal which is two-footed and featherless', and
similarly if the definition includes more terms. And in general it
makes no difference whether it includes many or few terms, -
nor, therefore, whether it includes few or simply two; and of the
two the one is differentia and the other genus; e.g. in 'two-
footed animal' 'animal' is genus, and the other is differentia.
If then the genus absolutely does not exist apart from the
species-of-a-genus, or if it exists but exists as matter (for the
voice is genus and matter, but its differentiae make the species,
i.e. the letters, out of it), clearly the definition is the formula
which comprises the differentiae.
But it is also necessary that the division be by the differentia of
the diferentia; e.g. 'endowed with feet' is a differentia of
'animal'; again the differentia of 'animal endowed with feet'
must be of it qua endowed with feet. Therefore we must not say,
if we are to speak rightly, that of that which is endowed with
feet one part has feathers and one is featherless (if we do this
we do it through incapacity); we must divide it only into cloven-
footed and not cloven; for these are differentiae in the foot;
cloven-footedness is a form of footedness. And the process
wants always to go on so till it reaches the species that contain
no differences. And then there will be as many kinds of foot as
there are differentiae, and the kinds of animals endowed with
feet will be equal in number to the differentiae. If then this is so,
2367
clearly the last differentia will be the substance of the thing and
its definition, since it is not right to state the same things more
than once in our definitions; for it is superfluous. And this does
happen; for when we say 'animal endowed with feet and two-
footed' we have said nothing other than 'animal having feet,
having two feet'; and if we divide this by the proper division, we
shall be saying the same thing more than once - as many times
as there are differentiae.
If then a differentia of a differentia be taken at each step, one
differentia - the last - will be the form and the substance; but if
we divide according to accidental qualities, e.g. if we were to
divide that which is endowed with feet into the white and the
black, there will be as many differentiae as there are cuts.
Therefore it is plain that the definition is the formula which
contains the differentiae, or, according to the right method, the
last of these. This would be evident, if we were to change the
order of such definitions, e.g. of that of man, saying 'animal
which is two-footed and endowed with feet'; for 'endowed with
feet' is superfluous when 'two-footed' has been said. But there
is no order in the substance; for how are we to think the one
element posterior and the other prior? Regarding the
definitions, then, which are reached by the method of divisions,
let this suffice as our first attempt at stating their nature.
13
Let us return to the subject of our inquiry, which is substance.
As the substratum and the essence and the compound of these
are called substance, so also is the universal. About two of these
we have spoken; both about the essence and about the
substratum, of which we have said that it underlies in two
2368
senses, either being a 'this' - which is the way in which an
animal underlies its attributes - or as the matter underlies the
complete reality. The universal also is thought by some to be in
the fullest sense a cause, and a principle; therefore let us attack
the discussion of this point also. For it seems impossible that
any universal term should be the name of a substance. For
firstly the substance of each thing is that which is peculiar to it,
which does not belong to anything else; but the universal is
common, since that is called universal which is such as to
belong to more than one thing. Of which individual then will
this be the substance? Either of all or of none; but it cannot be
the substance of all. And if it is to be the substance of one, this
one will be the others also; for things whose substance is one
and whose essence is one are themselves also one.
Further, substance means that which is not predicable of a
subject, but the universal is predicable of some subject always.
But perhaps the universal, while it cannot be substance in the
way in which the essence is so, can be present in this; e.g.
'animal' can be present in 'man' and 'horse'. Then clearly it is a
formula of the essence. And it makes no difference even if it is
not a formula of everything that is in the substance; for none
the less the universal will be the substance of something, as
'man' is the substance of the individual man in whom it is
present, so that the same result will follow once more; for the
universal, e.g. 'animal', will be the substance of that in which it
is present as something peculiar to it. And further it is
impossible and absurd that the 'this', i.e. the substance, if it
consists of parts, should not consist of substances nor of what
is a 'this', but of quality; for that which is not substance, i.e. the
quality, will then be prior to substance and to the 'this'. Which is
impossible; for neither in formula nor in time nor in coming to
be can the modifications be prior to the substance; for then they
will also be separable from it. Further, Socrates will contain a
2369
substance present in a substance, so that this will be the
substance of two things. And in general it follows, if man and
such things are substance, that none of the elements in their
formulae is the substance of anything, nor does it exist apart
from the species or in anything else; I mean, for instance, that
no 'animal' exists apart from the particular kinds of animal, nor
does any other of the elements present in formulae exist apart.
If, then, we view the matter from these standpoints, it is plain
that no universal attribute is a substance, and this is plain also
from the fact that no common predicate indicates a 'this', but
rather a 'such'. If not, many difficulties follow and especially the
'third man'.
The conclusion is evident also from the following consideration.
A substance cannot consist of substances present in it in
complete reality; for things that are thus in complete reality two
are never in complete reality one, though if they are potentially
two, they can be one (e.g. the double line consists of two halves
- potentially; for the complete realization of the halves divides
them from one another); therefore if the substance is one, it will
not consist of substances present in it and present in this way,
which Democritus describes rightly; he says one thing cannot be
made out of two nor two out of one; for he identifies substances
with his indivisible magnitudes. It is clear therefore that the
same will hold good of number, if number is a synthesis of
units, as is said by some; for two is either not one, or there is no
unit present in it in complete reality. But our result involves a
difficulty. If no substance can consist of universals because a
universal indicates a 'such', not a 'this', and if no substance can
be composed of substances existing in complete reality, every
substance would be incomposite, so that there would not even
be a formula of any substance. But it is thought by all and was
stated long ago that it is either only, or primarily, substance that
can defined; yet now it seems that not even substance can.
2370
There cannot, then, be a definition of anything; or in a sense
there can be, and in a sense there cannot. And what we are
saying will be plainer from what follows.
14
It is clear also from these very facts what consequence
confronts those who say the Ideas are substances capable of
separate existence, and at the same time make the Form consist
of the genus and the differentiae. For if the Forms exist and
'animal' is present in 'man' and 'horse', it is either one and the
same in number, or different. (In formula it is clearly one; for he
who states the formula will go through the formula in either
case.) If then there is a 'man-in-himself who is a 'this' and
exists apart, the parts also of which he consists, e.g. 'animal'
and 'two-footed', must indicate 'thises', and be capable of
separate existence, and substances; therefore 'animal', as well
as 'man', must be of this sort.
Now (1) if the 'animal' in 'the horse' and in 'man' is one and the
same, as you are with yourself, (a) how will the one in things
that exist apart be one, and how will this 'animal' escape being
divided even from itself?
Further, (b) if it is to share in 'two-footed' and 'many-footed', an
impossible conclusion follows; for contrary attributes will
belong at the same time to it although it is one and a 'this'. If it
is not to share in them, what is the relation implied when one
says the animal is two-footed or possessed of feet? But perhaps
the two things are 'put together' and are 'in contact', or are
'mixed'. Yet all these expressions are absurd.
2371
But (2) suppose the Form to be different in each species. Then
there will be practically an infinite number of things whose
substance is animal'; for it is not by accident that 'man' has
'animal' for one of its elements. Further, many things will be
'animal-itself. For (i) the 'animal' in each species will be the
substance of the species; for it is after nothing else that the
species is called; if it were, that other would be an element in
'man', i.e. would be the genus of man. And further, (ii) all the
elements of which 'man' is composed will be Ideas. None of
them, then, will be the Idea of one thing and the substance of
another; this is impossible. The 'animal', then, present in each
species of animals will be animal-itself. Further, from what is
this 'animal' in each species derived, and how will it be derived
from animal-itself? Or how can this 'animal', whose essence is
simply animality, exist apart from animal-itself?
Further, (3)in the case of sensible things both these
consequences and others still more absurd follow. If, then, these
consequences are impossible, clearly there are not Forms of
sensible things in the sense in which some maintain their
existence.
15
Since substance is of two kinds, the concrete thing and the
formula (I mean that one kind of substance is the formula taken
with the matter, while another kind is the formula in its
generality), substances in the former sense are capable of
destruction (for they are capable also of generation), but there is
no destruction of the formula in the sense that it is ever in
course of being destroyed (for there is no generation of it either;
the being of house is not generated, but only the being of this
2372
house), but without generation and destruction formulae are
and are not; for it has been shown that no one begets nor
makes these. For this reason, also, there is neither definition of
nor demonstration about sensible individual substances,
because they have matter whose nature is such that they are
capable both of being and of not being; for which reason all the
individual instances of them are destructible. If then
demonstration is of necessary truths and definition is a
scientific process, and if, just as knowledge cannot be
sometimes knowledge and sometimes ignorance, but the state
which varies thus is opinion, so too demonstration and
definition cannot vary thus, but it is opinion that deals with
that which can be otherwise than as it is, clearly there can
neither be definition of nor demonstration about sensible
individuals. For perishing things are obscure to those who have
the relevant knowledge, when they have passed from our
perception; and though the formulae remain in the soul
unchanged, there will no longer be either definition or
demonstration. And so when one of the definition-mongers
defines any individual, he must recognize that his definition
may always be overthrown; for it is not possible to define such
things.
Nor is it possible to define any Idea. For the Idea is, as its
supporters say, an individual, and can exist apart; and the
formula must consist of words; and he who defines must not
invent a word (for it would be unknown), but the established
words are common to all the members of a class; these then
must apply to something besides the thing defined; e.g. if one
were defining you, he would say 'an animal which is lean' or
'pale', or something else which will apply also to some one
other than you. If any one were to say that perhaps all the
attributes taken apart may belong to many subjects, but
together they belong only to this one, we must reply first that
they belong also to both the elements; e.g. 'two-footed animal'
2373
belongs to animal and to the two-footed. (And in the case of
eternal entities this is even necessary, since the elements are
prior to and parts of the compound; nay more, they can also
exist apart, if 'man' can exist apart. For either neither or both
can. If, then, neither can, the genus will not exist apart from the
various species; but if it does, the differentia will also.) Secondly,
we must reply that 'animal' and 'two-footed' are prior in being
to 'two-footed animal'; and things which are prior to others are
not destroyed when the others are.
Again, if the Ideas consist of Ideas (as they must, since elements
are simpler than the compound), it will be further necessary
that the elements also of which the Idea consists, e.g. 'animal'
and 'two-footed', should be predicated of many subjects. If not,
how will they come to be known? For there will then be an Idea
which cannot be predicated of more subjects than one. But this
is not thought possible - every Idea is thought to be capable of
being shared.
As has been said, then, the impossibility of defining individuals
escapes notice in the case of eternal things, especially those
which are unique, like the sun or the moon. For people err not
only by adding attributes whose removal the sun would survive,
e.g. 'going round the earth' or 'night-hidden' (for from their view
it follows that if it stands still or is visible, it will no longer be
the sun; but it is strange if this is so; for 'the sun' means a
certain substance); but also by the mention of attributes which
can belong to another subject; e.g. if another thing with the
stated attributes comes into existence, clearly it will be a sun;
the formula therefore is general. But the sun was supposed to
be an individual, like Cleon or Socrates. After all, why does not
one of the supporters of the Ideas produce a definition of an
Idea? It would become clear, if they tried, that what has now
been said is true.
2374
16
Evidently even of the things that are thought to be substances,
most are only potencies, - both the parts of animals (for none of
them exists separately; and when they are separated, then too
they exist, all of them, merely as matter) and earth and fire and
air; for none of them is a unity, but as it were a mere heap, till
they are worked up and some unity is made out of them. One
might most readily suppose the parts of living things and the
parts of the soul nearly related to them to turn out to be both,
i.e. existent in complete reality as well as in potency, because
they have sources of movement in something in their joints; for
which reason some animals live when divided. Yet all the parts
must exist only potentially, when they are one and continuous
by nature, - not by force or by growing into one, for such a
phenomenon is an abnormality.
Since the term 'unity' is used like the term 'being', and the
substance of that which is one is one, and things whose
substance is numerically one are numerically one, evidently
neither unity nor being can be the substance of things, just as
being an element or a principle cannot be the substance, but we
ask what, then, the principle is, that we may reduce the thing to
something more knowable. Now of these concepts 'being' and
'unity' are more substantial than 'principle' or 'element' or
'cause', but not even the former are substance, since in general
nothing that is common is substance; for substance does not
belong to anything but to itself and to that which has it, of
which it is the substance. Further, that which is one cannot be
in many places at the same time, but that which is common is
present in many places at the same time; so that clearly no
universal exists apart from its individuals.
2375
But those who say the Forms exist, in one respect are right, in
giving the Forms separate existence, if they are substances; but
in another respect they are not right, because they say the one
over many is a Form. The reason for their doing this is that they
cannot declare what are the substances of this sort, the
imperishable substances which exist apart from the individual
and sensible substances. They make them, then, the same in
kind as the perishable things (for this kind of substance we
know) - 'man-himself and 'horse-itself , adding to the sensible
things the word 'itself. Yet even if we had not seen the stars,
none the less, I suppose, would they have been eternal
substances apart from those which we knew; so that now also if
we do not know what non-sensible substances there are, yet it
is doubtless necessary that there should he some. - Clearly,
then, no universal term is the name of a substance, and no
substance is composed of substances.
17
Let us state what, i.e. what kind of thing, substance should be
said to be, taking once more another starting-point; for perhaps
from this we shall get a clear view also of that substance which
exists apart from sensible substances. Since, then, substance is
a principle and a cause, let us pursue it from this starting-point.
The 'why' is always sought in this form - 'why does one thing
attach to some other?' For to inquire why the musical man is a
musical man, is either to inquire - as we have said why the man
is musical, or it is something else. Now 'why a thing is itself is a
meaningless inquiry (for (to give meaning to the question 'why')
the fact or the existence of the thing must already be evident -
e.g. that the moon is eclipsed - but the fact that a thing is itself
is the single reason and the single cause to be given in answer
2376
to all such questions as why the man is man, or the musician
musical', unless one were to answer 'because each thing is
inseparable from itself, and its being one just meant this'; this,
however, is common to all things and is a short and easy way
with the question). But we can inquire why man is an animal of
such and such a nature. This, then, is plain, that we are not
inquiring why he who is a man is a man. We are inquiring, then,
why something is predicable of something (that it is predicable
must be clear; for if not, the inquiry is an inquiry into nothing).
E.g. why does it thunder? This is the same as 'why is sound
produced in the clouds?' Thus the inquiry is about the
predication of one thing of another. And why are these things,
i.e. bricks and stones, a house? Plainly we are seeking the cause.
And this is the essence (to speak abstractly), which in some
cases is the end, e.g. perhaps in the case of a house or a bed,
and in some cases is the first mover; for this also is a cause. But
while the efficient cause is sought in the case of genesis and
destruction, the final cause is sought in the case of being also.
The object of the inquiry is most easily overlooked where one
term is not expressly predicated of another (e.g. when we
inquire 'what man is'), because we do not distinguish and do
not say definitely that certain elements make up a certain
whole. But we must articulate our meaning before we begin to
inquire; if not, the inquiry is on the border-line between being a
search for something and a search for nothing. Since we must
have the existence of the thing as something given, clearly the
question is why the matter is some definite thing; e.g. why are
these materials a house? Because that which was the essence of
a house is present. And why is this individual thing, or this body
having this form, a man? Therefore what we seek is the cause,
i.e. the form, by reason of which the matter is some definite
thing; and this is the substance of the thing. Evidently, then, in
the case of simple terms no inquiry nor teaching is possible; our
attitude towards such things is other than that of inquiry.
2377
Since that which is compounded out of something so that the
whole is one, not like a heap but like a syllable - now the
syllable is not its elements, ba is not the same as b and a, nor is
flesh fire and earth (for when these are separated the wholes,
i.e. the flesh and the syllable, no longer exist, but the elements
of the syllable exist, and so do fire and earth); the syllable, then,
is something - not only its elements (the vowel and the
consonant) but also something else, and the flesh is not only
fire and earth or the hot and the cold, but also something else: -
if, then, that something must itself be either an element or
composed of elements, (1) if it is an element the same argument
will again apply; for flesh will consist of this and fire and earth
and something still further, so that the process will go on to
infinity. But (2) if it is a compound, clearly it will be a compound
not of one but of more than one (or else that one will be the
thing itself), so that again in this case we can use the same
argument as in the case of flesh or of the syllable. But it would
seem that this 'other' is something, and not an element, and
that it is the cause which makes this thing flesh and that a
syllable. And similarly in all other cases. And this is the
substance of each thing (for this is the primary cause of its
being); and since, while some things are not substances, as
many as are substances are formed in accordance with a nature
of their own and by a process of nature, their substance would
seem to be this kind of 'nature', which is not an element but a
principle. An element, on the other hand, is that into which a
thing is divided and which is present in it as matter; e.g. a and b
are the elements of the syllable.
2378
BookH
We must reckon up the results arising from what has been said,
and compute the sum of them, and put the finishing touch to
our inquiry. We have said that the causes, principles, and
elements of substances are the object of our search. And some
substances are recognized by every one, but some have been
advocated by particular schools. Those generally recognized are
the natural substances, i.e. fire, earth, water, air, &c, the simple
bodies; second plants and their parts, and animals and the
parts of animals; and finally the physical universe and its parts;
while some particular schools say that Forms and the objects of
mathematics are substances. But there are arguments which
lead to the conclusion that there are other substances, the
essence and the substratum. Again, in another way the genus
seems more substantial than the various species, and the
universal than the particulars. And with the universal and the
genus the Ideas are connected; it is in virtue of the same
argument that they are thought to be substances. And since the
essence is substance, and the definition is a formula of the
essence, for this reason we have discussed definition and
essential predication. Since the definition is a formula, and a
formula has parts, we had to consider also with respect to the
notion of 'part', what are parts of the substance and what are
not, and whether the parts of the substance are also parts of the
definition. Further, too, neither the universal nor the genus is a
substance; we must inquire later into the Ideas and the objects
of mathematics; for some say these are substances as well as
the sensible substances.
2379
But now let us resume the discussion of the generally
recognized substances. These are the sensible substances, and
sensible substances all have matter. The substratum is
substance, and this is in one sense the matter (and by matter I
mean that which, not being a 'this' actually, is potentially a
'this'), and in another sense the formula or shape (that which
being a 'this' can be separately formulated), and thirdly the
complex of these two, which alone is generated and destroyed,
and is, without qualification, capable of separate existence; for
of substances completely expressible in a formula some are
separable and some are separable and some are not.
But clearly matter also is substance; for in all the opposite
changes that occur there is something which underlies the
changes, e.g. in respect of place that which is now here and
again elsewhere, and in respect of increase that which is now of
one size and again less or greater, and in respect of alteration
that which is now healthy and again diseased; and similarly in
respect of substance there is something that is now being
generated and again being destroyed, and now underlies the
process as a 'this' and again underlies it in respect of a privation
of positive character. And in this change the others are involved.
But in either one or two of the others this is not involved; for it
is not necessary if a thing has matter for change of place that it
should also have matter for generation and destruction.
The difference between becoming in the full sense and
becoming in a qualified sense has been stated in our physical
works.
2380
Since the substance which exists as underlying and as matter is
generally recognized, and this that which exists potentially, it
remains for us to say what is the substance, in the sense of
actuality, of sensible things. Democritus seems to think there
are three kinds of difference between things; the underlying
body, the matter, is one and the same, but they differ either in
rhythm, i.e. shape, or in turning, i.e. position, or in inter-contact,
i.e. order. But evidently there are many differences; for instance,
some things are characterized by the mode of composition of
their matter, e.g. the things formed by blending, such as honey-
water; and others by being bound together, e.g. bundle; and
others by being glued together, e.g. a book; and others by being
nailed together, e.g. a casket; and others in more than one of
these ways; and others by position, e.g. threshold and lintel (for
these differ by being placed in a certain way); and others by
time, e.g. dinner and breakfast; and others by place, e.g. the
winds; and others by the affections proper to sensible things,
e.g. hardness and softness, density and rarity, dryness and
wetness; and some things by some of these qualities, others by
them all, and in general some by excess and some by defect.
Clearly, then, the word 'is' has just as many meanings; a thing is
a threshold because it lies in such and such a position, and its
being means its lying in that position, while being ice means
having been solidified in such and such a way. And the being of
some things will be defined by all these qualities, because some
parts of them are mixed, others are blended, others are bound
together, others are solidified, and others use the other
differentiae; e.g. the hand or the foot requires such complex
definition. We must grasp, then, the kinds of differentiae (for
these will be the principles of the being of things), e.g. the
things characterized by the more and the less, or by the dense
and the rare, and by other such qualities; for all these are forms
of excess and defect. And anything that is characterized by
2381
shape or by smoothness and roughness is characterized by the
straight and the curved. And for other things their being will
mean their being mixed, and their not being will mean the
opposite.
It is clear, then, from these facts that, since its substance is the
cause of each thing's being, we must seek in these differentiae
what is the cause of the being of each of these things. Now none
of these differentiae is substance, even when coupled with
matter, yet it is what is analogous to substance in each case;
and as in substances that which is predicated of the matter is
the actuality itself, in all other definitions also it is what most
resembles full actuality. E.g. if we had to define a threshold, we
should say 'wood or stone in such and such a position', and a
house we should define as 'bricks and timbers in such and such
a position', (or a purpose may exist as well in some cases), and if
we had to define ice we should say 'water frozen or solidified in
such and such a way', and harmony is 'such and such a
blending of high and low'; and similarly in all other cases.
Obviously, then, the actuality or the formula is different when
the matter is different; for in some cases it is the composition,
in others the mixing, and in others some other of the attributes
we have named. And so, of the people who go in for defining,
those who define a house as stones, bricks, and timbers are
speaking of the potential house, for these are the matter; but
those who propose 'a receptacle to shelter chattels and living
beings', or something of the sort, speak of the actuality. Those
who combine both of these speak of the third kind of substance,
which is composed of matter and form (for the formula that
gives the differentiae seems to be an account of the form or
actuality, while that which gives the components is rather an
account of the matter); and the same is true of the kind of
definitions which Archytas used to accept; they are accounts of
the combined form and matter. E.g. what is still weather?
2382
Absence of motion in a large expanse of air; air is the matter,
and absence of motion is the actuality and substance. What is a
calm? Smoothness of sea; the material substratum is the sea,
and the actuality or shape is smoothness. It is obvious then,
from what has been said, what sensible substance is and how it
exists - one kind of it as matter, another as form or actuality,
while the third kind is that which is composed of these two.
We must not fail to notice that sometimes it is not clear
whether a name means the composite substance, or the
actuality or form, e.g. whether 'house' is a sign for the
composite thing, 'a covering consisting of bricks and stones laid
thus and thus', or for the actuality or form, 'a covering', and
whether a line is 'twoness in length' or 'twoness', and whether
an animal is soul in a body' or 'a soul'; for soul is the substance
or actuality of some body. 'Animal' might even be applied to
both, not as something definable by one formula, but as related
to a single thing. But this question, while important for another
purpose, is of no importance for the inquiry into sensible
substance; for the essence certainly attaches to the form and
the actuality. For 'soul' and 'to be soul' are the same, but 'to be
man' and 'man' are not the same, unless even the bare soul is to
be called man; and thus on one interpretation the thing is the
same as its essence, and on another it is not.
If we examine we find that the syllable does not consist of the
letters + juxtaposition, nor is the house bricks + juxtaposition.
And this is right; for the juxtaposition or mixing does not
consist of those things of which it is the juxtaposition or
mixing. And the same is true in all other cases; e.g. if the
2383
threshold is characterized by its position, the position is not
constituted by the threshold, but rather the latter is constituted
by the former. Nor is man animal + biped, but there must be
something besides these, if these are matter, - something which
is neither an element in the whole nor a compound, but is the
substance; but this people eliminate, and state only the matter.
If, then, this is the cause of the thing's being, and if the cause of
its being is its substance, they will not be stating the substance
itself.
(This, then, must either be eternal or it must be destructible
without being ever in course of being destroyed, and must have
come to be without ever being in course of coming to be. But it
has been proved and explained elsewhere that no one makes or
begets the form, but it is the individual that is made, i.e. the
complex of form and matter that is generated. Whether the
substances of destructible things can exist apart, is not yet at all
clear; except that obviously this is impossible in some cases - in
the case of things which cannot exist apart from the individual
instances, e.g. house or utensil. Perhaps, indeed, neither these
things themselves, nor any of the other things which are not
formed by nature, are substances at all; for one might say that
the nature in natural objects is the only substance to be found
in destructible things.)
Therefore the difficulty which used to be raised by the school of
Antisthenes and other such uneducated people has a certain
timeliness. They said that the 'what' cannot be defined (for the
definition so called is a 'long rigmarole') but of what sort a
thing, e.g. silver, is, they thought it possible actually to explain,
not saying what it is, but that it is like tin. Therefore one kind of
substance can be defined and formulated, i.e. the composite
kind, whether it be perceptible or intelligible; but the primary
parts of which this consists cannot be defined, since a
definitory formula predicates something of something, and one
2384
part of the definition must play the part of matter and the other
that of form.
It is also obvious that, if substances are in a sense numbers,
they are so in this sense and not, as some say, as numbers of
units. For a definition is a sort of number; for (1) it is divisible,
and into indivisible parts (for definitory formulae are not
infinite), and number also is of this nature. And (2) as, when one
of the parts of which a number consists has been taken from or
added to the number, it is no longer the same number, but a
different one, even if it is the very smallest part that has been
taken away or added, so the definition and the essence will no
longer remain when anything has been taken away or added.
And (3) the number must be something in virtue of which it is
one, and this these thinkers cannot state, what makes it one, if
it is one (for either it is not one but a sort of heap, or if it is, we
ought to say what it is that makes one out of many); and the
definition is one, but similarly they cannot say what makes it
one. And this is a natural result; for the same reason is
applicable, and substance is one in the sense which we have
explained, and not, as some say, by being a sort of unit or point;
each is a complete reality and a definite nature. And (4) as
number does not admit of the more and the less, neither does
substance, in the sense of form, but if any substance does, it is
only the substance which involves matter. Let this, then, suffice
for an account of the generation and destruction of so-called
substances in what sense it is possible and in what sense
impossible - and of the reduction of things to number.
2385
Regarding material substance we must not forget that even if all
things come from the same first cause or have the same things
for their first causes, and if the same matter serves as starting-
point for their generation, yet there is a matter proper to each,
e.g. for phlegm the sweet or the fat, and for bile the bitter, or
something else; though perhaps these come from the same
original matter. And there come to be several matters for the
same thing, when the one matter is matter for the other; e.g.
phlegm comes from the fat and from the sweet, if the fat comes
from the sweet; and it comes from bile by analysis of the bile
into its ultimate matter. For one thing comes from another in
two senses, either because it will be found at a later stage, or
because it is produced if the other is analysed into its original
constituents. When the matter is one, different things may be
produced owing to difference in the moving cause; e.g. from
wood may be made both a chest and a bed. But some different
things must have their matter different; e.g. a saw could not be
made of wood, nor is this in the power of the moving cause; for
it could not make a saw of wool or of wood. But if, as a matter of
fact, the same thing can be made of different material, clearly
the art, i.e. the moving principle, is the same; for if both the
matter and the moving cause were different, the product would
be so too.
When one inquires into the cause of something, one should,
since 'causes' are spoken of in several senses, state all the
possible causes, what is the material cause of man? Shall we
say 'the menstrual fluid? What is moving cause? Shall we say
'the seed? The formal cause? His essence. The final cause? His
end. But perhaps the latter two are the same. - It is the
proximate causes we must state. What is the material cause?
We must name not fire or earth, but the matter peculiar to the
thing.
2386
Regarding the substances that are natural and generable, if the
causes are really these and of this number and we have to learn
the causes, we must inquire thus, if we are to inquire rightly.
But in the case of natural but eternal substances another
account must be given. For perhaps some have no matter, or not
matter of this sort but only such as can be moved in respect of
place. Nor does matter belong to those things which exist by
nature but are not substances; their substratum is the
substance. E.g what is the cause of eclipse? What is its matter?
There is none; the moon is that which suffers eclipse. What is
the moving cause which extinguished the light? The earth. The
final cause perhaps does not exist. The formal principle is the
definitory formula, but this is obscure if it does not include the
cause. E.g. what is eclipse? Deprivation of light. But if we add 'by
the earth's coming in between', this is the formula which
includes the cause. In the case of sleep it is not clear what it is
that proximately has this affection. Shall we say that it is the
animal? Yes, but the animal in virtue of what, i.e. what is the
proximate subject? The heart or some other part. Next, by what
is it produced? Next, what is the affection - that of the
proximate subject, not of the whole animal? Shall we say that it
is immobility of such and such a kind? Yes, but to what process
in the proximate subject is this due?
Since some things are and are not, without coming to be and
ceasing to be, e.g. points, if they can be said to be, and in general
forms (for it is not 'white' comes to be, but the wood comes to
be white, if everything that comes to be comes from something
and comes to be something), not all contraries can come from
one another, but it is in different senses that a pale man comes
2387
from a dark man, and pale comes from dark. Nor has everything
matter, but only those things which come to be and change into
one another. Those things which, without ever being in course
of changing, are or are not, have no matter.
There is difficulty in the question how the matter of each thing
is related to its contrary states. E.g. if the body is potentially
healthy, and disease is contrary to health, is it potentially both
healthy and diseased? And is water potentially wine and
vinegar? We answer that it is the matter of one in virtue of its
positive state and its form, and of the other in virtue of the
privation of its positive state and the corruption of it contrary to
its nature. It is also hard to say why wine is not said to be the
matter of vinegar nor potentially vinegar (though vinegar is
produced from it), and why a living man is not said to be
potentially dead. In fact they are not, but the corruptions in
question are accidental, and it is the matter of the animal that
is itself in virtue of its corruption the potency and matter of a
corpse, and it is water that is the matter of vinegar. For the
corpse comes from the animal, and vinegar from wine, as night
from day. And all the things which change thus into one
another must go back to their matter; e.g. if from a corpse is
produced an animal, the corpse first goes back to its matter, and
only then becomes an animal; and vinegar first goes back to
water, and only then becomes wine.
To return to the difficulty which has been stated with respect
both to definitions and to numbers, what is the cause of their
unity? In the case of all things which have several parts and in
which the totality is not, as it were, a mere heap, but the whole
2388
is something beside the parts, there is a cause; for even in
bodies contact is the cause of unity in some cases, and in others
viscosity or some other such quality. And a definition is a set of
words which is one not by being connected together, like the
Iliad, but by dealing with one object. - What then, is it that
makes man one; why is he one and not many, e.g. animal +
biped, especially if there are, as some say, an animal-itself and a
biped-itself? Why are not those Forms themselves the man, so
that men would exist by participation not in man, nor in one
Form, but in two, animal and biped, and in general man would
be not one but more than one thing, animal and biped?
Clearly, then, if people proceed thus in their usual manner of
definition and speech, they cannot explain and solve the
difficulty. But if, as we say, one element is matter and another is
form, and one is potentially and the other actually, the question
will no longer be thought a difficulty. For this difficulty is the
same as would arise if 'round bronze' were the definition of
'cloak'; for this word would be a sign of the definitory formula,
so that the question is, what is the cause of the unity of 'round'
and 'bronze? The difficulty disappears, because the one is
matter, the other form. What, then, causes this - that which was
potentially to be actually - except, in the case of things which
are generated, the agent? For there is no other cause of the
potential sphere's becoming actually a sphere, but this was the
essence of either. Of matter some is intelligible, some
perceptible, and in a formula there is always an element of
matter as well as one of actuality; e.g. the circle is 'a plane
figure'. But of the things which have no matter, either
intelligible or perceptible, each is by its nature essentially a kind
of unity, as it is essentially a kind of being - individual
substance, quality, or quantity (and so neither 'existent' nor
'one' is present in their definitions), and the essence of each of
them is by its very nature a kind of unity as it is a kind of being
- and so none of these has any reason outside itself, for being
2389
one, nor for being a kind of being; for each is by its nature a kind
of being and a kind of unity, not as being in the genus 'being' or
'one' nor in the sense that being and unity can exist apart from
particulars.
Owing to the difficulty about unity some speak of
'participation', and raise the question, what is the cause of
participation and what is it to participate; and others speak of
'communion', as Lycophron says knowledge is a communion of
knowing with the soul; and others say life is a 'composition' or
'connexion' of soul with body. Yet the same account applies to
all cases; for being healthy, too, will on this showing be either a
'communion' or a 'connexion' or a 'composition' of soul and
health, and the fact that the bronze is a triangle will be a
'composition' of bronze and triangle, and the fact that a thing is
white will be a 'composition' of surface and whiteness. The
reason is that people look for a unifying formula, and a
difference, between potency and complete reality. But, as has
been said, the proximate matter and the form are one and the
same thing, the one potentially, and the other actually.
Therefore it is like asking what in general is the cause of unity
and of a thing's being one; for each thing is a unity, and the
potential and the actual are somehow one. Therefore there is no
other cause here unless there is something which caused the
movement from potency into actuality. And all things which
have no matter are without qualification essentially unities.
2390
BookG
We have treated of that which is primarily and to which all the
other categories of being are referred - i.e. of substance. For it is
in virtue of the concept of substance that the others also are
said to be - quantity and quality and the like; for all will be
found to involve the concept of substance, as we said in the first
part of our work. And since 'being' is in one way divided into
individual thing, quality, and quantity, and is in another way
distinguished in respect of potency and complete reality, and of
function, let us now add a discussion of potency and complete
reality. And first let us explain potency in the strictest sense,
which is, however, not the most useful for our present purpose.
For potency and actuality extend beyond the cases that involve
a reference to motion. But when we have spoken of this first
kind, we shall in our discussions of actuality' explain the other
kinds of potency as well.
We have pointed out elsewhere that 'potency' and the word
'can' have several senses. Of these we may neglect all the
potencies that are so called by an equivocation. For some are
called so by analogy, as in geometry we say one thing is or is not
a 'power' of another by virtue of the presence or absence of
some relation between them. But all potencies that conform to
the same type are originative sources of some kind, and are
called potencies in reference to one primary kind of potency,
which is an originative source of change in another thing or in
the thing itself qua other. For one kind is a potency of being
acted on, i.e. the originative source, in the very thing acted on,
of its being passively changed by another thing or by itself qua
2391
other; and another kind is a state of insusceptibility to change
for the worse and to destruction by another thing or by the
thing itself qua other by virtue of an originative source of
change. In all these definitions is implied the formula if potency
in the primary sense. - And again these so-called potencies are
potencies either of merely acting or being acted on, or of acting
or being acted on well, so that even in the formulae of the latter
the formulae of the prior kinds of potency are somehow
implied.
Obviously, then, in a sense the potency of acting and of being
acted on is one (for a thing may be 'capable' either because it
can itself be acted on or because something else can be acted
on by it), but in a sense the potencies are different. For the one
is in the thing acted on; it is because it contains a certain
originative source, and because even the matter is an originative
source, that the thing acted on is acted on, and one thing by
one, another by another; for that which is oily can be burnt, and
that which yields in a particular way can be crushed; and
similarly in all other cases. But the other potency is in the agent,
e.g. heat and the art of building are present, one in that which
can produce heat and the other in the man who can build. And
so, in so far as a thing is an organic unity, it cannot be acted on
by itself; for it is one and not two different things. And
'impotence'and 'impotent' stand for the privation which is
contrary to potency of this sort, so that every potency belongs to
the same subject and refers to the same process as a
corresponding impotence. Privation has several senses; for it
means (1) that which has not a certain quality and (2) that
which might naturally have it but has not it, either (a) in general
or (b) when it might naturally have it, and either (a) in some
particular way, e.g. when it has not it completely, or (b) when it
has not it at all. And in certain cases if things which naturally
have a quality lose it by violence, we say they have suffered
privation.
2392
Since some such originative sources are present in soulless
things, and others in things possessed of soul, and in soul, and
in the rational part of the soul, clearly some potencies will, be
non-rational and some will be non-rational and some will be
accompanied by a rational formula. This is why all arts, i.e. all
productive forms of knowledge, are potencies; they are
originative sources of change in another thing or in the artist
himself considered as other.
And each of those which are accompanied by a rational formula
is alike capable of contrary effects, but one non-rational power
produces one effect; e.g. the hot is capable only of heating, but
the medical art can produce both disease and health. The
reason is that science is a rational formula, and the same
rational formula explains a thing and its privation, only not in
the same way; and in a sense it applies to both, but in a sense it
applies rather to the positive fact. Therefore such sciences must
deal with contraries, but with one in virtue of their own nature
and with the other not in virtue of their nature; for the rational
formula applies to one object in virtue of that object's nature,
and to the other, in a sense, accidentally. For it is by denial and
removal that it exhibits the contrary; for the contrary is the
primary privation, and this is the removal of the positive term.
Now since contraries do not occur in the same thing, but
science is a potency which depends on the possession of a
rational formula, and the soul possesses an originative source of
movement; therefore, while the wholesome produces only
health and the calorific only heat and the frigorific only cold,
the scientific man produces both the contrary effects. For the
rational formula is one which applies to both, though not in the
2393
same way, and it is in a soul which possesses an originative
source of movement; so that the soul will start both processes
from the same originative source, having linked them up with
the same thing. And so the things whose potency is according
to a rational formula act contrariwise to the things whose
potency is non-rational; for the products of the former are
included under one originative source, the rational formula.
It is obvious also that the potency of merely doing a thing or
having it done to one is implied in that of doing it or having it
done well, but the latter is not always implied in the former: for
he who does a thing well must also do it, but he who does it
merely need not also do it well.
There are some who say, as the Megaric school does, that a
thing 'can' act only when it is acting, and when it is not acting it
'cannot' act, e.g. that he who is not building cannot build, but
only he who is building, when he is building; and so in all other
cases. It is not hard to see the absurdities that attend this view.
For it is clear that on this view a man will not be a builder
unless he is building (for to be a builder is to be able to build),
and so with the other arts. If, then, it is impossible to have such
arts if one has not at some time learnt and acquired them, and
it is then impossible not to have them if one has not sometime
lost them (either by forgetfulness or by some accident or by
time; for it cannot be by the destruction of the object, for that
lasts for ever), a man will not have the art when he has ceased
to use it, and yet he may immediately build again; how then will
he have got the art? And similarly with regard to lifeless things;
nothing will be either cold or hot or sweet or perceptible at all if
2394
people are not perceiving it; so that the upholders of this view
will have to maintain the doctrine of Protagoras. But, indeed,
nothing will even have perception if it is not perceiving, i.e.
exercising its perception. If, then, that is blind which has not
sight though it would naturally have it, when it would naturally
have it and when it still exists, the same people will be blind
many times in the day - and deaf too.
Again, if that which is deprived of potency is incapable, that
which is not happening will be incapable of happening; but he
who says of that which is incapable of happening either that it
is or that it will be will say what is untrue; for this is what
incapacity meant. Therefore these views do away with both
movement and becoming. For that which stands will always
stand, and that which sits will always sit, since if it is sitting it
will not get up; for that which, as we are told, cannot get up will
be incapable of getting up. But we cannot say this, so that
evidently potency and actuality are different (but these views
make potency and actuality the same, and so it is no small
thing they are seeking to annihilate), so that it is possible that a
thing may be capable of being and not he, and capable of not
being and yet he, and similarly with the other kinds of
predicate; it may be capable of walking and yet not walk, or
capable of not walking and yet walk. And a thing is capable of
doing something if there will be nothing impossible in its
having the actuality of that of which it is said to have the
capacity. I mean, for instance, if a thing is capable of sitting and
it is open to it to sit, there will be nothing impossible in its
actually sitting; and similarly if it is capable of being moved or
moving, or of standing or making to stand, or of being or
coming to be, or of not being or not coming to be.
The word 'actuality', which we connect with 'complete reality',
has, in the main, been extended from movements to other
things; for actuality in the strict sense is thought to be identical
2395
with movement. And so people do not assign movement to non-
existent things, though they do assign some other predicates.
E.g. they say that non-existent things are objects of thought and
desire, but not that they are moved; and this because, while ex
hypothesi they do not actually exist, they would have to exist
actually if they were moved. For of non-existent things some
exist potentially; but they do not exist, because they do not exist
in complete reality.
If what we have described is identical with the capable or
convertible with it, evidently it cannot be true to say 'this is
capable of being but will not be', which would imply that the
things incapable of being would on this showing vanish.
Suppose, for instance, that a man - one who did not take
account of that which is incapable of being - were to say that
the diagonal of the square is capable of being measured but will
not be measured, because a thing may well be capable of being
or coming to be, and yet not be or be about to be. But from the
premisses this necessarily follows, that if we actually supposed
that which is not, but is capable of being, to be or to have come
to be, there will be nothing impossible in this; but the result will
be impossible, for the measuring of the diagonal is impossible.
For the false and the impossible are not the same; that you are
standing now is false, but that you should be standing is not
impossible.
At the same time it is clear that if, when A is real, B must be
real, then, when A is possible, B also must be possible. For if B
need not be possible, there is nothing to prevent its not being
possible. Now let A be supposed possible. Then, when A was
2396
possible, we agreed that nothing impossible followed if A were
supposed to be real; and then B must of course be real. But we
supposed B to be impossible. Let it be impossible then. If, then,
B is impossible, A also must be so. But the first was supposed
impossible; therefore the second also is impossible. If, then, A is
possible, B also will be possible, if they were so related that if
A,is real, B must be real. If, then, A and B being thus related, B is
not possible on this condition, and B will not be related as was
supposed. And if when A is possible, B must be possible, then if
A is real, B also must be real. For to say that B must be possible,
if A is possible, means this, that if A is real both at the time
when and in the way in which it was supposed capable of being
real, B also must then and in that way be real.
As all potencies are either innate, like the senses, or come by
practice, like the power of playing the flute, or by learning, like
artistic power, those which come by practice or by rational
formula we must acquire by previous exercise but this is not
necessary with those which are not of this nature and which
imply passivity.
Since that which is 'capable' is capable of something and at
some time in some way (with all the other qualifications which
must be present in the definition), and since some things can
produce change according to a rational formula and their
potencies involve such a formula, while other things are
nonrational and their potencies are non-rational, and the
former potencies must be in a living thing, while the latter can
be both in the living and in the lifeless; as regards potencies of
the latter kind, when the agent and the patient meet in the way
2397
appropriate to the potency in question, the one must act and
the other be acted on, but with the former kind of potency this
is not necessary. For the nonrational potencies are all
productive of one effect each, but the rational produce contrary
effects, so that if they produced their effects necessarily they
would produce contrary effects at the same time; but this is
impossible. There must, then, be something else that decides; I
mean by this, desire or will. For whichever of two things the
animal desires decisively, it will do, when it is present, and
meets the passive object, in the way appropriate to the potency
in question. Therefore everything which has a rational potency,
when it desires that for which it has a potency and in the
circumstances in which it has the potency, must do this. And it
has the potency in question when the passive object is present
and is in a certain state; if not it will not be able to act. (To add
the qualification 'if nothing external prevents it' is not further
necessary; for it has the potency on the terms on which this is a
potency of acting, and it is this not in all circumstances but on
certain conditions, among which will be the exclusion of
external hindrances; for these are barred by some of the
positive qualifications.) And so even if one has a rational wish,
or an appetite, to do two things or contrary things at the same
time, one will not do them; for it is not on these terms that one
has the potency for them, nor is it a potency of doing both at
the same time, since one will do the things which it is a potency
of doing, on the terms on which one has the potency.
Since we have treated of the kind of potency which is related to
movement, let us discuss actuality - what, and what kind of
thing, actuality is. For in the course of our analysis it will also
2398
become clear, with regard to the potential, that we not only
ascribe potency to that whose nature it is to move something
else, or to be moved by something else, either without
qualification or in some particular way, but also use the word in
another sense, which is the reason of the inquiry in the course
of which we have discussed these previous senses also.
Actuality, then, is the existence of a thing not in the way which
we express by 'potentially'; we say that potentially, for instance,
a statue of Hermes is in the block of wood and the half- line is in
the whole, because it might be separated out, and we call even
the man who is not studying a man of science, if he is capable
of studying; the thing that stands in contrast to each of these
exists actually. Our meaning can be seen in the particular cases
by induction, and we must not seek a definition of everything
but be content to grasp the analogy, that it is as that which is
building is to that which is capable of building, and the waking
to the sleeping, and that which is seeing to that which has its
eyes shut but has sight, and that which has been shaped out of
the matter to the matter, and that which has been wrought up
to the unwrought. Let actuality be defined by one member of
this antithesis, and the potential by the other. But all things are
not said in the same sense to exist actually, but only by analogy
- as A is in B or to B, C is in D or to D; for some are as movement
to potency, and the others as substance to some sort of matter.
But also the infinite and the void and all similar things are said
to exist potentially and actually in a different sense from that
which applies to many other things, e.g. to that which sees or
walks or is seen. For of the latter class these predicates can at
some time be also truly asserted without qualification; for the
seen is so called sometimes because it is being seen, sometimes
because it is capable of being seen. But the infinite does not
exist potentially in the sense that it will ever actually have
separate existence; it exists potentially only for knowledge. For
the fact that the process of dividing never comes to an end
2399
ensures that this activity exists potentially, but not that the
infinite exists separately.
Since of the actions which have a limit none is an end but all
are relative to the end, e.g. the removing of fat, or fat-removal,
and the bodily parts themselves when one is making them thin
are in movement in this way (i.e. without being already that at
which the movement aims), this is not an action or at least not
a complete one (for it is not an end); but that movement in
which the end is present is an action. E.g. at the same time we
are seeing and have seen, are understanding and have
understood, are thinking and have thought (while it is not true
that at the same time we are learning and have learnt, or are
being cured and have been cured). At the same time we are
living well and have lived well, and are happy and have been
happy. If not, the process would have had sometime to cease, as
the process of making thin ceases: but, as things are, it does not
cease; we are living and have lived. Of these processes, then, we
must call the one set movements, and the other actualities. For
every movement is incomplete - making thin, learning, walking,
building; these are movements, and incomplete at that. For it is
not true that at the same time a thing is walking and has
walked, or is building and has built, or is coming to be and has
come to be, or is being moved and has been moved, but what is
being moved is different from what has been moved, and what
is moving from what has moved. But it is the same thing that at
the same time has seen and is seeing, seeing, or is thinking and
has thought. The latter sort of process, then, I call an actuality,
and the former a movement.
2400
What, and what kind of thing, the actual is, may be taken as
explained by these and similar considerations. But we must
distinguish when a thing exists potentially and when it does
not; for it is not at any and every time. E.g. is earth potentially a
man? No - but rather when it has already become seed, and
perhaps not even then. It is just as it is with being healed; not
everything can be healed by the medical art or by luck, but there
is a certain kind of thing which is capable of it, and only this is
potentially healthy. And (1) the delimiting mark of that which as
a result of thought comes to exist in complete reality from
having existed potentially is that if the agent has willed it it
comes to pass if nothing external hinders, while the condition
on the other side - viz. in that which is healed - is that nothing
in it hinders the result. It is on similar terms that we have what
is potentially a house; if nothing in the thing acted on - i.e. in
the matter - prevents it from becoming a house, and if there is
nothing which must be added or taken away or changed, this is
potentially a house; and the same is true of all other things the
source of whose becoming is external. And (2) in the cases in
which the source of the becoming is in the very thing which
comes to be, a thing is potentially all those things which it will
be of itself if nothing external hinders it. E.g. the seed is not yet
potentially a man; for it must be deposited in something other
than itself and undergo a change. But when through its own
motive principle it has already got such and such attributes, in
this state it is already potentially a man; while in the former
state it needs another motive principle, just as earth is not yet
potentially a statue (for it must first change in order to become
brass.)
It seems that when we call a thing not something else but
'thaten' - e.g. a casket is not 'wood' but 'wooden', and wood is
not 'earth' but 'earthen', and again earth will illustrate our point
2401
if it is similarly not something else but 'thaten' - that other
thing is always potentially (in the full sense of that word) the
thing which comes after it in this series. E.g. a casket is not
'earthen' nor 'earth', but 'wooden'; for this is potentially a
casket and this is the matter of a casket, wood in general of a
casket in general, and this particular wood of this particular
casket. And if there is a first thing, which is no longer, in
reference to something else, called 'thaten', this is prime
matter; e.g. if earth is 'airy' and air is not 'fire' but 'fiery', fire is
prime matter, which is not a 'this'. For the subject or substratum
is differentiated by being a 'this' or not being one; i.e. the
substratum of modifications is, e.g. a man, i.e. a body and a soul,
while the modification is 'musical' or 'pale'. (The subject is
called, when music comes to be present in it, not 'music' but
'musical', and the man is not 'paleness' but 'pale', and not
'ambulation' or 'movement' but 'walking' or 'moving', - which is
akin to the 'thaten'.) Wherever this is so, then, the ultimate
subject is a substance; but when this is not so but the predicate
is a form and a 'this', the ultimate subject is matter and
material substance. And it is only right that 'thaten' should be
used with reference both to the matter and to the accidents; for
both are indeterminates.
We have stated, then, when a thing is to be said to exist
potentially and when it is not.
8
From our discussion of the various senses of 'prior', it is clear
that actuality is prior to potency. And I mean by potency not
only that definite kind which is said to be a principle of change
in another thing or in the thing itself regarded as other, but in
2402
general every principle of movement or of rest. For nature also
is in the same genus as potency; for it is a principle of
movement - not, however, in something else but in the thing
itself qua itself. To all such potency, then, actuality is prior both
in formula and in substantiality; and in time it is prior in one
sense, and in another not.
(1) Clearly it is prior in formula; for that which is in the primary
sense potential is potential because it is possible for it to
become active; e.g. I mean by 'capable of building' that which
can build, and by 'capable of seeing' that which can see, and by
'visible' that which can be seen. And the same account applies
to all other cases, so that the formula and the knowledge of the
one must precede the knowledge of the other.
(2) In time it is prior in this sense: the actual which is identical
in species though not in number with a potentially existing
thing is to it. I mean that to this particular man who now exists
actually and to the corn and to the seeing subject the matter
and the seed and that which is capable of seeing, which are
potentially a man and corn and seeing, but not yet actually so,
are prior in time; but prior in time to these are other actually
existing things, from which they were produced. For from the
potentially existing the actually existing is always produced by
an actually existing thing, e.g. man from man, musician by
musician; there is always a first mover, and the mover already
exists actually. We have said in our account of substance that
everything that is produced is something produced from
something and by something, and that the same in species as it.
This is why it is thought impossible to be a builder if one has
built nothing or a harper if one has never played the harp; for
he who learns to play the harp learns to play it by playing it,
and all other learners do similarly. And thence arose the
sophistical quibble, that one who does not possess a science
2403
will be doing that which is the object of the science; for he who
is learning it does not possess it. But since, of that which is
coming to be, some part must have come to be, and, of that
which, in general, is changing, some part must have changed
(this is shown in the treatise on movement), he who is learning
must, it would seem, possess some part of the science. But here
too, then, it is clear that actuality is in this sense also, viz. in
order of generation and of time, prior to potency.
But (3) it is also prior in substantiality; firstly, (a) because the
things that are posterior in becoming are prior in form and in
substantiality (e.g. man is prior to boy and human being to seed;
for the one already has its form, and the other has not), and
because everything that comes to be moves towards a principle,
i.e. an end (for that for the sake of which a thing is, is its
principle, and the becoming is for the sake of the end), and the
actuality is the end, and it is for the sake of this that the
potency is acquired. For animals do not see in order that they
may have sight, but they have sight that they may see. And
similarly men have the art of building that they may build, and
theoretical science that they may theorize; but they do not
theorize that they may have theoretical science, except those
who are learning by practice; and these do not theorize except
in a limited sense, or because they have no need to theorize.
Further, matter exists in a potential state, just because it may
come to its form; and when it exists actually, then it is in its
form. And the same holds good in all cases, even those in which
the end is a movement. And so, as teachers think they have
achieved their end when they have exhibited the pupil at work,
nature does likewise. For if this is not the case, we shall have
Pauson's Hermes over again, since it will be hard to say about
the knowledge, as about the figure in the picture, whether it is
within or without. For the action is the end, and the actuality is
the action. And so even the word 'actuality' is derived from
'action', and points to the complete reality.
2404
And while in some cases the exercise is the ultimate thing (e.g.
in sight the ultimate thing is seeing, and no other product
besides this results from sight), but from some things a product
follows (e.g. from the art of building there results a house as
well as the act of building), yet none the less the act is in the
former case the end and in the latter more of an end than the
potency is. For the act of building is realized in the thing that is
being built, and comes to be, and is, at the same time as the
house.
Where, then, the result is something apart from the exercise,
the actuality is in the thing that is being made, e.g. the act of
building is in the thing that is being built and that of weaving in
the thing that is being woven, and similarly in all other cases,
and in general the movement is in the thing that is being
moved; but where there is no product apart from the actuality,
the actuality is present in the agents, e.g. the act of seeing is in
the seeing subject and that of theorizing in the theorizing
subject and the life is in the soul (and therefore well-being also;
for it is a certain kind of life).
Obviously, therefore, the substance or form is actuality.
According to this argument, then, it is obvious that actuality is
prior in substantial being to potency; and as we have said, one
actuality always precedes another in time right back to the
actuality of the eternal prime mover.
But (b) actuality is prior in a stricter sense also; for eternal
things are prior in substance to perishable things, and no
eternal thing exists potentially. The reason is this. Every potency
is at one and the same time a potency of the opposite; for, while
that which is not capable of being present in a subject cannot be
present, everything that is capable of being may possibly not be
actual. That, then, which is capable of being may either be or
not be; the same thing, then, is capable both of being and of not
2405
being. And that which is capable of not being may possibly not
be; and that which may possibly not be is perishable, either in
the full sense, or in the precise sense in which it is said that it
possibly may not be, i.e. in respect either of place or of quantity
or quality; 'in the full sense' means 'in respect of substance'.
Nothing, then, which is in the full sense imperishable is in the
full sense potentially existent (though there is nothing to
prevent its being so in some respect, e.g. potentially of a certain
quality or in a certain place); all imperishable things, then, exist
actually. Nor can anything which is of necessity exist
potentially; yet these things are primary; for if these did not
exist, nothing would exist. Nor does eternal movement, if there
be such, exist potentially; and, if there is an eternal mobile, it is
not in motion in virtue of a potentiality, except in respect of
'whence' and 'whither' (there is nothing to prevent its having
matter which makes it capable of movement in various
directions). And so the sun and the stars and the whole heaven
are ever active, and there is no fear that they may sometime
stand still, as the natural philosophers fear they may. Nor do
they tire in this activity; for movement is not for them, as it is
for perishable things, connected with the potentiality for
opposites, so that the continuity of the movement should be
laborious; for it is that kind of substance which is matter and
potency, not actuality, that causes this.
Imperishable things are imitated by those that are involved in
change, e.g. earth and fire. For these also are ever active; for
they have their movement of themselves and in themselves. But
the other potencies, according to our previous discussion, are all
potencies for opposites; for that which can move another in this
way can also move it not in this way, i.e. if it acts according to a
rational formula; and the same non-rational potencies will
produce opposite results by their presence or absence.
2406
If, then, there are any entities or substances such as the
dialecticians say the Ideas are, there must be something much
more scientific than science-itself and something more mobile
than movement-itself; for these will be more of the nature of
actualities, while science-itself and movement-itself are
potencies for these.
Obviously, then, actuality is prior both to potency and to every
principle of change.
That the actuality is also better and more valuable than the
good potency is evident from the following argument.
Everything of which we say that it can do something, is alike
capable of contraries, e.g. that of which we say that it can be
well is the same as that which can be ill, and has both potencies
at once; for the same potency is a potency of health and illness,
of rest and motion, of building and throwing down, of being
built and being thrown down. The capacity for contraries, then,
is present at the same time; but contraries cannot be present at
the same time, and the actualities also cannot be present at the
same time, e.g. health and illness. Therefore, while the good
must be one of them, the capacity is both alike, or neither; the
actuality, then, is better. Also in the case of bad things the end
or actuality must be worse than the potency; for that which
'can' is both contraries alike. Clearly, then, the bad does not
exist apart from bad things; for the bad is in its nature posterior
to the potency. And therefore we may also say that in the things
which are from the beginning, i.e. in eternal things, there is
nothing bad, nothing defective, nothing perverted (for
perversion is something bad).
2407
It is an activity also that geometrical constructions are
discovered; for we find them by dividing. If the figures had been
already divided, the constructions would have been obvious; but
as it is they are present only potentially. Why are the angles of
the triangle equal to two right angles? Because the angles about
one point are equal to two right angles. If, then, the line parallel
to the side had been already drawn upwards, the reason would
have been evident to any one as soon as he saw the figure. Why
is the angle in a semicircle in all cases a right angle? If three
lines are equal the two which form the base, and the
perpendicular from the centre - the conclusion is evident at a
glance to one who knows the former proposition. Obviously,
therefore, the potentially existing constructions are discovered
by being brought to actuality; the reason is that the geometer's
thinking is an actuality; so that the potency proceeds from an
actuality; and therefore it is by making constructions that
people come to know them (though the single actuality is later
in generation than the corresponding potency). (See diagram.)
10
The terms 'being' and 'non-being' are employed firstly with
reference to the categories, and secondly with reference to the
potency or actuality of these or their non-potency or
nonactuality, and thirdly in the sense of true and false. This
depends, on the side of the objects, on their being combined or
separated, so that he who thinks the separated to be separated
and the combined to be combined has the truth, while he
whose thought is in a state contrary to that of the objects is in
error. This being so, when is what is called truth or falsity
present, and when is it not? We must consider what we mean
by these terms. It is not because we think truly that you are
2408
pale, that you are pale, but because you are pale we who say
this have the truth. If, then, some things are always combined
and cannot be separated, and others are always separated and
cannot be combined, while others are capable either of
combination or of separation, 'being' is being combined and
one, and 'not being' is being not combined but more than one.
Regarding contingent facts, then, the same opinion or the same
statement comes to be false and true, and it is possible for it to
be at one time correct and at another erroneous; but regarding
things that cannot be otherwise opinions are not at one time
true and at another false, but the same opinions are always true
or always false.
But with regard to incomposites, what is being or not being, and
truth or falsity? A thing of this sort is not composite, so as to
'be' when it is compounded, and not to 'be' if it is separated, like
'that the wood is white' or 'that the diagonal is
incommensurable'; nor will truth and falsity be still present in
the same way as in the previous cases. In fact, as truth is not
the same in these cases, so also being is not the same; but (a)
truth or falsity is as follows - contact and assertion are truth
(assertion not being the same as affirmation), and ignorance is
non-contact. For it is not possible to be in error regarding the
question what a thing is, save in an accidental sense; and the
same holds good regarding non-composite substances (for it is
not possible to be in error about them). And they all exist
actually, not potentially; for otherwise they would have come to
be and ceased to be; but, as it is, being itself does not come to be
(nor cease to be); for if it had done so it would have had to come
out of something. About the things, then, which are essences
and actualities, it is not possible to be in error, but only to know
them or not to know them. But we do inquire what they are, viz.
whether they are of such and such a nature or not.
2409
(b) As regards the 'being' that answers to truth and the 'non-
being' that answers to falsity, in one case there is truth if the
subject and the attribute are really combined, and falsity if they
are not combined; in the other case, if the object is existent it
exists in a particular way, and if it does not exist in this way
does not exist at all. And truth means knowing these objects,
and falsity does not exist, nor error, but only ignorance - and
not an ignorance which is like blindness; for blindness is akin to
a total absence of the faculty of thinking.
It is evident also that about unchangeable things there can be
no error in respect of time, if we assume them to be
unchangeable. E.g. if we suppose that the triangle does not
change, we shall not suppose that at one time its angles are
equal to two right angles while at another time they are not (for
that would imply change). It is possible, however, to suppose
that one member of such a class has a certain attribute and
another has not; e.g. while we may suppose that no even
number is prime, we may suppose that some are and some are
not. But regarding a numerically single number not even this
form of error is possible; for we cannot in this case suppose that
one instance has an attribute and another has not, but whether
our judgement be true or false, it is implied that the fact is
eternal.
2410
Book I
We have said previously, in our distinction of the various
meanings of words, that 'one' has several meanings; the things
that are directly and of their own nature and not accidentally
called one may be summarized under four heads, though the
word is used in more senses. (1) There is the continuous, either
in general, or especially that which is continuous by nature and
not by contact nor by being together; and of these, that has
more unity and is prior, whose movement is more indivisible
and simpler. (2) That which is a whole and has a certain shape
and form is one in a still higher degree; and especially if a thing
is of this sort by nature, and not by force like the things which
are unified by glue or nails or by being tied together, i.e. if it has
in itself the cause of its continuity. A thing is of this sort
because its movement is one and indivisible in place and time;
so that evidently if a thing has by nature a principle of
movement that is of the first kind (i.e. local movement) and the
first in that kind (i.e. circular movement), this is in the primary
sense one extended thing. Some things, then, are one in this
way, qua continuous or whole, and the other things that are one
are those whose definition is one. Of this sort are the things the
thought of which is one, i.e. those the thought of which is
indivisible; and it is indivisible if the thing is indivisible in kind
or in number. (3) In number, then, the individual is indivisible,
and (4) in kind, that which in intelligibility and in knowledge is
indivisible, so that that which causes substances to be one must
be one in the primary sense. 'One', then, has all these meanings
- the naturally continuous and the whole, and the individual
and the universal. And all these are one because in some cases
2411
the movement, in others the thought or the definition is
indivisible.
But it must be observed that the questions, what sort of things
are said to be one, and what it is to be one and what is the
definition of it, should not be assumed to be the same. 'One' has
all these meanings, and each of the things to which one of
these kinds of unity belongs will be one; but 'to be one' will
sometimes mean being one of these things, and sometimes
being something else which is even nearer to the meaning of
the word 'one' while these other things approximate to its
application. This is also true of 'element' or 'cause', if one had
both to specify the things of which it is predicable and to render
the definition of the word. For in a sense fire is an element (and
doubtless also 'the indefinite' or something else of the sort is by
its own nature the element), but in a sense it is not; for it is not
the same thing to be fire and to be an element, but while as a
particular thing with a nature of its own fire is an element, the
name 'element' means that it has this attribute, that there is
something which is made of it as a primary constituent. And so
with 'cause' and 'one' and all such terms. For this reason, too,
'to be one' means 'to be indivisible, being essentially one means
a «this» and capable of being isolated either in place, or in form
or thought'; or perhaps 'to be whole and indivisible'; but it
means especially 'to be the first measure of a kind', and most
strictly of quantity; for it is from this that it has been extended
to the other categories. For measure is that by which quantity is
known; and quantity qua quantity is known either by a 'one' or
by a number, and all number is known by a 'one'. Therefore all
quantity qua quantity is known by the one, and that by which
quantities are primarily known is the one itself; and so the one
is the starting-point of number qua number. And hence in the
other classes too 'measure' means that by which each is first
known, and the measure of each is a unit - in length, in breadth,
in depth, in weight, in speed. (The words 'weight' and 'speed'
2412
are common to both contraries; for each of them has two
meanings - 'weight' means both that which has any amount of
gravity and that which has an excess of gravity, and 'speed' both
that which has any amount of movement and that which has
an excess of movement; for even the slow has a certain speed
and the comparatively light a certain weight.)
In all these, then, the measure and starting-point is something
one and indivisible, since even in lines we treat as indivisible
the line a foot long. For everywhere we seek as the measure
something one and indivisible; and this is that which is simple
either in quality or in quantity. Now where it is thought
impossible to take away or to add, there the measure is exact
(hence that of number is most exact; for we posit the unit as
indivisible in every respect); but in all other cases we imitate
this sort of measure. For in the case of a furlong or a talent or of
anything comparatively large any addition or subtraction might
more easily escape our notice than in the case of something
smaller; so that the first thing from which, as far as our
perception goes, nothing can be subtracted, all men make the
measure, whether of liquids or of solids, whether of weight or of
size; and they think they know the quantity when they know it
by means of this measure. And indeed they know movement
too by the simple movement and the quickest; for this occupies
least time. And so in astronomy a 'one' of this sort is the
starting-point and measure (for they assume the movement of
the heavens to be uniform and the quickest, and judge the
others by reference to it), and in music the quarter-tone
(because it is the least interval), and in speech the letter. And all
these are ones in this sense - not that 'one' is something
predicable in the same sense of all of these, but in the sense we
have mentioned.
But the measure is not always one in number - sometimes there
are several; e.g. the quarter-tones (not to the ear, but as
2413
determined by the ratios) are two, and the articulate sounds by
which we measure are more than one, and the diagonal of the
square and its side are measured by two quantities, and all
spatial magnitudes reveal similar varieties of unit. Thus, then,
the one is the measure of all things, because we come to know
the elements in the substance by dividing the things either in
respect of quantity or in respect of kind. And the one is
indivisible just because the first of each class of things is
indivisible. But it is not in the same way that every 'one' is
indivisible e.g. a foot and a unit; the latter is indivisible in every
respect, while the former must be placed among things which
are undivided to perception, as has been said already - only to
perception, for doubtless every continuous thing is divisible.
The measure is always homogeneous with the thing measured;
the measure of spatial magnitudes is a spatial magnitude, and
in particular that of length is a length, that of breadth a breadth,
that of articulate sound an articulate sound, that of weight a
weight, that of units a unit. (For we must state the matter so,
and not say that the measure of numbers is a number; we ought
indeed to say this if we were to use the corresponding form of
words, but the claim does not really correspond - it is as if one
claimed that the measure of units is units and not a unit;
number is a plurality of units.)
Knowledge, also, and perception, we call the measure of things
for the same reason, because we come to know something by
them - while as a matter of fact they are measured rather than
measure other things. But it is with us as if some one else
measured us and we came to know how big we are by seeing
that he applied the cubit-measure to such and such a fraction of
us. But Protagoras says 'man is the measure of all things', as if
he had said 'the man who knows' or 'the man who perceives';
and these because they have respectively knowledge and
perception, which we say are the measures of objects. Such
2414
thinkers are saying nothing, then, while they appear to be
saying something remarkable.
Evidently, then, unity in the strictest sense, if we define it
according to the meaning of the word, is a measure, and most
properly of quantity, and secondly of quality. And some things
will be one if they are indivisible in quantity, and others if they
are indivisible in quality; and so that which is one is indivisible,
either absolutely or qua one.
With regard to the substance and nature of the one we must ask
in which of two ways it exists. This is the very question that we
reviewed in our discussion of problems, viz. what the one is and
how we must conceive of it, whether we must take the one
itself as being a substance (as both the Pythagoreans say in
earlier and Plato in later times), or there is, rather, an underlying
nature and the one should be described more intelligibly and
more in the manner of the physical philosophers, of whom one
says the one is love, another says it is air, and another the
indefinite.
If, then, no universal can be a substance, as has been said our
discussion of substance and being, and if being itself cannot be
a substance in the sense of a one apart from the many (for it is
common to the many), but is only a predicate, clearly unity also
cannot be a substance; for being and unity are the most
universal of all predicates. Therefore, on the one hand, genera
are not certain entities and substances separable from other
things; and on the other hand the one cannot be a genus, for
the same reasons for which being and substance cannot be
genera.
2415
Further, the position must be similar in all the kinds of unity.
Now 'unity' has just as many meanings as 'being'; so that since
in the sphere of qualities the one is something definite - some
particular kind of thing - and similarly in the sphere of
quantities, clearly we must in every category ask what the one
is, as we must ask what the existent is, since it is not enough to
say that its nature is just to be one or existent. But in colours
the one is a colour, e.g. white, and then the other colours are
observed to be produced out of this and black, and black is the
privation of white, as darkness of light. Therefore if all existent
things were colours, existent things would have been a number,
indeed, but of what? Clearly of colours; and the 'one' would
have been a particular 'one', i.e. white. And similarly if all
existing things were tunes, they would have been a number, but
a number of quarter-tones, and their essence would not have
been number; and the one would have been something whose
substance was not to be one but to be the quarter-tone. And
similarly if all existent things had been articulate sounds, they
would have been a number of letters, and the one would have
been a vowel. And if all existent things were rectilinear figures,
they would have been a number of figures, and the one would
have been the triangle. And the same argument applies to all
other classes. Since, therefore, while there are numbers and a
one both in affections and in qualities and in quantities and in
movement, in all cases the number is a number of particular
things and the one is one something, and its substance is not
just to be one, the same must be true of substances also; for it is
true of all cases alike.
That the one, then, in every class is a definite thing, and in no
case is its nature just this, unity, is evident; but as in colours the
one-itself which we must seek is one colour, so too in substance
the one-itself is one substance. That in a sense unity means the
same as being is clear from the facts that its meanings
correspond to the categories one to one, and it is not comprised
2416
within any category (e.g. it is comprised neither in 'what a thing
is' nor in quality, but is related to them just as being is); that in
'one man' nothing more is predicated than in 'man' (just as
being is nothing apart from substance or quality or quantity);
and that to be one is just to be a particular thing.
The one and the many are opposed in several ways, of which
one is the opposition of the one and plurality as indivisible and
divisible; for that which is either divided or divisible is called a
plurality, and that which is indivisible or not divided is called
one. Now since opposition is of four kinds, and one of these two
terms is privative in meaning, they must be contraries, and
neither contradictory nor correlative in meaning. And the one
derives its name and its explanation from its contrary, the
indivisible from the divisible, because plurality and the divisible
is more perceptible than the indivisible, so that in definition
plurality is prior to the indivisible, because of the conditions of
perception.
To the one belong, as we indicated graphically in our distinction
of the contraries, the same and the like and the equal, and to
plurality belong the other and the unlike and the unequal. 'The
same' has several meanings; (1) we sometimes mean 'the same
numerically'; again, (2) we call a thing the same if it is one both
in definition and in number, e.g. you are one with yourself both
in form and in matter; and again, (3) if the definition of its
primary essence is one; e.g. equal straight lines are the same,
and so are equal and equal-angled quadrilaterals; there are
many such, but in these equality constitutes unity.
2417
Things are like if, not being absolutely the same, nor without
difference in respect of their concrete substance, they are the
same in form; e.g. the larger square is like the smaller, and
unequal straight lines are like; they are like, but not absolutely
the same. Other things are like, if, having the same form, and
being things in which difference of degree is possible, they have
no difference of degree. Other things, if they have a quality that
is in form one and same - e.g. whiteness - in a greater or less
degree, are called like because their form is one. Other things
are called like if the qualities they have in common are more
numerous than those in which they differ - either the qualities
in general or the prominent qualities; e.g. tin is like silver, qua
white, and gold is like fire, qua yellow and red.
Evidently, then, 'other' and 'unlike' also have several meanings.
And the other in one sense is the opposite of the same (so that
everything is either the same as or other than everything else).
In another sense things are other unless both their matter and
their definition are one (so that you are other than your
neighbour). The other in the third sense is exemplified in the
objects of mathematics. 'Other or the same' can therefore be
predicated of everything with regard to everything else - but
only if the things are one and existent, for 'other' is not the
contradictory of 'the same'; which is why it is not predicated of
non-existent things (while 'not the same' is so predicated). It is
predicated of all existing things; for everything that is existent
and one is by its very nature either one or not one with
anything else.
The other, then, and the same are thus opposed. But difference
is not the same as otherness. For the other and that which it is
other than need not be other in some definite respect (for
everything that is existent is either other or the same), but that
which is different is different from some particular thing in
some particular respect, so that there must be something
2418
identical whereby they differ. And this identical thing is genus
or species; for everything that differs differs either in genus or
in species, in genus if the things have not their matter in
common and are not generated out of each other (i.e. if they
belong to different figures of predication), and in species if they
have the same genus ('genus' meaning that identical thing
which is essentially predicated of both the different things).
Contraries are different, and contrariety is a kind of difference.
That we are right in this supposition is shown by induction. For
all of these too are seen to be different; they are not merely
other, but some are other in genus, and others are in the same
line of predication, and therefore in the same genus, and the
same in genus. We have distinguished elsewhere what sort of
things are the same or other in genus.
Since things which differ may differ from one another more or
less, there is also a greatest difference, and this I call contrariety.
That contrariety is the greatest difference is made clear by
induction. For things which differ in genus have no way to one
another, but are too far distant and are not comparable; and for
things that differ in species the extremes from which
generation takes place are the contraries, and the distance
between extremes - and therefore that between the contraries -
is the greatest.
But surely that which is greatest in each class is complete. For
that is greatest which cannot be exceeded, and that is complete
beyond which nothing can be found. For the complete
difference marks the end of a series (just as the other things
which are called complete are so called because they have
2419
attained an end), and beyond the end there is nothing; for in
everything it is the extreme and includes all else, and therefore
there is nothing beyond the end, and the complete needs
nothing further. From this, then, it is clear that contrariety is
complete difference; and as contraries are so called in several
senses, their modes of completeness will answer to the various
modes of contrariety which attach to the contraries.
This being so, it is clear that one thing have more than one
contrary (for neither can there be anything more extreme than
the extreme, nor can there be more than two extremes for the
one interval), and, to put the matter generally, this is clear if
contrariety is a difference, and if difference, and therefore also
the complete difference, must be between two things.
And the other commonly accepted definitions of contraries are
also necessarily true. For not only is (1) the complete difference
the greatest difference (for we can get no difference beyond it of
things differing either in genus or in species; for it has been
shown that there is no 'difference' between anything and the
things outside its genus, and among the things which differ in
species the complete difference is the greatest); but also (2) the
things in the same genus which differ most are contrary (for the
complete difference is the greatest difference between species
of the same genus); and (3) the things in the same receptive
material which differ most are contrary (for the matter is the
same for contraries); and (4) of the things which fall under the
same faculty the most different are contrary (for one science
deals with one class of things, and in these the complete
difference is the greatest).
The primary contrariety is that between positive state and
privation - not every privation, however (for 'privation' has
several meanings), but that which is complete. And the other
contraries must be called so with reference to these, some
2420
because they possess these, others because they produce or
tend to produce them, others because they are acquisitions or
losses of these or of other contraries. Now if the kinds of
opposition are contradiction and privation and contrariety and
relation, and of these the first is contradiction, and
contradiction admits of no intermediate, while contraries admit
of one, clearly contradiction and contrariety are not the same.
But privation is a kind of contradiction; for what suffers
privation, either in general or in some determinate way, either
that which is quite incapable of having some attribute or that
which, being of such a nature as to have it, has it not; here we
have already a variety of meanings, which have been
distinguished elsewhere. Privation, therefore, is a contradiction
or incapacity which is determinate or taken along with the
receptive material. This is the reason why, while contradiction
does not admit of an intermediate, privation sometimes does;
for everything is equal or not equal, but not everything is equal
or unequal, or if it is, it is only within the sphere of that which is
receptive of equality. If, then, the comings-to-be which happen
to the matter start from the contraries, and proceed either from
the form and the possession of the form or from a privation of
the form or shape, clearly all contrariety must be privation, but
presumably not all privation is contrariety (the reason being
that that has suffered privation may have suffered it in several
ways); for it is only the extremes from which changes proceed
that are contraries.
And this is obvious also by induction. For every contrariety
involves, as one of its terms, a privation, but not all cases are
alike; inequality is the privation of equality and unlikeness of
likeness, and on the other hand vice is the privation of virtue.
But the cases differ in a way already described; in one case we
mean simply that the thing has suffered privation, in another
case that it has done so either at a certain time or in a certain
part (e.g. at a certain age or in the dominant part), or
2421
throughout. This is why in some cases there is a mean (there
are men who are neither good nor bad), and in others there is
not (a number must be either odd or even). Further, some
contraries have their subject defined, others have not. Therefore
it is evident that one of the contraries is always privative; but it
is enough if this is true of the first - i.e. the generic - contraries,
e.g. the one and the many; for the others can be reduced to
these.
Since one thing has one contrary, we might raise the question
how the one is opposed to the many, and the equal to the great
and the small. For if we used the word 'whether' only in an
antithesis such as 'whether it is white or black', or 'whether it is
white or not white' (we do not ask 'whether it is a man or
white'), unless we are proceeding on a prior assumption and
asking something such as 'whether it was Cleon or Socrates
that came' as this is not a necessary disjunction in any class of
things; yet even this is an extension from the case of opposites;
for opposites alone cannot be present together; and we assume
this incompatibility here too in asking which of the two came;
for if they might both have come, the question would have been
absurd; but if they might, even so this falls just as much into an
antithesis, that of the 'one or many', i.e. 'whether both came or
one of the two': - if, then, the question 'whether' is always
concerned with opposites, and we can ask 'whether it is greater
or less or equal', what is the opposition of the equal to the other
two? It is not contrary either to one alone or to both; for why
should it be contrary to the greater rather than to the less?
Further, the equal is contrary to the unequal. Therefore if it is
contrary to the greater and the less, it will be contrary to more
2422
things than one. But if the unequal means the same as both the
greater and the less together, the equal will be opposite to both
(and the difficulty supports those who say the unequal is a
'two'), but it follows that one thing is contrary to two others,
which is impossible. Again, the equal is evidently intermediate
between the great and the small, but no contrariety is either
observed to be intermediate, or, from its definition, can be so;
for it would not be complete if it were intermediate between
any two things, but rather it always has something intermediate
between its own terms.
It remains, then, that it is opposed either as negation or as
privation. It cannot be the negation or privation of one of the
two; for why of the great rather than of the small? It is, then, the
privative negation of both. This is why 'whether' is said with
reference to both, not to one of the two (e.g. 'whether it is
greater or equal' or 'whether it is equal or less'); there are
always three cases. But it is not a necessary privation; for not
everything which is not greater or less is equal, but only the
things which are of such a nature as to have these attributes.
The equal, then, is that which is neither great nor small but is
naturally fitted to be either great or small; and it is opposed to
both as a privative negation (and therefore is also intermediate).
And that which is neither good nor bad is opposed to both, but
has no name; for each of these has several meanings and the
recipient subject is not one; but that which is neither white nor
black has more claim to unity. Yet even this has not one name,
though the colours of which this negation is privatively
predicated are in a way limited; for they must be either grey or
yellow or something else of the kind. Therefore it is an incorrect
criticism that is passed by those who think that all such phrases
are used in the same way, so that that which is neither a shoe
nor a hand would be intermediate between a shoe and a hand,
since that which is neither good nor bad is intermediate
2423
between the good and the bad - as if there must be an
intermediate in all cases. But this does not necessarily follow.
For the one phrase is a joint denial of opposites between which
there is an intermediate and a certain natural interval; but
between the other two there is no 'difference'; for the things,
the denials of which are combined, belong to different classes,
so that the substratum is not one.
We might raise similar questions about the one and the many.
For if the many are absolutely opposed to the one, certain
impossible results follow. One will then be few, whether few be
treated here as singular or plural; for the many are opposed also
to the few. Further, two will be many, since the double is
multiple and 'double' derives its meaning from 'two'; therefore
one will be few; for what is that in comparison with which two
are many, except one, which must therefore be few? For there is
nothing fewer. Further, if the much and the little are in plurality
what the long and the short are in length, and whatever is
much is also many, and the many are much (unless, indeed,
there is a difference in the case of an easily-bounded
continuum), the little (or few) will be a plurality. Therefore one is
a plurality if it is few; and this it must be, if two are many. But
perhaps, while the 'many' are in a sense said to be also 'much',
it is with a difference; e.g. water is much but not many. But
'many' is applied to the things that are divisible; in the one
sense it means a plurality which is excessive either absolutely
or relatively (while 'few' is similarly a plurality which is
deficient), and in another sense it means number, in which
sense alone it is opposed to the one. For we say 'one or many',
just as if one were to say 'one and ones' or 'white thing and
2424
white things', or to compare the things that have been
measured with the measure. It is in this sense also that
multiples are so called. For each number is said to be many
because it consists of ones and because each number is
measurable by one; and it is 'many' as that which is opposed to
one, not to the few. In this sense, then, even two is many - not,
however, in the sense of a plurality which is excessive either
relatively or absolutely; it is the first plurality. But without
qualification two is few; for it is first plurality which is deficient
(for this reason Anaxagoras was not right in leaving the subject
with the statement that 'all things were together, boundless
both in plurality and in smallness' - where for 'and in
smallness' he should have said 'and in fewness'; for they could
not have been boundless in fewness), since it is not one, as
some say, but two, that make a few.
The one is opposed then to the many in numbers as measure to
thing measurable; and these are opposed as are the relatives
which are not from their very nature relatives. We have
distinguished elsewhere the two senses in which relatives are
so called: - (1) as contraries; (2) as knowledge to thing known, a
term being called relative because another is relative to it. There
is nothing to prevent one from being fewer than something, e.g.
than two; for if one is fewer, it is not therefore few. Plurality is as
it were the class to which number belongs; for number is
plurality measurable by one, and one and number are in a sense
opposed, not as contrary, but as we have said some relative
terms are opposed; for inasmuch as one is measure and the
other measurable, they are opposed. This is why not everything
that is one is a number; i.e. if the thing is indivisible it is not a
number. But though knowledge is similarly spoken of as relative
to the knowable, the relation does not work out similarly; for
while knowledge might be thought to be the measure, and the
knowable the thing measured, the fact that all knowledge is
knowable, but not all that is knowable is knowledge, because in
2425
a sense knowledge is measured by the knowable. - Plurality is
contrary neither to the few (the many being contrary to this as
excessive plurality to plurality exceeded), nor to the one in
every sense; but in the one sense these are contrary, as has been
said, because the former is divisible and the latter indivisible,
while in another sense they are relative as knowledge is to
knowable, if plurality is number and the one is a measure.
Since contraries admit of an intermediate and in some cases
have it, intermediates must be composed of the contraries. For
(1) all intermediates are in the same genus as the things
between which they stand. For we call those things
intermediates, into which that which changes must change
first; e.g. if we were to pass from the highest string to the lowest
by the smallest intervals, we should come sooner to the
intermediate notes, and in colours if we were to pass from
white to black, we should come sooner to crimson and grey
than to black; and similarly in all other cases. But to change
from one genus to another genus is not possible except in an
incidental way, as from colour to figure. Intermediates, then,
must be in the same genus both as one another and as the
things they stand between.
But (2) all intermediates stand between opposites of some kind;
for only between these can change take place in virtue of their
own nature (so that an intermediate is impossible between
things which are not opposite; for then there would be change
which was not from one opposite towards the other). Of
opposites, contradictories admit of no middle term; for this is
what contradiction is - an opposition, one or other side of
2426
which must attach to anything whatever, i.e. which has no
intermediate. Of other opposites, some are relative, others
privative, others contrary. Of relative terms, those which are not
contrary have no intermediate; the reason is that they are not in
the same genus. For what intermediate could there be between
knowledge and knowable? But between great and small there is
one.
(3) If intermediates are in the same genus, as has been shown,
and stand between contraries, they must be composed of these
contraries. For either there will be a genus including the
contraries or there will be none. And if (a) there is to be a genus
in such a way that it is something prior to the contraries, the
differentiae which constituted the contrary species-of-a-genus
will be contraries prior to the species; for species are composed
of the genus and the differentiae. (E.g. if white and black are
contraries, and one is a piercing colour and the other a
compressing colour, these differentiae - 'piercing' and
'compressing' - are prior; so that these are prior contraries of
one another.) But, again, the species which differ contrariwise
are the more truly contrary species. And the other.species, i.e.
the intermediates, must be composed of their genus and their
differentiae. (E.g. all colours which are between white and black
must be said to be composed of the genus, i.e. colour, and
certain differentiae. But these differentiae will not be the
primary contraries; otherwise every colour would be either
white or black. They are different, then, from the primary
contraries; and therefore they will be between the primary
contraries; the primary differentiae are 'piercing' and
'compressing'.)
Therefore it is (b) with regard to these contraries which do not
fall within a genus that we must first ask of what their
intermediates are composed. (For things which are in the same
genus must be composed of terms in which the genus is not an
2427
element, or else be themselves incomposite.) Now contraries do
not involve one another in their composition, and are therefore
first principles; but the intermediates are either all incomposite,
or none of them. But there is something compounded out of the
contraries, so that there can be a change from a contrary to it
sooner than to the other contrary; for it will have less of the
quality in question than the one contrary and more than the
other. This also, then, will come between the contraries. All the
other intermediates also, therefore, are composite; for that
which has more of a quality than one thing and less than
another is compounded somehow out of the things than which
it is said to have more and less respectively of the quality. And
since there are no other things prior to the contraries and
homogeneous with the intermediates, all intermediates must
be compounded out of the contraries. Therefore also all the
inferior classes, both the contraries and their intermediates, will
be compounded out of the primary contraries. Clearly, then,
intermediates are (1) all in the same genus and (2) intermediate
between contraries, and (3) all compounded out of the
contraries.
8
That which is other in species is other than something in
something, and this must belong to both; e.g. if it is an animal
other in species, both are animals. The things, then, which are
other in species must be in the same genus. For by genus I
mean that one identical thing which is predicated of both and is
differentiated in no merely accidental way, whether conceived
as matter or otherwise. For not only must the common nature
attach to the different things, e.g. not only must both be
animals, but this very animality must also be different for each
2428
(e.g. in the one case equinity, in the other humanity), and so this
common nature is specifically different for each from what it is
for the other. One, then, will be in virtue of its own nature one
sort of animal, and the other another, e.g. one a horse and the
other a man. This difference, then, must be an otherness of the
genus. For I give the name of 'difference in the genus' an
otherness which makes the genus itself other.
This, then, will be a contrariety (as can be shown also by
induction). For all things are divided by opposites, and it has
been proved that contraries are in the same genus. For
contrariety was seen to be complete difference; and all
difference in species is a difference from something in
something; so that this is the same for both and is their genus.
(Hence also all contraries which are different in species and not
in genus are in the same line of predication, and other than one
another in the highest degree - for the difference is complete - ,
and cannot be present along with one another.) The difference,
then, is a contrariety.
This, then, is what it is to be 'other in species' - to have a
contrariety, being in the same genus and being indivisible (and
those things are the same in species which have no contrariety,
being indivisible); we say 'being indivisible', for in the process of
division contrarieties arise in the intermediate stages before we
come to the indivisibles. Evidently, therefore, with reference to
that which is called the genus, none of the species-of-a-genus is
either the same as it or other than it in species (and this is
fitting; for the matter is indicated by negation, and the genus is
the matter of that of which it is called the genus, not in the
sense in which we speak of the genus or family of the
Heraclidae, but in that in which the genus is an element in a
thing's nature), nor is it so with reference to things which are
not in the same genus, but it will differ in genus from them, and
in species from things in the same genus. For a thing's
2429
difference from that from which it differs in species must be a
contrariety; and this belongs only to things in the same genus.
One might raise the question, why woman does not differ from
man in species, when female and male are contrary and their
difference is a contrariety; and why a female and a male animal
are not different in species, though this difference belongs to
animal in virtue of its own nature, and not as paleness or
darkness does; both 'female' and 'male' belong to it qua animal.
This question is almost the same as the other, why one
contrariety makes things different in species and another does
not, e.g. 'with feet' and 'with wings' do, but paleness and
darkness do not. Perhaps it is because the former are
modifications peculiar to the genus, and the latter are less so.
And since one element is definition and one is matter,
contrarieties which are in the definition make a difference in
species, but those which are in the thing taken as including its
matter do not make one. And so paleness in a man, or darkness,
does not make one, nor is there a difference in species between
the pale man and the dark man, not even if each of them be
denoted by one word. For man is here being considered on his
material side, and matter does not create a difference; for it
does not make individual men species of man, though the flesh
and the bones of which this man and that man consist are
other. The concrete thing is other, but not other in species,
because in the definition there is no contrariety. This is the
ultimate indivisible kind. Callias is definition + matter, the pale
man, then, is so also, because it is the individual Callias that is
pale; man, then, is pale only incidentally. Neither do a brazen
and a wooden circle, then, differ in species; and if a brazen
2430
triangle and a wooden circle differ in species, it is not because
of the matter, but because there is a contrariety in the
definition. But does the matter not make things other in
species, when it is other in a certain way, or is there a sense in
which it does? For why is this horse other than this man in
species, although their matter is included with their
definitions? Doubtless because there is a contrariety in the
definition. For while there is a contrariety also between pale
man and dark horse, and it is a contrariety in species, it does
not depend on the paleness of the one and the darkness of the
other, since even if both had been pale, yet they would have
been other in species. But male and female, while they are
modifications peculiar to 'animal', are so not in virtue of its
essence but in the matter, ie. the body. This is why the same
seed becomes female or male by being acted on in a certain
way. We have stated, then, what it is to be other in species, and
why some things differ in species and others do not.
10
Since contraries are other in form, and the perishable and the
imperishable are contraries (for privation is a determinate
incapacity), the perishable and the imperishable must be
different in kind.
Now so far we have spoken of the general terms themselves, so
that it might be thought not to be necessary that every
imperishable thing should be different from every perishable
thing in form, just as not every pale thing is different in form
from every dark thing. For the same thing can be both, and even
at the same time if it is a universal (e.g. man can be both pale
and dark), and if it is an individual it can still be both; for the
2431
same man can be, though not at the same time, pale and dark.
Yet pale is contrary to dark.
But while some contraries belong to certain things by accident
(e.g. both those now mentioned and many others), others
cannot, and among these are 'perishable' and 'imperishable'. For
nothing is by accident perishable. For what is accidental is
capable of not being present, but perishableness is one of the
attributes that belong of necessity to the things to which they
belong; or else one and the same thing may be perishable and
imperishable, if perishableness is capable of not belonging to it.
Perishableness then must either be the essence or be present in
the essence of each perishable thing. The same account holds
good for imperishableness also; for both are attributes which
are present of necessity. The characteristics, then, in respect of
which and in direct consequence of which one thing is
perishable and another imperishable, are opposite, so that the
things must be different in kind.
Evidently, then, there cannot be Forms such as some maintain,
for then one man would be perishable and another
imperishable. Yet the Forms are said to be the same in form
with the individuals and not merely to have the same name; but
things which differ in kind are farther apart than those which
differ in form.
2432
BookK
That Wisdom is a science of first principles is evident from the
introductory chapters, in which we have raised objections to the
statements of others about the first principles; but one might
ask the question whether Wisdom is to be conceived as one
science or as several. If as one, it may be objected that one
science always deals with contraries, but the first principles are
not contrary. If it is not one, what sort of sciences are those with
which it is to be identified?
Further, is it the business of one science, or of more than one, to
examine the first principles of demonstration? If of one, why of
this rather than of any other? If of more, what sort of sciences
must these be said to be?
Further, does Wisdom investigate all substances or not? If not
all, it is hard to say which; but if, being one, it investigates them
all, it is doubtful how the same science can embrace several
subject-matters.
Further, does it deal with substances only or also with their
attributes? If in the case of attributes demonstration is possible,
in that of substances it is not. But if the two sciences are
different, what is each of them and which is Wisdom? If we
think of it as demonstrative, the science of the attributes is
Wisdom, but if as dealing with what is primary, the science of
substances claims the tide.
But again the science we are looking for must not be supposed
to deal with the causes which have been mentioned in the
2433
Physics. For (A) it does not deal with the final cause (for that is
the nature of the good, and this is found in the field of action
and movement; and it is the first mover - for that is the nature
of the end - but in the case of things unmovable there is
nothing that moved them first), and (B) in general it is hard to
say whether perchance the science we are now looking for deals
with perceptible substances or not with them, but with certain
others. If with others, it must deal either with the Forms or with
the objects of mathematics. Now (a) evidently the Forms do not
exist. (But it is hard to say, even if one suppose them to exist,
why in the world the same is not true of the other things of
which there are Forms, as of the objects of mathematics. I mean
that these thinkers place the objects of mathematics between
the Forms and perceptible things, as a kind of third set of things
apart both from the Forms and from the things in this world;
but there is not a third man or horse besides the ideal and the
individuals. If on the other hand it is not as they say, with what
sort of things must the mathematician be supposed to deal?
Certainly not with the things in this world; for none of these is
the sort of thing which the mathematical sciences demand.)
Nor (b) does the science which we are now seeking treat of the
objects of mathematics; for none of them can exist separately.
But again it does not deal with perceptible substances; for they
are perishable.
In general one might raise the question, to what kind of science
it belongs to discuss the difficulties about the matter of the
objects of mathematics. Neither to physics (because the whole
inquiry of the physicist is about the things that have in
themselves a principle, of movement and rest), nor yet to the
science which inquires into demonstration and science; for this
is just the subject which it investigates. It remains then that it is
the philosophy which we have set before ourselves that treats
of those subjects.
2434
One might discuss the question whether the science we are
seeking should be said to deal with the principles which are by
some called elements; all men suppose these to be present in
composite things. But it might be thought that the science we
seek should treat rather of universals; for every definition and
every science is of universals and not of infimae species, so that
as far as this goes it would deal with the highest genera. These
would turn out to be being and unity; for these might most of
all be supposed to contain all things that are, and to be most
like principles because they are by nature; for if they perish all
other things are destroyed with them; for everything is and is
one. But inasmuch as, if one is to suppose them to be genera,
they must be predicable of their differentiae, and no genus is
predicable of any of its differentiae, in this way it would seem
that we should not make them genera nor principles. Further, if
the simpler is more of a principle than the less simple, and the
ultimate members of the genus are simpler than the genera (for
they are indivisible, but the genera are divided into many and
differing species), the species might seem to be the principles,
rather than the genera. But inasmuch as the species are
involved in the destruction of the genera, the genera are more
like principles; for that which involves another in its destruction
is a principle of it. These and others of the kind are the subjects
that involve difficulties.
Further, must we suppose something apart from individual
things, or is it these that the science we are seeking treats of?
But these are infinite in number. Yet the things that are apart
from the individuals are genera or species; but the science we
now seek treats of neither of these. The reason why this is
2435
impossible has been stated. Indeed, it is in general hard to say
whether one must assume that there is a separable substance
besides the sensible substances (i.e. the substances in this
world), or that these are the real things and Wisdom is
concerned with them. For we seem to seek another kind of
substance, and this is our problem, i.e. to see if there is
something which can exist apart by itself and belongs to no
sensible thing. - Further, if there is another substance apart
from and corresponding to sensible substances, which kinds of
sensible substance must be supposed to have this
corresponding to them? Why should one suppose men or
horses to have it, more than either the other animals or even all
lifeless things? On the other hand to set up other and eternal
substances equal in number to the sensible and perishable
substances would seem to fall beyond the bounds of probability.
- But if the principle we now seek is not separable from
corporeal things, what has a better claim to the name matter?
This, however, does not exist in actuality, but exists in potency.
And it would seem rather that the form or shape is a more
important principle than this; but the form is perishable, so that
there is no eternal substance at all which can exist apart and
independent. But this is paradoxical; for such a principle and
substance seems to exist and is sought by nearly all the most
refined thinkers as something that exists; for how is there to be
order unless there is something eternal and independent and
permanent?
Further, if there is a substance or principle of such a nature as
that which we are now seeking, and if this is one for all things,
and the same for eternal and for perishable things, it is hard to
say why in the world, if there is the same principle, some of the
things that fall under the principle are eternal, and others are
not eternal; this is paradoxical. But if there is one principle of
perishable and another of eternal things, we shall be in a like
difficulty if the principle of perishable things, as well as that of
2436
eternal, is eternal; for why, if the principle is eternal, are not the
things that fall under the principle also eternal? But if it is
perishable another principle is involved to account for it, and
another to account for that, and this will go on to infinity.
If on the other hand we are to set up what are thought to be the
most unchangeable principles, being and unity, firstly, if each of
these does not indicate a 'this' or substance, how will they be
separable and independent? Yet we expect the eternal and
primary principles to be so. But if each of them does signify a
'this' or substance, all things that are are substances; for being
is predicated of all things (and unity also of some); but that all
things that are are substance is false. Further, how can they be
right who say that the first principle is unity and this is
substance, and generate number as the first product from unity
and from matter, assert that number is substance? How are we
to think of 'two', and each of the other numbers composed of
units, as one? On this point neither do they say anything nor is
it easy to say anything. But if we are to suppose lines or what
comes after these (I mean the primary surfaces) to be principles,
these at least are not separable substances, but sections and
divisions - the former of surfaces, the latter of bodies (while
points are sections and divisions of lines); and further they are
limits of these same things; and all these are in other things
and none is separable. Further, how are we to suppose that
there is a substance of unity and the point? Every substance
comes into being by a gradual process, but a point does not; for
the point is a division.
A further difficulty is raised by the fact that all knowledge is of
universals and of the 'such', but substance is not a universal,
but is rather a 'this' - a separable thing, so that if there is
knowledge about the first principles, the question arises, how
are we to suppose the first principle to be substance?
2437
Further, is there anything apart from the concrete thing (by
which I mean the matter and that which is joined with it), or
not? If not, we are met by the objection that all things that are
in matter are perishable. But if there is something, it must be
the form or shape. Now it is hard to determine in which cases
this exists apart and in which it does not; for in some cases the
form is evidently not separable, e.g. in the case of a house.
Further, are the principles the same in kind or in number? If
they are one in number, all things will be the same.
Since the science of the philosopher treats of being qua being
universally and not in respect of a part of it, and 'being' has
many senses and is not used in one only, it follows that if the
word is used equivocally and in virtue of nothing common to its
various uses, being does not fall under one science (for the
meanings of an equivocal term do not form one genus); but if
the word is used in virtue of something common, being will fall
under one science. The term seems to be used in the way we
have mentioned, like 'medical' and 'healthy'. For each of these
also we use in many senses. Terms are used in this way by
virtue of some kind of reference, in the one case to medical
science, in the other to health, in others to something else, but
in each case to one identical concept. For a discussion and a
knife are called medical because the former proceeds from
medical science, and the latter is useful to it. And a thing is
called healthy in a similar way; one thing because it is
indicative of health, another because it is productive of it. And
the same is true in the other cases. Everything that is, then, is
said to 'be' in this same way; each thing that is is said to 'be'
2438
because it is a modification of being qua being or a permanent
or a transient state or a movement of it, or something else of
the sort. And since everything that is may be referred to
something single and common, each of the contrarieties also
may be referred to the first differences and contrarieties of
being, whether the first differences of being are plurality and
unity, or likeness and unlikeness, or some other differences; let
these be taken as already discussed. It makes no difference
whether that which is be referred to being or to unity. For even
if they are not the same but different, at least they are
convertible; for that which is one is also somehow being, and
that which is being is one.
But since every pair of contraries falls to be examined by one
and the same science, and in each pair one term is the privative
of the other though one might regarding some contraries raise
the question, how they can be privately related, viz. those which
have an intermediate, e.g. unjust and just - in all such cases one
must maintain that the privation is not of the whole definition,
but of the infima species, if the just man is 'by virtue of some
permanent disposition obedient to the laws', the unjust man
will not in every case have the whole definition denied of him,
but may be merely 'in some respect deficient in obedience to
the laws', and in this respect the privation will attach to him;
and similarly in all other cases.
As the mathematician investigates abstractions (for before
beginning his investigation he strips off all the sensible
qualities, e.g. weight and lightness, hardness and its contrary,
and also heat and cold and the other sensible contrarieties, and
leaves only the quantitative and continuous, sometimes in one,
sometimes in two, sometimes in three dimensions, and the
attributes of these qua quantitative and continuous, and does
not consider them in any other respect, and examines the
relative positions of some and the attributes of these, and the
2439
commensurabilities and incommensurabilities of others, and
the ratios of others; but yet we posit one and the same science
of all these things - geometry) - the same is true with regard to
being. For the attributes of this in so far as it is being, and the
contrarieties in it qua being, it is the business of no other
science than philosophy to investigate; for to physics one would
assign the study of things not qua being, but rather qua sharing
in movement; while dialectic and sophistic deal with the
attributes of things that are, but not of things qua being, and
not with being itself in so far as it is being; therefore it remains
that it is the philosopher who studies the things we have
named, in so far as they are being. Since all that is is to 'be' in
virtue of something single and common, though the term has
many meanings, and contraries are in the same case (for they
are referred to the first contrarieties and differences of being),
and things of this sort can fall under one science, the difficulty
we stated at the beginning appears to be solved, - I mean the
question how there can be a single science of things which are
many and different in genus.
Since even the mathematician uses the common axioms only in
a special application, it must be the business of first philosophy
to examine the principles of mathematics also. That when
equals are taken from equals the remainders are equal, is
common to all quantities, but mathematics studies a part of its
proper matter which it has detached, e.g. lines or angles or
numbers or some other kind of quantity - not, however, qua
being but in so far as each of them is continuous in one or two
or three dimensions; but philosophy does not inquire about
particular subjects in so far as each of them has some attribute
2440
or other, but speculates about being, in so far as each particular
thing is. - Physics is in the same position as mathematics; for
physics studies the attributes and the principles of the things
that are, qua moving and not qua being (whereas the primary
science, we have said, deals with these, only in so far as the
underlying subjects are existent, and not in virtue of any other
character); and so both physics and mathematics must be
classed as parts of Wisdom.
There is a principle in things, about which we cannot be
deceived, but must always, on the contrary recognize the truth,
- viz. that the same thing cannot at one and the same time be
and not be, or admit any other similar pair of opposites. About
such matters there is no proof in the full sense, though there is
proof ad hominem. For it is not possible to infer this truth itself
from a more certain principle, yet this is necessary if there is to
be completed proof of it in the full sense. But he who wants to
prove to the asserter of opposites that he is wrong must get
from him an admission which shall be identical with the
principle that the same thing cannot be and not be at one and
the same time, but shall not seem to be identical; for thus alone
can his thesis be demonstrated to the man who asserts that
opposite statements can be truly made about the same subject.
Those, then, who are to join in argument with one another must
to some extent understand one another; for if this does not
happen how are they to join in argument with one another?
Therefore every word must be intelligible and indicate
something, and not many things but only one; and if it signifies
more than one thing, it must be made plain to which of these
the word is being applied. He, then, who says 'this is and is not'
2441
denies what he affirms, so that what the word signifies, he says
it does not signify; and this is impossible. Therefore if 'this is'
signifies something, one cannot truly assert its contradictory.
Further, if the word signifies something and this is asserted
truly, this connexion must be necessary; and it is not possible
that that which necessarily is should ever not be; it is not
possible therefore to make the opposed affirmations and
negations truly of the same subject. Further, if the affirmation is
no more true than the negation, he who says 'man' will be no
more right than he who says 'not-man'. It would seem also that
in saying the man is not a horse one would be either more or
not less right than in saying he is not a man, so that one will
also be right in saying that the same person is a horse; for it was
assumed to be possible to make opposite statements equally
truly. It follows then that the same person is a man and a horse,
or any other animal.
While, then, there is no proof of these things in the full sense,
there is a proof which may suffice against one who will make
these suppositions. And perhaps if one had questioned
Heraclitus himself in this way one might have forced him to
confess that opposite statements can never be true of the same
subjects. But, as it is, he adopted this opinion without
understanding what his statement involves. But in any case if
what is said by him is true, not even this itself will be true - viz.
that the same thing can at one and the same time both be and
not be. For as, when the statements are separated, the
affirmation is no more true than the negation, in the same way
- the combined and complex statement being like a single
affirmation - the whole taken as an affirmation will be no more
true than the negation. Further, if it is not possible to affirm
anything truly, this itself will be false - the assertion that there
is no true affirmation. But if a true affirmation exists, this
2442
appears to refute what is said by those who raise such
objections and utterly destroy rational discourse.
The saying of Protagoras is like the views we have mentioned;
he said that man is the measure of all things, meaning simply
that that which seems to each man also assuredly is. If this is
so, it follows that the same thing both is and is not, and is bad
and good, and that the contents of all other opposite
statements are true, because often a particular thing appears
beautiful to some and the contrary of beautiful to others, and
that which appears to each man is the measure. This difficulty
may be solved by considering the source of this opinion. It
seems to have arisen in some cases from the doctrine of the
natural philosophers, and in others from the fact that all men
have not the same views about the same things, but a particular
thing appears pleasant to some and the contrary of pleasant to
others.
That nothing comes to be out of that which is not, but
everything out of that which is, is a dogma common to nearly
all the natural philosophers. Since, then, white cannot come to
be if the perfectly white and in no respect not-white existed
before, that which becomes white must come from that which
is not white; so that it must come to be out of that which is not
(so they argue), unless the same thing was at the beginning
white and not-white. But it is not hard to solve this difficulty;
for we have said in our works on physics in what sense things
that come to be come to be from that which is not, and in what
sense from that which is.
2443
But to attend equally to the opinions and the fancies of
disputing parties is childish; for clearly one of them must be
mistaken. And this is evident from what happens in respect of
sensation; for the same thing never appears sweet to some and
the contrary of sweet to others, unless in the one case the
sense-organ which discriminates the aforesaid flavours has
been perverted and injured. And if this is so the one party must
be taken to be the measure, and the other must not. And say the
same of good and bad, and beautiful and ugly, and all other
such qualities. For to maintain the view we are opposing is just
like maintaining that the things that appear to people who put
their finger under their eye and make the object appear two
instead of one must be two (because they appear to be of that
number) and again one (for to those who do not interfere with
their eye the one object appears one).
In general, it is absurd to make the fact that the things of this
earth are observed to change and never to remain in the same
state, the basis of our judgement about the truth. For in
pursuing the truth one must start from the things that are
always in the same state and suffer no change. Such are the
heavenly bodies; for these do not appear to be now of one
nature and again of another, but are manifestly always the
same and share in no change.
Further, if there is movement, there is also something moved,
and everything is moved out of something and into something;
it follows that that that which is moved must first be in that out
of which it is to be moved, and then not be in it, and move into
the other and come to be in it, and that the contradictory
statements are not true at the same time, as these thinkers
assert they are.
And if the things of this earth continuously flow and move in
respect of quantity - if one were to suppose this, although it is
2444
not true - why should they not endure in respect of quality? For
the assertion of contradictory statements about the same thing
seems to have arisen largely from the belief that the quantity of
bodies does not endure, which, our opponents hold, justifies
them in saying that the same thing both is and is not four
cubits long. But essence depends on quality, and this is of
determinate nature, though quantity is of indeterminate.
Further, when the doctor orders people to take some particular
food, why do they take it? In what respect is 'this is bread' truer
than 'this is not bread'? And so it would make no difference
whether one ate or not. But as a matter of fact they take the
food which is ordered, assuming that they know the truth about
it and that it is bread. Yet they should not, if there were no fixed
constant nature in sensible things, but all natures moved and
flowed for ever.
Again, if we are always changing and never remain the same,
what wonder is it if to us, as to the sick, things never appear the
same? (For to them also, because they are not in the same
condition as when they were well, sensible qualities do not
appear alike; yet, for all that, the sensible things themselves
need not share in any change, though they produce different,
and not identical, sensations in the sick. And the same must
surely happen to the healthy if the afore-said change takes
place.) But if we do not change but remain the same, there will
be something that endures.
As for those to whom the difficulties mentioned are suggested
by reasoning, it is not easy to solve the difficulties to their
satisfaction, unless they will posit something and no longer
demand a reason for it; for it is only thus that all reasoning and
all proof is accomplished; if they posit nothing, they destroy
discussion and all reasoning. Therefore with such men there is
no reasoning. But as for those who are perplexed by the
2445
traditional difficulties, it is easy to meet them and to dissipate
the causes of their perplexity. This is evident from what has
been said.
It is manifest, therefore, from these arguments that
contradictory statements cannot be truly made about the same
subject at one time, nor can contrary statements, because every
contrariety depends on privation. This is evident if we reduce
the definitions of contraries to their principle.
Similarly, no intermediate between contraries can be predicated
of one and the same subject, of which one of the contraries is
predicated. If the subject is white we shall be wrong in saying it
is neither black nor white, for then it follows that it is and is not
white; for the second of the two terms we have put together is
true of it, and this is the contradictory of white.
We could not be right, then, in accepting the views either of
Heraclitus or of Anaxagoras. If we were, it would follow that
contraries would be predicated of the same subject; for when
Anaxagoras says that in everything there is a part of everything,
he says nothing is sweet any more than it is bitter, and so with
any other pair of contraries, since in everything everything is
present not potentially only, but actually and separately. And
similarly all statements cannot be false nor all true, both
because of many other difficulties which might be adduced as
arising from this position, and because if all are false it will not
be true to say even this, and if all are true it will not be false to
say all are false.
2446
Every science seeks certain principles and causes for each of its
objects - e.g. medicine and gymnastics and each of the other
sciences, whether productive or mathematical. For each of
these marks off a certain class of things for itself and busies
itself about this as about something existing and real, - not
however qua real; the science that does this is another distinct
from these. Of the sciences mentioned each gets somehow the
'what' in some class of things and tries to prove the other
truths, with more or less precision. Some get the 'what' through
perception, others by hypothesis; so that it is clear from an
induction of this sort that there is no demonstration, of the
substance or 'what'.
There is a science of nature, and evidently it must be different
both from practical and from productive science. For in the case
of productive science the principle of movement is in the
producer and not in the product, and is either an art or some
other faculty. And similarly in practical science the movement is
not in the thing done, but rather in the doers. But the science of
the natural philosopher deals with the things that have in
themselves a principle of movement. It is clear from these facts,
then, that natural science must be neither practical nor
productive, but theoretical (for it must fall into some one of
these classes). And since each of the sciences must somehow
know the 'what' and use this as a principle, we must not fall to
observe how the natural philosopher should define things and
how he should state the definition of the essence - whether as
akin to 'snub' or rather to 'concave'. For of these the definition
of 'snub' includes the matter of the thing, but that of 'concave'
is independent of the matter; for snubness is found in a nose, so
that we look for its definition without eliminating the nose, for
what is snub is a concave nose. Evidently then the definition of
2447
flesh also and of the eye and of the other parts must always be
stated without eliminating the matter.
Since there is a science of being qua being and capable of
existing apart, we must consider whether this is to be regarded
as the same as physics or rather as different. Physics deals with
the things that have a principle of movement in themselves;
mathematics is theoretical, and is a science that deals with
things that are at rest, but its subjects cannot exist apart.
Therefore about that which can exist apart and is unmovable
there is a science different from both of these, if there is a
substance of this nature (I mean separable and unmovable), as
we shall try to prove there is. And if there is such a kind of thing
in the world, here must surely be the divine, and this must be
the first and most dominant principle. Evidently, then, there are
three kinds of theoretical sciences - physics, mathematics,
theology. The class of theoretical sciences is the best, and of
these themselves the last named is best; for it deals with the
highest of existing things, and each science is called better or
worse in virtue of its proper object.
One might raise the question whether the science of being qua
being is to be regarded as universal or not. Each of the
mathematical sciences deals with some one determinate class
of things, but universal mathematics applies alike to all. Now if
natural substances are the first of existing things, physics must
be the first of sciences; but if there is another entity and
substance, separable and unmovable, the knowledge of it must
be different and prior to physics and universal because it is
prior.
2448
8
Since 'being' in general has several senses, of which one is
'being by accident', we must consider first that which 'is' in this
sense. Evidently none of the traditional sciences busies itself
about the accidental. For neither does architecture consider
what will happen to those who are to use the house (e.g.
whether they have a painful life in it or not), nor does weaving,
or shoemaking, or the confectioner's art, do the like; but each of
these sciences considers only what is peculiar to it, i.e. its
proper end. And as for the argument that 'when he who is
musical becomes lettered he'll be both at once, not having been
both before; and that which is, not always having been, must
have come to be; therefore he must have at once become
musical and lettered', - this none of the recognized sciences
considers, but only sophistic; for this alone busies itself about
the accidental, so that Plato is not far wrong when he says that
the sophist spends his time on non-being.
That a science of the accidental is not even possible will be
evident if we try to see what the accidental really is. We say that
everything either is always and of necessity (necessity not in
the sense of violence, but that which we appeal to in
demonstrations), or is for the most part, or is neither for the
most part, nor always and of necessity, but merely as it chances;
e.g. there might be cold in the dogdays, but this occurs neither
always and of necessity, nor for the most part, though it might
happen sometimes. The accidental, then, is what occurs, but not
always nor of necessity, nor for the most part. Now we have said
what the accidental is, and it is obvious why there is no science
of such a thing; for all science is of that which is always or for
the most part, but the accidental is in neither of these classes.
Evidently there are not causes and principles of the accidental,
of the same kind as there are of the essential; for if there were,
2449
everything would be of necessity. If A is when B is, and B is
when C is, and if C exists not by chance but of necessity, that
also of which C was cause will exist of necessity, down to the
last causatum as it is called (but this was supposed to be
accidental). Therefore all things will be of necessity, and chance
and the possibility of a thing's either occurring or not occurring
are removed entirely from the range of events. And if the cause
be supposed not to exist but to be coming to be, the same
results will follow; everything will occur of necessity. For to-
morrow's eclipse will occur if A occurs, and A if B occurs, and B
if C occurs; and in this way if we subtract time from the limited
time between now and to-morrow we shall come sometime to
the already existing condition. Therefore since this exists,
everything after this will occur of necessity, so that all things
occur of necessity.
As to that which 'is' in the sense of being true or of being by
accident, the former depends on a combination in thought and
is an affection of thought (which is the reason why it is the
principles, not of that which 'is' in this sense, but of that which
is outside and can exist apart, that are sought); and the latter is
not necessary but indeterminate (I mean the accidental); and of
such a thing the causes are unordered and indefinite.
Adaptation to an end is found in events that happen by nature
or as the result of thought. It is 'luck' when one of these events
happens by accident. For as a thing may exist, so it may be a
cause, either by its own nature or by accident. Luck is an
accidental cause at work in such events adapted to an end as
are usually effected in accordance with purpose. And so luck
and thought are concerned with the same sphere; for purpose
cannot exist without thought. The causes from which lucky
results might happen are indeterminate; and so luck is obscure
to human calculation and is a cause by accident, but in the
unqualified sense a cause of nothing. It is good or bad luck
2450
when the result is good or evil; and prosperity or misfortune
when the scale of the results is large.
Since nothing accidental is prior to the essential, neither are
accidental causes prior. If, then, luck or spontaneity is a cause of
the material universe, reason and nature are causes before it.
Some things are only actually, some potentially, some
potentially and actually, what they are, viz. in one case a
particular reality, in another, characterized by a particular
quantity, or the like. There is no movement apart from things;
for change is always according to the categories of being, and
there is nothing common to these and in no one category. But
each of the categories belongs to all its subjects in either of two
ways (e.g. 'this-ness' - for one kind of it is 'positive form', and
the other is 'privation'; and as regards quality one kind is 'white'
and the other 'black', and as regards quantity one kind is
'complete' and the other 'incomplete', and as regards spatial
movement one is 'upwards' and the other 'downwards', or one
thing is 'light' and another 'heavy'); so that there are as many
kinds of movement and change as of being. There being a
distinction in each class of things between the potential and the
completely real, I call the actuality of the potential as such,
movement. That what we say is true, is plain from the following
facts. When the 'buildable', in so far as it is what we mean by
'buildable', exists actually, it is being built, and this is the
process of building. Similarly with learning, healing, walking,
leaping, ageing, ripening. Movement takes when the complete
reality itself exists, and neither earlier nor later. The complete
reality, then, of that which exists potentially, when it is
2451
completely real and actual, not qua itself, but qua movable, is
movement. By qua I mean this: bronze is potentially a statue;
but yet it is not the complete reality of bronze qua bronze that
is movement. For it is not the same thing to be bronze and to be
a certain potency. If it were absolutely the same in its definition,
the complete reality of bronze would have been a movement.
But it is not the same. (This is evident in the case of contraries;
for to be capable of being well and to be capable of being ill are
not the same - for if they were, being well and being ill would
have been the same - it is that which underlies and is healthy
or diseased, whether it is moisture or blood, that is one and the
same.) And since it is not. the same, as colour and the visible
are not the same, it is the complete reality of the potential, and
as potential, that is movement. That it is this, and that
movement takes place when the complete reality itself exists,
and neither earlier nor later, is evident. For each thing is capable
of being sometimes actual, sometimes not, e.g. the buildable
qua buildable; and the actuality of the buildable qua buildable is
building. For the actuality is either this - the act of building - or
the house. But when the house exists, it is no longer buildable;
the buildable is what is being built. The actuality, then, must be
the act of building, and this is a movement. And the same
account applies to all other movements.
That what we have said is right is evident from what all others
say about movement, and from the fact that it is not easy to
define it otherwise. For firstly one cannot put it in any class.
This is evident from what people say. Some call it otherness and
inequality and the unreal; none of these, however, is necessarily
moved, and further, change is not either to these or from these
any more than from their opposites. The reason why people put
movement in these classes is that it is thought to be something
indefinite, and the principles in one of the two 'columns of
contraries' are indefinite because they are privative, for none of
them is either a 'this' or a 'such' or in any of the other
2452
categories. And the reason why movement is thought to be
indefinite is that it cannot be classed either with the potency of
things or with their actuality; for neither that which is capable
of being of a certain quantity, nor that which is actually of a
certain quantity, is of necessity moved, and movement is
thought to be an actuality, but incomplete; the reason is that
the potential, whose actuality it is, is incomplete. And therefore
it is hard to grasp what movement is; for it must be classed
either under privation or under potency or under absolute
actuality, but evidently none of these is possible. Therefore what
remains is that it must be what we said - both actuality and the
actuality we have described - which is hard to detect but
capable of existing.
And evidently movement is in the movable; for it is the
complete realization of this by that which is capable of causing
movement. And the actuality of that which is capable of causing
movement is no other than that of the movable. For it must be
the complete reality of both. For while a thing is capable of
causing movement because it can do this, it is a mover because
it is active; but it is on the movable that it is capable of acting,
so that the actuality of both is one, just as there is the same
interval from one to two as from two to one, and as the steep
ascent and the steep descent are one, but the being of them is
not one; the case of the mover and the moved is similar.
10
The infinite is either that which is incapable of being traversed
because it is not its nature to be traversed (this corresponds to
the sense in which the voice is 'invisible'), or that which admits
only of incomplete traverse or scarcely admits of traverse, or
2453
that which, though it naturally admits of traverse, is not
traversed or limited; further, a thing may be infinite in respect
of addition or of subtraction, or both. The infinite cannot be a
separate, independent thing. For if it is neither a spatial
magnitude nor a plurality, but infinity itself is its substance and
not an accident of it, it will be indivisible; for the divisible is
either magnitude or plurality. But if indivisible, it is not infinite,
except as the voice is invisible; but people do not mean this, nor
are we examining this sort of infinite, but the infinite as
untraversable. Further, how can an infinite exist by itself, unless
number and magnitude also exist by themselvess - since
infinity is an attribute of these? Further, if the infinite is an
accident of something else, it cannot be qua infinite an element
in things, as the invisible is not an element in speech, though
the voice is invisible. And evidently the infinite cannot exist
actually. For then any part of it that might be taken would be
infinite (for 'to be infinite' and 'the infinite' are the same, if the
infinite is substance and not predicated of a subject). Therefore
it is either indivisible, or if it is partible, it is divisible into
infinites; but the same thing cannot be many infinites (as a part
of air is air, so a part of the infinite would be infinite, if the
infinite is substance and a principle). Therefore it must be
impartible and indivisible. But the actually infinite cannot be
indivisible; for it must be of a certain quantity. Therefore infinity
belongs to its subject incidentally. But if so, then (as we have
said) it cannot be it that is a principle, but that of which it is an
accident - the air or the even number.
This inquiry is universal; but that the infinite is not among
sensible things, is evident from the following argument. If the
definition of a body is 'that which is bounded by planes', there
cannot be an infinite body either sensible or intelligible; nor a
separate and infinite number, for number or that which has a
number is numerable. Concretely, the truth is evident from the
following argument. The infinite can neither be composite nor
2454
simple. For (a) it cannot be a composite body, since the elements
are limited in multitude. For the contraries must be equal and
no one of them must be infinite; for if one of the two bodies
falls at all short of the other in potency, the finite will be
destroyed by the infinite. And that each should be infinite is
impossible. For body is that which has extension in all
directions, and the infinite is the boundlessly extended, so that
if the infinite is a body it will be infinite in every direction. Nor
(b) can the infinite body be one and simple - neither, as some
say, something apart from the elements, from which they
generate these (for there is no such body apart from the
elements; for everything can be resolved into that of which it
consists, but no such product of analysis is observed except the
simple bodies), nor fire nor any other of the elements. For apart
from the question how any of them could be infinite, the All,
even if it is finite, cannot either be or become any one of them,
as Heraclitus says all things sometime become fire. The same
argument applies to this as to the One which the natural
philosophers posit besides the elements. For everything
changes from contrary to contrary, e.g. from hot to cold.
Further, a sensible body is somewhere, and whole and part have
the same proper place, e.g. the whole earth and part of the
earth. Therefore if (a) the infinite body is homogeneous, it will
be unmovable or it will be always moving. But this is impossible;
for why should it rather rest, or move, down, up, or anywhere,
rather than anywhere else? E.g. if there were a clod which were
part of an infinite body, where will this move or rest? The proper
place of the body which is homogeneous with it is infinite. Will
the clod occupy the whole place, then? And how? (This is
impossible.) What then is its rest or its movement? It will either
rest everywhere, and then it cannot move; or it will move
everywhere, and then it cannot be still. But (b) if the All has
unlike parts, the proper places of the parts are unlike also, and,
firstly, the body of the All is not one except by contact, and,
2455
secondly, the parts will be either finite or infinite in variety of
kind. Finite they cannot be; for then those of one kind will be
infinite in quantity and those of another will not (if the All is
infinite), e.g. fire or water would be infinite, but such an infinite
element would be destruction to the contrary elements. But if
the parts are infinite and simple, their places also are infinite
and there will be an infinite number of elements; and if this is
impossible, and the places are finite, the All also must be
limited.
In general, there cannot be an infinite body and also a proper
place for bodies, if every sensible body has either weight or
lightness. For it must move either towards the middle or
upwards, and the infinite either the whole or the half of it -
cannot do either; for how will you divide it? Or how will part of
the infinite be down and part up, or part extreme and part
middle? Further, every sensible body is in a place, and there are
six kinds of place, but these cannot exist in an infinite body. In
general, if there cannot be an infinite place, there cannot be an
infinite body; (and there cannot be an infinite place,) for that
which is in a place is somewhere, and this means either up or
down or in one of the other directions, and each of these is a
limit.
The infinite is not the same in the sense that it is a single thing
whether exhibited in distance or in movement or in time, but
the posterior among these is called infinite in virtue of its
relation to the prior; i.e. a movement is called infinite in virtue
of the distance covered by the spatial movement or alteration or
growth, and a time is called infinite because of the movement
which occupies it.
2456
11
Of things which change, some change in an accidental sense,
like that in which 'the musical' may be said to walk, and others
are said, without qualification, to change, because something in
them changes, i.e. the things that change in parts; the body
becomes healthy, because the eye does. But there is something
which is by its own nature moved directly, and this is the
essentially movable. The same distinction is found in the case of
the mover; for it causes movement either in an accidental sense
or in respect of a part of itself or essentially. There is something
that directly causes movement; and there is something that is
moved, also the time in which it is moved, and that from which
and that into which it is moved. But the forms and the
affections and the place, which are the terminals of the
movement of moving things, are unmovable, e.g. knowledge or
heat; it is not heat that is a movement, but heating. Change
which is not accidental is found not in all things, but between
contraries, and their intermediates, and between
contradictories. We may convince ourselves of this by induction.
That which changes changes either from positive into positive,
or from negative into negative, or from positive into negative, or
from negative into positive. (By positive I mean that which is
expressed by an affirmative term.) Therefore there must be
three changes; that from negative into negative is not change,
because (since the terms are neither contraries nor
contradictories) there is no opposition. The change from the
negative into the positive which is its contradictory is
generation - absolute change absolute generation, and partial
change partial generation; and the change from positive to
negative is destruction - absolute change absolute destruction,
and partial change partial destruction. If, then, 'that which is
not' has several senses, and movement can attach neither to
that which implies putting together or separating, nor to that
2457
which implies potency and is opposed to that which is in the
full sense (true, the not-white or not-good can be moved
incidentally, for the not-white might be a man; but that which is
not a particular thing at all can in no wise be moved), that
which is not cannot be moved (and if this is so, generation
cannot be movement; for that which is not is generated; for
even if we admit to the full that its generation is accidental, yet
it is true to say that 'not-being' is predicable of that which is
generated absolutely). Similarly rest cannot be long to that
which is not. These consequences, then, turn out to be
awkward, and also this, that everything that is moved is in a
place, but that which is not is not in a place; for then it would be
somewhere. Nor is destruction movement; for the contrary of
movement is rest, but the contrary of destruction is generation.
Since every movement is a change, and the kinds of change are
the three named above, and of these those in the way of
generation and destruction are not movements, and these are
the changes from a thing to its contradictory, it follows that only
the change from positive into positive is movement. And the
positives are either contrary or intermediate (for even privation
must be regarded as contrary), and are expressed by an
affirmative term, e.g. 'naked' or 'toothless' or 'black'.
12
If the categories are classified as substance, quality, place, acting
or being acted on, relation, quantity, there must be three kinds
of movement - of quality, of quantity, of place. There is no
movement in respect of substance (because there is nothing
contrary to substance), nor of relation (for it is possible that if
one of two things in relation changes, the relative term which
was true of the other thing ceases to be true, though this other
2458
does not change at all, - so that their movement is accidental),
nor of agent and patient, or mover and moved, because there is
no movement of movement nor generation of generation, nor,
in general, change of change. For there might be movement of
movement in two senses; (1) movement might be the subject
moved, as a man is moved because he changes from pale to
dark, - so that on this showing movement, too, may be either
heated or cooled or change its place or increase. But this is
impossible; for change is not a subject. Or (2) some other subject
might change from change into some other form of existence
(e.g. a man from disease into health). But this also is not
possible except incidentally. For every movement is change
from something into something. (And so are generation and
destruction; only, these are changes into things opposed in
certain ways while the other, movement, is into things opposed
in another way.) A thing changes, then, at the same time from
health into illness, and from this change itself into another.
Clearly, then, if it has become ill, it will have changed into
whatever may be the other change concerned (though it may be
at rest), and, further, into a determinate change each time; and
that new change will be from something definite into some
other definite thing; therefore it will be the opposite change,
that of growing well. We answer that this happens only
incidentally; e.g. there is a change from the process of
recollection to that of forgetting, only because that to which the
process attaches is changing, now into a state of knowledge,
now into one of ignorance.
Further, the process will go on to infinity, if there is to be change
of change and coming to be of coming to be. What is true of the
later, then, must be true of the earlier; e.g. if the simple coming
to be was once coming to be, that which comes to be something
was also once coming to be; therefore that which simply comes
to be something was not yet in existence, but something which
was coming to be coming to be something was already in
2459
existence. And this was once coming to be, so that at that time
it was not yet coming to be something else. Now since of an
infinite number of terms there is not a first, the first in this
series will not exist, and therefore no following term exist.
Nothing, then, can either come term wi to be or move or
change. Further, that which is capable of a movement is also
capable of the contrary movement and rest, and that which
comes to be also ceases to be. Therefore that which is coming to
be is ceasing to be when it has come to be coming to be; for it
cannot cease to be as soon as it is coming to be coming to be,
nor after it has come to be; for that which is ceasing to be must
be. Further, there must be a matter underlying that which
comes to be and changes. What will this be, then, - what is it
that becomes movement or becoming, as body or soul is that
which suffers alteration? And; again, what is it that they move
into? For it must be the movement or becoming of something
from something into something. How, then, can this condition
be fulfilled? There can be no learning of learning, and therefore
no becoming of becoming. Since there is not movement either
of substance or of relation or of activity and passivity, it remains
that movement is in respect of quality and quantity and place;
for each of these admits of contrariety. By quality I mean not
that which is in the substance (for even the differentia is a
quality), but the passive quality, in virtue of which a thing is
said to be acted on or to be incapable of being acted on. The
immobile is either that which is wholly incapable of being
moved, or that which is moved with difficulty in a long time or
begins slowly, or that which is of a nature to be moved and can
be moved but is not moved when and where and as it would
naturally be moved. This alone among immobiles I describe as
being at rest; for rest is contrary to movement, so that it must
be a privation in that which is receptive of movement.
Things which are in one proximate place are together in place,
and things which are in different places are apart: things whose
2460
extremes are together touch: that at which a changing thing, if
it changes continuously according to its nature, naturally arrives
before it arrives at the extreme into which it is changing, is
between. That which is most distant in a straight line is
contrary in place. That is successive which is after the beginning
(the order being determined by position or form or in some
other way) and has nothing of the same class between it and
that which it succeeds, e.g. lines in the case of a line, units in
that of a unit, or a house in that of a house. (There is nothing to
prevent a thing of some other class from being between.) For
the successive succeeds something and is something later; 'one'
does not succeed 'two', nor the first day of the month the
second. That which, being successive, touches, is contiguous.
(Since all change is between opposites, and these are either
contraries or contradictories, and there is no middle term for
contradictories, clearly that which is between is between
contraries.) The continuous is a species of the contiguous. I call
two things continuous when the limits of each, with which they
touch and by which they are kept together, become one and the
same, so that plainly the continuous is found in the things out
of which a unity naturally arises in virtue of their contact. And
plainly the successive is the first of these concepts (for the
successive does not necessarily touch, but that which touches is
successive; and if a thing is continuous, it touches, but if it
touches, it is not necessarily continuous; and in things in which
there is no touching, there is no organic unity); therefore a point
is not the same as a unit; for contact belongs to points, but not
to units, which have only succession; and there is something
between two of the former, but not between two of the latter.
2461
Book A
The subject of our inquiry is substance; for the principles and
the causes we are seeking are those of substances. For if the
universe is of the nature of a whole, substance is its first part;
and if it coheres merely by virtue of serial succession, on this
view also substance is first, and is succeeded by quality, and
then by quantity. At the same time these latter are not even
being in the full sense, but are qualities and movements of it, -
or else even the not-white and the not-straight would be being;
at least we say even these are, e.g. 'there is a not-white'. Further,
none of the categories other than substance can exist apart.
And the early philosophers also in practice testify to the
primacy of substance; for it was of substance that they sought
the principles and elements and causes. The thinkers of the
present day tend to rank universals as substances (for genera
are universals, and these they tend to describe as principles and
substances, owing to the abstract nature of their inquiry); but
the thinkers of old ranked particular things as substances, e.g.
fire and earth, not what is common to both, body.
There are three kinds of substance - one that is sensible (of
which one subdivision is eternal and another is perishable; the
latter is recognized by all men, and includes e.g. plants and
animals), of which we must grasp the elements, whether one or
many; and another that is immovable, and this certain thinkers
assert to be capable of existing apart, some dividing it into two,
others identifying the Forms and the objects of mathematics,
and others positing, of these two, only the objects of
mathematics. The former two kinds of substance are the subject
2462
of physics (for they imply movement); but the third kind
belongs to another science, if there is no principle common to it
and to the other kinds.
Sensible substance is changeable. Now if change proceeds from
opposites or from intermediates, and not from all opposites (for
the voice is not-white, but it does not therefore change to
white), but from the contrary, there must be something
underlying which changes into the contrary state; for the
contraries do not change. Further, something persists, but the
contrary does not persist; there is, then, some third thing
besides the contraries, viz. the matter. Now since changes are of
four kinds - either in respect of the 'what' or of the quality or of
the quantity or of the place, and change in respect of 'thisness'
is simple generation and destruction, and change in quantity is
increase and diminution, and change in respect of an affection
is alteration, and change of place is motion, changes will be
from given states into those contrary to them in these several
respects. The matter, then, which changes must be capable of
both states. And since that which 'is' has two senses, we must
say that everything changes from that which is potentially to
that which is actually, e.g. from potentially white to actually
white, and similarly in the case of increase and diminution.
Therefore not only can a thing come to be, incidentally, out of
that which is not, but also all things come to be out of that
which is, but is potentially, and is not actually. And this is the
'One' of Anaxagoras; for instead of 'all things were together' -
and the 'Mixture' of Empedocles and Anaximander and the
account given by Democritus - it is better to say 'all things were
together potentially but not actually'. Therefore these thinkers
2463
seem to have had some notion of matter. Now all things that
change have matter, but different matter; and of eternal things
those which are not generable but are movable in space have
matter - not matter for generation, however, but for motion
from one place to another.
One might raise the question from what sort of non-being
generation proceeds; for 'non-being' has three senses. If, then,
one form of non-being exists potentially, still it is not by virtue
of a potentiality for any and every thing, but different things
come from different things; nor is it satisfactory to say that 'all
things were together'; for they differ in their matter, since
otherwise why did an infinity of things come to be, and not one
thing? For 'reason' is one, so that if matter also were one, that
must have come to be in actuality which the matter was in
potency. The causes and the principles, then, are three, two
being the pair of contraries of which one is definition and form
and the other is privation, and the third being the matter.
Note, next, that neither the matter nor the form comes to be -
and I mean the last matter and form. For everything that
changes is something and is changed by something and into
something. That by which it is changed is the immediate mover;
that which is changed, the matter; that into which it is changed,
the form. The process, then, will go on to infinity, if not only the
bronze comes to be round but also the round or the bronze
comes to be; therefore there must be a stop.
Note, next, that each substance comes into being out of
something that shares its name. (Natural objects and other
things both rank as substances.) For things come into being
2464
either by art or by nature or by luck or by spontaneity. Now art is
a principle of movement in something other than the thing
moved, nature is a principle in the thing itself (for man begets
man), and the other causes are privations of these two.
There are three kinds of substance - the matter, which is a 'this'
in appearance (for all things that are characterized by contact
and not, by organic unity are matter and substratum, e.g. fire,
flesh, head; for these are all matter, and the last matter is the
matter of that which is in the full sense substance); the nature,
which is a 'this' or positive state towards which movement
takes place; and again, thirdly, the particular substance which is
composed of these two, e.g. Socrates or Callias. Now in some
cases the 'this' does not exist apart from the composite
substance, e.g. the form of house does not so exist, unless the
art of building exists apart (nor is there generation and
destruction of these forms, but it is in another way that the
house apart from its matter, and health, and all ideals of art,
exist and do not exist); but if the 'this' exists apart from the
concrete thing, it is only in the case of natural objects. And so
Plato was not far wrong when he said that there are as many
Forms as there are kinds of natural object (if there are Forms
distinct from the things of this earth). The moving causes exist
as things preceding the effects, but causes in the sense of
definitions are simultaneous with their effects. For when a man
is healthy, then health also exists; and the shape of a bronze
sphere exists at the same time as the bronze sphere. (But we
must examine whether any form also survives afterwards. For
in some cases there is nothing to prevent this; e.g. the soul may
be of this sort - not all soul but the reason; for presumably it is
impossible that all soul should survive.) Evidently then there is
no necessity, on this ground at least, for the existence of the
Ideas. For man is begotten by man, a given man by an individual
father; and similarly in the arts; for the medical art is the formal
cause of health.
2465
The causes and the principles of different things are in a sense
different, but in a sense, if one speaks universally and
analogically, they are the same for all. For one might raise the
question whether the principles and elements are different or
the same for substances and for relative terms, and similarly in
the case of each of the categories. But it would be paradoxical if
they were the same for all. For then from the same elements
will proceed relative terms and substances. What then will this
common element be? For (1) (a) there is nothing common to and
distinct from substance and the other categories, viz. those
which are predicated; but an element is prior to the things of
which it is an element. But again (b) substance is not an
element in relative terms, nor is any of these an element in
substance. Further, (2) how can all things have the same
elements? For none of the elements can be the same as that
which is composed of elements, e.g. b or a cannot be the same
as ba. (None, therefore, of the intelligibles, e.g. being or unity, is
an element; for these are predicable of each of the compounds
as well.) None of the elements, then, will be either a substance
or a relative term; but it must be one or other. All things, then,
have not the same elements.
Or, as we are wont to put it, in a sense they have and in a sense
they have not; e.g. perhaps the elements of perceptible bodies
are, as form, the hot, and in another sense the cold, which is the
privation; and, as matter, that which directly and of itself
potentially has these attributes; and substances comprise both
these and the things composed of these, of which these are the
principles, or any unity which is produced out of the hot and
the cold, e.g. flesh or bone; for the product must be different
2466
from the elements. These things then have the same elements
and principles (though specifically different things have
specifically different elements); but all things have not the same
elements in this sense, but only analogically; i.e. one might say
that there are three principles - the form, the privation, and the
matter. But each of these is different for each class; e.g. in
colour they are white, black, and surface, and in day and night
they are light, darkness, and air.
Since not only the elements present in a thing are causes, but
also something external, i.e. the moving cause, clearly while
'principle' and 'element' are different both are causes, and
'principle' is divided into these two kinds; and that which acts
as producing movement or rest is a principle and a substance.
Therefore analogically there are three elements, and four
causes and principles; but the elements are different in
different things, and the proximate moving cause is different
for different things. Health, disease, body; the moving cause is
the medical art. Form, disorder of a particular kind, bricks; the
moving cause is the building art. And since the moving cause in
the case of natural things is - for man, for instance, man, and in
the products of thought the form or its contrary, there will be in
a sense three causes, while in a sense there are four. For the
medical art is in some sense health, and the building art is the
form of the house, and man begets man; further, besides these
there is that which as first of all things moves all things.
Some things can exist apart and some cannot, and it is the
former that are substances. And therefore all things have the
same causes, because, without substances, modifications and
2467
movements do not exist. Further, these causes will probably be
soul and body, or reason and desire and body.
And in yet another way, analogically identical things are
principles, i.e. actuality and potency; but these also are not only
different for different things but also apply in different ways to
them. For in some cases the same thing exists at one time
actually and at another potentially, e.g. wine or flesh or man
does so. (And these too fall under the above-named causes. For
the form exists actually, if it can exist apart, and so does the
complex of form and matter, and the privation, e.g. darkness or
disease; but the matter exists potentially; for this is that which
can become qualified either by the form or by the privation.) But
the distinction of actuality and potentiality applies in another
way to cases where the matter of cause and of effect is not the
same, in some of which cases the form is not the same but
different; e.g. the cause of man is (1) the elements in man (viz.
fire and earth as matter, and the peculiar form), and further (2)
something else outside, i.e. the father, and (3) besides these the
sun and its oblique course, which are neither matter nor form
nor privation of man nor of the same species with him, but
moving causes.
Further, one must observe that some causes can be expressed in
universal terms, and some cannot. The proximate principles of
all things are the 'this' which is proximate in actuality, and
another which is proximate in potentiality. The universal
causes, then, of which we spoke do not exist. For it is the
individual that is the originative principle of the individuals. For
while man is the originative principle of man universally, there
is no universal man, but Peleus is the originative principle of
Achilles, and your father of you, and this particular b of this
particular ba, though b in general is the originative principle of
ba taken without qualification.
2468
Further, if the causes of substances are the causes of all things,
yet different things have different causes and elements, as was
said; the causes of things that are not in the same class, e.g. of
colours and sounds, of substances and quantities, are different
except in an analogical sense; and those of things in the same
species are different, not in species, but in the sense that the
causes of different individuals are different, your matter and
form and moving cause being different from mine, while in
their universal definition they are the same. And if we inquire
what are the principles or elements of substances and relations
and qualities - whether they are the same or different - clearly
when the names of the causes are used in several senses the
causes of each are the same, but when the senses are
distinguished the causes are not the same but different, except
that in the following senses the causes of all are the same. They
are (1) the same or analogous in this sense, that matter, form,
privation, and the moving cause are common to all things; and
(2) the causes of substances may be treated as causes of all
things in this sense, that when substances are removed all
things are removed; further, (3) that which is first in respect of
complete reality is the cause of all things. But in another sense
there are different first causes, viz. all the contraries which are
neither generic nor ambiguous terms; and, further, the matters
of different things are different. We have stated, then, what are
the principles of sensible things and how many they are, and in
what sense they are the same and in what sense different.
Since there were three kinds of substance, two of them physical
and one unmovable, regarding the latter we must assert that it
is necessary that there should be an eternal unmovable
2469
substance. For substances are the first of existing things, and if
they are all destructible, all things are destructible. But it is
impossible that movement should either have come into being
or cease to be (for it must always have existed), or that time
should. For there could not be a before and an after if time did
not exist. Movement also is continuous, then, in the sense in
which time is; for time is either the same thing as movement or
an attribute of movement. And there is no continuous
movement except movement in place, and of this only that
which is circular is continuous.
But if there is something which is capable of moving things or
acting on them, but is not actually doing so, there will not
necessarily be movement; for that which has a potency need
not exercise it. Nothing, then, is gained even if we suppose
eternal substances, as the believers in the Forms do, unless
there is to be in them some principle which can cause change;
nay, even this is not enough, nor is another substance besides
the Forms enough; for if it is not to act, there will be no
movement. Further even if it acts, this will not be enough, if its
essence is potency; for there will not be eternal movement,
since that which is potentially may possibly not be. There must,
then, be such a principle, whose very essence is actuality.
Further, then, these substances must be without matter; for
they must be eternal, if anything is eternal. Therefore they must
be actuality.
Yet there is a difficulty; for it is thought that everything that
acts is able to act, but that not everything that is able to act acts,
so that the potency is prior. But if this is so, nothing that is need
be; for it is possible for all things to be capable of existing but
not yet to exist.
Yet if we follow the theologians who generate the world from
night, or the natural philosophers who say that 'all things were
2470
together', the same impossible result ensues. For how will there
be movement, if there is no actually existing cause? Wood will
surely not move itself - the carpenter's art must act on it; nor
will the menstrual blood nor the earth set themselves in
motion, but the seeds must act on the earth and the semen on
the menstrual blood.
This is why some suppose eternal actuality - e.g. Leucippus and
Plato; for they say there is always movement. But why and what
this movement is they do say, nor, if the world moves in this
way or that, do they tell us the cause of its doing so. Now
nothing is moved at random, but there must always be
something present to move it; e.g. as a matter of fact a thing
moves in one way by nature, and in another by force or through
the influence of reason or something else. (Further, what sort of
movement is primary? This makes a vast difference.) But again
for Plato, at least, it is not permissible to name here that which
he sometimes supposes to be the source of movement - that
which moves itself; for the soul is later, and coeval with the
heavens, according to his account. To suppose potency prior to
actuality, then, is in a sense right, and in a sense not; and we
have specified these senses. That actuality is prior is testified by
Anaxagoras (for his 'reason' is actuality) and by Empedocles in
his doctrine of love and strife, and by those who say that there
is always movement, e.g. Leucippus. Therefore chaos or night
did not exist for an infinite time, but the same things have
always existed (either passing through a cycle of changes or
obeying some other law), since actuality is prior to potency. If,
then, there is a constant cycle, something must always remain,
acting in the same way. And if there is to be generation and
destruction, there must be something else which is always
acting in different ways. This must, then, act in one way in
virtue of itself, and in another in virtue of something else -
either of a third agent, therefore, or of the first. Now it must be
in virtue of the first. For otherwise this again causes the motion
2471
both of the second agent and of the third. Therefore it is better
to say 'the first'. For it was the cause of eternal uniformity; and
something else is the cause of variety, and evidently both
together are the cause of eternal variety. This, accordingly, is the
character which the motions actually exhibit. What need then is
there to seek for other principles?
Since (1) this is a possible account of the matter, and (2) if it
were not true, the world would have proceeded out of night and
'all things together' and out of non-being, these difficulties may
be taken as solved. There is, then, something which is always
moved with an unceasing motion, which is motion in a circle;
and this is plain not in theory only but in fact. Therefore the
first heaven must be eternal. There is therefore also something
which moves it. And since that which moves and is moved is
intermediate, there is something which moves without being
moved, being eternal, substance, and actuality. And the object of
desire and the object of thought move in this way; they move
without being moved. The primary objects of desire and of
thought are the same. For the apparent good is the object of
appetite, and the real good is the primary object of rational
wish. But desire is consequent on opinion rather than opinion
on desire; for the thinking is the starting-point. And thought is
moved by the object of thought, and one of the two columns of
opposites is in itself the object of thought; and in this,
substance is first, and in substance, that which is simple and
exists actually. (The one and the simple are not the same; for
'one' means a measure, but 'simple' means that the thing itself
has a certain nature.) But the beautiful, also, and that which is
2472
in itself desirable are in the same column; and the first in any
class is always best, or analogous to the best.
That a final cause may exist among unchangeable entities is
shown by the distinction of its meanings. For the final cause is
(a) some being for whose good an action is done, and (b)
something at which the action aims; and of these the latter
exists among unchangeable entities though the former does
not. The final cause, then, produces motion as being loved, but
all other things move by being moved. Now if something is
moved it is capable of being otherwise than as it is. Therefore if
its actuality is the primary form of spatial motion, then in so far
as it is subject to change, in this respect it is capable of being
otherwise, - in place, even if not in substance. But since there is
something which moves while itself unmoved, existing actually,
this can in no way be otherwise than as it is. For motion in
space is the first of the kinds of change, and motion in a circle
the first kind of spatial motion; and this the first mover
produces. The first mover, then, exists of necessity; and in so far
as it exists by necessity, its mode of being is good, and it is in
this sense a first principle. For the necessary has all these
senses - that which is necessary perforce because it is contrary
to the natural impulse, that without which the good is
impossible, and that which cannot be otherwise but can exist
only in a single way.
On such a principle, then, depend the heavens and the world of
nature. And it is a life such as the best which we enjoy, and
enjoy for but a short time (for it is ever in this state, which we
cannot be), since its actuality is also pleasure. (And for this
reason are waking, perception, and thinking most pleasant, and
hopes and memories are so on account of these.) And thinking
in itself deals with that which is best in itself, and that which is
thinking in the fullest sense with that which is best in the
fullest sense. And thought thinks on itself because it shares the
2473
nature of the object of thought; for it becomes an object of
thought in coming into contact with and thinking its objects, so
that thought and object of thought are the same. For that which
is capable of receiving the object of thought, i.e. the essence, is
thought. But it is active when it possesses this object. Therefore
the possession rather than the receptivity is the divine element
which thought seems to contain, and the act of contemplation
is what is most pleasant and best. If, then, God is always in that
good state in which we sometimes are, this compels our
wonder; and if in a better this compels it yet more. And God is
in a better state. And life also belongs to God; for the actuality of
thought is life, and God is that actuality; and God's self-
dependent actuality is life most good and eternal. We say
therefore that God is a living being, eternal, most good, so that
life and duration continuous and eternal belong to God; for this
is God.
Those who suppose, as the Pythagoreans and Speusippus do,
that supreme beauty and goodness are not present in the
beginning, because the beginnings both of plants and of
animals are causes, but beauty and completeness are in the
effects of these, are wrong in their opinion. For the seed comes
from other individuals which are prior and complete, and the
first thing is not seed but the complete being; e.g. we must say
that before the seed there is a man, - not the man produced
from the seed, but another from whom the seed comes.
It is clear then from what has been said that there is a
substance which is eternal and unmovable and separate from
sensible things. It has been shown also that this substance
cannot have any magnitude, but is without parts and indivisible
(for it produces movement through infinite time, but nothing
finite has infinite power; and, while every magnitude is either
infinite or finite, it cannot, for the above reason, have finite
magnitude, and it cannot have infinite magnitude because there
2474
is no infinite magnitude at all). But it has also been shown that
it is impassive and unalterable; for all the other changes are
posterior to change of place.
8
It is clear, then, why these things are as they are. But we must
not ignore the question whether we have to suppose one such
substance or more than one, and if the latter, how many; we
must also mention, regarding the opinions expressed by others,
that they have said nothing about the number of the substances
that can even be clearly stated. For the theory of Ideas has no
special discussion of the subject; for those who speak of Ideas
say the Ideas are numbers, and they speak of numbers now as
unlimited, now as limited by the number 10; but as for the
reason why there should be just so many numbers, nothing is
said with any demonstrative exactness. We however must
discuss the subject, starting from the presuppositions and
distinctions we have mentioned. The first principle or primary
being is not movable either in itself or accidentally, but
produces the primary eternal and single movement. But since
that which is moved must be moved by something, and the first
mover must be in itself unmovable, and eternal movement
must be produced by something eternal and a single movement
by a single thing, and since we see that besides the simple
spatial movement of the universe, which we say the first and
unmovable substance produces, there are other spatial
movements - those of the planets - which are eternal (for a
body which moves in a circle is eternal and unresting; we have
proved these points in the physical treatises), each of these
movements also must be caused by a substance both
unmovable in itself and eternal. For the nature of the stars is
2475
eternal just because it is a certain kind of substance, and the
mover is eternal and prior to the moved, and that which is prior
to a substance must be a substance. Evidently, then, there must
be substances which are of the same number as the movements
of the stars, and in their nature eternal, and in themselves
unmovable, and without magnitude, for the reason before
mentioned. That the movers are substances, then, and that one
of these is first and another second according to the same order
as the movements of the stars, is evident. But in the number of
the movements we reach a problem which must be treated from
the standpoint of that one of the mathematical sciences which
is most akin to philosophy - viz. of astronomy; for this science
speculates about substance which is perceptible but eternal, but
the other mathematical sciences, i.e. arithmetic and geometry,
treat of no substance. That the movements are more numerous
than the bodies that are moved is evident to those who have
given even moderate attention to the matter; for each of the
planets has more than one movement. But as to the actual
number of these movements, we now - to give some notion of
the subject - quote what some of the mathematicians say, that
our thought may have some definite number to grasp; but, for
the rest, we must partly investigate for ourselves, Partly learn
from other investigators, and if those who study this subject
form an opinion contrary to what we have now stated, we must
esteem both parties indeed, but follow the more accurate.
Eudoxus supposed that the motion of the sun or of the moon
involves, in either case, three spheres, of which the first is the
sphere of the fixed stars, and the second moves in the circle
which runs along the middle of the zodiac, and the third in the
circle which is inclined across the breadth of the zodiac; but the
circle in which the moon moves is inclined at a greater angle
than that in which the sun moves. And the motion of the
planets involves, in each case, four spheres, and of these also
the first and second are the same as the first two mentioned
2476
above (for the sphere of the fixed stars is that which moves all
the other spheres, and that which is placed beneath this and
has its movement in the circle which bisects the zodiac is
common to all), but the poles of the third sphere of each planet
are in the circle which bisects the zodiac, and the motion of the
fourth sphere is in the circle which is inclined at an angle to the
equator of the third sphere; and the poles of the third sphere
are different for each of the other planets, but those of Venus
and Mercury are the same.
Callippus made the position of the spheres the same as
Eudoxus did, but while he assigned the same number as
Eudoxus did to Jupiter and to Saturn, he thought two more
spheres should be added to the sun and two to the moon, if one
is to explain the observed facts; and one more to each of the
other planets.
But it is necessary, if all the spheres combined are to explain the
observed facts, that for each of the planets there should be
other spheres (one fewer than those hitherto assigned) which
counteract those already mentioned and bring back to the same
position the outermost sphere of the star which in each case is
situated below the star in question; for only thus can all the
forces at work produce the observed motion of the planets.
Since, then, the spheres involved in the movement of the
planets themselves are - eight for Saturn and Jupiter and
twenty-five for the others, and of these only those involved in
the movement of the lowest-situated planet need not be
counteracted the spheres which counteract those of the
outermost two planets will be six in number, and the spheres
which counteract those of the next four planets will be sixteen;
therefore the number of all the spheres - both those which
move the planets and those which counteract these - will be
fifty-five. And if one were not to add to the moon and to the sun
2477
the movements we mentioned, the whole set of spheres will be
forty-seven in number.
Let this, then, be taken as the number of the spheres, so that
the unmovable substances and principles also may probably be
taken as just so many; the assertion of necessity must be left to
more powerful thinkers. But if there can be no spatial
movement which does not conduce to the moving of a star, and
if further every being and every substance which is immune
from change and in virtue of itself has attained to the best must
be considered an end, there can be no other being apart from
these we have named, but this must be the number of the
substances. For if there are others, they will cause change as
being a final cause of movement; but there cannot he other
movements besides those mentioned. And it is reasonable to
infer this from a consideration of the bodies that are moved; for
if everything that moves is for the sake of that which is moved,
and every movement belongs to something that is moved, no
movement can be for the sake of itself or of another movement,
but all the movements must be for the sake of the stars. For if
there is to be a movement for the sake of a movement, this
latter also will have to be for the sake of something else; so that
since there cannot be an infinite regress, the end of every
movement will be one of the divine bodies which move through
the heaven.
(Evidently there is but one heaven. For if there are many
heavens as there are many men, the moving principles, of
which each heaven will have one, will be one in form but in
number many. But all things that are many in number have
matter; for one and the same definition, e.g. that of man,
applies to many things, while Socrates is one. But the primary
essence has not matter; for it is complete reality. So the
unmovable first mover is one both in definition and in number;
so too, therefore, is that which is moved always and
2478
continuously; therefore there is one heaven alone.) Our
forefathers in the most remote ages have handed down to their
posterity a tradition, in the form of a myth, that these bodies
are gods, and that the divine encloses the whole of nature. The
rest of the tradition has been added later in mythical form with
a view to the persuasion of the multitude and to its legal and
utilitarian expediency; they say these gods are in the form of
men or like some of the other animals, and they say other
things consequent on and similar to these which we have
mentioned. But if one were to separate the first point from
these additions and take it alone - that they thought the first
substances to be gods, one must regard this as an inspired
utterance, and reflect that, while probably each art and each
science has often been developed as far as possible and has
again perished, these opinions, with others, have been
preserved until the present like relics of the ancient treasure.
Only thus far, then, is the opinion of our ancestors and of our
earliest predecessors clear to us.
The nature of the divine thought involves certain problems; for
while thought is held to be the most divine of things observed
by us, the question how it must be situated in order to have that
character involves difficulties. For if it thinks of nothing, what is
there here of dignity? It is just like one who sleeps. And if it
thinks, but this depends on something else, then (since that
which is its substance is not the act of thinking, but a potency)
it cannot be the best substance; for it is through thinking that
its value belongs to it. Further, whether its substance is the
faculty of thought or the act of thinking, what does it think of?
Either of itself or of something else; and if of something else,
2479
either of the same thing always or of something different. Does
it matter, then, or not, whether it thinks of the good or of any
chance thing? Are there not some things about which it is
incredible that it should think? Evidently, then, it thinks of that
which is most divine and precious, and it does not change; for
change would be change for the worse, and this would be
already a movement. First, then, if 'thought' is not the act of
thinking but a potency, it would be reasonable to suppose that
the continuity of its thinking is wearisome to it. Secondly, there
would evidently be something else more precious than thought,
viz. that which is thought of. For both thinking and the act of
thought will belong even to one who thinks of the worst thing
in the world, so that if this ought to be avoided (and it ought, for
there are even some things which it is better not to see than to
see), the act of thinking cannot be the best of things. Therefore
it must be of itself that the divine thought thinks (since it is the
most excellent of things), and its thinking is a thinking on
thinking.
But evidently knowledge and perception and opinion and
understanding have always something else as their object, and
themselves only by the way. Further, if thinking and being
thought of are different, in respect of which does goodness
belong to thought? For to he an act of thinking and to he an
object of thought are not the same thing. We answer that in
some cases the knowledge is the object. In the productive
sciences it is the substance or essence of the object, matter
omitted, and in the theoretical sciences the definition or the act
of thinking is the object. Since, then, thought and the object of
thought are not different in the case of things that have not
matter, the divine thought and its object will be the same, i.e.
the thinking will be one with the object of its thought.
A further question is left - whether the object of the divine
thought is composite; for if it were, thought would change in
2480
passing from part to part of the whole. We answer that
everything which has not matter is indivisible - as human
thought, or rather the thought of composite beings, is in a
certain period of time (for it does not possess the good at this
moment or at that, but its best, being something different from
it, is attained only in a whole period of time), so throughout
eternity is the thought which has itself for its object.
10
We must consider also in which of two ways the nature of the
universe contains the good, and the highest good, whether as
something separate and by itself, or as the order of the parts.
Probably in both ways, as an army does; for its good is found
both in its order and in its leader, and more in the latter; for he
does not depend on the order but it depends on him. And all
things are ordered together somehow, but not all alike, - both
fishes and fowls and plants; and the world is not such that one
thing has nothing to do with another, but they are connected.
For all are ordered together to one end, but it is as in a house,
where the freemen are least at liberty to act at random, but all
things or most things are already ordained for them, while the
slaves and the animals do little for the common good, and for
the most part live at random; for this is the sort of principle that
constitutes the nature of each. I mean, for instance, that all
must at least come to be dissolved into their elements, and
there are other functions similarly in which all share for the
good of the whole.
We must not fail to observe how many impossible or
paradoxical results confront those who hold different views
from our own, and what are the views of the subtler thinkers,
2481
and which views are attended by fewest difficulties. All make all
things out of contraries. But neither 'all things' nor 'out of
contraries' is right; nor do these thinkers tell us how all the
things in which the contraries are present can be made out of
the contraries; for contraries are not affected by one another.
Now for us this difficulty is solved naturally by the fact that
there is a third element. These thinkers however make one of
the two contraries matter; this is done for instance by those
who make the unequal matter for the equal, or the many
matter for the one. But this also is refuted in the same way; for
the one matter which underlies any pair of contraries is
contrary to nothing. Further, all things, except the one, will, on
the view we are criticizing, partake of evil; for the bad itself is
one of the two elements. But the other school does not treat the
good and the bad even as principles; yet in all things the good is
in the highest degree a principle. The school we first mentioned
is right in saying that it is a principle, but how the good is a
principle they do not say -whether as end or as mover or as
form.
Empedocles also has a paradoxical view; for he identifies the
good with love, but this is a principle both as mover (for it brings
things together) and as matter (for it is part of the mixture).
Now even if it happens that the same thing is a principle both
as matter and as mover, still the being, at least, of the two is not
the same. In which respect then is love a principle? It is
paradoxical also that strife should be imperishable; the nature
of his 'evil' is just strife.
Anaxagoras makes the good a motive principle; for his 'reason'
moves things. But it moves them for an end, which must be
something other than it, except according to our way of stating
the case; for, on our view, the medical art is in a sense health. It
is paradoxical also not to suppose a contrary to the good, i.e. to
reason. But all who speak of the contraries make no use of the
2482
contraries, unless we bring their views into shape. And why
some things are perishable and others imperishable, no one
tells us; for they make all existing things out of the same
principles. Further, some make existing things out of the
nonexistent; and others to avoid the necessity of this make all
things one.
Further, why should there always be becoming, and what is the
cause of becoming? - This no one tells us. And those who
suppose two principles must suppose another, a superior
principle, and so must those who believe in the Forms; for why
did things come to participate, or why do they participate, in the
Forms? And all other thinkers are confronted by the necessary
consequence that there is something contrary to Wisdom, i.e. to
the highest knowledge; but we are not. For there is nothing
contrary to that which is primary; for all contraries have matter,
and things that have matter exist only potentially; and the
ignorance which is contrary to any knowledge leads to an object
contrary to the object of the knowledge; but what is primary has
no contrary.
Again, if besides sensible things no others exist, there will be no
first principle, no order, no becoming, no heavenly bodies, but
each principle will have a principle before it, as in the accounts
of the theologians and all the natural philosophers. But if the
Forms or the numbers are to exist, they will be causes of
nothing; or if not that, at least not of movement. Further, how is
extension, i.e. a continuum, to be produced out of unextended
parts? For number will not, either as mover or as form, produce
a continuum. But again there cannot be any contrary that is also
essentially a productive or moving principle; for it would be
possible for it not to be. Or at least its action would be posterior
to its potency. The world, then, would not be eternal. But it is;
one of these premisses, then, must be denied. And we have said
how this must be done. Further, in virtue of what the numbers,
2483
or the soul and the body, or in general the form and the thing,
are one - of this no one tells us anything; nor can any one tell,
unless he says, as we do, that the mover makes them one. And
those who say mathematical number is first and go on to
generate one kind of substance after another and give different
principles for each, make the substance of the universe a mere
series of episodes (for one substance has no influence on
another by its existence or nonexistence), and they give us
many governing principles; but the world refuses to be governed
badly.
'The rule of many is not good; one ruler let there be.'
BookM
We have stated what is the substance of sensible things, dealing
in the treatise on physics with matter, and later with the
substance which has actual existence. Now since our inquiry is
whether there is or is not besides the sensible substances any
which is immovable and eternal, and, if there is, what it is, we
must first consider what is said by others, so that, if there is
anything which they say wrongly, we may not be liable to the
same objections, while, if there is any opinion common to them
and us, we shall have no private grievance against ourselves on
that account; for one must be content to state some points
better than one's predecessors, and others no worse.
2484
Two opinions are held on this subject; it is said that the objects
of mathematics - i.e. numbers and lines and the like - are
substances, and again that the Ideas are substances. And (1)
since some recognize these as two different classes - the Ideas
and the mathematical numbers, and (2) some recognize both as
having one nature, while (3) some others say that the
mathematical substances are the only substances, we must
consider first the objects of mathematics, not qualifying them
by any other characteristic - not asking, for instance, whether
they are in fact Ideas or not, or whether they are the principles
and substances of existing things or not, but only whether as
objects of mathematics they exist or not, and if they exist, how
they exist. Then after this we must separately consider the
Ideas themselves in a general way, and only as far as the
accepted mode of treatment demands; for most of the points
have been repeatedly made even by the discussions outside our
school, and, further, the greater part of our account must finish
by throwing light on that inquiry, viz. when we examine
whether the substances and the principles of existing things are
numbers and Ideas; for after the discussion of the Ideas this
remans as a third inquiry.
If the objects of mathematics exist, they must exist either in
sensible objects, as some say, or separate from sensible objects
(and this also is said by some); or if they exist in neither of these
ways, either they do not exist, or they exist only in some special
sense. So that the subject of our discussion will be not whether
they exist but how they exist.
2485
That it is impossible for mathematical objects to exist in
sensible things, and at the same time that the doctrine in
question is an artificial one, has been said already in our
discussion of difficulties we have pointed out that it is
impossible for two solids to be in the same place, and also that
according to the same argument the other powers and
characteristics also should exist in sensible things and none of
them separately. This we have said already. But, further, it is
obvious that on this theory it is impossible for any body
whatever to be divided; for it would have to be divided at a
plane, and the plane at a line, and the line at a point, so that if
the point cannot be divided, neither can the line, and if the line
cannot, neither can the plane nor the solid. What difference,
then, does it make whether sensible things are such indivisible
entities, or, without being so themselves, have indivisible
entities in them? The result will be the same; if the sensible
entities are divided the others will be divided too, or else not
even the sensible entities can be divided.
But, again, it is not possible that such entities should exist
separately. For if besides the sensible solids there are to be other
solids which are separate from them and prior to the sensible
solids, it is plain that besides the planes also there must be
other and separate planes and points and lines; for consistency
requires this. But if these exist, again besides the planes and
lines and points of the mathematical solid there must be others
which are separate. (For incomposites are prior to compounds;
and if there are, prior to the sensible bodies, bodies which are
not sensible, by the same argument the planes which exist by
themselves must be prior to those which are in the motionless
solids. Therefore these will be planes and lines other than those
that exist along with the mathematical solids to which these
thinkers assign separate existence; for the latter exist along
2486
with the mathematical solids, while the others are prior to the
mathematical solids.) Again, therefore, there will be, belonging
to these planes, lines, and prior to them there will have to be, by
the same argument, other lines and points; and prior to these
points in the prior lines there will have to be other points,
though there will be no others prior to these. Now (1) the
accumulation becomes absurd; for we find ourselves with one
set of solids apart from the sensible solids; three sets of planes
apart from the sensible planes - those which exist apart from
the sensible planes, and those in the mathematical solids, and
those which exist apart from those in the mathematical solids;
four sets of lines, and five sets of points. With which of these,
then, will the mathematical sciences deal? Certainly not with
the planes and lines and points in the motionless solid; for
science always deals with what is prior. And (the same account
will apply also to numbers; for there will be a different set of
units apart from each set of points, and also apart from each set
of realities, from the objects of sense and again from those of
thought; so that there will be various classes of mathematical
numbers.
Again, how is it possible to solve the questions which we have
already enumerated in our discussion of difficulties? For the
objects of astronomy will exist apart from sensible things just
as the objects of geometry will; but how is it possible that a
heaven and its parts - or anything else which has movement -
should exist apart? Similarly also the objects of optics and of
harmonics will exist apart; for there will be both voice and sight
besides the sensible or individual voices and sights. Therefore it
is plain that the other senses as well, and the other objects of
sense, will exist apart; for why should one set of them do so and
another not? And if this is so, there will also be animals existing
apart, since there will be senses.
2487
Again, there are certain mathematical theorems that are
universal, extending beyond these substances. Here then we
shall have another intermediate substance separate both from
the Ideas and from the intermediates, - a substance which is
neither number nor points nor spatial magnitude nor time. And
if this is impossible, plainly it is also impossible that the former
entities should exist separate from sensible things.
And, in general, conclusion contrary alike to the truth and to
the usual views follow, if one is to suppose the objects of
mathematics to exist thus as separate entities. For because they
exist thus they must be prior to sensible spatial magnitudes, but
in truth they must be posterior; for the incomplete spatial
magnitude is in the order of generation prior, but in the order of
substance posterior, as the lifeless is to the living.
Again, by virtue of what, and when, will mathematical
magnitudes be one? For things in our perceptible world are one
in virtue of soul, or of a part of soul, or of something else that is
reasonable enough; when these are not present, the thing is a
plurality, and splits up into parts. But in the case of the subjects
of mathematics, which are divisible and are quantities, what is
the cause of their being one and holding together?
Again, the modes of generation of the objects of mathematics
show that we are right. For the dimension first generated is
length, then comes breadth, lastly depth, and the process is
complete. If, then, that which is posterior in the order of
generation is prior in the order of substantiality, the solid will be
prior to the plane and the line. And in this way also it is both
more complete and more whole, because it can become
animate. How, on the other hand, could a line or a plane be
animate? The supposition passes the power of our senses.
Again, the solid is a sort of substance; for it already has in a
sense completeness. But how can lines be substances? Neither
2488
as a form or shape, as the soul perhaps is, nor as matter, like the
solid; for we have no experience of anything that can be put
together out of lines or planes or points, while if these had been
a sort of material substance, we should have observed things
which could be put together out of them.
Grant, then, that they are prior in definition. Still not all things
that are prior in definition are also prior in substantiality. For
those things are prior in substantiality which when separated
from other things surpass them in the power of independent
existence, but things are prior in definition to those whose
definitions are compounded out of their definitions; and these
two properties are not coextensive. For if attributes do not exist
apart from the substances (e.g. a 'mobile' or a pale'), pale is prior
to the pale man in definition, but not in substantiality. For it
cannot exist separately, but is always along with the concrete
thing; and by the concrete thing I mean the pale man. Therefore
it is plain that neither is the result of abstraction prior nor that
which is produced by adding determinants posterior; for it is by
adding a determinant to pale that we speak of the pale man.
It has, then, been sufficiently pointed out that the objects of
mathematics are not substances in a higher degree than bodies
are, and that they are not prior to sensibles in being, but only in
definition, and that they cannot exist somewhere apart. But
since it was not possible for them to exist in sensibles either, it
is plain that they either do not exist at all or exist in a special
sense and therefore do not 'exist' without qualification. For
'exist' has many senses.
2489
For just as the universal propositions of mathematics deal not
with objects which exist separately, apart from extended
magnitudes and from numbers, but with magnitudes and
numbers, not however qua such as to have magnitude or to be
divisible, clearly it is possible that there should also be both
propositions and demonstrations about sensible magnitudes,
not however qua sensible but qua possessed of certain definite
qualities. For as there are many propositions about things
merely considered as in motion, apart from what each such
thing is and from their accidents, and as it is not therefore
necessary that there should be either a mobile separate from
sensibles, or a distinct mobile entity in the sensibles, so too in
the case of mobiles there will be propositions and sciences,
which treat them however not qua mobile but only qua bodies,
or again only qua planes, or only qua lines, or qua divisibles, or
qua indivisibles having position, or only qua indivisibles. Thus
since it is true to say without qualification that not only things
which are separable but also things which are inseparable exist
(for instance, that mobiles exist), it is true also to say without
qualification that the objects of mathematics exist, and with
the character ascribed to them by mathematicians. And as it is
true to say of the other sciences too, without qualification, that
they deal with such and such a subject - not with what is
accidental to it (e.g. not with the pale, if the healthy thing is
pale, and the science has the healthy as its subject), but with
that which is the subject of each science - with the healthy if it
treats its object qua healthy, with man if qua man: - so too is it
with geometry; if its subjects happen to be sensible, though it
does not treat them qua sensible, the mathematical sciences
will not for that reason be sciences of sensibles - nor, on the
other hand, of other things separate from sensibles. Many
properties attach to things in virtue of their own nature as
possessed of each such character; e.g. there are attributes
2490
peculiar to the animal qua female or qua male (yet there is no
'female' nor 'male' separate from animals); so that there are
also attributes which belong to things merely as lengths or as
planes. And in proportion as we are dealing with things which
are prior in definition and simpler, our knowledge has more
accuracy, i.e. simplicity. Therefore a science which abstracts
from spatial magnitude is more precise than one which takes it
into account; and a science is most precise if it abstracts from
movement, but if it takes account of movement, it is most
precise if it deals with the primary movement, for this is the
simplest; and of this again uniform movement is the simplest
form.
The same account may be given of harmonics and optics; for
neither considers its objects qua sight or qua voice, but qua
lines and numbers; but the latter are attributes proper to the
former. And mechanics too proceeds in the same way. Therefore
if we suppose attributes separated from their fellow attributes
and make any inquiry concerning them as such, we shall not for
this reason be in error, any more than when one draws a line on
the ground and calls it a foot long when it is not; for the error is
not included in the premisses.
Each question will be best investigated in this way - by setting
up by an act of separation what is not separate, as the
arithmetician and the geometer do. For a man qua man is one
indivisible thing; and the arithmetician supposed one
indivisible thing, and then considered whether any attribute
belongs to a man qua indivisible. But the geometer treats him
neither qua man nor qua indivisible, but as a solid. For evidently
the properties which would have belonged to him even if
perchance he had not been indivisible, can belong to him even
apart from these attributes. Thus, then, geometers speak
correctly; they talk about existing things, and their subjects do
2491
exist; for being has two forms - it exists not only in complete
reality but also materially.
Now since the good and the beautiful are different (for the
former always implies conduct as its subject, while the
beautiful is found also in motionless things), those who assert
that the mathematical sciences say nothing of the beautiful or
the good are in error. For these sciences say and prove a great
deal about them; if they do not expressly mention them, but
prove attributes which are their results or their definitions, it is
not true to say that they tell us nothing about them. The chief
forms of beauty are order and symmetry and definiteness,
which the mathematical sciences demonstrate in a special
degree. And since these (e.g. order and definiteness) are
obviously causes of many things, evidently these sciences must
treat this sort of causative principle also (i.e. the beautiful) as in
some sense a cause. But we shall speak more plainly elsewhere
about these matters.
So much then for the objects of mathematics; we have said that
they exist and in what sense they exist, and in what sense they
are prior and in what sense not prior. Now, regarding the Ideas,
we must first examine the ideal theory itself, not connecting it
in any way with the nature of numbers, but treating it in the
form in which it was originally understood by those who first
maintained the existence of the Ideas. The supporters of the
ideal theory were led to it because on the question about the
truth of things they accepted the Heraclitean sayings which
describe all sensible things as ever passing away, so that if
knowledge or thought is to have an object, there must be some
2492
other and permanent entities, apart from those which are
sensible; for there could be no knowledge of things which were
in a state of flux. But when Socrates was occupying himself
with the excellences of character, and in connexion with them
became the first to raise the problem of universal definition (for
of the physicists Democritus only touched on the subject to a
small extent, and defined, after a fashion, the hot and the cold;
while the Pythagoreans had before this treated of a few things,
whose definitions - e.g. those of opportunity, justice, or
marriage - they connected with numbers; but it was natural
that Socrates should be seeking the essence, for he was seeking
to syllogize, and 'what a thing is' is the starting-point of
syllogisms; for there was as yet none of the dialectical power
which enables people even without knowledge of the essence to
speculate about contraries and inquire whether the same
science deals with contraries; for two things may be fairly
ascribed to Socrates - inductive arguments and universal
definition, both of which are concerned with the starting-point
of science): - but Socrates did not make the universals or the
definitions exist apart: they, however, gave them separate
existence, and this was the kind of thing they called Ideas.
Therefore it followed for them, almost by the same argument,
that there must be Ideas of all things that are spoken of
universally, and it was almost as if a man wished to count
certain things, and while they were few thought he would not
be able to count them, but made more of them and then
counted them; for the Forms are, one may say, more numerous
than the particular sensible things, yet it was in seeking the
causes of these that they proceeded from them to the Forms.
For to each thing there answers an entity which has the same
name and exists apart from the substances, and so also in the
case of all other groups there is a one over many, whether these
be of this world or eternal.
2493
Again, of the ways in which it is proved that the Forms exist,
none is convincing; for from some no inference necessarily
follows, and from some arise Forms even of things of which
they think there are no Forms. For according to the arguments
from the sciences there will be Forms of all things of which
there are sciences, and according to the argument of the 'one
over many' there will be Forms even of negations, and according
to the argument that thought has an object when the individual
object has perished, there will be Forms of perishable things; for
we have an image of these. Again, of the most accurate
arguments, some lead to Ideas of relations, of which they say
there is no independent class, and others introduce the 'third
man'.
And in general the arguments for the Forms destroy things for
whose existence the believers in Forms are more zealous than
for the existence of the Ideas; for it follows that not the dyad
but number is first, and that prior to number is the relative, and
that this is prior to the absolute - besides all the other points on
which certain people, by following out the opinions held about
the Forms, came into conflict with the principles of the theory.
Again, according to the assumption on the belief in the Ideas
rests, there will be Forms not only of substances but also of
many other things; for the concept is single not only in the case
of substances, but also in that of non-substances, and there are
sciences of other things than substance; and a thousand other
such difficulties confront them. But according to the necessities
of the case and the opinions about the Forms, if they can be
shared in there must be Ideas of substances only. For they are
not shared in incidentally, but each Form must be shared in as
something not predicated of a subject. (By 'being shared in
incidentally' I mean that if a thing shares in 'double itself, it
shares also in 'eternal', but incidentally; for 'the double'
happens to be eternal.) Therefore the Forms will be substance.
2494
But the same names indicate substance in this and in the ideal
world (or what will be the meaning of saying that there is
something apart from the particulars - the one over many?).
And if the Ideas and the things that share in them have the
same form, there will be something common: for why should '2'
be one and the same in the perishable 2's, or in the 2's which
are many but eternal, and not the same in the '2 itself as in the
individual 2? But if they have not the same form, they will have
only the name in common, and it is as if one were to call both
Callias and a piece of wood a 'man', without observing any
community between them.
But if we are to suppose that in other respects the common
definitions apply to the Forms, e.g. that 'plane figure' and the
other parts of the definition apply to the circle itself, but 'what
really is' has to be added, we must inquire whether this is not
absolutely meaningless. For to what is this to be added? To
'centre' or to 'plane' or to all the parts of the definition? For all
the elements in the essence are Ideas, e.g. 'animal' and 'two-
footed'. Further, there must be some Ideal answering to 'plane'
above, some nature which will be present in all the Forms as
their genus.
Above all one might discuss the question what in the world the
Forms contribute to sensible things, either to those that are
eternal or to those that come into being and cease to be; for
they cause neither movement nor any change in them. But
again they help in no wise either towards the knowledge of
other things (for they are not even the substance of these, else
they would have been in them), or towards their being, if they
2495
are not in the individuals which share in them; though if they
were, they might be thought to be causes, as white causes
whiteness in a white object by entering into its composition. But
this argument, which was used first by Anaxagoras, and later by
Eudoxus in his discussion of difficulties and by certain others, is
very easily upset; for it is easy to collect many and insuperable
objections to such a view.
But, further, all other things cannot come from the Forms in any
of the usual senses of 'from'. And to say that they are patterns
and the other things share in them is to use empty words and
poetical metaphors. For what is it that works, looking to the
Ideas? And any thing can both be and come into being without
being copied from something else, so that, whether Socrates
exists or not, a man like Socrates might come to be. And
evidently this might be so even if Socrates were eternal. And
there will be several patterns of the same thing, and therefore
several Forms; e.g. 'animal' and 'two-footed', and also 'man-
himself, will be Forms of man. Again, the Forms are patterns
not only of sensible things, but of Forms themselves also; i.e.
the genus is the pattern of the various forms-of-a-genus;
therefore the same thing will be pattern and copy.
Again, it would seem impossible that substance and that whose
substance it is should exist apart; how, therefore, could the
Ideas, being the substances of things, exist apart?
In the Phaedo the case is stated in this way - that the Forms are
causes both of being and of becoming. Yet though the Forms
exist, still things do not come into being, unless there is
something to originate movement; and many other things come
into being (e.g. a house or a ring) of which they say there are no
Forms. Clearly therefore even the things of which they say there
are Ideas can both be and come into being owing to such causes
as produce the things just mentioned, and not owing to the
2496
Forms. But regarding the Ideas it is possible, both in this way
and by more abstract and accurate arguments, to collect many
objections like those we have considered.
Since we have discussed these points, it is well to consider
again the results regarding numbers which confront those who
say that numbers are separable substances and first causes of
things. If number is an entity and its substance is nothing other
than just number, as some say, it follows that either (1) there is
a first in it and a second, each being different in species, - and
either (a) this is true of the units without exception, and any
unit is inassociable with any unit, or (b) they are all without
exception successive, and any of them are associable with any,
as they say is the case with mathematical number; for in
mathematical number no one unit is in any way different from
another. Or (c) some units must be associable and some not; e.g.
suppose that 2 is first after 1, and then comes 3 and then the
rest of the number series, and the units in each number are
associable, e.g. those in the first 2 are associable with one
another, and those in the first 3 with one another, and so with
the other numbers; but the units in the '2-itself are inassociable
with those in the '3-itself ; and similarly in the case of the other
successive numbers. And so while mathematical number is
counted thus - after 1, 2 (which consists of another 1 besides
the former 1), and 3 which consists of another 1 besides these
two), and the other numbers similarly, ideal number is counted
thus - after 1, a distinct 2 which does not include the first 1, and
a 3 which does not include the 2 and the rest of the number
series similarly. Or (2) one kind of number must be like the first
2497
that was named, one like that which the mathematicians speak
of, and that which we have named last must be a third kind.
Again, these kinds of numbers must either be separable from
things, or not separable but in objects of perception (not
however in the way which we first considered, in the sense that
objects of perception consists of numbers which are present in
them) - either one kind and not another, or all of them.
These are of necessity the only ways in which the numbers can
exist. And of those who say that the 1 is the beginning and
substance and element of all things, and that number is formed
from the 1 and something else, almost every one has described
number in one of these ways; only no one has said all the units
are inassociable. And this has happened reasonably enough; for
there can be no way besides those mentioned. Some say both
kinds of number exist, that which has a before and after being
identical with the Ideas, and mathematical number being
different from the Ideas and from sensible things, and both
being separable from sensible things; and others say
mathematical number alone exists, as the first of realities,
separate from sensible things. And the Pythagoreans, also,
believe in one kind of number - the mathematical; only they say
it is not separate but sensible substances are formed out of it.
For they construct the whole universe out of numbers - only not
numbers consisting of abstract units; they suppose the units to
have spatial magnitude. But how the first 1 was constructed so
as to have magnitude, they seem unable to say.
Another thinker says the first kind of number, that of the Forms,
alone exists, and some say mathematical number is identical
with this.
The case of lines, planes, and solids is similar. For some think
that those which are the objects of mathematics are different
from those which come after the Ideas; and of those who
2498
express themselves otherwise some speak of the objects of
mathematics and in a mathematical way - viz. those who do
not make the Ideas numbers nor say that Ideas exist; and others
speak of the objects of mathematics, but not mathematically;
for they say that neither is every spatial magnitude divisible
into magnitudes, nor do any two units taken at random make 2.
All who say the 1 is an element and principle of things suppose
numbers to consist of abstract units, except the Pythagoreans;
but they suppose the numbers to have magnitude, as has been
said before. It is clear from this statement, then, in how many
ways numbers may be described, and that all the ways have
been mentioned; and all these views are impossible, but some
perhaps more than others.
First, then, let us inquire if the units are associable or
inassociable, and if inassociable, in which of the two ways we
distinguished. For it is possible that any unity is inassociable
with any, and it is possible that those in the 'itself are
inassociable with those in the 'itself, and, generally, that those
in each ideal number are inassociable with those in other ideal
numbers. Now (1) all units are associable and without
difference, we get mathematical number - only one kind of
number, and the Ideas cannot be the numbers. For what sort of
number will man-himself or animal-itself or any other Form be?
There is one Idea of each thing e.g. one of man-himself and
another one of animal-itself; but the similar and
undifferentiated numbers are infinitely many, so that any
particular 3 is no more man-himself than any other 3. But if the
Ideas are not numbers, neither can they exist at all. For from
what principles will the Ideas come? It is number that comes
2499
from the 1 and the indefinite dyad, and the principles or
elements are said to be principles and elements of number, and
the Ideas cannot be ranked as either prior or posterior to the
numbers.
But (2) if the units are inassociable, and inassociable in the
sense that any is inassociable with any other, number of this
sort cannot be mathematical number; for mathematical
number consists of undifferentiated units, and the truths
proved of it suit this character. Nor can it be ideal number. For 2
will not proceed immediately from 1 and the indefinite dyad,
and be followed by the successive numbers, as they say '2,3,4'
for the units in the ideal are generated at the same time,
whether, as the first holder of the theory said, from unequals
(coming into being when these were equalized) or in some other
way - since, if one unit is to be prior to the other, it will be prior
also to 2 the composed of these; for when there is one thing
prior and another posterior, the resultant of these will be prior
to one and posterior to the other. Again, since the 1-itself is
first, and then there is a particular 1 which is first among the
others and next after the 1-itself, and again a third which is
next after the second and next but one after the first 1, - so the
units must be prior to the numbers after which they are named
when we count them; e.g. there will be a third unit in 2 before 3
exists, and a fourth and a fifth in 3 before the numbers 4 and 5
exist. - Now none of these thinkers has said the units are
inassociable in this way, but according to their principles it is
reasonable that they should be so even in this way, though in
truth it is impossible. For it is reasonable both that the units
should have priority and posteriority if there is a first unit or
first 1, and also that the 2's should if there is a first 2; for after
the first it is reasonable and necessary that there should be a
second, and if a second, a third, and so with the others
successively. (And to say both things at the same time, that a
unit is first and another unit is second after the ideal 1, and that
2500
a 2 is first after it, is impossible.) But they make a first unit or 1,
but not also a second and a third, and a first 2, but not also a
second and a third. Clearly, also, it is not possible, if all the units
are inassociable, that there should be a 2-itself and a 3-itself;
and so with the other numbers. For whether the units are
undifferentiated or different each from each, number must be
counted by addition, e.g. 2 by adding another 1 to the one, 3 by
adding another 1 to the two, and similarly. This being so,
numbers cannot be generated as they generate them, from the 2
and the 1; for 2 becomes part of 3 and 3 of 4 and the same
happens in the case of the succeeding numbers, but they say 4
came from the first 2 and the indefinite which makes it two 2's
other than the 2-itself; if not, the 2-itself will be a part of 4 and
one other 2 will be added. And similarly 2 will consist of the 1-
itself and another 1; but if this is so, the other element cannot
be an indefinite 2; for it generates one unit, not, as the
indefinite 2 does, a definite 2.
Again, besides the 3-itself and the 2-itself how can there be
other 3's and 2's? And how do they consist of prior and posterior
units? All this is absurd and fictitious, and there cannot be a
first 2 and then a 3-itself. Yet there must, if the 1 and the
indefinite dyad are to be the elements. But if the results are
impossible, it is also impossible that these are the generating
principles.
If the units, then, are differentiated, each from each, these
results and others similar to these follow of necessity. But (3) if
those in different numbers are differentiated, but those in the
same number are alone undifferentiated from one another,
even so the difficulties that follow are no less. E.g. in the 10-
itself their are ten units, and the 10 is composed both of them
and of two 5's. But since the 10-itself is not any chance number
nor composed of any chance 5's - or, for that matter, units - the
units in this 10 must differ. For if they do not differ, neither will
2501
the 5's of which the 10 consists differ; but since these differ, the
units also will differ. But if they differ, will there be no other 5's
in the 10 but only these two, or will there be others? If there are
not, this is paradoxical; and if there are, what sort of 10 will
consist of them? For there is no other in the 10 but the 10 itself.
But it is actually necessary on their view that the 4 should not
consist of any chance 2's; for the indefinite as they say, received
the definite 2 and made two 2's; for its nature was to double
what it received.
Again, as to the 2 being an entity apart from its two units, and
the 3 an entity apart from its three units, how is this possible?
Either by one's sharing in the other, as 'pale man' is different
from 'pale' and 'man' (for it shares in these), or when one is a
differentia of the other, as 'man' is different from 'animal' and
'two-footed'.
Again, some things are one by contact, some by intermixture,
some by position; none of which can belong to the units of
which the 2 or the 3 consists; but as two men are not a unity
apart from both, so must it be with the units. And their being
indivisible will make no difference to them; for points too are
indivisible, but yet a pair of them is nothing apart from the two.
But this consequence also we must not forget, that it follows
that there are prior and posterior 2 and similarly with the other
numbers. For let the 2's in the 4 be simultaneous; yet these are
prior to those in the 8 and as the 2 generated them, they
generated the 4's in the 8-itself. Therefore if the first 2 is an
Idea, these 2's also will be Ideas of some kind. And the same
account applies to the units; for the units in the first 2 generate
the four in 4, so that all the units come to be Ideas and an Idea
will be composed of Ideas. Clearly therefore those things also of
which these happen to be the Ideas will be composite, e.g. one
2502
might say that animals are composed of animals, if there are
Ideas of them.
In general, to differentiate the units in any way is an absurdity
and a fiction; and by a fiction I mean a forced statement made
to suit a hypothesis. For neither in quantity nor in quality do we
see unit differing from unit, and number must be either equal
or unequal - all number but especially that which consists of
abstract units - so that if one number is neither greater nor less
than another, it is equal to it; but things that are equal and in
no wise differentiated we take to be the same when we are
speaking of numbers. If not, not even the 2 in the 10-itself will
be undifferentiated, though they are equal; for what reason will
the man who alleges that they are not differentiated be able to
give?
Again, if every unit + another unit makes two, a unit from the 2-
itself and one from the 3-itself will make a 2. Now (a) this will
consist of differentiated units; and will it be prior to the 3 or
posterior? It rather seems that it must be prior; for one of the
units is simultaneous with the 3 and the other is simultaneous
with the 2. And we, for our part, suppose that in general 1 and 1,
whether the things are equal or unequal, is 2, e.g. the good and
the bad, or a man and a horse; but those who hold these views
say that not even two units are 2.
If the number of the 3-itself is not greater than that of the 2, this
is surprising; and if it is greater, clearly there is also a number in
it equal to the 2, so that this is not different from the 2-itself.
But this is not possible, if there is a first and a second number.
Nor will the Ideas be numbers. For in this particular point they
are right who claim that the units must be different, if there are
to be Ideas; as has been said before. For the Form is unique; but
if the units are not different, the 2's and the 3's also will not be
different. This is also the reason why they must say that when
2503
we count thus - '1,2' - we do not proceed by adding to the given
number; for if we do, neither will the numbers be generated
from the indefinite dyad, nor can a number be an Idea; for then
one Idea will be in another, and all Forms will be parts of one
Form. And so with a view to their hypothesis their statements
are right, but as a whole they are wrong; for their view is very
destructive, since they will admit that this question itself
affords some difficulty - whether, when we count and say -
1,2,3 - we count by addition or by separate portions. But we do
both; and so it is absurd to reason back from this problem to so
great a difference of essence.
8
First of all it is well to determine what is the differentia of a
number - and of a unit, if it has a differentia. Units must differ
either in quantity or in quality; and neither of these seems to be
possible. But number qua number differs in quantity. And if the
units also did differ in quantity, number would differ from
number, though equal in number of units. Again, are the first
units greater or smaller, and do the later ones increase or
diminish? All these are irrational suppositions. But neither can
they differ in quality. For no attribute can attach to them; for
even to numbers quality is said to belong after quantity. Again,
quality could not come to them either from the 1 or the dyad;
for the former has no quality, and the latter gives quantity; for
this entity is what makes things to be many. If the facts are
really otherwise, they should state this quite at the beginning
and determine if possible, regarding the differentia of the unit,
why it must exist, and, failing this, what differentia they mean.
2504
Evidently then, if the Ideas are numbers, the units cannot all be
associable, nor can they be inassociable in either of the two
ways. But neither is the way in which some others speak about
numbers correct. These are those who do not think there are
Ideas, either without qualification or as identified with certain
numbers, but think the objects of mathematics exist and the
numbers are the first of existing things, and the 1-itself is the
starting-point of them. It is paradoxical that there should be a 1
which is first of l's, as they say, but not a 2 which is first of 2's,
nor a 3 of 3's; for the same reasoning applies to all. If, then, the
facts with regard to number are so, and one supposes
mathematical number alone to exist, the 1 is not the starting-
point (for this sort of 1 must differ from the other units; and if
this is so, there must also be a 2 which is first of 2's, and
similarly with the other successive numbers). But if the 1 is the
starting-point, the truth about the numbers must rather be
what Plato used to say, and there must be a first 2 and 3 and
numbers must not be associable with one another. But if on the
other hand one supposes this, many impossible results, as we
have said, follow. But either this or the other must be the case,
so that if neither is, number cannot exist separately.
It is evident, also, from this that the third version is the worst, -
the view ideal and mathematical number is the same. For two
mistakes must then meet in the one opinion. (1) Mathematical
number cannot be of this sort, but the holder of this view has to
spin it out by making suppositions peculiar to himself. And (2)
he must also admit all the consequences that confront those
who speak of number in the sense of 'Forms'.
The Pythagorean version in one way affords fewer difficulties
than those before named, but in another way has others
peculiar to itself. For not thinking of number as capable of
existing separately removes many of the impossible
consequences; but that bodies should be composed of numbers,
2505
and that this should be mathematical number, is impossible.
For it is not true to speak of indivisible spatial magnitudes; and
however much there might be magnitudes of this sort, units at
least have not magnitude; and how can a magnitude be
composed of indivisibles? But arithmetical number, at least,
consists of units, while these thinkers identify number with real
things; at any rate they apply their propositions to bodies as if
they consisted of those numbers.
If, then, it is necessary, if number is a self-subsistent real thing,
that it should exist in one of these ways which have been
mentioned, and if it cannot exist in any of these, evidently
number has no such nature as those who make it separable set
up for it.
Again, does each unit come from the great and the small,
equalized, or one from the small, another from the great? (a) If
the latter, neither does each thing contain all the elements, nor
are the units without difference; for in one there is the great
and in another the small, which is contrary in its nature to the
great. Again, how is it with the units in the 3-itself? One of them
is an odd unit. But perhaps it is for this reason that they give 1-
itself the middle place in odd numbers, (b) But if each of the two
units consists of both the great and the small, equalized, how
will the 2 which is a single thing, consist of the great and the
small? Or how will it differ from the unit? Again, the unit is
prior to the 2; for when it is destroyed the 2 is destroyed. It
must, then, be the Idea of an Idea since it is prior to an Idea, and
it must have come into being before it. From what, then? Not
from the indefinite dyad, for its function was to double.
Again, number must be either infinite or finite; for these
thinkers think of number as capable of existing separately, so
that it is not possible that neither of those alternatives should
be true. Clearly it cannot be infinite; for infinite number is
2506
neither odd nor even, but the generation of numbers is always
the generation either of an odd or of an even number; in one
way, when 1 operates on an even number, an odd number is
produced; in another way, when 2 operates, the numbers got
from 1 by doubling are produced; in another way, when the odd
numbers operate, the other even numbers are produced. Again,
if every Idea is an Idea of something, and the numbers are
Ideas, infinite number itself will be an Idea of something, either
of some sensible thing or of something else. Yet this is not
possible in view of their thesis any more than it is reasonable in
itself, at least if they arrange the Ideas as they do.
But if number is finite, how far does it go? With regard to this
not only the fact but the reason should be stated. But if number
goes only up to 10 as some say, firstly the Forms will soon run
short; e.g. if 3 is man-himself, what number will be the horse-
itself? The series of the numbers which are the several things-
themselves goes up to 10. It must, then, be one of the numbers
within these limits; for it is these that are substances and Ideas.
Yet they will run short; for the various forms of animal will
outnumber them. At the same time it is clear that if in this way
the 3 is man-himself, the other 3's are so also (for those in
identical numbers are similar), so that there will be an infinite
number of men; if each 3 is an Idea, each of the numbers will be
man-himself, and if not, they will at least be men. And if the
smaller number is part of the greater (being number of such a
sort that the units in the same number are associable), then if
the 4-itself is an Idea of something, e.g. of 'horse' or of 'white',
man will be a part of horse, if man is It is paradoxical also that
there should be an Idea of 10 but not of 11, nor of the
succeeding numbers. Again, there both are and come to be
certain things of which there are no Forms; why, then, are there
not Forms of them also? We infer that the Forms are not causes.
Again, it is paradoxical - if the number series up to 10 is more of
a real thing and a Form than 10 itself. There is no generation of
2507
the former as one thing, and there is of the latter. But they try to
work on the assumption that the series of numbers up to 10 is a
complete series. At least they generate the derivatives - e.g. the
void, proportion, the odd, and the others of this kind - within
the decade. For some things, e.g. movement and rest, good and
bad, they assign to the originative principles, and the others to
the numbers. This is why they identify the odd with 1; for if the
odd implied 3 how would 5 be odd? Again, spatial magnitudes
and all such things are explained without going beyond a
definite number; e.g. the first, the indivisible, line, then the 2
&c; these entities also extend only up to 10.
Again, if number can exist separately, one might ask which is
prior -1, or 3 or 2? Inasmuch as the number is composite, 1 is
prior, but inasmuch as the universal and the form is prior, the
number is prior; for each of the units is part of the number as
its matter, and the number acts as form. And in a sense the
right angle is prior to the acute, because it is determinate and in
virtue of its definition; but in a sense the acute is prior, because
it is a part and the right angle is divided into acute angles. As
matter, then, the acute angle and the element and the unit are
prior, but in respect of the form and of the substance as
expressed in the definition, the right angle, and the whole
consisting of the matter and the form, are prior; for the concrete
thing is nearer to the form and to what is expressed in the
definition, though in generation it is later. How then is 1 the
starting-point? Because it is not divisiable, they say; but both
the universal, and the particular or the element, are indivisible.
But they are starting-points in different ways, one in definition
and the other in time. In which way, then, is 1 the starting-
point? As has been said, the right angle is thought to be prior to
the acute, and the acute to the right, and each is one.
Accordingly they make 1 the starting-point in both ways. But
this is impossible. For the universal is one as form or substance,
while the element is one as a part or as matter. For each of the
2508
two is in a sense one - in truth each of the two units exists
potentially (at least if the number is a unity and not like a heap,
i.e. if different numbers consist of differentiated units, as they
say), but not in complete reality; and the cause of the error they
fell into is that they were conducting their inquiry at the same
time from the standpoint of mathematics and from that of
universal definitions, so that (1) from the former standpoint
they treated unity, their first principle, as a point; for the unit is
a point without position. They put things together out of the
smallest parts, as some others also have done. Therefore the
unit becomes the matter of numbers and at the same time prior
to 2; and again posterior, 2 being treated as a whole, a unity, and
a form. But (2) because they were seeking the universal they
treated the unity which can be predicated of a number, as in
this sense also a part of the number. But these characteristics
cannot belong at the same time to the same thing.
If the 1-itself must be unitary (for it differs in nothing from
other l's except that it is the starting-point), and the 2 is
divisible but the unit is not, the unit must be liker the 1-itself
than the 2 is. But if the unit is liker it, it must be liker to the unit
than to the 2; therefore each of the units in 2 must be prior to
the 2. But they deny this; at least they generate the 2 first.
Again, if the 2-itself is a unity and the 3-itself is one also, both
form a 2. From what, then, is this 2 produced?
Since there is not contact in numbers, but succession, viz.
between the units between which there is nothing, e.g. between
those in 2 or in 3 one might ask whether these succeed the 1-
2509
itself or not, and whether, of the terms that succeed it, 2 or
either of the units in 2 is prior.
Similar difficulties occur with regard to the classes of things
posterior to number, - the line, the plane, and the solid. For
some construct these out of the species of the 'great and small';
e.g. lines from the 'long and short', planes from the 'broad and
narrow', masses from the 'deep and shallow'; which are species
of the 'great and small'. And the originative principle of such
things which answers to the 1 different thinkers describe in
different ways, And in these also the impossibilities, the
fictions, and the contradictions of all probability are seen to be
innumerable. For (i) geometrical classes are severed from one
another, unless the principles of these are implied in one
another in such a way that the 'broad and narrow' is also 'long
and short' (but if this is so, the plane will be line and the solid a
plane; again, how will angles and figures and such things be
explained?). And (ii) the same happens as in regard to number;
for 'long and short', &c, are attributes of magnitude, but
magnitude does not consist of these, any more than the line
consists of 'straight and curved', or solids of 'smooth and
rough'.
(All these views share a difficulty which occurs with regard to
species-of-a-genus, when one posits the universals, viz.
whether it is animal-itself or something other than animal-
itself that is in the particular animal. True, if the universal is not
separable from sensible things, this will present no difficulty;
but if the 1 and the numbers are separable, as those who
express these views say, it is not easy to solve the difficulty, if
one may apply the words 'not easy' to the impossible. For when
we apprehend the unity in 2, or in general in a number, do we
apprehend a thing-itself or something else?).
2510
Some, then, generate spatial magnitudes from matter of this
sort, others from the point - and the point is thought by them to
be not 1 but something like 1 - and from other matter like
plurality, but not identical with it; about which principles none
the less the same difficulties occur. For if the matter is one, line
and plane - and soli will be the same; for from the same
elements will come one and the same thing. But if the matters
are more than one, and there is one for the line and a second
for the plane and another for the solid, they either are implied
in one another or not, so that the same results will follow even
so; for either the plane will not contain a line or it will he a line.
Again, how number can consist of the one and plurality, they
make no attempt to explain; but however they express
themselves, the same objections arise as confront those who
construct number out of the one and the indefinite dyad. For
the one view generates number from the universally predicated
plurality, and not from a particular plurality; and the other
generates it from a particular plurality, but the first; for 2 is said
to be a 'first plurality'. Therefore there is practically no
difference, but the same difficulties will follow, - is it
intermixture or position or blending or generation? and so on.
Above all one might press the question 'if each unit is one, what
does it come from?' Certainly each is not the one-itself. It must,
then, come from the one itself and plurality, or a part of
plurality. To say that the unit is a plurality is impossible, for it is
indivisible; and to generate it from a part of plurality involves
many other objections; for (a) each of the parts must be
indivisible (or it will be a plurality and the unit will be divisible)
and the elements will not be the one and plurality; for the
single units do not come from plurality and the one. Again, (,the
holder of this view does nothing but presuppose another
number; for his plurality of indivisibles is a number. Again, we
must inquire, in view of this theory also, whether the number is
infinite or finite. For there was at first, as it seems, a plurality
2511
that was itself finite, from which and from the one comes the
finite number of units. And there is another plurality that is
plurality-itself and infinite plurality; which sort of plurality,
then, is the element which co-operates with the one? One
might inquire similarly about the point, i.e. the element out of
which they make spatial magnitudes. For surely this is not the
one and only point; at any rate, then, let them say out of what
each of the points is formed. Certainly not of some distance +
the point-itself. Nor again can there be indivisible parts of a
distance, as the elements out of which the units are said to be
made are indivisible parts of plurality; for number consists of
indivisibles, but spatial magnitudes do not.
All these objections, then, and others of the sort make it evident
that number and spatial magnitudes cannot exist apart from
things. Again, the discord about numbers between the various
versions is a sign that it is the incorrectness of the alleged facts
themselves that brings confusion into the theories. For those
who make the objects of mathematics alone exist apart from
sensible things, seeing the difficulty about the Forms and their
fictitiousness, abandoned ideal number and posited
mathematical. But those who wished to make the Forms at the
same time also numbers, but did not see, if one assumed these
principles, how mathematical number was to exist apart from
ideal, made ideal and mathematical number the same in words,
since in fact mathematical number has been destroyed; for they
state hypotheses peculiar to themselves and not those of
mathematics. And he who first supposed that the Forms exist
and that the Forms are numbers and that the objects of
mathematics exist, naturally separated the two. Therefore it
turns out that all of them are right in some respect, but on the
whole not right. And they themselves confirm this, for their
statements do not agree but conflict. The cause is that their
hypotheses and their principles are false. And it is hard to make
2512
a good case out of bad materials, according to Epicharmus: 'as
soon as 'tis said, 'tis seen to be wrong.'
But regarding numbers the questions we have raised and the
conclusions we have reached are sufficient (for while he who is
already convinced might be further convinced by a longer
discussion, one not yet convinced would not come any nearer to
conviction); regarding the first principles and the first causes
and elements, the views expressed by those who discuss only
sensible substance have been partly stated in our works on
nature, and partly do not belong to the present inquiry; but the
views of those who assert that there are other substances
besides the sensible must be considered next after those we
have been mentioning. Since, then, some say that the Ideas and
the numbers are such substances, and that the elements of
these are elements and principles of real things, we must
inquire regarding these what they say and in what sense they
say it.
Those who posit numbers only, and these mathematical, must
be considered later; but as regards those who believe in the
Ideas one might survey at the same time their way of thinking
and the difficulty into which they fall. For they at the same time
make the Ideas universal and again treat them as separable and
as individuals. That this is not possible has been argued before.
The reason why those who described their substances as
universal combined these two characteristics in one thing, is
that they did not make substances identical with sensible
things. They thought that the particulars in the sensible world
were a state of flux and none of them remained, but that the
universal was apart from these and something different. And
Socrates gave the impulse to this theory, as we said in our
earlier discussion, by reason of his definitions, but he did not
separate universals from individuals; and in this he thought
rightly, in not separating them. This is plain from the results; for
2513
without the universal it is not possible to get knowledge, but the
separation is the cause of the objections that arise with regard
to the Ideas. His successors, however, treating it as necessary, if
there are to be any substances besides the sensible and
transient substances, that they must be separable, had no
others, but gave separate existence to these universally
predicated substances, so that it followed that universals and
individuals were almost the same sort of thing. This in itself,
then, would be one difficulty in the view we have mentioned.
10
Let us now mention a point which presents a certain difficulty
both to those who believe in the Ideas and to those who do not,
and which was stated before, at the beginning, among the
problems. If we do not suppose substances to be separate, and
in the way in which individual things are said to be separate, we
shall destroy substance in the sense in which we understand
'substance'; but if we conceive substances to be separable, how
are we to conceive their elements and their principles?
If they are individual and not universal, (a) real things will be
just of the same number as the elements, and (b) the elements
will not be knowable. For (a) let the syllables in speech be
substances, and their elements elements of substances; then
there must be only one 'ba' and one of each of the syllables,
since they are not universal and the same in form but each is
one in number and a 'this' and not a kind possessed of a
common name (and again they suppose that the 'just what a
thing is' is in each case one). And if the syllables are unique, so
too are the parts of which they consist; there will not, then, be
more a's than one, nor more than one of any of the other
2514
elements, on the same principle on which an identical syllable
cannot exist in the plural number. But if this is so, there will not
be other things existing besides the elements, but only the
elements.
(b) Again, the elements will not be even knowable; for they are
not universal, and knowledge is of universals. This is clear from
demonstrations and from definitions; for we do not conclude
that this triangle has its angles equal to two right angles, unless
every triangle has its angles equal to two right angles, nor that
this man is an animal, unless every man is an animal.
But if the principles are universal, either the substances
composed of them are also universal, or non-substance will be
prior to substance; for the universal is not a substance, but the
element or principle is universal, and the element or principle is
prior to the things of which it is the principle or element.
All these difficulties follow naturally, when they make the Ideas
out of elements and at the same time claim that apart from the
substances which have the same form there are Ideas, a single
separate entity. But if, e.g. in the case of the elements of speech,
the a's and the b's may quite well be many and there need be no
a-itself and b-itself besides the many, there may be, so far as
this goes, an infinite number of similar syllables. The statement
that an knowledge is universal, so that the principles of things
must also be universal and not separate substances, presents
indeed, of all the points we have mentioned, the greatest
difficulty, but yet the statement is in a sense true, although in a
sense it is not. For knowledge, like the verb 'to know', means
two things, of which one is potential and one actual. The
potency, being, as matter, universal and indefinite, deals with
the universal and indefinite; but the actuality, being definite,
deals with a definite object, being a 'this', it deals with a 'this'.
But per accidens sight sees universal colour, because this
2515
individual colour which it sees is colour; and this individual a
which the grammarian investigates is an a. For if the principles
must be universal, what is derived from them must also be
universal, as in demonstrations; and if this is so, there will be
nothing capable of separate existence - i.e. no substance. But
evidently in a sense knowledge is universal, and in a sense it is
not.
BookN
Regarding this kind of substance, what we have said must be
taken as sufficient. All philosophers make the first principles
contraries: as in natural things, so also in the case of
unchangeable substances. But since there cannot be anything
prior to the first principle of all things, the principle cannot be
the principle and yet be an attribute of something else. To
suggest this is like saying that the white is a first principle, not
qua anything else but qua white, but yet that it is predicable of a
subject, i.e. that its being white presupposes its being
something else; this is absurd, for then that subject will be prior.
But all things which are generated from their contraries involve
an underlying subject; a subject, then, must be present in the
case of contraries, if anywhere. All contraries, then, are always
predicable of a subject, and none can exist apart, but just as
appearances suggest that there is nothing contrary to
2516
substance, argument confirms this. No contrary, then, is the
first principle of all things in the full sense; the first principle is
something different.
But these thinkers make one of the contraries matter, some
making the unequal which they take to be the essence of
plurality-matter for the One, and others making plurality matter
for the One. (The former generate numbers out of the dyad of
the unequal, i.e. of the great and small, and the other thinker
we have referred to generates them out of plurality, while
according to both it is generated by the essence of the One.) For
even the philosopher who says the unequal and the One are the
elements, and the unequal is a dyad composed of the great and
small, treats the unequal, or the great and the small, as being
one, and does not draw the distinction that they are one in
definition, but not in number. But they do not describe rightly
even the principles which they call elements, for some name
the great and the small with the One and treat these three as
elements of numbers, two being matter, one the form; while
others name the many and few, because the great and the small
are more appropriate in their nature to magnitude than to
number; and others name rather the universal character
common to these - 'that which exceeds and that which is
exceeded'. None of these varieties of opinion makes any
difference to speak of, in view of some of the consequences;
they affect only the abstract objections, which these thinkers
take care to avoid because the demonstrations they themselves
offer are abstract, - with this exception, that if the exceeding
and the exceeded are the principles, and not the great and the
small, consistency requires that number should come from the
elements before does; for number is more universal than as the
exceeding and the exceeded are more universal than the great
and the small. But as it is, they say one of these things but do
not say the other. Others oppose the different and the other to
the One, and others oppose plurality to the One. But if, as they
2517
claim, things consist of contraries, and to the One either there is
nothing contrary, or if there is to be anything it is plurality, and
the unequal is contrary to the equal, and the different to the
same, and the other to the thing itself, those who oppose the
One to plurality have most claim to plausibility, but even their
view is inadequate, for the One would on their view be a few; for
plurality is opposed to fewness, and the many to the few.
'The one' evidently means a measure. And in every case there is
some underlying thing with a distinct nature of its own, e.g. in
the scale a quarter-tone, in spatial magnitude a finger or a foot
or something of the sort, in rhythms a beat or a syllable; and
similarly in gravity it is a definite weight; and in the same way
in all cases, in qualities a quality, in quantities a quantity (and
the measure is indivisible, in the former case in kind, and in the
latter to the sense); which implies that the one is not in itself
the substance of anything. And this is reasonable; for 'the one'
means the measure of some plurality, and 'number' means a
measured plurality and a plurality of measures. (Thus it is
natural that one is not a number; for the measure is not
measures, but both the measure and the one are starting-
points.) The measure must always be some identical thing
predicable of all the things it measures, e.g. if the things are
horses, the measure is 'horse', and if they are men, 'man'. If
they are a man, a horse, and a god, the measure is perhaps
'living being', and the number of them will be a number of
living beings. If the things are 'man' and 'pale' and 'walking',
these will scarcely have a number, because all belong to a
subject which is one and the same in number, yet the number
of these will be a number of 'kinds' or of some such term.
Those who treat the unequal as one thing, and the dyad as an
indefinite compound of great and small, say what is very far
from being probable or possible. For (a) these are modifications
and accidents, rather than substrata, of numbers and
2518
magnitudes - the many and few of number, and the great and
small of magnitude - like even and odd, smooth and rough,
straight and curved. Again, (b) apart from this mistake, the great
and the small, and so on, must be relative to something; but
what is relative is least of all things a kind of entity or
substance, and is posterior to quality and quantity; and the
relative is an accident of quantity, as was said, not its matter,
since something with a distinct nature of its own must serve as
matter both to the relative in general and to its parts and kinds.
For there is nothing either great or small, many or few, or, in
general, relative to something else, which without having a
nature of its own is many or few, great or small, or relative to
something else. A sign that the relative is least of all a
substance and a real thing is the fact that it alone has no proper
generation or destruction or movement, as in respect of
quantity there is increase and diminution, in respect of quality
alteration, in respect of place locomotion, in respect of
substance simple generation and destruction. In respect of
relation there is no proper change; for, without changing, a
thing will be now greater and now less or equal, if that with
which it is compared has changed in quantity. And (c) the
matter of each thing, and therefore of substance, must be that
which is potentially of the nature in question; but the relative is
neither potentially nor actually substance. It is strange, then, or
rather impossible, to make not-substance an element in, and
prior to, substance; for all the categories are posterior to
substance. Again, (d) elements are not predicated of the things
of which they are elements, but many and few are predicated
both apart and together of number, and long and short of the
line, and both broad and narrow apply to the plane. If there is a
plurality, then, of which the one term, viz. few, is always
predicated, e.g. 2 (which cannot be many, for if it were many, 1
would be few), there must be also one which is absolutely many,
e.g. 10 is many (if there is no number which is greater than 10),
2519
or 10,000. How then, in view of this, can number consist of few
and many? Either both ought to be predicated of it, or neither;
but in fact only the one or the other is predicated.
We must inquire generally, whether eternal things can consist
of elements. If they do, they will have matter; for everything
that consists of elements is composite. Since, then, even if a
thing exists for ever, out of that of which it consists it would
necessarily also, if it had come into being, have come into being,
and since everything comes to be what it comes to be out of
that which is it potentially (for it could not have come to be out
of that which had not this capacity, nor could it consist of such
elements), and since the potential can be either actual or not, -
this being so, however everlasting number or anything else that
has matter is, it must be capable of not existing, just as that
which is any number of years old is as capable of not existing as
that which is a day old; if this is capable of not existing, so is
that which has lasted for a time so long that it has no limit.
They cannot, then, be eternal, since that which is capable of not
existing is not eternal, as we had occasion to show in another
context. If that which we are now saying is true universally -
that no substance is eternal unless it is actuality - and if the
elements are matter that underlies substance, no eternal
substance can have elements present in it, of which it consists.
There are some who describe the element which acts with the
One as an indefinite dyad, and object to 'the unequal',
reasonably enough, because of the ensuing difficulties; but they
have got rid only of those objections which inevitably arise from
the treatment of the unequal, i.e. the relative, as an element;
2520
those which arise apart from this opinion must confront even
these thinkers, whether it is ideal number, or mathematical,
that they construct out of those elements.
There are many causes which led them off into these
explanations, and especially the fact that they framed the
difficulty in an obsolete form. For they thought that all things
that are would be one (viz. Being itself), if one did not join issue
with and refute the saying of Parmenides:
'For never will this he proved, that things that are not are.'
They thought it necessary to prove that that which is not is; for
only thus - of that which is and something else - could the
things that are be composed, if they are many.
But, first, if 'being' has many senses (for it means sometimes
substance, sometimes that it is of a certain quality, sometimes
that it is of a certain quantity, and at other times the other
categories), what sort of 'one', then, are all the things that are, if
non-being is to be supposed not to be? Is it the substances that
are one, or the affections and similarly the other categories as
well, or all together - so that the 'this' and the 'such' and the 'so
much' and the other categories that indicate each some one
class of being will all be one? But it is strange, or rather
impossible, that the coming into play of a single thing should
bring it about that part of that which is is a 'this', part a 'such',
part a 'so much', part a 'here'.
Secondly, of what sort of non-being and being do the things that
are consist? For 'nonbeing' also has many senses, since 'being'
has; and 'not being a man' means not being a certain substance,
'not being straight' not being of a certain quality, 'not being
three cubits long' not being of a certain quantity. What sort of
being and non-being, then, by their union pluralize the things
that are? This thinker means by the non-being the union of
2521
which with being pluralizes the things that are, the false and
the character of falsity. This is also why it used to be said that
we must assume something that is false, as geometers assume
the line which is not a foot long to be a foot long. But this
cannot be so. For neither do geometers assume anything false
(for the enunciation is extraneous to the inference), nor is it
non-being in this sense that the things that are are generated
from or resolved into. But since 'non-being' taken in its various
cases has as many senses as there are categories, and besides
this the false is said not to be, and so is the potential, it is from
this that generation proceeds, man from that which is not man
but potentially man, and white from that which is not white but
potentially white, and this whether it is some one thing that is
generated or many.
The question evidently is, how being, in the sense of 'the
substances', is many; for the things that are generated are
numbers and lines and bodies. Now it is strange to inquire how
being in the sense of the 'what' is many, and not how either
qualities or quantities are many. For surely the indefinite dyad
or 'the great and the small' is not a reason why there should be
two kinds of white or many colours or flavours or shapes; for
then these also would be numbers and units. But if they had
attacked these other categories, they would have seen the cause
of the plurality in substances also; for the same thing or
something analogous is the cause. This aberration is the reason
also why in seeking the opposite of being and the one, from
which with being and the one the things that are proceed, they
posited the relative term (i.e. the unequal), which is neither the
contrary nor the contradictory of these, and is one kind of being
as 'what' and quality also are.
They should have asked this question also, how relative terms
are many and not one. But as it is, they inquire how there are
many units besides the first 1, but do not go on to inquire how
2522
there are many unequals besides the unequal. Yet they use
them and speak of great and small, many and few (from which
proceed numbers), long and short (from which proceeds the
line), broad and narrow (from which proceeds the plane), deep
and shallow (from which proceed solids); and they speak of yet
more kinds of relative term. What is the reason, then, why there
is a plurality of these?
It is necessary, then, as we say, to presuppose for each thing
that which is it potentially; and the holder of these views
further declared what that is which is potentially a 'this' and a
substance but is not in itself being - viz. that it is the relative (as
if he had said 'the qualitative'), which is neither potentially the
one or being, nor the negation of the one nor of being, but one
among beings. And it was much more necessary, as we said, if
he was inquiring how beings are many, not to inquire about
those in the same category - how there are many substances or
many qualities - but how beings as a whole are many; for some
are substances, some modifications, some relations. In the
categories other than substance there is yet another problem
involved in the existence of plurality. Since they are not
separable from substances, qualities and quantities are many
just because their substratum becomes and is many; yet there
ought to be a matter for each category; only it cannot be
separable from substances. But in the case of 'thises', it is
possible to explain how the 'this' is many things, unless a thing
is to be treated as both a 'this' and a general character. The
difficulty arising from the facts about substances is rather this,
how there are actually many substances and not one.
But further, if the 'this' and the quantitative are not the same,
we are not told how and why the things that are are many, but
how quantities are many. For all 'number' means a quantity, and
so does the 'unit', unless it means a measure or the
quantitatively indivisible. If, then, the quantitative and the
2523
'what' are different, we are not told whence or how the 'what' is
many; but if any one says they are the same, he has to face
many inconsistencies.
One might fix one's attention also on the question, regarding
the numbers, what justifies the belief that they exist. To the
believer in Ideas they provide some sort of cause for existing
things, since each number is an Idea, and the Idea is to other
things somehow or other the cause of their being; for let this
supposition be granted them. But as for him who does not hold
this view because he sees the inherent objections to the Ideas
(so that it is not for this reason that he posits numbers), but
who posits mathematical number, why must we believe his
statement that such number exists, and of what use is such
number to other things? Neither does he who says it exists
maintain that it is the cause of anything (he rather says it is a
thing existing by itself), nor is it observed to be the cause of
anything; for the theorems of arithmeticians will all be found
true even of sensible things, as was said before.
As for those, then, who suppose the Ideas to exist and to be
numbers, by their assumption in virtue of the method of setting
out each term apart from its instances - of the unity of each
general term they try at least to explain somehow why number
must exist. Since their reasons, however, are neither conclusive
nor in themselves possible, one must not, for these reasons at
least, assert the existence of number. Again, the Pythagoreans,
because they saw many attributes of numbers belonging te
sensible bodies, supposed real things to be numbers - not
separable numbers, however, but numbers of which real things
2524
consist. But why? Because the attributes of numbers are present
in a musical scale and in the heavens and in many other things.
Those, however, who say that mathematical number alone
exists cannot according to their hypotheses say anything of this
sort, but it used to be urged that these sensible things could not
be the subject of the sciences. But we maintain that they are, as
we said before. And it is evident that the objects of mathematics
do not exist apart; for if they existed apart their attributes
would not have been present in bodies. Now the Pythagoreans
in this point are open to no objection; but in that they construct
natural bodies out of numbers, things that have lightness and
weight out of things that have not weight or lightness, they
seem to speak of another heaven and other bodies, not of the
sensible. But those who make number separable assume that it
both exists and is separable because the axioms would not be
true of sensible things, while the statements of mathematics
are true and 'greet the soul'; and similarly with the spatial
magnitudes of mathematics. It is evident, then, both that the
rival theory will say the contrary of this, and that the difficulty
we raised just now, why if numbers are in no way present in
sensible things their attributes are present in sensible things,
has to be solved by those who hold these views.
There are some who, because the point is the limit and extreme
of the line, the line of the plane, and the plane of the solid, think
there must be real things of this sort. We must therefore
examine this argument too, and see whether it is not
remarkably weak. For (i) extremes are not substances, but rather
all these things are limits. For even walking, and movement in
general, has a limit, so that on their theory this will be a 'this'
and a substance. But that is absurd. Not but what (ii) even if
they are substances, they will all be the substances of the
sensible things in this world; for it is to these that the argument
applied. Why then should they be capable of existing apart?
2525
Again, if we are not too easily satisfied, we may, regarding all
number and the objects of mathematics, press this difficulty,
that they contribute nothing to one another, the prior to the
posterior; for if number did not exist, none the less spatial
magnitudes would exist for those who maintain the existence
of the objects of mathematics only, and if spatial magnitudes
did not exist, soul and sensible bodies would exist. But the
observed facts show that nature is not a series of episodes, like
a bad tragedy. As for the believers in the Ideas, this difficulty
misses them; for they construct spatial magnitudes out of
matter and number, lines out of the number planes doubtless
out of solids out of or they use other numbers, which makes no
difference. But will these magnitudes be Ideas, or what is their
manner of existence, and what do they contribute to things?
These contribute nothing, as the objects of mathematics
contribute nothing. But not even is any theorem true of them,
unless we want to change the objects of mathematics and
invent doctrines of our own. But it is not hard to assume any
random hypotheses and spin out a long string of conclusions.
These thinkers, then, are wrong in this way, in wanting to unite
the objects of mathematics with the Ideas. And those who first
posited two kinds of number, that of the Forms and that which
is mathematical, neither have said nor can say how
mathematical number is to exist and of what it is to consist. For
they place it between ideal and sensible number. If (i) it consists
of the great and small, it will be the same as the other-ideal-
number (he makes spatial magnitudes out of some other small
and great). And if (ii) he names some other element, he will be
making his elements rather many. And if the principle of each
of the two kinds of number is a 1, unity will be something
common to these, and we must inquire how the one is these
many things, while at the same time number, according to him,
cannot be generated except from one and an indefinite dyad.
2526
All this is absurd, and conflicts both with itself and with the
probabilities, and we seem to see in it Simonides 'long
rigmarole' for the long rigmarole comes into play, like those of
slaves, when men have nothing sound to say. And the very
elements - the great and the small - seem to cry out against the
violence that is done to them; for they cannot in any way
generate numbers other than those got from 1 by doubling.
It is strange also to attribute generation to things that are
eternal, or rather this is one of the things that are impossible.
There need be no doubt whether the Pythagoreans attribute
generation to them or not; for they say plainly that when the
one had been constructed, whether out of planes or of surface
or of seed or of elements which they cannot express,
immediately the nearest part of the unlimited began to be
constrained and limited by the limit. But since they are
constructing a world and wish to speak the language of natural
science, it is fair to make some examination of their physical
theories, but to let them off from the present inquiry; for we are
investigating the principles at work in unchangeable things, so
that it is numbers of this kind whose genesis we must study.
These thinkers say there is no generation of the odd number,
which evidently implies that there is generation of the even;
and some present the even as produced first from unequals -
the great and the small - when these are equalized. The
inequality, then, must belong to them before they are equalized.
If they had always been equalized, they would not have been
unequal before; for there is nothing before that which is always.
Therefore evidently they are not giving their account of the
2527
generation of numbers merely to assist contemplation of their
nature.
A difficulty, and a reproach to any one who finds it no difficulty,
are contained in the question how the elements and the
principles are related to the good and the beautiful; the
difficulty is this, whether any of the elements is such a thing as
we mean by the good itself and the best, or this is not so, but
these are later in origin than the elements. The theologians
seem to agree with some thinkers of the present day, who
answer the question in the negative, and say that both the good
and the beautiful appear in the nature of things only when that
nature has made some progress. (This they do to avoid a real
objection which confronts those who say, as some do, that the
one is a first principle. The objection arises not from their
ascribing goodness to the first principle as an attribute, but from
their making the one a principle - and a principle in the sense
of an element - and generating number from the one.) The old
poets agree with this inasmuch as they say that not those who
are first in time, e.g. Night and Heaven or Chaos or Ocean, reign
and rule, but Zeus. These poets, however, are led to speak thus
only because they think of the rulers of the world as changing;
for those of them who combine the two characters in that they
do not use mythical language throughout, e.g. Pherecydes and
some others, make the original generating agent the Best, and
so do the Magi, and some of the later sages also, e.g. both
Empedocles and Anaxagoras, of whom one made love an
element, and the other made reason a principle. Of those who
maintain the existence of the unchangeable substances some
say the One itself is the good itself; but they thought its
substance lay mainly in its unity.
This, then, is the problem, - which of the two ways of speaking
is right. It would be strange if to that which is primary and
eternal and most self-sufficient this very quality - self-
2528
sufficiency and self-maintenance - belongs primarily in some
other way than as a good. But indeed it can be for no other
reason indestructible or self-sufficient than because its nature
is good. Therefore to say that the first principle is good is
probably correct; but that this principle should be the One or, if
not that, at least an element, and an element of numbers, is
impossible. Powerful objections arise, to avoid which some have
given up the theory (viz. those who agree that the One is a first
principle and element, but only of mathematical number). For
on this view all the units become identical with species of good,
and there is a great profusion of goods. Again, if the Forms are
numbers, all the Forms are identical with species of good. But
let a man assume Ideas of anything he pleases. If these are
Ideas only of goods, the Ideas will not be substances; but if the
Ideas are also Ideas of substances, all animals and plants and
all individuals that share in Ideas will be good.
These absurdities follow, and it also follows that the contrary
element, whether it is plurality or the unequal, i.e. the great and
small, is the bad-itself. (Hence one thinker avoided attaching
the good to the One, because it would necessarily follow, since
generation is from contraries, that badness is the fundamental
nature of plurality; while others say inequality is the nature of
the bad.) It follows, then, that all things partake of the bad
except one - the One itself, and that numbers partake of it in a
more undiluted form than spatial magnitudes, and that the bad
is the space in which the good is realized, and that it partakes
in and desires that which tends to destroy it; for contrary tends
to destroy contrary. And if, as we were saying, the matter is that
which is potentially each thing, e.g. that of actual fire is that
which is potentially fire, the bad will be just the potentially
good.
All these objections, then, follow, partly because they make
every principle an element, partly because they make contraries
2529
principles, partly because they make the One a principle, partly
because they treat the numbers as the first substances, and as
capable of existing apart, and as Forms.
If, then, it is equally impossible not to put the good among the
first principles and to put it among them in this way, evidently
the principles are not being correctly described, nor are the first
substances. Nor does any one conceive the matter correctly if
he compares the principles of the universe to that of animals
and plants, on the ground that the more complete always
comes from the indefinite and incomplete - which is what leads
this thinker to say that this is also true of the first principles of
reality, so that the One itself is not even an existing thing. This
is incorrect, for even in this world of animals and plants the
principles from which these come are complete; for it is a man
that produces a man, and the seed is not first.
It is out of place, also, to generate place simultaneously with the
mathematical solids (for place is peculiar to the individual
things, and hence they are separate in place; but mathematical
objects are nowhere), and to say that they must be somewhere,
but not say what kind of thing their place is.
Those who say that existing things come from elements and
that the first of existing things are the numbers, should have
first distinguished the senses in which one thing comes from
another, and then said in which sense number comes from its
first principles.
By intermixture? But (1) not everything is capable of
intermixture, and (2) that which is produced by it is different
2530
from its elements, and on this view the one will not remain
separate or a distinct entity; but they want it to be so.
By juxtaposition, like a syllable? But then (1) the elements must
have position; and (2) he who thinks of number will be able to
think of the unity and the plurality apart; number then will be
this - a unit and plurality, or the one and the unequal.
Again, coming from certain things means in one sense that
these are still to be found in the product, and in another that
they are not; which sense does number come from these
elements? Only things that are generated can come from
elements which are present in them. Does number come, then,
from its elements as from seed? But nothing can be excreted
from that which is indivisible. Does it come from its contrary, its
contrary not persisting? But all things that come in this way
come also from something else which does persist. Since, then,
one thinker places the 1 as contrary to plurality, and another
places it as contrary to the unequal, treating the 1 as equal,
number must be being treated as coming from contraries. There
is, then, something else that persists, from which and from one
contrary the compound is or has come to be. Again, why in the
world do the other things that come from contraries, or that
have contraries, perish (even when all of the contrary is used to
produce them), while number does not? Nothing is said about
this. Yet whether present or not present in the compound the
contrary destroys it, e.g. 'strife' destroys the 'mixture' (yet it
should not; for it is not to that that is contrary).
Once more, it has not been determined at all in which way
numbers are the causes of substances and of being - whether
(1) as boundaries (as points are of spatial magnitudes). This is
how Eurytus decided what was the number of what (e.g. one of
man and another of horse), viz. by imitating the figures of living
things with pebbles, as some people bring numbers into the
2531
forms of triangle and square. Or (2) is it because harmony is a
ratio of numbers, and so is man and everything else? But how
are the attributes - white and sweet and hot - numbers?
Evidently it is not the numbers that are the essence or the
causes of the form; for the ratio is the essence, while the
number the causes of the form; for the ratio is the essence,
while the number is the matter. E.g. the essence of flesh or bone
is number only in this way, 'three parts of fire and two of earth'.
And a number, whatever number it is, is always a number of
certain things, either of parts of fire or earth or of units; but the
essence is that there is so much of one thing to so much of
another in the mixture; and this is no longer a number but a
ratio of mixture of numbers, whether these are corporeal or of
any other kind.
Number, then, whether it be number in general or the number
which consists of abstract units, is neither the cause as agent,
nor the matter, nor the ratio and form of things. Nor, of course,
is it the final cause.
One might also raise the question what the good is that things
get from numbers because their composition is expressible by a
number, either by one which is easily calculable or by an odd
number. For in fact honey-water is no more wholesome if it is
mixed in the proportion of three times three, but it would do
more good if it were in no particular ratio but well diluted than
if it were numerically expressible but strong. Again, the ratios of
mixtures are expressed by the adding of numbers, not by mere
numbers; e.g. it is 'three parts to two', not 'three times two'. For
in any multiplication the genus of the things multiplied must be
2532
the same; therefore the product 1x2x3 must be measurable by 1,
and 4x5x6 by 4 and therefore all products into which the same
factor enters must be measurable by that factor. The number of
fire, then, cannot be 2x5x3x6 and at the same time that of water
2x3.
If all things must share in number, it must follow that many
things are the same, and the same number must belong to one
thing and to another. Is number the cause, then, and does the
thing exist because of its number, or is this not certain? E.g. the
motions of the sun have a number, and again those of the
moon, - yes, and the life and prime of each animal. Why, then,
should not some of these numbers be squares, some cubes, and
some equal, others double? There is no reason why they should
not, and indeed they must move within these limits, since all
things were assumed to share in number. And it was assumed
that things that differed might fall under the same number.
Therefore if the same number had belonged to certain things,
these would have been the same as one another, since they
would have had the same form of number; e.g. sun and moon
would have been the same. But why need these numbers be
causes? There are seven vowels, the scale consists of seven
strings, the Pleiades are seven, at seven animals lose their teeth
(at least some do, though some do not), and the champions who
fought against Thebes were seven. Is it then because the
number is the kind of number it is, that the champions were
seven or the Pleiad consists of seven stars? Surely the
champions were seven because there were seven gates or for
some other reason, and the Pleiad we count as seven, as we
count the Bear as twelve, while other peoples count more stars
in both. Nay they even say that X, Ps and Z are concords and
that because there are three concords, the double consonants
also are three. They quite neglect the fact that there might be a
thousand such letters; for one symbol might be assigned to GP.
But if they say that each of these three is equal to two of the
2533
other letters, and no other is so, and if the cause is that there
are three parts of the mouth and one letter is in each applied to
sigma, it is for this reason that there are only three, not because
the concords are three; since as a matter of fact the concords
are more than three, but of double consonants there cannot be
more.
These people are like the old-fashioned Homeric scholars, who
see small resemblances but neglect great ones. Some say that
there are many such cases, e.g. that the middle strings are
represented by nine and eight, and that the epic verse has
seventeen syllables, which is equal in number to the two
strings, and that the scansion is, in the right half of the line nine
syllables, and in the left eight. And they say that the distance in
the letters from alpha to omega is equal to that from the lowest
note of the flute to the highest, and that the number of this
note is equal to that of the whole choir of heaven. It may be
suspected that no one could find difficulty either in stating such
analogies or in finding them in eternal things, since they can be
found even in perishable things.
But the lauded characteristics of numbers, and the contraries of
these, and generally the mathematical relations, as some
describe them, making them causes of nature, seem, when we
inspect them in this way, to vanish; for none of them is a cause
in any of the senses that have been distinguished in reference
to the first principles. In a sense, however, they make it plain
that goodness belongs to numbers, and that the odd, the
straight, the square, the potencies of certain numbers, are in the
column of the beautiful. For the seasons and a particular kind of
number go together; and the other agreements that they collect
from the theorems of mathematics all have this meaning.
Hence they are like coincidences. For they are accidents, but the
things that agree are all appropriate to one another, and one by
analogy. For in each category of being an analogous term is
2534
found - as the straight is in length, so is the level in surface,
perhaps the odd in number, and the white in colour.
Again, it is not the ideal numbers that are the causes of musical
phenomena and the like (for equal ideal numbers differ from
one another in form; for even the units do); so that we need not
assume Ideas for this reason at least.
These, then, are the results of the theory, and yet more might be
brought together. The fact that our opponnts have much trouble
with the generation of numbers and can in no way make a
system of them, seems to indicate that the objects of
mathematics are not separable from sensible things, as some
say, and that they are not the first principles.
2535
Aristotle - Nicomachean Ethics
[Translated by W. D. Ross]
Book I
Every art and every inquiry, and similarly every action and
pursuit, is thought to aim at some good; and for this reason the
good has rightly been declared to be that at which all things
aim. But a certain difference is found among ends; some are
activities, others are products apart from the activities that
produce them. Where there are ends apart from the actions, it is
the nature of the products to be better than the activities. Now,
as there are many actions, arts, and sciences, their ends also are
many; the end of the medical art is health, that of shipbuilding
a vessel, that of strategy victory, that of economics wealth. But
where such arts fall under a single capacity - as bridle-making
and the other arts concerned with the equipment of horses fall
under the art of riding, and this and every military action under
strategy, in the same way other arts fall under yet others - in all
of these the ends of the master arts are to be preferred to all the
subordinate ends; for it is for the sake of the former that the
latter are pursued. It makes no difference whether the activities
themselves are the ends of the actions, or something else apart
from the activities, as in the case of the sciences just
mentioned.
2536
If, then, there is some end of the things we do, which we desire
for its own sake (everything else being desired for the sake of
this), and if we do not choose everything for the sake of
something else (for at that rate the process would go on to
infinity, so that our desire would be empty and vain), clearly
this must be the good and the chief good. Will not the
knowledge of it, then, have a great influence on life? Shall we
not, like archers who have a mark to aim at, be more likely to
hit upon what is right? If so, we must try, in outline at least, to
determine what it is, and of which of the sciences or capacities
it is the object. It would seem to belong to the most
authoritative art and that which is most truly the master art.
And politics appears to be of this nature; for it is this that
ordains which of the sciences should be studied in a state, and
which each class of citizens should learn and up to what point
they should learn them; and we see even the most highly
esteemed of capacities to fall under this, e.g. strategy,
economics, rhetoric; now, since politics uses the rest of the
sciences, and since, again, it legislates as to what we are to do
and what we are to abstain from, the end of this science must
include those of the others, so that this end must be the good
for man. For even if the end is the same for a single man and for
a state, that of the state seems at all events something greater
and more complete whether to attain or to preserve; though it
is worth while to attain the end merely for one man, it is finer
and more godlike to attain it for a nation or for city-states.
These, then, are the ends at which our inquiry aims, since it is
political science, in one sense of that term.
2537
Our discussion will be adequate if it has as much clearness as
the subject-matter admits of, for precision is not to be sought
for alike in all discussions, any more than in all the products of
the crafts. Now fine and just actions, which political science
investigates, admit of much variety and fluctuation of opinion,
so that they may be thought to exist only by convention, and
not by nature. And goods also give rise to a similar fluctuation
because they bring harm to many people; for before now men
have been undone by reason of their wealth, and others by
reason of their courage. We must be content, then, in speaking
of such subjects and with such premisses to indicate the truth
roughly and in outline, and in speaking about things which are
only for the most part true and with premisses of the same kind
to reach conclusions that are no better. In the same spirit,
therefore, should each type of statement be received; for it is
the mark of an educated man to look for precision in each class
of things just so far as the nature of the subject admits; it is
evidently equally foolish to accept probable reasoning from a
mathematician and to demand from a rhetorician scientific
proofs.
Now each man judges well the things he knows, and of these he
is a good judge. And so the man who has been educated in a
subject is a good judge of that subject, and the man who has
received an all-round education is a good judge in general.
Hence a young man is not a proper hearer of lectures on
political science; for he is inexperienced in the actions that
occur in life, but its discussions start from these and are about
these; and, further, since he tends to follow his passions, his
study will be vain and unprofitable, because the end aimed at is
not knowledge but action. And it makes no difference whether
he is young in years or youthful in character; the defect does
not depend on time, but on his living, and pursuing each
2538
successive object, as passion directs. For to such persons, as to
the incontinent, knowledge brings no profit; but to those who
desire and act in accordance with a rational principle
knowledge about such matters will be of great benefit.
These remarks about the student, the sort of treatment to be
expected, and the purpose of the inquiry, may be taken as our
preface.
Let us resume our inquiry and state, in view of the fact that all
knowledge and every pursuit aims at some good, what it is that
we say political science aims at and what is the highest of all
goods achievable by action. Verbally there is very general
agreement; for both the general run of men and people of
superior refinement say that it is happiness, and identify living
well and doing well with being happy; but with regard to what
happiness is they differ, and the many do not give the same
account as the wise. For the former think it is some plain and
obvious thing, like pleasure, wealth, or honour; they differ,
however, from one another - and often even the same man
identifies it with different things, with health when he is ill,
with wealth when he is poor; but, conscious of their ignorance,
they admire those who proclaim some great ideal that is above
their comprehension. Now some thought that apart from these
many goods there is another which is self-subsistent and
causes the goodness of all these as well. To examine all the
opinions that have been held were perhaps somewhat fruitless;
enough to examine those that are most prevalent or that seem
to be arguable.
2539
Let us not fail to notice, however, that there is a difference
between arguments from and those to the first principles. For
Plato, too, was right in raising this question and asking, as he
used to do, 'are we on the way from or to the first principles?'
There is a difference, as there is in a race-course between the
course from the judges to the turning-point and the way back.
For, while we must begin with what is known, things are objects
of knowledge in two senses - some to us, some without
qualification. Presumably, then, we must begin with things
known to us. Hence any one who is to listen intelligently to
lectures about what is noble and just, and generally, about the
subjects of political science must have been brought up in good
habits. For the fact is the starting-point, and if this is
sufficiently plain to him, he will not at the start need the reason
as well; and the man who has been well brought up has or can
easily get startingpoints. And as for him who neither has nor
can get them, let him hear the words of Hesiod:
Far best is he who knows all things himself;
Good, he that hearkens when men counsel right;
But he who neither knows, nor lays to heart
Another's wisdom, is a useless wight.
Let us, however, resume our discussion from the point at which
we digressed. To judge from the lives that men lead, most men,
and men of the most vulgar type, seem (not without some
ground) to identify the good, or happiness, with pleasure; which
is the reason why they love the life of enjoyment. For there are,
2540
we may say, three prominent types of life - that just mentioned,
the political, and thirdly the contemplative life. Now the mass of
mankind are evidently quite slavish in their tastes, preferring a
life suitable to beasts, but they get some ground for their view
from the fact that many of those in high places share the tastes
of Sardanapallus. A consideration of the prominent types of life
shows that people of superior refinement and of active
disposition identify happiness with honour; for this is, roughly
speaking, the end of the political life. But it seems too
superficial to be what we are looking for, since it is thought to
depend on those who bestow honour rather than on him who
receives it, but the good we divine to be something proper to a
man and not easily taken from him. Further, men seem to
pursue honour in order that they may be assured of their
goodness; at least it is by men of practical wisdom that they
seek to be honoured, and among those who know them, and on
the ground of their virtue; clearly, then, according to them, at
any rate, virtue is better. And perhaps one might even suppose
this to be, rather than honour, the end of the political life. But
even this appears somewhat incomplete; for possession of
virtue seems actually compatible with being asleep, or with
lifelong inactivity, and, further, with the greatest sufferings and
misfortunes; but a man who was living so no one would call
happy, unless he were maintaining a thesis at all costs. But
enough of this; for the subject has been sufficiently treated even
in the current discussions. Third comes the contemplative life,
which we shall consider later.
The life of money-making is one undertaken under compulsion,
and wealth is evidently not the good we are seeking; for it is
merely useful and for the sake of something else. And so one
might rather take the aforenamed objects to be ends; for they
are loved for themselves. But it is evident that not even these
are ends; yet many arguments have been thrown away in
support of them. Let us leave this subject, then.
2541
We had perhaps better consider the universal good and discuss
thoroughly what is meant by it, although such an inquiry is
made an uphill one by the fact that the Forms have been
introduced by friends of our own. Yet it would perhaps be
thought to be better, indeed to be our duty, for the sake of
maintaining the truth even to destroy what touches us closely,
especially as we are philosophers or lovers of wisdom; for, while
both are dear, piety requires us to honour truth above our
friends.
The men who introduced this doctrine did not posit Ideas of
classes within which they recognized priority and posteriority
(which is the reason why they did not maintain the existence of
an Idea embracing all numbers); but the term 'good' is used
both in the category of substance and in that of quality and in
that of relation, and that which is per se, i.e. substance, is prior
in nature to the relative (for the latter is like an off shoot and
accident of being); so that there could not be a common Idea set
over all these goods. Further, since 'good' has as many senses as
'being' (for it is predicated both in the category of substance, as
of God and of reason, and in quality, i.e. of the virtues, and in
quantity, i.e. of that which is moderate, and in relation, i.e. of
the useful, and in time, i.e. of the right opportunity, and in place,
i.e. of the right locality and the like), clearly it cannot be
something universally present in all cases and single; for then it
could not have been predicated in all the categories but in one
only. Further, since of the things answering to one Idea there is
one science, there would have been one science of all the goods;
but as it is there are many sciences even of the things that fall
under one category, e.g. of opportunity, for opportunity in war is
2542
studied by strategics and in disease by medicine, and the
moderate in food is studied by medicine and in exercise by the
science of gymnastics. And one might ask the question, what in
the world they mean by 'a thing itself, is (as is the case) in 'man
himself and in a particular man the account of man is one and
the same. For in so far as they are man, they will in no respect
differ; and if this is so, neither will 'good itself and particular
goods, in so far as they are good. But again it will not be good
any the more for being eternal, since that which lasts long is no
whiter than that which perishes in a day. The Pythagoreans
seem to give a more plausible account of the good, when they
place the one in the column of goods; and it is they that
Speusippus seems to have followed.
But let us discuss these matters elsewhere; an objection to what
we have said, however, may be discerned in the fact that the
Platonists have not been speaking about all goods, and that the
goods that are pursued and loved for themselves are called
good by reference to a single Form, while those which tend to
produce or to preserve these somehow or to prevent their
contraries are called so by reference to these, and in a
secondary sense. Clearly, then, goods must be spoken of in two
ways, and some must be good in themselves, the others by
reason of these. Let us separate, then, things good in themselves
from things useful, and consider whether the former are called
good by reference to a single Idea. What sort of goods would one
call good in themselves? Is it those that are pursued even when
isolated from others, such as intelligence, sight, and certain
pleasures and honours? Certainly, if we pursue these also for
the sake of something else, yet one would place them among
things good in themselves. Or is nothing other than the Idea of
good good in itself? In that case the Form will be empty. But if
the things we have named are also things good in themselves,
the account of the good will have to appear as something
identical in them all, as that of whiteness is identical in snow
2543
and in white lead. But of honour, wisdom, and pleasure, just in
respect of their goodness, the accounts are distinct and diverse.
The good, therefore, is not some common element answering to
one Idea.
But what then do we mean by the good? It is surely not like the
things that only chance to have the same name. Are goods one,
then, by being derived from one good or by all contributing to
one good, or are they rather one by analogy? Certainly as sight
is in the body, so is reason in the soul, and so on in other cases.
But perhaps these subjects had better be dismissed for the
present; for perfect precision about them would be more
appropriate to another branch of philosophy. And similarly with
regard to the Idea; even if there is some one good which is
universally predicable of goods or is capable of separate and
independent existence, clearly it could not be achieved or
attained by man; but we are now seeking something attainable.
Perhaps, however, some one might think it worth while to
recognize this with a view to the goods that are attainable and
achievable; for having this as a sort of pattern we shall know
better the goods that are good for us, and if we know them shall
attain them. This argument has some plausibility, but seems to
clash with the procedure of the sciences; for all of these, though
they aim at some good and seek to supply the deficiency of it,
leave on one side the knowledge of the good. Yet that all the
exponents of the arts should be ignorant of, and should not
even seek, so great an aid is not probable. It is hard, too, to see
how a weaver or a carpenter will be benefited in regard to his
own craft by knowing this 'good itself, or how the man who has
viewed the Idea itself will be a better doctor or general thereby.
For a doctor seems not even to study health in this way, but the
health of man, or perhaps rather the health of a particular man;
it is individuals that he is healing. But enough of these topics.
2544
Let us again return to the good we are seeking, and ask what it
can be. It seems different in different actions and arts; it is
different in medicine, in strategy, and in the other arts likewise.
What then is the good of each? Surely that for whose sake
everything else is done. In medicine this is health, in strategy
victory, in architecture a house, in any other sphere something
else, and in every action and pursuit the end; for it is for the
sake of this that all men do whatever else they do. Therefore, if
there is an end for all that we do, this will be the good
achievable by action, and if there are more than one, these will
be the goods achievable by action.
So the argument has by a different course reached the same
point; but we must try to state this even more clearly. Since
there are evidently more than one end, and we choose some of
these (e.g. wealth, flutes, and in general instruments) for the
sake of something else, clearly not all ends are final ends; but
the chief good is evidently something final. Therefore, if there is
only one final end, this will be what we are seeking, and if there
are more than one, the most final of these will be what we are
seeking. Now we call that which is in itself worthy of pursuit
more final than that which is worthy of pursuit for the sake of
something else, and that which is never desirable for the sake of
something else more final than the things that are desirable
both in themselves and for the sake of that other thing, and
therefore we call final without qualification that which is
always desirable in itself and never for the sake of something
else.
Now such a thing happiness, above all else, is held to be; for this
we choose always for self and never for the sake of something
else, but honour, pleasure, reason, and every virtue we choose
2545
indeed for themselves (for if nothing resulted from them we
should still choose each of them), but we choose them also for
the sake of happiness, judging that by means of them we shall
be happy. Happiness, on the other hand, no one chooses for the
sake of these, nor, in general, for anything other than itself.
From the point of view of self-sufficiency the same result seems
to follow; for the final good is thought to be self-sufficient. Now
by self-sufficient we do not mean that which is sufficient for a
man by himself, for one who lives a solitary life, but also for
parents, children, wife, and in general for his friends and fellow
citizens, since man is born for citizenship. But some limit must
be set to this; for if we extend our requirement to ancestors and
descendants and friends' friends we are in for an infinite series.
Let us examine this question, however, on another occasion; the
self-sufficient we now define as that which when isolated
makes life desirable and lacking in nothing; and such we think
happiness to be; and further we think it most desirable of all
things, without being counted as one good thing among others -
if it were so counted it would clearly be made more desirable by
the addition of even the least of goods; for that which is added
becomes an excess of goods, and of goods the greater is always
more desirable. Happiness, then, is something final and self-
sufficient, and is the end of action.
Presumably, however, to say that happiness is the chief good
seems a platitude, and a clearer account of what it is still
desired. This might perhaps be given, if we could first ascertain
the function of man. For just as for a flute-player, a sculptor, or
an artist, and, in general, for all things that have a function or
activity, the good and the 'well' is thought to reside in the
function, so would it seem to be for man, if he has a function.
Have the carpenter, then, and the tanner certain functions or
activities, and has man none? Is he born without a function? Or
as eye, hand, foot, and in general each of the parts evidently has
2546
a function, may one lay it down that man similarly has a
function apart from all these? What then can this be? Life
seems to be common even to plants, but we are seeking what is
peculiar to man. Let us exclude, therefore, the life of nutrition
and growth. Next there would be a life of perception, but it also
seems to be common even to the horse, the ox, and every
animal. There remains, then, an active life of the element that
has a rational principle; of this, one part has such a principle in
the sense of being obedient to one, the other in the sense of
possessing one and exercising thought. And, as 'life of the
rational element' also has two meanings, we must state that life
in the sense of activity is what we mean; for this seems to be
the more proper sense of the term. Now if the function of man
is an activity of soul which follows or implies a rational
principle, and if we say 'so-and-so-and 'a good so-and-so' have a
function which is the same in kind, e.g. a lyre, and a good lyre-
player, and so without qualification in all cases, eminence in
respect of goodness being idded to the name of the function (for
the function of a lyre-player is to play the lyre, and that of a
good lyre-player is to do so well): if this is the case, and we state
the function of man to be a certain kind of life, and this to be an
activity or actions of the soul implying a rational principle, and
the function of a good man to be the good and noble
performance of these, and if any action is well performed when
it is performed in accordance with the appropriate excellence: if
this is the case, human good turns out to be activity of soul in
accordance with virtue, and if there are more than one virtue, in
accordance with the best and most complete.
But we must add 'in a complete life.' For one swallow does not
make a summer, nor does one day; and so too one day, or a
short time, does not make a man blessed and happy.
Let this serve as an outline of the good; for we must presumably
first sketch it roughly, and then later fill in the details. But it
2547
would seem that any one is capable of carrying on and
articulating what has once been well outlined, and that time is
a good discoverer or partner in such a work; to which facts the
advances of the arts are due; for any one can add what is
lacking. And we must also remember what has been said before,
and not look for precision in all things alike, but in each class of
things such precision as accords with the subject-matter, and so
much as is appropriate to the inquiry. For a carpenter and a
geometer investigate the right angle in different ways; the
former does so in so far as the right angle is useful for his work,
while the latter inquires what it is or what sort of thing it is; for
he is a spectator of the truth. We must act in the same way,
then, in all other matters as well, that our main task may not be
subordinated to minor questions. Nor must we demand the
cause in all matters alike; it is enough in some cases that the
fact be well established, as in the case of the first principles; the
fact is the primary thing or first principle. Now of first principles
we see some by induction, some by perception, some by a
certain habituation, and others too in other ways. But each set
of principles we must try to investigate in the natural way, and
we must take pains to state them definitely, since they have a
great influence on what follows. For the beginning is thought to
be more than half of the whole, and many of the questions we
ask are cleared up by it.
8
We must consider it, however, in the light not only of our
conclusion and our premisses, but also of what is commonly
said about it; for with a true view all the data harmonize, but
with a false one the facts soon clash. Now goods have been
divided into three classes, and some are described as external,
2548
others as relating to soul or to body; we call those that relate to
soul most properly and truly goods, and psychical actions and
activities we class as relating to soul. Therefore our account
must be sound, at least according to this view, which is an old
one and agreed on by philosophers. It is correct also in that we
identify the end with certain actions and activities; for thus it
falls among goods of the soul and not among external goods.
Another belief which harmonizes with our account is that the
happy man lives well and does well; for we have practically
defined happiness as a sort of good life and good action. The
characteristics that are looked for in happiness seem also, all of
them, to belong to what we have defined happiness as being.
For some identify happiness with virtue, some with practical
wisdom, others with a kind of philosophic wisdom, others with
these, or one of these, accompanied by pleasure or not without
pleasure; while others include also external prosperity. Now
some of these views have been held by many men and men of
old, others by a few eminent persons; and it is not probable that
either of these should be entirely mistaken, but rather that they
should be right in at least some one respect or even in most
respects.
With those who identify happiness with virtue or some one
virtue our account is in harmony; for to virtue belongs virtuous
activity. But it makes, perhaps, no small difference whether we
place the chief good in possession or in use, in state of mind or
in activity. For the state of mind may exist without producing
any good result, as in a man who is asleep or in some other way
quite inactive, but the activity cannot; for one who has the
activity will of necessity be acting, and acting well. And as in the
Olympic Games it is not the most beautiful and the strongest
that are crowned but those who compete (for it is some of these
that are victorious), so those who act win, and rightly win, the
noble and good things in life.
2549
Their life is also in itself pleasant. For pleasure is a state of soul,
and to each man that which he is said to be a lover of is
pleasant; e.g. not only is a horse pleasant to the lover of horses,
and a spectacle to the lover of sights, but also in the same way
just acts are pleasant to the lover of justice and in general
virtuous acts to the lover of virtue. Now for most men their
pleasures are in conflict with one another because these are not
by nature pleasant, but the lovers of what is noble find pleasant
the things that are by nature pleasant; and virtuous actions are
such, so that these are pleasant for such men as well as in their
own nature. Their life, therefore, has no further need of pleasure
as a sort of adventitious charm, but has its pleasure in itself. For,
besides what we have said, the man who does not rejoice in
noble actions is not even good; since no one would call a man
just who did not enjoy acting justly, nor any man liberal who
did not enjoy liberal actions; and similarly in all other cases. If
this is so, virtuous actions must be in themselves pleasant. But
they are also good and noble, and have each of these attributes
in the highest degree, since the good man judges well about
these attributes; his judgement is such as we have described.
Happiness then is the best, noblest, and most pleasant thing in
the world, and these attributes are not severed as in the
inscription at Delos:
Most noble is that which is justest, and best is health;
But pleasantest is it to win what we love.
For all these properties belong to the best activities; and these,
or one - the best - of these, we identify with happiness.
Yet evidently, as we said, it needs the external goods as well; for
it is impossible, or not easy, to do noble acts without the proper
equipment. In many actions we use friends and riches and
political power as instruments; and there are some things the
lack of which takes the lustre from happiness, as good birth,
2550
goodly children, beauty; for the man who is very ugly in
appearance or ill-born or solitary and childless is not very likely
to be happy, and perhaps a man would be still less likely if he
had thoroughly bad children or friends or had lost good children
or friends by death. As we said, then, happiness seems to need
this sort of prosperity in addition; for which reason some
identify happiness with good fortune, though others identify it
with virtue.
For this reason also the question is asked, whether happiness is
to be acquired by learning or by habituation or some other sort
of training, or comes in virtue of some divine providence or
again by chance. Now if there is any gift of the gods to men, it is
reasonable that happiness should be god-given, and most surely
god-given of all human things inasmuch as it is the best. But
this question would perhaps be more appropriate to another
inquiry; happiness seems, however, even if it is not god-sent but
comes as a result of virtue and some process of learning or
training, to be among the most godlike things; for that which is
the prize and end of virtue seems to be the best thing in the
world, and something godlike and blessed.
It will also on this view be very generally shared; for all who are
not maimed as regards their potentiality for virtue may win it
by a certain kind of study and care. But if it is better to be happy
thus than by chance, it is reasonable that the facts should be so,
since everything that depends on the action of nature is by
nature as good as it can be, and similarly everything that
depends on art or any rational cause, and especially if it
2551
depends on the best of all causes. To entrust to chance what is
greatest and most noble would be a very defective arrangement.
The answer to the question we are asking is plain also from the
definition of happiness; for it has been said to be a virtuous
activity of soul, of a certain kind. Of the remaining goods, some
must necessarily pre-exist as conditions of happiness, and
others are naturally co-operative and useful as instruments.
And this will be found to agree with what we said at the outset;
for we stated the end of political science to be the best end, and
political science spends most of its pains on making the citizens
to be of a certain character, viz. good and capable of noble acts.
It is natural, then, that we call neither ox nor horse nor any
other of the animals happy; for none of them is capable of
sharing in such activity. For this reason also a boy is not happy;
for he is not yet capable of such acts, owing to his age; and boys
who are called happy are being congratulated by reason of the
hopes we have for them. For there is required, as we said, not
only complete virtue but also a complete life, since many
changes occur in life, and all manner of chances, and the most
prosperous may fall into great misfortunes in old age, as is told
of Priam in the Trojan Cycle; and one who has experienced such
chances and has ended wretchedly no one calls happy.
10
Must no one at all, then, be called happy while he lives; must
we, as Solon says, see the end? Even if we are to lay down this
doctrine, is it also the case that a man is happy when he is
dead? Or is not this quite absurd, especially for us who say that
happiness is an activity? But if we do not call the dead man
happy, and if Solon does not mean this, but that one can then
2552
safely call a man blessed as being at last beyond evils and
misfortunes, this also affords matter for discussion; for both evil
and good are thought to exist for a dead man, as much as for
one who is alive but not aware of them; e.g. honours and
dishonours and the good or bad fortunes of children and in
general of descendants. And this also presents a problem; for
though a man has lived happily up to old age and has had a
death worthy of his life, many reverses may befall his
descendants - some of them may be good and attain the life
they deserve, while with others the opposite may be the case;
and clearly too the degrees of relationship between them and
their ancestors may vary indefinitely. It would be odd, then, if
the dead man were to share in these changes and become at
one time happy, at another wretched; while it would also be odd
if the fortunes of the descendants did not for some time have
some effect on the happiness of their ancestors.
But we must return to our first difficulty; for perhaps by a
consideration of it our present problem might be solved. Now if
we must see the end and only then call a man happy, not as
being happy but as having been so before, surely this is a
paradox, that when he is happy the attribute that belongs to
him is not to be truly predicated of him because we do not wish
to call living men happy, on account of the changes that may
befall them, and because we have assumed happiness to be
something permanent and by no means easily changed, while a
single man may suffer many turns of fortune's wheel. For
clearly if we were to keep pace with his fortunes, we should
often call the same man happy and again wretched, making the
happy man out to be chameleon and insecurely based. Or is this
keeping pace with his fortunes quite wrong? Success or failure
in life does not depend on these, but human life, as we said,
needs these as mere additions, while virtuous activities or their
opposites are what constitute happiness or the reverse.
2553
The question we have now discussed confirms our definition.
For no function of man has so much permanence as virtuous
activities (these are thought to be more durable even than
knowledge of the sciences), and of these themselves the most
valuable are more durable because those who are happy spend
their life most readily and most continuously in these; for this
seems to be the reason why we do not forget them. The
attribute in question, then, will belong to the happy man, and
he will be happy throughout his life; for always, or by preference
to everything else, he will be engaged in virtuous action and
contemplation, and he will bear the chances of life most nobly
and altogether decorously, if he is 'truly good' and 'foursquare
beyond reproach'.
Now many events happen by chance, and events differing in
importance; small pieces of good fortune or of its opposite
clearly do not weigh down the scales of life one way or the
other, but a multitude of great events if they turn out well will
make life happier (for not only are they themselves such as to
add beauty to life, but the way a man deals with them may be
noble and good), while if they turn out ill they crush and maim
happiness; for they both bring pain with them and hinder many
activities. Yet even in these nobility shines through, when a
man bears with resignation many great misfortunes, not
through insensibility to pain but through nobility and greatness
of soul.
If activities are, as we said, what gives life its character, no
happy man can become miserable; for he will never do the acts
that are hateful and mean. For the man who is truly good and
wise, we think, bears all the chances life becomingly and always
makes the best of circumstances, as a good general makes the
best military use of the army at his command and a good
shoemaker makes the best shoes out of the hides that are given
him; and so with all other craftsmen. And if this is the case, the
2554
happy man can never become miserable; though he will not
reach blessedness, if he meet with fortunes like those of Priam.
Nor, again, is he many-coloured and changeable; for neither will
he be moved from his happy state easily or by any ordinary
misadventures, but only by many great ones, nor, if he has had
many great misadventures, will he recover his happiness in a
short time, but if at all, only in a long and complete one in
which he has attained many splendid successes.
When then should we not say that he is happy who is active in
accordance with complete virtue and is sufficiently equipped
with external goods, not for some chance period but throughout
a complete life? Or must we add 'and who is destined to live
thus and die as befits his life'? Certainly the future is obscure to
us, while happiness, we claim, is an end and something in every
way final. If so, we shall call happy those among living men in
whom these conditions are, and are to be, fulfilled - but happy
men. So much for these questions.
11
That the fortunes of descendants and of all a man's friends
should not affect his happiness at all seems a very unfriendly
doctrine, and one opposed to the opinions men hold; but since
the events that happen are numerous and admit of all sorts of
difference, and some come more near to us and others less so, it
seems a long - nay, an infinite - task to discuss each in detail; a
general outline will perhaps suffice. If, then, as some of a man's
own misadventures have a certain weight and influence on life
while others are, as it were, lighter, so too there are differences
among the misadventures of our friends taken as a whole, and
it makes a difference whether the various suffering befall the
2555
living or the dead (much more even than whether lawless and
terrible deeds are presupposed in a tragedy or done on the
stage), this difference also must be taken into account; or rather,
perhaps, the fact that doubt is felt whether the dead share in
any good or evil. For it seems, from these considerations, that
even if anything whether good or evil penetrates to them, it
must be something weak and negligible, either in itself or for
them, or if not, at least it must be such in degree and kind as
not to make happy those who are not happy nor to take away
their blessedness from those who are. The good or bad fortunes
of friends, then, seem to have some effects on the dead, but
effects of such a kind and degree as neither to make the happy
unhappy nor to produce any other change of the kind.
12
These questions having been definitely answered, let us
consider whether happiness is among the things that are
praised or rather among the things that are prized; for clearly it
is not to be placed among potentialities. Everything that is
praised seems to be praised because it is of a certain kind and is
related somehow to something else; for we praise the just or
brave man and in general both the good man and virtue itself
because of the actions and functions involved, and we praise
the strong man, the good runner, and so on, because he is of a
certain kind and is related in a certain way to something good
and important. This is clear also from the praises of the gods;
for it seems absurd that the gods should be referred to our
standard, but this is done because praise involves a reference, to
something else. But if if praise is for things such as we have
described, clearly what applies to the best things is not praise,
but something greater and better, as is indeed obvious; for what
2556
we do to the gods and the most godlike of men is to call them
blessed and happy. And so too with good things; no one praises
happiness as he does justice, but rather calls it blessed, as being
something more divine and better.
Eudoxus also seems to have been right in his method of
advocating the supremacy of pleasure; he thought that the fact
that, though a good, it is not praised indicated it to be better
than the things that are praised, and that this is what God and
the good are; for by reference to these all other things are
judged. Praise is appropriate to virtue, for as a result of virtue
men tend to do noble deeds, but encomia are bestowed on acts,
whether of the body or of the soul. But perhaps nicety in these
matters is more proper to those who have made a study of
encomia; to us it is clear from what has been said that
happiness is among the things that are prized and perfect. It
seems to be so also from the fact that it is a first principle; for it
is for the sake of this that we all do all that we do, and the first
principle and cause of goods is, we claim, something prized and
divine.
13
Since happiness is an activity of soul in accordance with perfect
virtue, we must consider the nature of virtue; for perhaps we
shall thus see better the nature of happiness. The true student
of politics, too, is thought to have studied virtue above all
things; for he wishes to make his fellow citizens good and
obedient to the laws. As an example of this we have the
lawgivers of the Cretans and the Spartans, and any others of the
kind that there may have been. And if this inquiry belongs to
political science, clearly the pursuit of it will be in accordance
2557
with our original plan. But clearly the virtue we must study is
human virtue; for the good we were seeking was human good
and the happiness human happiness. By human virtue we
mean not that of the body but that of the soul; and happiness
also we call an activity of soul. But if this is so, clearly the
student of politics must know somehow the facts about soul, as
the man who is to heal the eyes or the body as a whole must
know about the eyes or the body; and all the more since politics
is more prized and better than medicine; but even among
doctors the best educated spend much labour on acquiring
knowledge of the body. The student of politics, then, must study
the soul, and must study it with these objects in view, and do so
just to the extent which is sufficient for the questions we are
discussing; for further precision is perhaps something more
laborious than our purposes require.
Some things are said about it, adequately enough, even in the
discussions outside our school, and we must use these; e.g. that
one element in the soul is irrational and one has a rational
principle. Whether these are separated as the parts of the body
or of anything divisible are, or are distinct by definition but by
nature inseparable, like convex and concave in the
circumference of a circle, does not affect the present question.
Of the irrational element one division seems to be widely
distributed, and vegetative in its nature, I mean that which
causes nutrition and growth; for it is this kind of power of the
soul that one must assign to all nurslings and to embryos, and
this same power to fullgrown creatures; this is more reasonable
than to assign some different power to them. Now the
excellence of this seems to be common to all species and not
specifically human; for this part or faculty seems to function
most in sleep, while goodness and badness are least manifest in
sleep (whence comes the saying that the happy are not better
off than the wretched for half their lives; and this happens
2558
naturally enough, since sleep is an inactivity of the soul in that
respect in which it is called good or bad), unless perhaps to a
small extent some of the movements actually penetrate to the
soul, and in this respect the dreams of good men are better than
those of ordinary people. Enough of this subject, however; let us
leave the nutritive faculty alone, since it has by its nature no
share in human excellence.
There seems to be also another irrational element in the soul-
one which in a sense, however, shares in a rational principle. For
we praise the rational principle of the continent man and of the
incontinent, and the part of their soul that has such a principle,
since it urges them aright and towards the best objects; but
there is found in them also another element naturally opposed
to the rational principle, which fights against and resists that
principle. For exactly as paralysed limbs when we intend to
move them to the right turn on the contrary to the left, so is it
with the soul; the impulses of incontinent people move in
contrary directions. But while in the body we see that which
moves astray, in the soul we do not. No doubt, however, we
must none the less suppose that in the soul too there is
something contrary to the rational principle, resisting and
opposing it. In what sense it is distinct from the other elements
does not concern us. Now even this seems to have a share in a
rational principle, as we said; at any rate in the continent man it
obeys the rational principle and presumably in the temperate
and brave man it is still more obedient; for in him it speaks, on
all matters, with the same voice as the rational principle.
Therefore the irrational element also appears to be two-fold. For
the vegetative element in no way shares in a rational principle,
but the appetitive and in general the desiring element in a
sense shares in it, in so far as it listens to and obeys it; this is
the sense in which we speak of 'taking account' of one's father
or one's friends, not that in which we speak of 'accounting for a
2559
mathematical property. That the irrational element is in some
sense persuaded by a rational principle is indicated also by the
giving of advice and by all reproof and exhortation. And if this
element also must be said to have a rational principle, that
which has a rational principle (as well as that which has not)
will be twofold, one subdivision having it in the strict sense and
in itself, and the other having a tendency to obey as one does
one's father.
Virtue too is distinguished into kinds in accordance with this
difference; for we say that some of the virtues are intellectual
and others moral, philosophic wisdom and understanding and
practical wisdom being intellectual, liberality and temperance
moral. For in speaking about a man's character we do not say
that he is wise or has understanding but that he is good-
tempered or temperate; yet we praise the wise man also with
respect to his state of mind; and of states of mind we call those
which merit praise virtues.
Book II
Virtue, then, being of two kinds, intellectual and moral,
intellectual virtue in the main owes both its birth and its growth
to teaching (for which reason it requires experience and time),
while moral virtue comes about as a result of habit, whence also
its name (ethike) is one that is formed by a slight variation from
2560
the word ethos (habit). From this it is also plain that none of the
moral virtues arises in us by nature; for nothing that exists by
nature can form a habit contrary to its nature. For instance the
stone which by nature moves downwards cannot be habituated
to move upwards, not even if one tries to train it by throwing it
up ten thousand times; nor can fire be habituated to move
downwards, nor can anything else that by nature behaves in
one way be trained to behave in another. Neither by nature,
then, nor contrary to nature do the virtues arise in us; rather we
are adapted by nature to receive them, and are made perfect by
habit.
Again, of all the things that come to us by nature we first
acquire the potentiality and later exhibit the activity (this is
plain in the case of the senses; for it was not by often seeing or
often hearing that we got these senses, but on the contrary we
had them before we used them, and did not come to have them
by using them); but the virtues we get by first exercising them,
as also happens in the case of the arts as well. For the things we
have to learn before we can do them, we learn by doing them,
e.g. men become builders by building and lyreplayers by playing
the lyre; so too we become just by doing just acts, temperate by
doing temperate acts, brave by doing brave acts.
This is confirmed by what happens in states; for legislators
make the citizens good by forming habits in them, and this is
the wish of every legislator, and those who do not effect it miss
their mark, and it is in this that a good constitution differs from
a bad one.
Again, it is from the same causes and by the same means that
every virtue is both produced and destroyed, and similarly every
art; for it is from playing the lyre that both good and bad lyre-
players are produced. And the corresponding statement is true
of builders and of all the rest; men will be good or bad builders
2561
as a result of building well or badly. For if this were not so, there
would have been no need of a teacher, but all men would have
been born good or bad at their craft. This, then, is the case with
the virtues also; by doing the acts that we do in our transactions
with other men we become just or unjust, and by doing the acts
that we do in the presence of danger, and being habituated to
feel fear or confidence, we become brave or cowardly. The same
is true of appetites and feelings of anger; some men become
temperate and good-tempered, others self-indulgent and
irascible, by behaving in one way or the other in the appropriate
circumstances. Thus, in one word, states of character arise out
of like activities. This is why the activities we exhibit must be of
a certain kind; it is because the states of character correspond
to the differences between these. It makes no small difference,
then, whether we form habits of one kind or of another from
our very youth; it makes a very great difference, or rather all the
difference.
Since, then, the present inquiry does not aim at theoretical
knowledge like the others (for we are inquiring not in order to
know what virtue is, but in order to become good, since
otherwise our inquiry would have been of no use), we must
examine the nature of actions, namely how we ought to do
them; for these determine also the nature of the states of
character that are produced, as we have said. Now, that we must
act according to the right rule is a common principle and must
be assumed - it will be discussed later, i.e. both what the right
rule is, and how it is related to the other virtues. But this must
be agreed upon beforehand, that the whole account of matters
of conduct must be given in outline and not precisely, as we
2562
said at the very beginning that the accounts we demand must
be in accordance with the subject-matter; matters concerned
with conduct and questions of what is good for us have no
fixity, any more than matters of health. The general account
being of this nature, the account of particular cases is yet more
lacking in exactness; for they do not fall under any art or
precept but the agents themselves must in each case consider
what is appropriate to the occasion, as happens also in the art
of medicine or of navigation.
But though our present account is of this nature we must give
what help we can. First, then, let us consider this, that it is the
nature of such things to be destroyed by defect and excess, as
we see in the case of strength and of health (for to gain light on
things imperceptible we must use the evidence of sensible
things); both excessive and defective exercise destroys the
strength, and similarly drink or food which is above or below a
certain amount destroys the health, while that which is
proportionate both produces and increases and preserves it. So
too is it, then, in the case of temperance and courage and the
other virtues. For the man who flies from and fears everything
and does not stand his ground against anything becomes a
coward, and the man who fears nothing at all but goes to meet
every danger becomes rash; and similarly the man who
indulges in every pleasure and abstains from none becomes
self-indulgent, while the man who shuns every pleasure, as
boors do, becomes in a way insensible; temperance and courage,
then, are destroyed by excess and defect, and preserved by the
mean.
But not only are the sources and causes of their origination and
growth the same as those of their destruction, but also the
sphere of their actualization will be the same; for this is also
true of the things which are more evident to sense, e.g. of
strength; it is produced by taking much food and undergoing
2563
much exertion, and it is the strong man that will be most able to
do these things. So too is it with the virtues; by abstaining from
pleasures we become temperate, and it is when we have
become so that we are most able to abstain from them; and
similarly too in the case of courage; for by being habituated to
despise things that are terrible and to stand our ground against
them we become brave, and it is when we have become so that
we shall be most able to stand our ground against them.
We must take as a sign of states of character the pleasure or
pain that ensues on acts; for the man who abstains from bodily
pleasures and delights in this very fact is temperate, while the
man who is annoyed at it is self-indulgent, and he who stands
his ground against things that are terrible and delights in this or
at least is not pained is brave, while the man who is pained is a
coward. For moral excellence is concerned with pleasures and
pains; it is on account of the pleasure that we do bad things,
and on account of the pain that we abstain from noble ones.
Hence we ought to have been brought up in a particular way
from our very youth, as Plato says, so as both to delight in and
to be pained by the things that we ought; for this is the right
education.
Again, if the virtues are concerned with actions and passions,
and every passion and every action is accompanied by pleasure
and pain, for this reason also virtue will be concerned with
pleasures and pains. This is indicated also by the fact that
punishment is inflicted by these means; for it is a kind of cure,
and it is the nature of cures to be effected by contraries.
2564
Again, as we said but lately, every state of soul has a nature
relative to and concerned with the kind of things by which it
tends to be made worse or better; but it is by reason of
pleasures and pains that men become bad, by pursuing and
avoiding these - either the pleasures and pains they ought not
or when they ought not or as they ought not, or by going wrong
in one of the other similar ways that may be distinguished.
Hence men even define the virtues as certain states of
impassivity and rest; not well, however, because they speak
absolutely, and do not say 'as one ought' and 'as one ought not'
and 'when one ought or ought not', and the other things that
may be added. We assume, then, that this kind of excellence
tends to do what is best with regard to pleasures and pains, and
vice does the contrary.
The following facts also may show us that virtue and vice are
concerned with these same things. There being three objects of
choice and three of avoidance, the noble, the advantageous, the
pleasant, and their contraries, the base, the injurious, the
painful, about all of these the good man tends to go right and
the bad man to go wrong, and especially about pleasure; for this
is common to the animals, and also it accompanies all objects
of choice; for even the noble and the advantageous appear
pleasant.
Again, it has grown up with us all from our infancy; this is why
it is difficult to rub off this passion, engrained as it is in our life.
And we measure even our actions, some of us more and others
less, by the rule of pleasure and pain. For this reason, then, our
whole inquiry must be about these; for to feel delight and pain
rightly or wrongly has no small effect on our actions.
Again, it is harder to fight with pleasure than with anger, to use
Heraclitus' phrase', but both art and virtue are always
concerned with what is harder; for even the good is better when
2565
it is harder. Therefore for this reason also the whole concern
both of virtue and of political science is with pleasures and
pains; for the man who uses these well will be good, he who
uses them badly bad.
That virtue, then, is concerned with pleasures and pains, and
that by the acts from which it arises it is both increased and, if
they are done differently, destroyed, and that the acts from
which it arose are those in which it actualizes itself - let this be
taken as said.
The question might be asked,; what we mean by saying that we
must become just by doing just acts, and temperate by doing
temperate acts; for if men do just and temperate acts, they are
already just and temperate, exactly as, if they do what is in
accordance with the laws of grammar and of music, they are
grammarians and musicians.
Or is this not true even of the arts? It is possible to do
something that is in accordance with the laws of grammar,
either by chance or at the suggestion of another. A man will be a
grammarian, then, only when he has both done something
grammatical and done it grammatically; and this means doing
it in accordance with the grammatical knowledge in himself.
Again, the case of the arts and that of the virtues are not
similar; for the products of the arts have their goodness in
themselves, so that it is enough that they should have a certain
character, but if the acts that are in accordance with the virtues
have themselves a certain character it does not follow that they
are done justly or temperately. The agent also must be in a
2566
certain condition when he does them; in the first place he must
have knowledge, secondly he must choose the acts, and choose
them for their own sakes, and thirdly his action must proceed
from a firm and unchangeable character. These are not
reckoned in as conditions of the possession of the arts, except
the bare knowledge; but as a condition of the possession of the
virtues knowledge has little or no weight, while the other
conditions count not for a little but for everything, i.e. the very
conditions which result from often doing just and temperate
acts.
Actions, then, are called just and temperate when they are such
as the just or the temperate man would do; but it is not the man
who does these that is just and temperate, but the man who
also does them as just and temperate men do them. It is well
said, then, that it is by doing just acts that the just man is
produced, and by doing temperate acts the temperate man;
without doing these no one would have even a prospect of
becoming good.
But most people do not do these, but take refuge in theory and
think they are being philosophers and will become good in this
way, behaving somewhat like patients who listen attentively to
their doctors, but do none of the things they are ordered to do.
As the latter will not be made well in body by such a course of
treatment, the former will not be made well in soul by such a
course of philosophy.
Next we must consider what virtue is. Since things that are
found in the soul are of three kinds - passions, faculties, states
of character, virtue must be one of these. By passions I mean
2567
appetite, anger, fear, confidence, envy, joy, friendly feeling,
hatred, longing, emulation, pity, and in general the feelings that
are accompanied by pleasure or pain; by faculties the things in
virtue of which we are said to be capable of feeling these, e.g. of
becoming angry or being pained or feeling pity; by states of
character the things in virtue of which we stand well or badly
with reference to the passions, e.g. with reference to anger we
stand badly if we feel it violently or too weakly, and well if we
feel it moderately; and similarly with reference to the other
passions.
Now neither the virtues nor the vices are passions, because we
are not called good or bad on the ground of our passions, but
are so called on the ground of our virtues and our vices, and
because we are neither praised nor blamed for our passions (for
the man who feels fear or anger is not praised, nor is the man
who simply feels anger blamed, but the man who feels it in a
certain way), but for our virtues and our vices we are praised or
blamed.
Again, we feel anger and fear without choice, but the virtues are
modes of choice or involve choice. Further, in respect of the
passions we are said to be moved, but in respect of the virtues
and the vices we are said not to be moved but to be disposed in
a particular way.
For these reasons also they are not faculties; for we are neither
called good nor bad, nor praised nor blamed, for the simple
capacity of feeling the passions; again, we have the faculties by
nature, but we are not made good or bad by nature; we have
spoken of this before. If, then, the virtues are neither passions
nor faculties, all that remains is that they should be states of
character.
Thus we have stated what virtue is in respect of its genus.
2568
We must, however, not only describe virtue as a state of
character, but also say what sort of state it is. We may remark,
then, that every virtue or excellence both brings into good
condition the thing of which it is the excellence and makes the
work of that thing be done well; e.g. the excellence of the eye
makes both the eye and its work good; for it is by the excellence
of the eye that we see well. Similarly the excellence of the horse
makes a horse both good in itself and good at running and at
carrying its rider and at awaiting the attack of the enemy.
Therefore, if this is true in every case, the virtue of man also will
be the state of character which makes a man good and which
makes him do his own work well.
How this is to happen we have stated already, but it will be
made plain also by the following consideration of the specific
nature of virtue. In everything that is continuous and divisible it
is possible to take more, less, or an equal amount, and that
either in terms of the thing itself or relatively to us; and the
equal is an intermediate between excess and defect. By the
intermediate in the object I mean that which is equidistant
from each of the extremes, which is one and the same for all
men; by the intermediate relatively to us that which is neither
too much nor too little - and this is not one, nor the same for
all. For instance, if ten is many and two is few, six is the
intermediate, taken in terms of the object; for it exceeds and is
exceeded by an equal amount; this is intermediate according to
arithmetical proportion. But the intermediate relatively to us is
not to be taken so; if ten pounds are too much for a particular
person to eat and two too little, it does not follow that the
trainer will order six pounds; for this also is perhaps too much
2569
for the person who is to take it, or too little - too little for Milo,
too much for the beginner in athletic exercises. The same is true
of running and wrestling. Thus a master of any art avoids
excess and defect, but seeks the intermediate and chooses this
- the intermediate not in the object but relatively to us.
If it is thus, then, that every art does its work well - by looking
to the intermediate and judgling its works by this standard (so
that we often say of good works of art that it is not possible
either to take away or to add anything, implying that excess and
defect destroy the goodness of works of art, while the mean
preserves it; and good artists, as we say, look to this in their
work), and if, further, virtue is more exact and better than any
art, as nature also is, then virtue must have the quality of
aiming at the intermediate. I mean moral virtue; for it is this
that is concerned with passions and actions, and in these there
is excess, defect, and the intermediate. For instance, both fear
and confidence and appetite and anger and pity and in general
pleasure and pain may be felt both too much and too little, and
in both cases not well; but to feel them at the right times, with
reference to the right objects, towards the right people, with the
right motive, and in the right way, is what is both intermediate
and best, and this is characteristic of virtue. Similarly with
regard to actions also there is excess, defect, and the
intermediate. Now virtue is concerned with passions and
actions, in which excess is a form of failure, and so is defect,
while the intermediate is praised and is a form of success; and
being praised and being successful are both characteristics of
virtue. Therefore virtue is a kind of mean, since, as we have
seen, it aims at what is intermediate.
Again, it is possible to fail in many ways (for evil belongs to the
class of the unlimited, as the Pythagoreans conjectured, and
good to that of the limited), while to succeed is possible only in
one way (for which reason also one is easy and the other
2570
difficult - to miss the mark easy, to hit it difficult); for these
reasons also, then, excess and defect are characteristic of vice,
and the mean of virtue;
For men are good in but one way, but bad in many.
Virtue, then, is a state of character concerned with choice, lying
in a mean, i.e. the mean relative to us, this being determined by
a rational principle, and by that principle by which the man of
practical wisdom would determine it. Now it is a mean between
two vices, that which depends on excess and that which
depends on defect; and again it is a mean because the vices
respectively fall short of or exceed what is right in both
passions and actions, while virtue both finds and chooses that
which is intermediate. Hence in respect of its substance and the
definition which states its essence virtue is a mean, with regard
to what is best and right an extreme.
But not every action nor every passion admits of a mean; for
some have names that already imply badness, e.g. spite,
shamelessness, envy, and in the case of actions adultery, theft,
murder; for all of these and suchlike things imply by their
names that they are themselves bad, and not the excesses or
deficiencies of them. It is not possible, then, ever to be right
with regard to them; one must always be wrong. Nor does
goodness or badness with regard to such things depend on
committing adultery with the right woman, at the right time,
and in the right way, but simply to do any of them is to go
wrong. It would be equally absurd, then, to expect that in
unjust, cowardly, and voluptuous action there should be a
mean, an excess, and a deficiency; for at that rate there would
be a mean of excess and of deficiency, an excess of excess, and
a deficiency of deficiency. But as there is no excess and
deficiency of temperance and courage because what is
intermediate is in a sense an extreme, so too of the actions we
2571
have mentioned there is no mean nor any excess and
deficiency, but however they are done they are wrong; for in
general there is neither a mean of excess and deficiency, nor
excess and deficiency of a mean.
We must, however, not only make this general statement, but
also apply it to the individual facts. For among statements about
conduct those which are general apply more widely, but those
which are particular are more genuine, since conduct has to do
with individual cases, and our statements must harmonize with
the facts in these cases. We may take these cases from our table.
With regard to feelings of fear and confidence courage is the
mean; of the people who exceed, he who exceeds in
fearlessness has no name (many of the states have no name),
while the man who exceeds in confidence is rash, and he who
exceeds in fear and falls short in confidence is a coward. With
regard to pleasures and pains - not all of them, and not so much
with regard to the pains - the mean is temperance, the excess
self-indulgence. Persons deficient with regard to the pleasures
are not often found; hence such persons also have received no
name. But let us call them 'insensible'.
With regard to giving and taking of money the mean is liberality,
the excess and the defect prodigality and meanness. In these
actions people exceed and fall short in contrary ways; the
prodigal exceeds in spending and falls short in taking, while the
mean man exceeds in taking and falls short in spending. (At
present we are giving a mere outline or summary, and are
satisfied with this; later these states will be more exactly
determined.) With regard to money there are also other
2572
dispositions - a mean, magnificence (for the magnificent man
differs from the liberal man; the former deals with large sums,
the latter with small ones), an excess, tastelessness and
vulgarity, and a deficiency, niggardliness; these differ from the
states opposed to liberality, and the mode of their difference
will be stated later. With regard to honour and dishonour the
mean is proper pride, the excess is known as a sort of 'empty
vanity', and the deficiency is undue humility; and as we said
liberality was related to magnificence, differing from it by
dealing with small sums, so there is a state similarly related to
proper pride, being concerned with small honours while that is
concerned with great. For it is possible to desire honour as one
ought, and more than one ought, and less, and the man who
exceeds in his desires is called ambitious, the man who falls
short unambitious, while the intermediate person has no name.
The dispositions also are nameless, except that that of the
ambitious man is called ambition. Hence the people who are at
the extremes lay claim to the middle place; and we ourselves
sometimes call the intermediate person ambitious and
sometimes unambitious, and sometimes praise the ambitious
man and sometimes the unambitious. The reason of our doing
this will be stated in what follows; but now let us speak of the
remaining states according to the method which has been
indicated.
With regard to anger also there is an excess, a deficiency, and a
mean. Although they can scarcely be said to have names, yet
since we call the intermediate person good-tempered let us call
the mean good temper; of the persons at the extremes let the
one who exceeds be called irascible, and his vice irascibility, and
the man who falls short an inirascible sort of person, and the
deficiency inirascibility.
There are also three other means, which have a certain likeness
to one another, but differ from one another: for they are all
2573
concerned with intercourse in words and actions, but differ in
that one is concerned with truth in this sphere, the other two
with pleasantness; and of this one kind is exhibited in giving
amusement, the other in all the circumstances of life. We must
therefore speak of these too, that we may the better see that in
all things the mean is praise-worthy, and the extremes neither
praiseworthy nor right, but worthy of blame. Now most of these
states also have no names, but we must try, as in the other
cases, to invent names ourselves so that we may be clear and
easy to follow. With regard to truth, then, the intermediate is a
truthful sort of person and the mean may be called
truthfulness, while the pretence which exaggerates is
boastfulness and the person characterized by it a boaster, and
that which understates is mock modesty and the person
characterized by it mock-modest. With regard to pleasantness in
the giving of amusement the intermediate person is ready-
witted and the disposition ready wit, the excess is buffoonery
and the person characterized by it a buffoon, while the man
who falls short is a sort of boor and his state is boorishness.
With regard to the remaining kind of pleasantness, that which
is exhibited in life in general, the man who is pleasant in the
right way is friendly and the mean is friendliness, while the
man who exceeds is an obsequious person if he has no end in
view, a flatterer if he is aiming at his own advantage, and the
man who falls short and is unpleasant in all circumstances is a
quarrelsome and surly sort of person.
There are also means in the passions and concerned with the
passions; since shame is not a virtue, and yet praise is extended
to the modest man. For even in these matters one man is said
to be intermediate, and another to exceed, as for instance the
bashful man who is ashamed of everything; while he who falls
short or is not ashamed of anything at all is shameless, and the
intermediate person is modest. Righteous indignation is a mean
between envy and spite, and these states are concerned with
2574
the pain and pleasure that are felt at the fortunes of our
neighbours; the man who is characterized by righteous
indignation is pained at undeserved good fortune, the envious
man, going beyond him, is pained at all good fortune, and the
spiteful man falls so far short of being pained that he even
rejoices. But these states there will be an opportunity of
describing elsewhere; with regard to justice, since it has not one
simple meaning, we shall, after describing the other states,
distinguish its two kinds and say how each of them is a mean;
and similarly we shall treat also of the rational virtues.
8
There are three kinds of disposition, then, two of them vices,
involving excess and deficiency respectively, and one a virtue,
viz. the mean, and all are in a sense opposed to all; for the
extreme states are contrary both to the intermediate state and
to each other, and the intermediate to the extremes; as the
equal is greater relatively to the less, less relatively to the
greater, so the middle states are excessive relatively to the
deficiencies, deficient relatively to the excesses, both in
passions and in actions. For the brave man appears rash
relatively to the coward, and cowardly relatively to the rash
man; and similarly the temperate man appears self-indulgent
relatively to the insensible man, insensible relatively to the self-
indulgent, and the liberal man prodigal relatively to the mean
man, mean relatively to the prodigal. Hence also the people at
the extremes push the intermediate man each over to the other,
and the brave man is called rash by the coward, cowardly by the
rash man, and correspondingly in the other cases.
2575
These states being thus opposed to one another, the greatest
contrariety is that of the extremes to each other, rather than to
the intermediate; for these are further from each other than
from the intermediate, as the great is further from the small
and the small from the great than both are from the equal.
Again, to the intermediate some extremes show a certain
likeness, as that of rashness to courage and that of prodigality
to liberality; but the extremes show the greatest unlikeness to
each other; now contraries are defined as the things that are
furthest from each other, so that things that are further apart
are more contrary.
To the mean in some cases the deficiency, in some the excess is
more opposed; e.g. it is not rashness, which is an excess, but
cowardice, which is a deficiency, that is more opposed to
courage, and not insensibility, which is a deficiency, but self-
indulgence, which is an excess, that is more opposed to
temperance. This happens from two reasons, one being drawn
from the thing itself; for because one extreme is nearer and
liker to the intermediate, we oppose not this but rather its
contrary to the intermediate. E.g. since rashness is thought liker
and nearer to courage, and cowardice more unlike, we oppose
rather the latter to courage; for things that are further from the
intermediate are thought more contrary to it. This, then, is one
cause, drawn from the thing itself; another is drawn from
ourselves; for the things to which we ourselves more naturally
tend seem more contrary to the intermediate. For instance, we
ourselves tend more naturally to pleasures, and hence are more
easily carried away towards self-indulgence than towards
propriety. We describe as contrary to the mean, then, rather the
directions in which we more often go to great lengths; and
therefore self-indulgence, which is an excess, is the more
contrary to temperance.
2576
That moral virtue is a mean, then, and in what sense it is so,
and that it is a mean between two vices, the one involving
excess, the other deficiency, and that it is such because its
character is to aim at what is intermediate in passions and in
actions, has been sufficiently stated. Hence also it is no easy
task to be good. For in everything it is no easy task to find the
middle, e.g. to find the middle of a circle is not for every one but
for him who knows; so, too, any one can get angry - that is easy
- or give or spend money; but to do this to the right person, to
the right extent, at the right time, with the right motive, and in
the right way, that is not for every one, nor is it easy; wherefore
goodness is both rare and laudable and noble.
Hence he who aims at the intermediate must first depart from
what is the more contrary to it, as Calypso advises:
Hold the ship out beyond that surf and spray.
For of the extremes one is more erroneous, one less so;
therefore, since to hit the mean is hard in the extreme, we must
as a second best, as people say, take the least of the evils; and
this will be done best in the way we describe. But we must
consider the things towards which we ourselves also are easily
carried away; for some of us tend to one thing, some to another;
and this will be recognizable from the pleasure and the pain we
feel. We must drag ourselves away to the contrary extreme; for
we shall get into the intermediate state by drawing well away
from error, as people do in straightening sticks that are bent.
Now in everything the pleasant or pleasure is most to be
guarded against; for we do not judge it impartially. We ought,
then, to feel towards pleasure as the elders of the people felt
towards Helen, and in all circumstances repeat their saying; for
2577
if we dismiss pleasure thus we are less likely to go astray. It is by
doing this, then, (to sum the matter up) that we shall best be
able to hit the mean.
But this is no doubt difficult, and especially in individual cases;
for or is not easy to determine both how and with whom and on
what provocation and how long one should be angry; for we too
sometimes praise those who fall short and call them good-
tempered, but sometimes we praise those who get angry and
call them manly. The man, however, who deviates little from
goodness is not blamed, whether he do so in the direction of the
more or of the less, but only the man who deviates more widely;
for he does not fail to be noticed. But up to what point and to
what extent a man must deviate before he becomes
blameworthy it is not easy to determine by reasoning, any more
than anything else that is perceived by the senses; such things
depend on particular facts, and the decision rests with
perception. So much, then, is plain, that the intermediate state
is in all things to be praised, but that we must incline
sometimes towards the excess, sometimes towards the
deficiency; for so shall we most easily hit the mean and what is
right.
2578
Book III
Since virtue is concerned with passions and actions, and on
voluntary passions and actions praise and blame are bestowed,
on those that are involuntary pardon, and sometimes also pity,
to distinguish the voluntary and the involuntary is presumably
necessary for those who are studying the nature of virtue, and
useful also for legislators with a view to the assigning both of
honours and of punishments. Those things, then, are thought-
involuntary, which take place under compulsion or owing to
ignorance; and that is compulsory of which the moving
principle is outside, being a principle in which nothing is
contributed by the person who is acting or is feeling the
passion, e.g. if he were to be carried somewhere by a wind, or by
men who had him in their power.
But with regard to the things that are done from fear of greater
evils or for some noble object (e.g. if a tyrant were to order one
to do something base, having one's parents and children in his
power, and if one did the action they were to be saved, but
otherwise would be put to death), it may be debated whether
such actions are involuntary or voluntary. Something of the sort
happens also with regard to the throwing of goods overboard in
a storm; for in the abstract no one throws goods away
voluntarily, but on condition of its securing the safety of himself
and his crew any sensible man does so. Such actions, then, are
mixed, but are more like voluntary actions; for they are worthy
of choice at the time when they are done, and the end of an
action is relative to the occasion. Both the terms, then,
'voluntary' and 'involuntary', must be used with reference to the
2579
moment of action. Now the man acts voluntarily; for the
principle that moves the instrumental parts of the body in such
actions is in him, and the things of which the moving principle
is in a man himself are in his power to do or not to do. Such
actions, therefore, are voluntary, but in the abstract perhaps
involuntary; for no one would choose any such act in itself.
For such actions men are sometimes even praised, when they
endure something base or painful in return for great and noble
objects gained; in the opposite case they are blamed, since to
endure the greatest indignities for no noble end or for a trifling
end is the mark of an inferior person. On some actions praise
indeed is not bestowed, but pardon is, when one does what he
ought not under pressure which overstrains human nature and
which no one could withstand. But some acts, perhaps, we
cannot be forced to do, but ought rather to face death after the
most fearful sufferings; for the things that 'forced' Euripides
Alcmaeon to slay his mother seem absurd. It is difficult
sometimes to determine what should be chosen at what cost,
and what should be endured in return for what gain, and yet
more difficult to abide by our decisions; for as a rule what is
expected is painful, and what we are forced to do is base,
whence praise and blame are bestowed on those who have been
compelled or have not.
What sort of acts, then, should be called compulsory? We
answer that without qualification actions are so when the cause
is in the external circumstances and the agent contributes
nothing. But the things that in themselves are involuntary, but
now and in return for these gains are worthy of choice, and
whose moving principle is in the agent, are in themselves
involuntary, but now and in return for these gains voluntary.
They are more like voluntary acts; for actions are in the class of
particulars, and the particular acts here are voluntary. What sort
2580
of things are to be chosen, and in return for what, it is not easy
to state; for there are many differences in the particular cases.
But if some one were to say that pleasant and noble objects
have a compelling power, forcing us from without, all acts
would be for him compulsory; for it is for these objects that all
men do everything they do. And those who act under
compulsion and unwillingly act with pain, but those who do
acts for their pleasantness and nobility do them with pleasure;
it is absurd to make external circumstances responsible, and
not oneself, as being easily caught by such attractions, and to
make oneself responsible for noble acts but the pleasant objects
responsible for base acts. The compulsory, then, seems to be
that whose moving principle is outside, the person compelled
contributing nothing.
Everything that is done by reason of ignorance is not voluntary;
it is only what produces pain and repentance that is
involuntary. For the man who has done something owing to
ignorance, and feels not the least vexation at his action, has not
acted voluntarily, since he did not know what he was doing, nor
yet involuntarily, since he is not pained. Of people, then, who
act by reason of ignorance he who repents is thought an
involuntary agent, and the man who does not repent may, since
he is different, be called a not voluntary agent; for, since he
differs from the other, it is better that he should have a name of
his own.
Acting by reason of ignorance seems also to be different from
acting in ignorance; for the man who is drunk or in a rage is
thought to act as a result not of ignorance but of one of the
causes mentioned, yet not knowingly but in ignorance.
Now every wicked man is ignorant of what he ought to do and
what he ought to abstain from, and it is by reason of error of
this kind that men become unjust and in general bad; but the
2581
term 'involuntary' tends to be used not if a man is ignorant of
what is to his advantage - for it is not mistaken purpose that
causes involuntary action (it leads rather to wickedness), nor
ignorance of the universal (for that men are blamed), but
ignorance of particulars, i.e. of the circumstances of the action
and the objects with which it is concerned. For it is on these
that both pity and pardon depend, since the person who is
ignorant of any of these acts involuntarily.
Perhaps it is just as well, therefore, to determine their nature
and number. A man may be ignorant, then, of who he is, what
he is doing, what or whom he is acting on, and sometimes also
what (e.g. what instrument) he is doing it with, and to what end
(e.g. he may think his act will conduce to some one's safety),
and how he is doing it (e.g. whether gently or violently). Now of
all of these no one could be ignorant unless he were mad, and
evidently also he could not be ignorant of the agent; for how
could he not know himself? But of what he is doing a man
might be ignorant, as for instance people say 'it slipped out of
their mouths as they were speaking', or 'they did not know it
was a secret', as Aeschylus said of the mysteries, or a man
might say he 'let it go off when he merely wanted to show its
working', as the man did with the catapult. Again, one might
think one's son was an enemy, as Merope did, or that a pointed
spear had a button on it, or that a stone was pumicestone; or
one might give a man a draught to save him, and really kill him;
or one might want to touch a man, as people do in sparring, and
really wound him. The ignorance may relate, then, to any of
these things, i.e. of the circumstances of the action, and the
man who was ignorant of any of these is thought to have acted
involuntarily, and especially if he was ignorant on the most
important points; and these are thought to be the
circumstances of the action and its end. Further, the doing of an
act that is called involuntary in virtue of ignorance of this sort
must be painful and involve repentance.
2582
Since that which is done under compulsion or by reason of
ignorance is involuntary, the voluntary would seem to be that of
which the moving principle is in the agent himself, he being
aware of the particular circumstances of the action. Presumably
acts done by reason of anger or appetite are not rightly called
involuntary. For in the first place, on that showing none of the
other animals will act voluntarily, nor will children; and
secondly, is it meant that we do not do voluntarily any of the
acts that are due to appetite or anger, or that we do the noble
acts voluntarily and the base acts involuntarily? Is not this
absurd, when one and the same thing is the cause? But it would
surely be odd to describe as involuntary the things one ought to
desire; and we ought both to be angry at certain things and to
have an appetite for certain things, e.g. for health and for
learning. Also what is involuntary is thought to be painful, but
what is in accordance with appetite is thought to be pleasant.
Again, what is the difference in respect of involuntariness
between errors committed upon calculation and those
committed in anger? Both are to be avoided, but the irrational
passions are thought not less human than reason is, and
therefore also the actions which proceed from anger or appetite
are the man's actions. It would be odd, then, to treat them as
involuntary.
Both the voluntary and the involuntary having been delimited,
we must next discuss choice; for it is thought to be most closely
bound up with virtue and to discriminate characters better than
actions do.
2583
Choice, then, seems to be voluntary, but not the same thing as
the voluntary; the latter extends more widely For both children
and the lower animals share in voluntary action, but not in
choice, and acts done on the spur of the moment we describe as
voluntary, but not as chosen.
Those who say it is appetite or anger or wish or a kind of
opinion do not seem to be right. For choice is not common to
irrational creatures as well, but appetite and anger are. Again,
the incontinent man acts with appetite, but not with choice;
while the continent man on the contrary acts with choice, but
not with appetite. Again, appetite is contrary to choice, but not
appetite to appetite. Again, appetite relates to the pleasant and
the painful, choice neither to the painful nor to the pleasant.
Still less is it anger; for acts due to anger are thought to be less
than any others objects of choice.
But neither is it wish, though it seems near to it; for choice
cannot relate to impossibles, and if any one said he chose them
he would be thought silly; but there may be a wish even for
impossibles, e.g. for immortality. And wish may relate to things
that could in no way be brought about by one's own efforts, e.g.
that a particular actor or athlete should win in a competition;
but no one chooses such things, but only the things that he
thinks could be brought about by his own efforts. Again, wish
relates rather to the end, choice to the means; for instance, we
wish to be healthy, but we choose the acts which will make us
healthy, and we wish to be happy and say we do, but we cannot
well say we choose to be so; for, in general, choice seems to
relate to the things that are in our own power.
For this reason, too, it cannot be opinion; for opinion is thought
to relate to all kinds of things, no less to eternal things and
impossible things than to things in our own power; and it is
2584
distinguished by its falsity or truth, not by its badness or
goodness, while choice is distinguished rather by these.
Now with opinion in general perhaps no one even says it is
identical. But it is not identical even with any kind of opinion;
for by choosing what is good or bad we are men of a certain
character, which we are not by holding certain opinions. And we
choose to get or avoid something good or bad, but we have
opinions about what a thing is or whom it is good for or how it
is good for him; we can hardly be said to opine to get or avoid
anything. And choice is praised for being related to the right
object rather than for being rightly related to it, opinion for
being truly related to its object. And we choose what we best
know to be good, but we opine what we do not quite know; and
it is not the same people that are thought to make the best
choices and to have the best opinions, but some are thought to
have fairly good opinions, but by reason of vice to choose what
they should not. If opinion precedes choice or accompanies it,
that makes no difference; for it is not this that we are
considering, but whether it is identical with some kind of
opinion.
What, then, or what kind of thing is it, since it is none of the
things we have mentioned? It seems to be voluntary, but not all
that is voluntary to be an object of choice. Is it, then, what has
been decided on by previous deliberation? At any rate choice
involves a rational principle and thought. Even the name seems
to suggest that it is what is chosen before other things.
Do we deliberate about everything, and is everything a possible
subject of deliberation, or is deliberation impossible about some
2585
things? We ought presumably to call not what a fool or a
madman would deliberate about, but what a sensible man
would deliberate about, a subject of deliberation. Now about
eternal things no one deliberates, e.g. about the material
universe or the incommensurability of the diagonal and the side
of a square. But no more do we deliberate about the things that
involve movement but always happen in the same way, whether
of necessity or by nature or from any other cause, e.g. the
solstices and the risings of the stars; nor about things that
happen now in one way, now in another, e.g. droughts and
rains; nor about chance events, like the finding of treasure. But
we do not deliberate even about all human affairs; for instance,
no Spartan deliberates about the best constitution for the
Scythians. For none of these things can be brought about by our
own efforts.
We deliberate about things that are in our power and can be
done; and these are in fact what is left. For nature, necessity,
and chance are thought to be causes, and also reason and
everything that depends on man. Now every class of men
deliberates about the things that can be done by their own
efforts. And in the case of exact and self-contained sciences
there is no deliberation, e.g. about the letters of the alphabet
(for we have no doubt how they should be written); but the
things that are brought about by our own efforts, but not always
in the same way, are the things about which we deliberate, e.g.
questions of medical treatment or of money-making. And we do
so more in the case of the art of navigation than in that of
gymnastics, inasmuch as it has been less exactly worked out,
and again about other things in the same ratio, and more also in
the case of the arts than in that of the sciences; for we have
more doubt about the former. Deliberation is concerned with
things that happen in a certain way for the most part, but in
which the event is obscure, and with things in which it is
indeterminate. We call in others to aid us in deliberation on
2586
important questions, distrusting ourselves as not being equal to
deciding.
We deliberate not about ends but about means. For a doctor
does not deliberate whether he shall heal, nor an orator
whether he shall persuade, nor a statesman whether he shall
produce law and order, nor does any one else deliberate about
his end. They assume the end and consider how and by what
means it is to be attained; and if it seems to be produced by
several means they consider by which it is most easily and best
produced, while if it is achieved by one only they consider how
it will be achieved by this and by what means this will be
achieved, till they come to the first cause, which in the order of
discovery is last. For the person who deliberates seems to
investigate and analyse in the way described as though he were
analysing a geometrical construction (not all investigation
appears to be deliberation - for instance mathematical
investigations - but all deliberation is investigation), and what is
last in the order of analysis seems to be first in the order of
becoming. And if we come on an impossibility, we give up the
search, e.g. if we need money and this cannot be got; but if a
thing appears possible we try to do it. By 'possible' things I
mean things that might be brought about by our own efforts;
and these in a sense include things that can be brought about
by the efforts of our friends, since the moving principle is in
ourselves. The subject of investigation is sometimes the
instruments, sometimes the use of them; and similarly in the
other cases - sometimes the means, sometimes the mode of
using it or the means of bringing it about. It seems, then, as has
been said, that man is a moving principle of actions; now
deliberation is about the things to be done by the agent himself,
and actions are for the sake of things other than themselves.
For the end cannot be a subject of deliberation, but only the
means; nor indeed can the particular facts be a subject of it, as
whether this is bread or has been baked as it should; for these
2587
are matters of perception. If we are to be always deliberating, we
shall have to go on to infinity.
The same thing is deliberated upon and is chosen, except that
the object of choice is already determinate, since it is that which
has been decided upon as a result of deliberation that is the
object of choice. For every one ceases to inquire how he is to act
when he has brought the moving principle back to himself and
to the ruling part of himself; for this is what chooses. This is
plain also from the ancient constitutions, which Homer
represented; for the kings announced their choices to the
people. The object of choice being one of the things in our own
power which is desired after deliberation, choice will be
deliberate desire of things in our own power; for when we have
decided as a result of deliberation, we desire in accordance with
our deliberation.
We may take it, then, that we have described choice in outline,
and stated the nature of its objects and the fact that it is
concerned with means.
That wish is for the end has already been stated; some think it
is for the good, others for the apparent good. Now those who
say that the good is the object of wish must admit in
consequence that that which the man who does not choose
aright wishes for is not an object of wish (for if it is to be so, it
must also be good; but it was, if it so happened, bad); while
those who say the apparent good is the object of wish must
admit that there is no natural object of wish, but only what
seems good to each man. Now different things appear good to
different people, and, if it so happens, even contrary things.
2588
If these consequences are unpleasing, are we to say that
absolutely and in truth the good is the object of wish, but for
each person the apparent good; that that which is in truth an
object of wish is an object of wish to the good man, while any
chance thing may be so the bad man, as in the case of bodies
also the things that are in truth wholesome are wholesome for
bodies which are in good condition, while for those that are
diseased other things are wholesome - or bitter or sweet or hot
or heavy, and so on; since the good man judges each class of
things rightly, and in each the truth appears to him? For each
state of character has its own ideas of the noble and the
pleasant, and perhaps the good man differs from others most
by seeing the truth in each class of things, being as it were the
norm and measure of them. In most things the error seems to
be due to pleasure; for it appears a good when it is not. We
therefore choose the pleasant as a good, and avoid pain as an
evil.
The end, then, being what we wish for, the means what we
deliberate about and choose, actions concerning means must be
according to choice and voluntary. Now the exercise of the
virtues is concerned with means. Therefore virtue also is in our
own power, and so too vice. For where it is in our power to act it
is also in our power not to act, and vice versa; so that, if to act,
where this is noble, is in our power, not to act, which will be
base, will also be in our power, and if not to act, where this is
noble, is in our power, to act, which will be base, will also be in
our power. Now if it is in our power to do noble or base acts, and
likewise in our power not to do them, and this was what being
2589
good or bad meant, then it is in our power to be virtuous or
vicious.
The saying that 'no one is voluntarily wicked nor involuntarily
happy' seems to be partly false and partly true; for no one is
involuntarily happy, but wickedness is voluntary. Or else we
shall have to dispute what has just been said, at any rate, and
deny that man is a moving principle or begetter of his actions as
of children. But if these facts are evident and we cannot refer
actions to moving principles other than those in ourselves, the
acts whose moving principles are in us must themselves also be
in our power and voluntary.
Witness seems to be borne to this both by individuals in their
private capacity and by legislators themselves; for these punish
and take vengeance on those who do wicked acts (unless they
have acted under compulsion or as a result of ignorance for
which they are not themselves responsible), while they honour
those who do noble acts, as though they meant to encourage
the latter and deter the former. But no one is encouraged to do
the things that are neither in our power nor voluntary; it is
assumed that there is no gain in being persuaded not to be hot
or in pain or hungry or the like, since we shall experience these
feelings none the less. Indeed, we punish a man for his very
ignorance, if he is thought responsible for the ignorance, as
when penalties are doubled in the case of drunkenness; for the
moving principle is in the man himself, since he had the power
of not getting drunk and his getting drunk was the cause of his
ignorance. And we punish those who are ignorant of anything in
the laws that they ought to know and that is not difficult, and
so too in the case of anything else that they are thought to be
ignorant of through carelessness; we assume that it is in their
power not to be ignorant, since they have the power of taking
care.
2590
But perhaps a man is the kind of man not to take care. Still they
are themselves by their slack lives responsible for becoming
men of that kind, and men make themselves responsible for
being unjust or self-indulgent, in the one case by cheating and
in the other by spending their time in drinking bouts and the
like; for it is activities exercised on particular objects that make
the corresponding character. This is plain from the case of
people training for any contest or action; they practise the
activity the whole time. Now not to know that it is from the
exercise of activities on particular objects that states of
character are produced is the mark of a thoroughly senseless
person. Again, it is irrational to suppose that a man who acts
unjustly does not wish to be unjust or a man who acts self-
indulgently to be self-indulgent. But if without being ignorant a
man does the things which will make him unjust, he will be
unjust voluntarily. Yet it does not follow that if he wishes he will
cease to be unjust and will be just. For neither does the man
who is ill become well on those terms. We may suppose a case
in which he is ill voluntarily, through living incontinently and
disobeying his doctors. In that case it was then open to him not
to be ill, but not now, when he has thrown away his chance, just
as when you have let a stone go it is too late to recover it; but
yet it was in your power to throw it, since the moving principle
was in you. So, too, to the unjust and to the self-indulgent man
it was open at the beginning not to become men of this kind,
and so they are unjust and selfindulgent voluntarily; but now
that they have become so it is not possible for them not to be
so.
But not only are the vices of the soul voluntary, but those of the
body also for some men, whom we accordingly blame; while no
one blames those who are ugly by nature, we blame those who
are so owing to want of exercise and care. So it is, too, with
respect to weakness and infirmity; no one would reproach a
man blind from birth or by disease or from a blow, but rather
2591
pity him, while every one would blame a man who was blind
from drunkenness or some other form of self-indulgence. Of
vices of the body, then, those in our own power are blamed,
those not in our power are not. And if this be so, in the other
cases also the vices that are blamed must be in our own power.
Now some one may say that all men desire the apparent good,
but have no control over the appearance, but the end appears to
each man in a form answering to his character. We reply that if
each man is somehow responsible for his state of mind, he will
also be himself somehow responsible for the appearance; but if
not, no one is responsible for his own evildoing, but every one
does evil acts through ignorance of the end, thinking that by
these he will get what is best, and the aiming at the end is not
self-chosen but one must be born with an eye, as it were, by
which to judge rightly and choose what is truly good, and he is
well endowed by nature who is well endowed with this. For it is
what is greatest and most noble, and what we cannot get or
learn from another, but must have just such as it was when
given us at birth, and to be well and nobly endowed with this
will be perfect and true excellence of natural endowment. If this
is true, then, how will virtue be more voluntary than vice? To
both men alike, the good and the bad, the end appears and is
fixed by nature or however it may be, and it is by referring
everything else to this that men do whatever they do.
Whether, then, it is not by nature that the end appears to each
man such as it does appear, but something also depends on
him, or the end is natural but because the good man adopts the
means voluntarily virtue is voluntary, vice also will be none the
less voluntary; for in the case of the bad man there is equally
present that which depends on himself in his actions even if
not in his end. If, then, as is asserted, the virtues are voluntary
(for we are ourselves somehow partly responsible for our states
of character, and it is by being persons of a certain kind that we
2592
assume the end to be so and so), the vices also will be
voluntary; for the same is true of them.
With regard to the virtues in general we have stated their genus
in outline, viz. that they are means and that they are states of
character, and that they tend, and by their own nature, to the
doing of the acts by which they are produced, and that they are
in our power and voluntary, and act as the right rule prescribes.
But actions and states of character are not voluntary in the
same way; for we are masters of our actions from the beginning
right to the end, if we know the particular facts, but though we
control the beginning of our states of character the gradual
progress is not obvious any more than it is in illnesses; because
it was in our power, however, to act in this way or not in this
way, therefore the states are voluntary.
Let us take up the several virtues, however, and say which they
are and what sort of things they are concerned with and how
they are concerned with them; at the same time it will become
plain how many they are. And first let us speak of courage.
That it is a mean with regard to feelings of fear and confidence
has already been made evident; and plainly the things we fear
are terrible things, and these are, to speak without qualification,
evils; for which reason people even define fear as expectation of
evil. Now we fear all evils, e.g. disgrace, poverty, disease,
friendlessness, death, but the brave man is not thought to be
concerned with all; for to fear some things is even right and
noble, and it is base not to fear them - e.g. disgrace; he who
fears this is good and modest, and he who does not is
shameless. He is, however, by some people called brave, by a
2593
transference of the word to a new meaning; for he has in him
something which is like the brave man, since the brave man
also is a fearless person. Poverty and disease we perhaps ought
not to fear, nor in general the things that do not proceed from
vice and are not due to a man himself. But not even the man
who is fearless of these is brave. Yet we apply the word to him
also in virtue of a similarity; for some who in the dangers of war
are cowards are liberal and are confident in face of the loss of
money. Nor is a man a coward if he fears insult to his wife and
children or envy or anything of the kind; nor brave if he is
confident when he is about to be flogged. With what sort of
terrible things, then, is the brave man concerned? Surely with
the greatest; for no one is more likely than he to stand his
ground against what is awe-inspiring. Now death is the most
terrible of all things; for it is the end, and nothing is thought to
be any longer either good or bad for the dead. But the brave
man would not seem to be concerned even with death in all
circumstances, e.g. at sea or in disease. In what circumstances,
then? Surely in the noblest. Now such deaths are those in battle;
for these take place in the greatest and noblest danger. And
these are correspondingly honoured in city-states and at the
courts of monarchs. Properly, then, he will be called brave who
is fearless in face of a noble death, and of all emergencies that
involve death; and the emergencies of war are in the highest
degree of this kind. Yet at sea also, and in disease, the brave
man is fearless, but not in the same way as the seaman; for he
has given up hope of safety, and is disliking the thought of
death in this shape, while they are hopeful because of their
experience. At the same time, we show courage in situations
where there is the opportunity of showing prowess or where
death is noble; but in these forms of death neither of these
conditions is fulfilled.
2594
What is terrible is not the same for all men; but we say there are
things terrible even beyond human strength. These, then, are
terrible to every one - at least to every sensible man; but the
terrible things that are not beyond human strength differ in
magnitude and degree, and so too do the things that inspire
confidence. Now the brave man is as dauntless as man may be.
Therefore, while he will fear even the things that are not beyond
human strength, he will face them as he ought and as the rule
directs, for honour's sake; for this is the end of virtue. But it is
possible to fear these more, or less, and again to fear things that
are not terrible as if they were. Of the faults that are committed
one consists in fearing what one should not, another in fearing
as we should not, another in fearing when we should not, and
so on; and so too with respect to the things that inspire
confidence. The man, then, who faces and who fears the right
things and from the right motive, in the right way and from the
right time, and who feels confidence under the corresponding
conditions, is brave; for the brave man feels and acts according
to the merits of the case and in whatever way the rule directs.
Now the end of every activity is conformity to the
corresponding state of character. This is true, therefore, of the
brave man as well as of others. But courage is noble. Therefore
the end also is noble; for each thing is defined by its end.
Therefore it is for a noble end that the brave man endures and
acts as courage directs.
Of those who go to excess he who exceeds in fearlessness has
no name (we have said previously that many states of character
have no names), but he would be a sort of madman or
insensible person if he feared nothing, neither earthquakes nor
the waves, as they say the Celts do not; while the man who
2595
exceeds in confidence about what really is terrible is rash. The
rash man, however, is also thought to be boastful and only a
pretender to courage; at all events, as the brave man is with
regard to what is terrible, so the rash man wishes to appear; and
so he imitates him in situations where he can. Hence also most
of them are a mixture of rashness and cowardice; for, while in
these situations they display confidence, they do not hold their
ground against what is really terrible. The man who exceeds in
fear is a coward; for he fears both what he ought not and as he
ought not, and all the similar characterizations attach to him.
He is lacking also in confidence; but he is more conspicuous for
his excess of fear in painful situations. The coward, then, is a
despairing sort of person; for he fears everything. The brave
man, on the other hand, has the opposite disposition; for
confidence is the mark of a hopeful disposition. The coward, the
rash man, and the brave man, then, are concerned with the
same objects but are differently disposed towards them; for the
first two exceed and fall short, while the third holds the middle,
which is the right, position; and rash men are precipitate, and
wish for dangers beforehand but draw back when they are in
them, while brave men are keen in the moment of action, but
quiet beforehand.
As we have said, then, courage is a mean with respect to things
that inspire confidence or fear, in the circumstances that have
been stated; and it chooses or endures things because it is noble
to do so, or because it is base not to do so. But to die to escape
from poverty or love or anything painful is not the mark of a
brave man, but rather of a coward; for it is softness to fly from
what is troublesome, and such a man endures death not
because it is noble but to fly from evil.
2596
8
Courage, then, is something of this sort, but the name is also
applied to five other kinds.
First comes the courage of the citizen-soldier; for this is most
like true courage. Citizen-soldiers seem to face dangers because
of the penalties imposed by the laws and the reproaches they
would otherwise incur, and because of the honours they win by
such action; and therefore those peoples seem to be bravest
among whom cowards are held in dishonour and brave men in
honour. This is the kind of courage that Homer depicts, e.g. in
Diomede and in Hector:
First will Polydamas be to heap reproach on me then; and
For Hector one day 'mid the Trojans shall utter his vaulting
harangue:
Afraid was Tydeides, and fled from my face.
This kind of courage is most like to that which we described
earlier, because it is due to virtue; for it is due to shame and to
desire of a noble object (i.e. honour) and avoidance of disgrace,
which is ignoble. One might rank in the same class even those
who are compelled by their rulers; but they are inferior,
inasmuch as they do what they do not from shame but from
fear, and to avoid not what is disgraceful but what is painful; for
their masters compel them, as Hector does:
But if I shall spy any dastard that cowers far from the fight,
Vainly will such an one hope to escape from the dogs.
And those who give them their posts, and beat them if they
retreat, do the same, and so do those who draw them up with
trenches or something of the sort behind them; all of these
2597
apply compulsion. But one ought to be brave not under
compulsion but because it is noble to be so.
(2) Experience with regard to particular facts is also thought to
be courage; this is indeed the reason why Socrates thought
courage was knowledge. Other people exhibit this quality in
other dangers, and professional soldiers exhibit it in the
dangers of war; for there seem to be many empty alarms in war,
of which these have had the most comprehensive experience;
therefore they seem brave, because the others do not know the
nature of the facts. Again, their experience makes them most
capable in attack and in defence, since they can use their arms
and have the kind that are likely to be best both for attack and
for defence; therefore they fight like armed men against
unarmed or like trained athletes against amateurs; for in such
contests too it is not the bravest men that fight best, but those
who are strongest and have their bodies in the best condition.
Professional soldiers turn cowards, however, when the danger
puts too great a strain on them and they are inferior in numbers
and equipment; for they are the first to fly, while citizen-forces
die at their posts, as in fact happened at the temple of Hermes.
For to the latter flight is disgraceful and death is preferable to
safety on those terms; while the former from the very beginning
faced the danger on the assumption that they were stronger,
and when they know the facts they fly, fearing death more than
disgrace; but the brave man is not that sort of person.
(3) Passion also is sometimes reckoned as courage; those who
act from passion, like wild beasts rushing at those who have
wounded them, are thought to be brave, because brave men also
are passionate; for passion above all things is eager to rush on
danger, and hence Homer's 'put strength into his passion' and
'aroused their spirit and passion and 'hard he breathed panting'
and 'his blood boiled'. For all such expressions seem to indicate
the stirring and onset of passion. Now brave men act for
2598
honour's sake, but passion aids them; while wild beasts act
under the influence of pain; for they attack because they have
been wounded or because they are afraid, since if they are in a
forest they do not come near one. Thus they are not brave
because, driven by pain and passion, they rush on danger
without foreseeing any of the perils, since at that rate even
asses would be brave when they are hungry; for blows will not
drive them from their food; and lust also makes adulterers do
many daring things. (Those creatures are not brave, then, which
are driven on to danger by pain or passion.) The 'courage' that is
due to passion seems to be the most natural, and to be courage
if choice and motive be added.
Men, then, as well as beasts, suffer pain when they are angry,
and are pleased when they exact their revenge; those who fight
for these reasons, however, are pugnacious but not brave; for
they do not act for honour's sake nor as the rule directs, but
from strength of feeling; they have, however, something akin to
courage.
(4) Nor are sanguine people brave; for they are confident in
danger only because they have conquered often and against
many foes. Yet they closely resemble brave men, because both
are confident; but brave men are confident for the reasons
stated earlier, while these are so because they think they are the
strongest and can suffer nothing. (Drunken men also behave in
this way; they become sanguine). When their adventures do not
succeed, however, they run away; but it was the mark of a brave
man to face things that are, and seem, terrible for a man,
because it is noble to do so and disgraceful not to do so. Hence
also it is thought the mark of a braver man to be fearless and
undisturbed in sudden alarms than to be so in those that are
foreseen; for it must have proceeded more from a state of
character, because less from preparation; acts that are foreseen
2599
may be chosen by calculation and rule, but sudden actions must
be in accordance with one's state of character.
(5) People who are ignorant of the danger also appear brave, and
they are not far removed from those of a sanguine temper, but
are inferior inasmuch as they have no self-reliance while these
have. Hence also the sanguine hold their ground for a time; but
those who have been deceived about the facts fly if they know
or suspect that these are different from what they supposed, as
happened to the Argives when they fell in with the Spartans
and took them for Sicyonians.
We have, then, described the character both of brave men and of
those who are thought to be brave.
Though courage is concerned with feelings of confidence and of
fear, it is not concerned with both alike, but more with the
things that inspire fear; for he who is undisturbed in face of
these and bears himself as he should towards these is more
truly brave than the man who does so towards the things that
inspire confidence. It is for facing what is painful, then, as has
been said, that men are called brave. Hence also courage
involves pain, and is justly praised; for it is harder to face what
is painful than to abstain from what is pleasant.
Yet the end which courage sets before it would seem to be
pleasant, but to be concealed by the attending circumstances, as
happens also in athletic contests; for the end at which boxers
aim is pleasant - the crown and the honours - but the blows
they take are distressing to flesh and blood, and painful, and so
is their whole exertion; and because the blows and the
2600
exertions are many the end, which is but small, appears to have
nothing pleasant in it. And so, if the case of courage is similar,
death and wounds will be painful to the brave man and against
his will, but he will face them because it is noble to do so or
because it is base not to do so. And the more he is possessed of
virtue in its entirety and the happier he is, the more he will be
pained at the thought of death; for life is best worth living for
such a man, and he is knowingly losing the greatest goods, and
this is painful. But he is none the less brave, and perhaps all the
more so, because he chooses noble deeds of war at that cost. It
is not the case, then, with all the virtues that the exercise of
them is pleasant, except in so far as it reaches its end. But it is
quite possible that the best soldiers may be not men of this sort
but those who are less brave but have no other good; for these
are ready to face danger, and they sell their life for trifling gains.
So much, then, for courage; it is not difficult to grasp its nature
in outline, at any rate, from what has been said.
10
After courage let us speak of temperance; for these seem to be
the virtues of the irrational parts. We have said that temperance
is a mean with regard to pleasures (for it is less, and not in the
same way, concerned with pains); self-indulgence also is
manifested in the same sphere. Now, therefore, let us determine
with what sort of pleasures they are concerned. We may assume
the distinction between bodily pleasures and those of the soul,
such as love of honour and love of learning; for the lover of each
of these delights in that of which he is a lover, the body being in
no way affected, but rather the mind; but men who are
concerned with such pleasures are called neither temperate nor
2601
self-indulgent. Nor, again, are those who are concerned with the
other pleasures that are not bodily; for those who are fond of
hearing and telling stories and who spend their days on
anything that turns up are called gossips, but not self-indulgent,
nor are those who are pained at the loss of money or of friends.
Temperance must be concerned with bodily pleasures, but not
all even of these; for those who delight in objects of vision, such
as colours and shapes and painting, are called neither
temperate nor self-indulgent; yet it would seem possible to
delight even in these either as one should or to excess or to a
deficient degree.
And so too is it with objects of hearing; no one calls those who
delight extravagantly in music or acting self-indulgent, nor
those who do so as they ought temperate.
Nor do we apply these names to those who delight in odour,
unless it be incidentally; we do not call those self-indulgent
who delight in the odour of apples or roses or incense, but
rather those who delight in the odour of unguents or of dainty
dishes; for self-indulgent people delight in these because these
remind them of the objects of their appetite. And one may see
even other people, when they are hungry, delighting in the
smell of food; but to delight in this kind of thing is the mark of
the self-indulgent man; for these are objects of appetite to him.
Nor is there in animals other than man any pleasure connected
with these senses, except incidentally. For dogs do not delight in
the scent of hares, but in the eating of them, but the scent told
them the hares were there; nor does the lion delight in the
lowing of the ox, but in eating it; but he perceived by the lowing
that it was near, and therefore appears to delight in the lowing;
and similarly he does not delight because he sees 'a stag or a
wild goat', but because he is going to make a meal of it.
Temperance and self-indulgence, however, are concerned with
2602
the kind of pleasures that the other animals share in, which
therefore appear slavish and brutish; these are touch and taste.
But even of taste they appear to make little or no use; for the
business of taste is the discriminating of flavours, which is done
by winetasters and people who season dishes; but they hardly
take pleasure in making these discriminations, or at least self-
indulgent people do not, but in the actual enjoyment, which in
all cases comes through touch, both in the case of food and in
that of drink and in that of sexual intercourse. This is why a
certain gourmand prayed that his throat might become longer
than a crane's, implying that it was the contact that he took
pleasure in. Thus the sense with which self-indulgence is
connected is the most widely shared of the senses; and self-
indulgence would seem to be justly a matter of reproach,
because it attaches to us not as men but as animals. To delight
in such things, then, and to love them above all others, is
brutish. For even of the pleasures of touch the most liberal have
been eliminated, e.g. those produced in the gymnasium by
rubbing and by the consequent heat; for the contact
characteristic of the self-indulgent man does not affect the
whole body but only certain parts.
11
Of the appetites some seem to be common, others to be
peculiar to individuals and acquired; e.g. the appetite for food is
natural, since every one who is without it craves for food or
drink, and sometimes for both, and for love also (as Homer says)
if he is young and lusty; but not every one craves for this or that
kind of nourishment or love, nor for the same things. Hence
such craving appears to be our very own. Yet it has of course
something natural about it; for different things are pleasant to
2603
different kinds of people, and some things are more pleasant to
every one than chance objects. Now in the natural appetites few
go wrong, and only in one direction, that of excess; for to eat or
drink whatever offers itself till one is surfeited is to exceed the
natural amount, since natural appetite is the replenishment of
one's deficiency. Hence these people are called belly-gods, this
implying that they fill their belly beyond what is right. It is
people of entirely slavish character that become like this. But
with regard to the pleasures peculiar to individuals many
people go wrong and in many ways. For while the people who
are 'fond of so and so' are so called because they delight either
in the wrong things, or more than most people do, or in the
wrong way, the self-indulgent exceed in all three ways; they
both delight in some things that they ought not to delight in
(since they are hateful), and if one ought to delight in some of
the things they delight in, they do so more than one ought and
than most men do.
Plainly, then, excess with regard to pleasures is self-indulgence
and is culpable; with regard to pains one is not, as in the case of
courage, called temperate for facing them or self-indulgent for
not doing so, but the selfindulgent man is so called because he
is pained more than he ought at not getting pleasant things
(even his pain being caused by pleasure), and the temperate
man is so called because he is not pained at the absence of
what is pleasant and at his abstinence from it.
The self-indulgent man, then, craves for all pleasant things or
those that are most pleasant, and is led by his appetite to
choose these at the cost of everything else; hence he is pained
both when he fails to get them and when he is merely craving
for them (for appetite involves pain); but it seems absurd to be
pained for the sake of pleasure. People who fall short with
regard to pleasures and delight in them less than they should
are hardly found; for such insensibility is not human. Even the
2604
other animals distinguish different kinds of food and enjoy
some and not others; and if there is any one who finds nothing
pleasant and nothing more attractive than anything else, he
must be something quite different from a man; this sort of
person has not received a name because he hardly occurs. The
temperate man occupies a middle position with regard to these
objects. For he neither enjoys the things that the self-indulgent
man enjoys most - but rather dislikes them - nor in general the
things that he should not, nor anything of this sort to excess,
nor does he feel pain or craving when they are absent, or does
so only to a moderate degree, and not more than he should, nor
when he should not, and so on; but the things that, being
pleasant, make for health or for good condition, he will desire
moderately and as he should, and also other pleasant things if
they are not hindrances to these ends, or contrary to what is
noble, or beyond his means. For he who neglects these
conditions loves such pleasures more than they are worth, but
the temperate man is not that sort of person, but the sort of
person that the right rule prescribes.
12
Self-indulgence is more like a voluntary state than cowardice.
For the former is actuated by pleasure, the latter by pain, of
which the one is to be chosen and the other to be avoided; and
pain upsets and destroys the nature of the person who feels it,
while pleasure does nothing of the sort. Therefore self-
indulgence is more voluntary. Hence also it is more a matter of
reproach; for it is easier to become accustomed to its objects,
since there are many things of this sort in life, and the process
of habituation to them is free from danger, while with terrible
objects the reverse is the case. But cowardice would seem to be
2605
voluntary in a different degree from its particular
manifestations; for it is itself painless, but in these we are upset
by pain, so that we even throw down our arms and disgrace
ourselves in other ways; hence our acts are even thought to be
done under compulsion. For the self-indulgent man, on the
other hand, the particular acts are voluntary (for he does them
with craving and desire), but the whole state is less so; for no
one craves to be self-indulgent.
The name self-indulgence is applied also to childish faults; for
they bear a certain resemblance to what we have been
considering. Which is called after which, makes no difference to
our present purpose; plainly, however, the later is called after
the earlier. The transference of the name seems not a bad one;
for that which desires what is base and which develops quickly
ought to be kept in a chastened condition, and these
characteristics belong above all to appetite and to the child,
since children in fact live at the beck and call of appetite, and it
is in them that the desire for what is pleasant is strongest. If,
then, it is not going to be obedient and subject to the ruling
principle, it will go to great lengths; for in an irrational being the
desire for pleasure is insatiable even if it tries every source of
gratification, and the exercise of appetite increases its innate
force, and if appetites are strong and violent they even expel the
power of calculation. Hence they should be moderate and few,
and should in no way oppose the rational principle - and this is
what we call an obedient and chastened state - and as the child
should live according to the direction of his tutor, so the
appetitive element should live according to rational principle.
Hence the appetitive element in a temperate man should
harmonize with the rational principle; for the noble is the mark
at which both aim, and the temperate man craves for the things
be ought, as he ought, as when he ought; and when he ought;
and this is what rational principle directs.
2606
Here we conclude our account of temperance.
Book IV
Let us speak next of liberality. It seems to be the mean with
regard to wealth; for the liberal man is praised not in respect of
military matters, nor of those in respect of which the temrate
man is praised, nor of judicial decisions, but with regard to the
giving and taking of wealth, and especially in respect of giving.
Now by 'wealth' we mean all the things whose value is
measured by money. Further, prodigality and meanness are
excesses and defects with regard to wealth; and meanness we
always impute to those who care more than they ought for
wealth, but we sometimes apply the word 'prodigality' in a
complex sense; for we call those men prodigals who are
incontinent and spend money on self-indulgence. Hence also
they are thought the poorest characters; for they combine more
vices than one. Therefore the application of the word to them is
not its proper use; for a 'prodigal' means a man who has a
single evil quality, that of wasting his substance; since a
prodigal is one who is being ruined by his own fault, and the
wasting of substance is thought to be a sort of ruining of
oneself, life being held to depend on possession of substance.
This, then, is the sense in which we take the word 'prodigality'.
Now the things that have a use may be used either well or
2607
badly; and riches is a useful thing; and everything is used best
by the man who has the virtue concerned with it; riches,
therefore, will be used best by the man who has the virtue
concerned with wealth; and this is the liberal man. Now
spending and giving seem to be the using of wealth; taking and
keeping rather the possession of it. Hence it is more the mark of
the liberal man to give to the right people than to take from the
right sources and not to take from the wrong. For it is more
characteristic of virtue to do good than to have good done to
one, and more characteristic to do what is noble than not to do
what is base; and it is not hard to see that giving implies doing
good and doing what is noble, and taking implies having good
done to one or not acting basely. And gratitude is felt towards
him who gives, not towards him who does not take, and praise
also is bestowed more on him. It is easier, also, not to take than
to give; for men are apter to give away their own too little than
to take what is another's. Givers, too, are called liberal; but those
who do not take are not praised for liberality but rather for
justice; while those who take are hardly praised at all. And the
liberal are almost the most loved of all virtuous characters,
since they are useful; and this depends on their giving.
Now virtuous actions are noble and done for the sake of the
noble. Therefore the liberal man, like other virtuous men, will
give for the sake of the noble, and rightly; for he will give to the
right people, the right amounts, and at the right time, with all
the other qualifications that accompany right giving; and that
too with pleasure or without pain; for that which is virtuous is
pleasant or free from pain - least of all will it be painful. But he
who gives to the wrong people or not for the sake of the noble
but for some other cause, will be called not liberal but by some
other name. Nor is he liberal who gives with pain; for he would
prefer the wealth to the noble act, and this is not characteristic
of a liberal man. But no more will the liberal man take from
wrong sources; for such taking is not characteristic of the man
2608
who sets no store by wealth. Nor will he be a ready asker; for it
is not characteristic of a man who confers benefits to accept
them lightly. But he will take from the right sources, e.g. from
his own possessions, not as something noble but as a necessity,
that he may have something to give. Nor will he neglect his own
property, since he wishes by means of this to help others. And
he will refrain from giving to anybody and everybody, that he
may have something to give to the right people, at the right
time, and where it is noble to do so. It is highly characteristic of
a liberal man also to go to excess in giving, so that he leaves too
little for himself; for it is the nature of a liberal man not to look
to himself. The term 'liberality' is used relatively to a man's
substance; for liberality resides not in the multitude of the gifts
but in the state of character of the giver, and this is relative to
the giver's substance. There is therefore nothing to prevent the
man who gives less from being the more liberal man, if he has
less to give those are thought to be more liberal who have not
made their wealth but inherited it; for in the first place they
have no experience of want, and secondly all men are fonder of
their own productions, as are parents and poets. It is not easy
for the liberal man to be rich, since he is not apt either at taking
or at keeping, but at giving away, and does not value wealth for
its own sake but as a means to giving. Hence comes the charge
that is brought against fortune, that those who deserve riches
most get it least. But it is not unreasonable that it should turn
out so; for he cannot have wealth, any more than anything else,
if he does not take pains to have it. Yet he will not give to the
wrong people nor at the wrong time, and so on; for he would no
longer be acting in accordance with liberality, and if he spent on
these objects he would have nothing to spend on the right
objects. For, as has been said, he is liberal who spends according
to his substance and on the right objects; and he who exceeds is
prodigal. Hence we do not call despots prodigal; for it is thought
not easy for them to give and spend beyond the amount of their
2609
possessions. Liberality, then, being a mean with regard to giving
and taking of wealth, the liberal man will both give and spend
the right amounts and on the right objects, alike in small things
and in great, and that with pleasure; he will also take the right
amounts and from the right sources. For, the virtue being a
mean with regard to both, he will do both as he ought; since
this sort of taking accompanies proper giving, and that which is
not of this sort is contrary to it, and accordingly the giving and
taking that accompany each other are present together in the
same man, while the contrary kinds evidently are not. But if he
happens to spend in a manner contrary to what is right and
noble, he will be pained, but moderately and as he ought; for it
is the mark of virtue both to be pleased and to be pained at the
right objects and in the right way. Further, the liberal man is
easy to deal with in money matters; for he can be got the better
of, since he sets no store by money, and is more annoyed if he
has not spent something that he ought than pained if he has
spent something that he ought not, and does not agree with the
saying of Simonides.
The prodigal errs in these respects also; for he is neither
pleased nor pained at the right things or in the right way; this
will be more evident as we go on. We have said that prodigality
and meanness are excesses and deficiencies, and in two things,
in giving and in taking; for we include spending under giving.
Now prodigality exceeds in giving and not taking, while
meanness falls short in giving, and exceeds in taking, except in
small things.
The characteristics of prodigality are not often combined; for it
is not easy to give to all if you take from none; private persons
soon exhaust their substance with giving, and it is to these that
the name of prodigals is applied - though a man of this sort
would seem to be in no small degree better than a mean man.
For he is easily cured both by age and by poverty, and thus he
2610
may move towards the middle state. For he has the
characteristics of the liberal man, since he both gives and
refrains from taking, though he does neither of these in the
right manner or well. Therefore if he were brought to do so by
habituation or in some other way, he would be liberal; for he
will then give to the right people, and will not take from the
wrong sources. This is why he is thought to have not a bad
character; it is not the mark of a wicked or ignoble man to go to
excess in giving and not taking, but only of a foolish one. The
man who is prodigal in this way is thought much better than
the mean man both for the aforesaid reasons and because he
benefits many while the other benefits no one, not even
himself.
But most prodigal people, as has been said, also take from the
wrong sources, and are in this respect mean. They become apt
to take because they wish to spend and cannot do this easily;
for their possessions soon run short. Thus they are forced to
provide means from some other source. At the same time,
because they care nothing for honour, they take recklessly and
from any source; for they have an appetite for giving, and they
do not mind how or from what source. Hence also their giving is
not liberal; for it is not noble, nor does it aim at nobility, nor is it
done in the right way; sometimes they make rich those who
should be poor, and will give nothing to people of respectable
character, and much to flatterers or those who provide them
with some other pleasure. Hence also most of them are self-
indulgent; for they spend lightly and waste money on their
indulgences, and incline towards pleasures because they do not
live with a view to what is noble.
The prodigal man, then, turns into what we have described if he
is left untutored, but if he is treated with care he will arrive at
the intermediate and right state. But meanness is both
incurable (for old age and every disability is thought to make
2611
men mean) and more innate in men than prodigality; for most
men are fonder of getting money than of giving. It also extends
widely, and is multiform, since there seem to be many kinds of
meanness.
For it consists in two things, deficiency in giving and excess in
taking, and is not found complete in all men but is sometimes
divided; some men go to excess in taking, others fall short in
giving. Those who are called by such names as 'miserly', 'close',
'stingy', all fall short in giving, but do not covet the possessions
of others nor wish to get them. In some this is due to a sort of
honesty and avoidance of what is disgraceful (for some seem, or
at least profess, to hoard their money for this reason, that they
may not some day be forced to do something disgraceful; to this
class belong the cheeseparer and every one of the sort; he is so
called from his excess of unwillingness to give anything); while
others again keep their hands off the property of others from
fear, on the ground that it is not easy, if one takes the property
of others oneself, to avoid having one's own taken by them; they
are therefore content neither to take nor to give.
Others again exceed in respect of taking by taking anything and
from any source, e.g. those who ply sordid trades, pimps and all
such people, and those who lend small sums and at high rates.
For all of these take more than they ought and from wrong
sources. What is common to them is evidently sordid love of
gain; they all put up with a bad name for the sake of gain, and
little gain at that. For those who make great gains but from
wrong sources, and not the right gains, e.g. despots when they
sack cities and spoil temples, we do not call mean but rather
wicked, impious, and unjust. But the gamester and the footpad
(and the highwayman) belong to the class of the mean, since
they have a sordid love of gain. For it is for gain that both of
them ply their craft and endure the disgrace of it, and the one
faces the greatest dangers for the sake of the booty, while the
2612
other makes gain from his friends, to whom he ought to be
giving. Both, then, since they are willing to make gain from
wrong sources, are sordid lovers of gain; therefore all such
forms of taking are mean.
And it is natural that meanness is described as the contrary of
liberality; for not only is it a greater evil than prodigality, but
men err more often in this direction than in the way of
prodigality as we have described it.
So much, then, for liberality and the opposed vices.
It would seem proper to discuss magnificence next. For this also
seems to be a virtue concerned with wealth; but it does not like
liberality extend to all the actions that are concerned with
wealth, but only to those that involve expenditure; and in these
it surpasses liberality in scale. For, as the name itself suggests, it
is a fitting expenditure involving largeness of scale. But the
scale is relative; for the expense of equipping a trireme is not
the same as that of heading a sacred embassy. It is what is
fitting, then, in relation to the agent, and to the circumstances
and the object. The man who in small or middling things
spends according to the merits of the case is not called
magnificent (e.g. the man who can say 'many a gift I gave the
wanderer'), but only the man who does so in great things. For
the magnificent man is liberal, but the liberal man is not
necessarily magnificent. The deficiency of this state of character
is called niggardliness, the excess vulgarity, lack of taste, and
the like, which do not go to excess in the amount spent on right
objects, but by showy expenditure in the wrong circumstances
and the wrong manner; we shall speak of these vices later.
2613
The magnificent man is like an artist; for he can see what is
fitting and spend large sums tastefully. For, as we said at the
begining, a state of character is determined by its activities and
by its objects. Now the expenses of the magnificent man are
large and fitting. Such, therefore, are also his results; for thus
there will be a great expenditure and one that is fitting to its
result. Therefore the result should be worthy of the expense,
and the expense should be worthy of the result, or should even
exceed it. And the magnificent man will spend such sums for
honour's sake; for this is common to the virtues. And further he
will do so gladly and lavishly; for nice calculation is a niggardly
thing. And he will consider how the result can be made most
beautiful and most becoming rather than for how much it can
be produced and how it can be produced most cheaply. It is
necessary, then, that the magnificent man be also liberal. For
the liberal man also will spend what he ought and as he ought;
and it is in these matters that the greatness implied in the
name of the magnificent man - his bigness, as it were - is
manifested, since liberality is concerned with these matters;
and at an equal expense he will produce a more magnificent
work of art. For a possession and a work of art have not the
same excellence. The most valuable possession is that which is
worth most, e.g. gold, but the most valuable work of art is that
which is great and beautiful (for the contemplation of such a
work inspires admiration, and so does magnificence); and a
work has an excellence - viz. magnificence - which involves
magnitude. Magnificence is an attribute of expenditures of the
kind which we call honourable, e.g. those connected with the
gods - votive offerings, buildings, and sacrifices - and similarly
with any form of religious worship, and all those that are proper
objects of public-spirited ambition, as when people think they
ought to equip a chorus or a trireme, or entertain the city, in a
brilliant way. But in all cases, as has been said, we have regard
to the agent as well and ask who he is and what means he has;
2614
for the expenditure should be worthy of his means, and suit not
only the result but also the producer. Hence a poor man cannot
be magnificent, since he has not the means with which to
spend large sums fittingly; and he who tries is a fool, since he
spends beyond what can be expected of him and what is proper,
but it is right expenditure that is virtuous. But great expenditure
is becoming to those who have suitable means to start with,
acquired by their own efforts or from ancestors or connexions,
and to people of high birth or reputation, and so on; for all these
things bring with them greatness and prestige. Primarily, then,
the magnificent man is of this sort, and magnificence is shown
in expenditures of this sort, as has been said; for these are the
greatest and most honourable. Of private occasions of
expenditure the most suitable are those that take place once for
all, e.g. a wedding or anything of the kind, or anything that
interests the whole city or the people of position in it, and also
the receiving of foreign guests and the sending of them on their
way, and gifts and counter-gifts; for the magnificent man
spends not on himself but on public objects, and gifts bear
some resemblance to votive offerings. A magnificent man will
also furnish his house suitably to his wealth (for even a house is
a sort of public ornament), and will spend by preference on
those works that are lasting (for these are the most beautiful),
and on every class of things he will spend what is becoming; for
the same things are not suitable for gods and for men, nor in a
temple and in a tomb. And since each expenditure may be great
of its kind, and what is most magnificent absolutely is great
expenditure on a great object, but what is magnificent here is
what is great in these circumstances, and greatness in the work
differs from greatness in the expense (for the most beautiful
ball or bottle is magnificent as a gift to a child, but the price of it
is small and mean), - therefore it is characteristic of the
magnificent man, whatever kind of result he is producing, to
2615
produce it magnificently (for such a result is not easily
surpassed) and to make it worthy of the expenditure.
Such, then, is the magnificent man; the man who goes to excess
and is vulgar exceeds, as has been said, by spending beyond
what is right. For on small objects of expenditure he spends
much and displays a tasteless showiness; e.g. he gives a club
dinner on the scale of a wedding banquet, and when he
provides the chorus for a comedy he brings them on to the
stage in purple, as they do at Megara. And all such things he will
do not for honour's sake but to show off his wealth, and because
he thinks he is admired for these things, and where he ought to
spend much he spends little and where little, much. The
niggardly man on the other hand will fall short in everything,
and after spending the greatest sums will spoil the beauty of
the result for a trifle, and whatever he is doing he will hesitate
and consider how he may spend least, and lament even that,
and think he is doing everything on a bigger scale than he
ought.
These states of character, then, are vices; yet they do not bring
disgrace because they are neither harmful to one's neighbour
nor very unseemly.
Pride seems even from its name to be concerned with great
things; what sort of great things, is the first question we must
try to answer. It makes no difference whether we consider the
state of character or the man characterized by it. Now the man
is thought to be proud who thinks himself worthy of great
things, being worthy of them; for he who does so beyond his
deserts is a fool, but no virtuous man is foolish or silly. The
2616
proud man, then, is the man we have described. For he who is
worthy of little and thinks himself worthy of little is temperate,
but not proud; for pride implies greatness, as beauty implies a
goodsized body, and little people may be neat and well-
proportioned but cannot be beautiful. On the other hand, he
who thinks himself worthy of great things, being unworthy of
them, is vain; though not every one who thinks himself worthy
of more than he really is worthy of in vain. The man who thinks
himself worthy of worthy of less than he is really worthy of is
unduly humble, whether his deserts be great or moderate, or his
deserts be small but his claims yet smaller. And the man whose
deserts are great would seem most unduly humble; for what
would he have done if they had been less? The proud man, then,
is an extreme in respect of the greatness of his claims, but a
mean in respect of the Tightness of them; for he claims what is
accordance with his merits, while the others go to excess or fall
short.
If, then, he deserves and claims great things, and above all the
great things, he will be concerned with one thing in particular.
Desert is relative to external goods; and the greatest of these,
we should say, is that which we render to the gods, and which
people of position most aim at, and which is the prize
appointed for the noblest deeds; and this is honour; that is
surely the greatest of external goods. Honours and dishonours,
therefore, are the objects with respect to which the proud man
is as he should be. And even apart from argument it is with
honour that proud men appear to be concerned; for it is honour
that they chiefly claim, but in accordance with their deserts.
The unduly humble man falls short both in comparison with his
own merits and in comparison with the proud man's claims.
The vain man goes to excess in comparison with his own
merits, but does not exceed the proud man's claims.
2617
Now the proud man, since he deserves most, must be good in
the highest degree; for the better man always deserves more,
and the best man most. Therefore the truly proud man must be
good. And greatness in every virtue would seem to be
characteristic of a proud man. And it would be most
unbecoming for a proud man to fly from danger, swinging his
arms by his sides, or to wrong another; for to what end should
he do disgraceful acts, he to whom nothing is great? If we
consider him point by point we shall see the utter absurdity of a
proud man who is not good. Nor, again, would he be worthy of
honour if he were bad; for honour is the prize of virtue, and it is
to the good that it is rendered. Pride, then, seems to be a sort of
crown of the virtues; for it makes them greater, and it is not
found without them. Therefore it is hard to be truly proud; for it
is impossible without nobility and goodness of character. It is
chiefly with honours and dishonours, then, that the proud man
is concerned; and at honours that are great and conferred by
good men he will be moderately Pleased, thinking that he is
coming by his own or even less than his own; for there can be
no honour that is worthy of perfect virtue, yet he will at any rate
accept it since they have nothing greater to bestow on him; but
honour from casual people and on trifling grounds he will
utterly despise, since it is not this that he deserves, and
dishonour too, since in his case it cannot be just. In the first
place, then, as has been said, the proud man is concerned with
honours; yet he will also bear himself with moderation towards
wealth and power and all good or evil fortune, whatever may
befall him, and will be neither over-joyed by good fortune nor
over-pained by evil. For not even towards honour does he bear
himself as if it were a very great thing. Power and wealth are
desirable for the sake of honour (at least those who have them
wish to get honour by means of them); and for him to whom
even honour is a little thing the others must be so too. Hence
proud men are thought to be disdainful.
2618
The goods of fortune also are thought to contribute towards
pride. For men who are well-born are thought worthy of honour,
and so are those who enjoy power or wealth; for they are in a
superior position, and everything that has a superiority in
something good is held in greater honour. Hence even such
things make men prouder; for they are honoured by some for
having them; but in truth the good man alone is to be
honoured; he, however, who has both advantages is thought the
more worthy of honour. But those who without virtue have such
goods are neither justified in making great claims nor entitled
to the name of 'proud'; for these things imply perfect virtue.
Disdainful and insolent, however, even those who have such
goods become. For without virtue it is not easy to bear
gracefully the goods of fortune; and, being unable to bear them,
and thinking themselves superior to others, they despise others
and themselves do what they please. They imitate the proud
man without being like him, and this they do where they can;
so they do not act virtuously, but they do despise others. For the
proud man despises justly (since he thinks truly), but the many
do so at random.
He does not run into trifling dangers, nor is he fond of danger,
because he honours few things; but he will face great dangers,
and when he is in danger he is unsparing of his life, knowing
that there are conditions on which life is not worth having. And
he is the sort of man to confer benefits, but he is ashamed of
receiving them; for the one is the mark of a superior, the other
of an inferior. And he is apt to confer greater benefits in return;
for thus the original benefactor besides being paid will incur a
debt to him, and will be the gainer by the transaction. They
seem also to remember any service they have done, but not
those they have received (for he who receives a service is
inferior to him who has done it, but the proud man wishes to be
superior), and to hear of the former with pleasure, of the latter
with displeasure; this, it seems, is why Thetis did not mention
2619
to Zeus the services she had done him, and why the Spartans
did not recount their services to the Athenians, but those they
had received. It is a mark of the proud man also to ask for
nothing or scarcely anything, but to give help readily, and to be
dignified towards people who enjoy high position and good
fortune, but unassuming towards those of the middle class; for
it is a difficult and lofty thing to be superior to the former, but
easy to be so to the latter, and a lofty bearing over the former is
no mark of ill-breeding, but among humble people it is as vulgar
as a display of strength against the weak. Again, it is
characteristic of the proud man not to aim at the things
commonly held in honour, or the things in which others excel;
to be sluggish and to hold back except where great honour or a
great work is at stake, and to be a man of few deeds, but of great
and notable ones. He must also be open in his hate and in his
love (for to conceal one's feelings, i.e. to care less for truth than
for what people will think, is a coward's part), and must speak
and act openly; for he is free of speech because he is
contemptuous, and he is given to telling the truth, except when
he speaks in irony to the vulgar. He must be unable to make his
life revolve round another, unless it be a friend; for this is
slavish, and for this reason all flatterers are servile and people
lacking in self-respect are flatterers. Nor is he given to
admiration; for nothing to him is great. Nor is he mindful of
wrongs; for it is not the part of a proud man to have a long
memory, especially for wrongs, but rather to overlook them. Nor
is he a gossip; for he will speak neither about himself nor about
another, since he cares not to be praised nor for others to be
blamed; nor again is he given to praise; and for the same reason
he is not an evil-speaker, even about his enemies, except from
haughtiness. With regard to necessary or small matters he is
least of all me given to lamentation or the asking of favours; for
it is the part of one who takes such matters seriously to behave
so with respect to them. He is one who will possess beautiful
2620
and profitless things rather than profitable and useful ones; for
this is more proper to a character that suffices to itself.
Further, a slow step is thought proper to the proud man, a deep
voice, and a level utterance; for the man who takes few things
seriously is not likely to be hurried, nor the man who thinks
nothing great to be excited, while a shrill voice and a rapid gait
are the results of hurry and excitement.
Such, then, is the proud man; the man who falls short of him is
unduly humble, and the man who goes beyond him is vain. Now
even these are not thought to be bad (for they are not
malicious), but only mistaken. For the unduly humble man,
being worthy of good things, robs himself of what he deserves,
and to have something bad about him from the fact that he
does not think himself worthy of good things, and seems also
not to know himself; else he would have desired the things he
was worthy of, since these were good. Yet such people are not
thought to be fools, but rather unduly retiring. Such a
reputation, however, seems actually to make them worse; for
each class of people aims at what corresponds to its worth, and
these people stand back even from noble actions and
undertakings, deeming themselves unworthy, and from external
goods no less. Vain people, on the other hand, are fools and
ignorant of themselves, and that manifestly; for, not being
worthy of them, they attempt honourable undertakings, and
then are found out; and tetadorn themselves with clothing and
outward show and such things, and wish their strokes of good
fortune to be made public, and speak about them as if they
would be honoured for them. But undue humility is more
opposed to pride than vanity is; for it is both commoner and
worse.
Pride, then, is concerned with honour on the grand scale, as has
been said.
2621
There seems to be in the sphere of honour also, as was said in
our first remarks on the subject, a virtue which would appear to
be related to pride as liberality is to magnificence. For neither of
these has anything to do with the grand scale, but both dispose
us as is right with regard to middling and unimportant objects;
as in getting and giving of wealth there is a mean and an excess
and defect, so too honour may be desired more than is right, or
less, or from the right sources and in the right way. We blame
both the ambitious man as am at honour more than is right and
from wrong sources, and the unambitious man as not willing to
be honoured even for noble reasons. But sometimes we praise
the ambitious man as being manly and a lover of what is noble,
and the unambitious man as being moderate and self-
controlled, as we said in our first treatment of the subject.
Evidently, since 'fond of such and such an object' has more than
one meaning, we do not assign the term 'ambition' or 'love of
honour' always to the same thing, but when we praise the
quality we think of the man who loves honour more than most
people, and when we blame it we think of him who loves it
more than is right. The mean being without a name, the
extremes seem to dispute for its place as though that were
vacant by default. But where there is excess and defect, there is
also an intermediate; now men desire honour both more than
they should and less; therefore it is possible also to do so as one
should; at all events this is the state of character that is praised,
being an unnamed mean in respect of honour. Relatively to
ambition it seems to be unambitiousness, and relatively to
unambitiousness it seems to be ambition, while relatively to
both severally it seems in a sense to be both together. This
2622
appears to be true of the other virtues also. But in this case the
extremes seem to be contradictories because the mean has not
received a name.
Good temper is a mean with respect to anger; the middle state
being unnamed, and the extremes almost without a name as
well, we place good temper in the middle position, though it
inclines towards the deficiency, which is without a name. The
excess might called a sort of 'irascibility'. For the passion is
anger, while its causes are many and diverse.
The man who is angry at the right things and with the right
people, and, further, as he ought, when he ought, and as long as
he ought, is praised. This will be the good-tempered man, then,
since good temper is praised. For the good-tempered man tends
to be unperturbed and not to be led by passion, but to be angry
in the manner, at the things, and for the length of time, that the
rule dictates; but he is thought to err rather in the direction of
deficiency; for the good-tempered man is not revengeful, but
rather tends to make allowances.
The deficiency, whether it is a sort of 'inirascibility' or whatever
it is, is blamed. For those who are not angry at the things they
should be angry at are thought to be fools, and so are those who
are not angry in the right way, at the right time, or with the right
persons; for such a man is thought not to feel things nor to be
pained by them, and, since he does not get angry, he is thought
unlikely to defend himself; and to endure being insulted and
put up with insult to one's friends is slavish.
2623
The excess can be manifested in all the points that have been
named (for one can be angry with the wrong persons, at the
wrong things, more than is right, too quickly, or too long); yet all
are not found in the same person. Indeed they could not; for evil
destroys even itself, and if it is complete becomes unbearable.
Now hot-tempered people get angry quickly and with the wrong
persons and at the wrong things and more than is right, but
their anger ceases quickly - which is the best point about them.
This happens to them because they do not restrain their anger
but retaliate openly owing to their quickness of temper, and
then their anger ceases. By reason of excess choleric people are
quick-tempered and ready to be angry with everything and on
every occasion; whence their name. Sulky people are hard to
appease, and retain their anger long; for they repress their
passion. But it ceases when they retaliate; for revenge relieves
them of their anger, producing in them pleasure instead of pain.
If this does not happen they retain their burden; for owing to its
not being obvious no one even reasons with them, and to digest
one's anger in oneself takes time. Such people are most
troublesome to themselves and to their dearest friends. We call
bad-tempered those who are angry at the wrong things, more
than is right, and longer, and cannot be appeased until they
inflict vengeance or punishment.
To good temper we oppose the excess rather than the defect; for
not only is it commoner since revenge is the more human), but
bad-tempered people are worse to live with.
What we have said in our earlier treatment of the subject is
plain also from what we are now saying; viz. that it is not easy
to define how, with whom, at what, and how long one should be
angry, and at what point right action ceases and wrong begins.
For the man who strays a little from the path, either towards the
more or towards the less, is not blamed; since sometimes we
praise those who exhibit the deficiency, and call them good-
2624
tempered, and sometimes we call angry people manly, as being
capable of ruling. How far, therefore, and how a man must stray
before he becomes blameworthy, it is not easy to state in words;
for the decision depends on the particular facts and on
perception. But so much at least is plain, that the middle state is
praiseworthy - that in virtue of which we are angry with the
right people, at the right things, in the right way, and so on,
while the excesses and defects are blameworthy - slightly so if
they are present in a low degree, more if in a higher degree, and
very much if in a high degree. Evidently, then, we must cling to
the middle state. - Enough of the states relative to anger.
In gatherings of men, in social life and the interchange of words
and deeds, some men are thought to be obsequious, viz. those
who to give pleasure praise everything and never oppose, but
think it their duty 'to give no pain to the people they meet';
while those who, on the contrary, oppose everything and care
not a whit about giving pain are called churlish and
contentious. That the states we have named are culpable is
plain enough, and that the middle state is laudable - that in
virtue of which a man will put up with, and will resent, the right
things and in the right way; but no name has been assigned to
it, though it most resembles friendship. For the man who
corresponds to this middle state is very much what, with
affection added, we call a good friend. But the state in question
differs from friendship in that it implies no passion or affection
for one's associates; since it is not by reason of loving or hating
that such a man takes everything in the right way, but by being
a man of a certain kind. For he will behave so alike towards
those he knows and those he does not know, towards intimates
2625
and those who are not so, except that in each of these cases he
will behave as is befitting; for it is not proper to have the same
care for intimates and for strangers, nor again is it the same
conditions that make it right to give pain to them. Now we have
said generally that he will associate with people in the right
way; but it is by reference to what is honourable and expedient
that he will aim at not giving pain or at contributing pleasure.
For he seems to be concerned with the pleasures and pains of
social life; and wherever it is not honourable, or is harmful, for
him to contribute pleasure, he will refuse, and will choose
rather to give pain; also if his acquiescence in another's action
would bring disgrace, and that in a high degree, or injury, on
that other, while his opposition brings a little pain, he will not
acquiesce but will decline. He will associate differently with
people in high station and with ordinary people, with closer and
more distant acquaintances, and so too with regard to all other
differences, rendering to each class what is befitting, and while
for its own sake he chooses to contribute pleasure, and avoids
the giving of pain, he will be guided by the consequences, if
these are greater, i.e. honour and expediency. For the sake of a
great future pleasure, too, he will inflict small pains.
The man who attains the mean, then, is such as we have
described, but has not received a name; of those who contribute
pleasure, the man who aims at being pleasant with no ulterior
object is obsequious, but the man who does so in order that he
may get some advantage in the direction of money or the things
that money buys is a flatterer; while the man who quarrels with
everything is, as has been said, churlish and contentious. And
the extremes seem to be contradictory to each other because
the mean is without a name.
2626
The mean opposed to boastfulness is found in almost the same
sphere; and this also is without a name. It will be no bad plan to
describe these states as well; for we shall both know the facts
about character better if we go through them in detail, and we
shall be convinced that the virtues are means if we see this to
be so in all cases. In the field of social life those who make the
giving of pleasure or pain their object in associating with others
have been described; let us now describe those who pursue
truth or falsehood alike in words and deeds and in the claims
they put forward. The boastful man, then, is thought to be apt to
claim the things that bring glory, when he has not got them, or
to claim more of them than he has, and the mock-modest man
on the other hand to disclaim what he has or belittle it, while
the man who observes the mean is one who calls a thing by its
own name, being truthful both in life and in word, owning to
what he has, and neither more nor less. Now each of these
courses may be adopted either with or without an object. But
each man speaks and acts and lives in accordance with his
character, if he is not acting for some ulterior object. And
falsehood is in itself mean and culpable, and truth noble and
worthy of praise. Thus the truthful man is another case of a
man who, being in the mean, is worthy of praise, and both
forms of untruthful man are culpable, and particularly the
boastful man.
Let us discuss them both, but first of all the truthful man. We
are not speaking of the man who keeps faith in his agreements,
i.e. in the things that pertain to justice or injustice (for this
would belong to another virtue), but the man who in the
matters in which nothing of this sort is at stake is true both in
word and in life because his character is such. But such a man
would seem to be as a matter of fact equitable. For the man who
loves truth, and is truthful where nothing is at stake, will still
2627
more be truthful where something is at stake; he will avoid
falsehood as something base, seeing that he avoided it even for
its own sake; and such a man is worthy of praise. He inclines
rather to understate the truth; for this seems in better taste
because exaggerations are wearisome.
He who claims more than he has with no ulterior object is a
contemptible sort of fellow (otherwise he would not have
delighted in falsehood), but seems futile rather than bad; but if
he does it for an object, he who does it for the sake of
reputation or honour is (for a boaster) not very much to be
blamed, but he who does it for money, or the things that lead to
money, is an uglier character (it is not the capacity that makes
the boaster, but the purpose; for it is in virtue of his state of
character and by being a man of a certain kind that he is
boaster); as one man is a liar because he enjoys the lie itself,
and another because he desires reputation or gain. Now those
who boast for the sake of reputation claim such qualities as will
praise or congratulation, but those whose object is gain claim
qualities which are of value to one's neighbours and one's lack
of which is not easily detected, e.g. the powers of a seer, a sage,
or a physician. For this reason it is such things as these that
most people claim and boast about; for in them the above-
mentioned qualities are found.
Mock-modest people, who understate things, seem more
attractive in character; for they are thought to speak not for
gain but to avoid parade; and here too it is qualities which bring
reputation that they disclaim, as Socrates used to do. Those who
disclaim trifling and obvious qualities are called humbugs and
are more contemptible; and sometimes this seems to be
boastfulness, like the Spartan dress; for both excess and great
deficiency are boastful. But those who use understatement with
moderation and understate about matters that do not very
much force themselves on our notice seem attractive. And it is
2628
the boaster that seems to be opposed to the truthful man; for he
is the worse character.
8
Since life includes rest as well as activity, and in this is included
leisure and amusement, there seems here also to be a kind of
intercourse which is tasteful; there is such a thing as saying -
and again listening to - what one should and as one should. The
kind of people one is speaking or listening to will also make a
difference. Evidently here also there is both an excess and a
deficiency as compared with the mean. Those who carry
humour to excess are thought to be vulgar buffoons, striving
after humour at all costs, and aiming rather at raising a laugh
than at saying what is becoming and at avoiding pain to the
object of their fun; while those who can neither make a joke
themselves nor put up with those who do are thought to be
boorish and unpolished. But those who joke in a tasteful way
are called ready-witted, which implies a sort of readiness to
turn this way and that; for such sallies are thought to be
movements of the character, and as bodies are discriminated by
their movements, so too are characters. The ridiculous side of
things is not far to seek, however, and most people delight more
than they should in amusement and in jestinly. and so even
buffoons are called ready-witted because they are found
attractive; but that they differ from the ready-witted man, and
to no small extent, is clear from what has been said.
To the middle state belongs also tact; it is the mark of a tactful
man to say and listen to such things as befit a good and well-
bred man; for there are some things that it befits such a man to
say and to hear by way of jest, and the well-bred man's jesting
2629
differs from that of a vulgar man, and the joking of an educated
man from that of an uneducated. One may see this even from
the old and the new comedies; to the authors of the former
indecency of language was amusing, to those of the latter
innuendo is more so; and these differ in no small degree in
respect of propriety. Now should we define the man who jokes
well by his saying what is not unbecoming to a well-bred man,
or by his not giving pain, or even giving delight, to the hearer?
Or is the latter definition, at any rate, itself indefinite, since
different things are hateful or pleasant to different people? The
kind of jokes he will listen to will be the same; for the kind he
can put up with are also the kind he seems to make. There are,
then, jokes he will not make; for the jest is a sort of abuse, and
there are things that lawgivers forbid us to abuse; and they
should, perhaps, have forbidden us even to make a jest of such.
The refined and well-bred man, therefore, will be as we have
described, being as it were a law to himself.
Such, then, is the man who observes the mean, whether he be
called tactful or ready-witted. The buffoon, on the other hand, is
the slave of his sense of humour, and spares neither himself nor
others if he can raise a laugh, and says things none of which a
man of refinement would say, and to some of which he would
not even listen. The boor, again, is useless for such social
intercourse; for he contributes nothing and finds fault with
everything. But relaxation and amusement are thought to be a
necessary element in life.
The means in life that have been described, then, are three in
number, and are all concerned with an interchange of words
and deeds of some kind. They differ, however, in that one is
concerned with truth; and the other two with pleasantness. Of
those concerned with pleasure, one is displayed in jests, the
other in the general social intercourse of life.
2630
Shame should not be described as a virtue; for it is more like a
feeling than a state of character. It is defined, at any rate, as a
kind of fear of dishonour, and produces an effect similar to that
produced by fear of danger; for people who feel disgraced blush,
and those who fear death turn pale. Both, therefore, seem to be
in a sense bodily conditions, which is thought to be
characteristic of feeling rather than of a state of character.
The feeling is not becoming to every age, but only to youth. For
we think young people should be prone to the feeling of shame
because they live by feeling and therefore commit many errors,
but are restrained by shame; and we praise young people who
are prone to this feeling, but an older person no one would
praise for being prone to the sense of disgrace, since we think
he should not do anything that need cause this sense. For the
sense of disgrace is not even characteristic of a good man, since
it is consequent on bad actions (for such actions should not be
done; and if some actions are disgraceful in very truth and
others only according to common opinion, this makes no
difference; for neither class of actions should be done, so that
no disgrace should be felt); and it is a mark of a bad man even
to be such as to do any disgraceful action. To be so constituted
as to feel disgraced if one does such an action, and for this
reason to think oneself good, is absurd; for it is for voluntary
actions that shame is felt, and the good man will never
voluntarily do bad actions. But shame may be said to be
conditionally a good thing; if a good man does such actions, he
will feel disgraced; but the virtues are not subject to such a
qualification. And if shamelessness - not to be ashamed of
doing base actions - is bad, that does not make it good to be
2631
ashamed of doing such actions. Continence too is not virtue, but
a mixed sort of state; this will be shown later. Now, however, let
us discuss justice.
BookV
With regards to justice and injustice we must (1) consider what
kind of actions they are concerned with, (2) what sort of mean
justice is, and (3) between what extremes the just act is
intermediate. Our investigation shall follow the same course as
the preceding discussions.
We see that all men mean by justice that kind of state of
character which makes people disposed to do what is just and
makes them act justly and wish for what is just; and similarly
by injustice that state which makes them act unjustly and wish
for what is unjust. Let us too, then, lay this down as a general
basis. For the same is not true of the sciences and the faculties
as of states of character. A faculty or a science which is one and
the same is held to relate to contrary objects, but a state of
character which is one of two contraries does not produce the
contrary results; e.g. as a result of health we do not do what is
the opposite of healthy, but only what is healthy; for we say a
man walks healthily, when he walks as a healthy man would.
2632
Now often one contrary state is recognized from its contrary,
and often states are recognized from the subjects that exhibit
them; for (A) if good condition is known, bad condition also
becomes known, and (B) good condition is known from the
things that are in good condition, and they from it. If good
condition is firmness of flesh, it is necessary both that bad
condition should be flabbiness of flesh and that the wholesome
should be that which causes firmness in flesh. And it follows for
the most part that if one contrary is ambiguous the other also
will be ambiguous; e.g. if 'just' is so, that 'unjust' will be so too.
Now 'justice' and 'injustice' seem to be ambiguous, but because
their different meanings approach near to one another the
ambiguity escapes notice and is not obvious as it is,
comparatively, when the meanings are far apart, e.g. (for here
the difference in outward form is great) as the ambiguity in the
use of kleis for the collar-bone of an animal and for that with
which we lock a door. Let us take as a starting-point, then, the
various meanings of 'an unjust man'. Both the lawless man and
the grasping and unfair man are thought to be unjust, so that
evidently both the law-abiding and the fair man will be just. The
just, then, is the lawful and the fair, the unjust the unlawful and
the unfair.
Since the unjust man is grasping, he must be concerned with
goods - not all goods, but those with which prosperity and
adversity have to do, which taken absolutely are always good,
but for a particular person are not always good. Now men pray
for and pursue these things; but they should not, but should
pray that the things that are good absolutely may also be good
for them, and should choose the things that are good for them.
The unjust man does not always choose the greater, but also the
less - in the case of things bad absolutely; but because the
lesser evil is itself thought to be in a sense good, and
graspingness is directed at the good, therefore he is thought to
2633
be grasping. And he is unfair; for this contains and is common
to both.
Since the lawless man was seen to be unjust and the law-
abiding man just, evidently all lawful acts are in a sense just
acts; for the acts laid down by the legislative art are lawful, and
each of these, we say, is just. Now the laws in their enactments
on all subjects aim at the common advantage either of all or of
the best or of those who hold power, or something of the sort;
so that in one sense we call those acts just that tend to produce
and preserve happiness and its components for the political
society. And the law bids us do both the acts of a brave man (e.g.
not to desert our post nor take to flight nor throw away our
arms), and those of a temperate man (e.g. not to commit
adultery nor to gratify one's lust), and those of a good-tempered
man (e.g. not to strike another nor to speak evil), and similarly
with regard to the other virtues and forms of wickedness,
commanding some acts and forbidding others; and the rightly-
framed law does this rightly, and the hastily conceived one less
well. This form of justice, then, is complete virtue, but not
absolutely, but in relation to our neighbour. And therefore
justice is often thought to be the greatest of virtues, and
'neither evening nor morning star' is so wonderful; and
proverbially 'in justice is every virtue comprehended'. And it is
complete virtue in its fullest sense, because it is the actual
exercise of complete virtue. It is complete because he who
possesses it can exercise his virtue not only in himself but
towards his neighbour also; for many men can exercise virtue in
their own affairs, but not in their relations to their neighbour.
This is why the saying of Bias is thought to be true, that 'rule
will show the man'; for a ruler is necessarily in relation to other
men and a member of a society. For this same reason justice,
alone of the virtues, is thought to be 'another's good', because it
is related to our neighbour; for it does what is advantageous to
another, either a ruler or a copartner. Now the worst man is he
2634
who exercises his wickedness both towards himself and
towards his friends, and the best man is not he who exercises
his virtue towards himself but he who exercises it towards
another; for this is a difficult task. Justice in this sense, then, is
not part of virtue but virtue entire, nor is the contrary injustice
a part of vice but vice entire. What the difference is between
virtue and justice in this sense is plain from what we have said;
they are the same but their essence is not the same; what, as a
relation to one's neighbour, is justice is, as a certain kind of
state without qualification, virtue.
But at all events what we are investigating is the justice which
is a part of virtue; for there is a justice of this kind, as we
maintain. Similarly it is with injustice in the particular sense
that we are concerned.
That there is such a thing is indicated by the fact that while the
man who exhibits in action the other forms of wickedness acts
wrongly indeed, but not graspingly (e.g. the man who throws
away his shield through cowardice or speaks harshly through
bad temper or fails to help a friend with money through
meanness), when a man acts graspingly he often exhibits none
of these vices, - no, nor all together, but certainly wickedness of
some kind (for we blame him) and injustice. There is, then,
another kind of injustice which is a part of injustice in the wide
sense, and a use of the word 'unjust' which answers to a part of
what is unjust in the wide sense of 'contrary to the law'. Again if
one man commits adultery for the sake of gain and makes
money by it, while another does so at the bidding of appetite
though he loses money and is penalized for it, the latter would
2635
be held to be self-indulgent rather than grasping, but the former
is unjust, but not self-indulgent; evidently, therefore, he is
unjust by reason of his making gain by his act. Again, all other
unjust acts are ascribed invariably to some particular kind of
wickedness, e.g. adultery to self-indulgence, the desertion of a
comrade in battle to cowardice, physical violence to anger; but if
a man makes gain, his action is ascribed to no form of
wickedness but injustice. Evidently, therefore, there is apart
from injustice in the wide sense another, 'particular', injustice
which shares the name and nature of the first, because its
definition falls within the same genus; for the significance of
both consists in a relation to one's neighbour, but the one is
concerned with honour or money or safety - or that which
includes all these, if we had a single name for it - and its motive
is the pleasure that arises from gain; while the other is
concerned with all the objects with which the good man is
concerned.
It is clear, then, that there is more than one kind of justice, and
that there is one which is distinct from virtue entire; we must
try to grasp its genus and differentia.
The unjust has been divided into the unlawful and the unfair,
and the just into the lawful and the fair. To the unlawful
answers the afore-mentioned sense of injustice. But since
unfair and the unlawful are not the same, but are different as a
part is from its whole (for all that is unfair is unlawful, but not
all that is unlawful is unfair), the unjust and injustice in the
sense of the unfair are not the same as but different from the
former kind, as part from whole; for injustice in this sense is a
part of injustice in the wide sense, and similarly justice in the
one sense of justice in the other. Therefore we must speak also
about particular justice and particular and similarly about the
just and the unjust. The justice, then, which answers to the
whole of virtue, and the corresponding injustice, one being the
2636
exercise of virtue as a whole, and the other that of vice as a
whole, towards one's neighbour, we may leave on one side. And
how the meanings of 'just' and 'unjust' which answer to these
are to be distinguished is evident; for practically the majority of
the acts commanded by the law are those which are prescribed
from the point of view of virtue taken as a whole; for the law
bids us practise every virtue and forbids us to practise any vice.
And the things that tend to produce virtue taken as a whole are
those of the acts prescribed by the law which have been
prescribed with a view to education for the common good. But
with regard to the education of the individual as such, which
makes him without qualification a good man, we must
determine later whether this is the function of the political art
or of another; for perhaps it is not the same to be a good man
and a good citizen of any state taken at random.
Of particular justice and that which is just in the corresponding
sense, (A) one kind is that which is manifested in distributions
of honour or money or the other things that fall to be divided
among those who have a share in the constitution (for in these
it is possible for one man to have a share either unequal or
equal to that of another), and (B) one is that which plays a
rectifying part in transactions between man and man. Of this
there are two divisions; of transactions (1) some are voluntary
and (2) others involuntary - voluntary such transactions as sale,
purchase, loan for consumption, pledging, loan for use,
depositing, letting (they are called voluntary because the origin
of these transactions is voluntary), while of the involuntary (a)
some are clandestine, such as theft, adultery, poisoning,
procuring, enticement of slaves, assassination, false witness,
and (b) others are violent, such as assault, imprisonment,
murder, robbery with violence, mutilation, abuse, insult.
2637
(A) We have shown that both the unjust man and the unjust act
are unfair or unequal; now it is clear that there is also an
intermediate between the two unequals involved in either case.
And this is the equal; for in any kind of action in which there's a
more and a less there is also what is equal. If, then, the unjust is
unequal, just is equal, as all men suppose it to be, even apart
from argument. And since the equal is intermediate, the just
will be an intermediate. Now equality implies at least two
things. The just, then, must be both intermediate and equal and
relative (i.e. for certain persons). And since the equall
intermediate it must be between certain things (which are
respectively greater and less); equal, it involves two things; qua
just, it is for certain people. The just, therefore, involves at least
four terms; for the persons for whom it is in fact just are two,
and the things in which it is manifested, the objects distributed,
are two. And the same equality will exist between the persons
and between the things concerned; for as the latter the things
concerned are related, so are the former; if they are not equal,
they will not have what is equal, but this is the origin of
quarrels and complaints - when either equals have and are
awarded unequal shares, or unequals equal shares. Further, this
is plain from the fact that awards should be 'according to merit';
for all men agree that what is just in distribution must be
according to merit in some sense, though they do not all specify
the same sort of merit, but democrats identify it with the status
of freeman, supporters of oligarchy with wealth (or with noble
birth), and supporters of aristocracy with excellence.
The just, then, is a species of the proportionate (proportion
being not a property only of the kind of number which consists
of abstract units, but of number in general). For proportion is
2638
equality of ratios, and involves four terms at least (that discrete
proportion involves four terms is plain, but so does continuous
proportion, for it uses one term as two and mentions it twice;
e.g. 'as the line A is to the line B, so is the line B to the line C;
the line B, then, has been mentioned twice, so that if the line B
be assumed twice, the proportional terms will be four); and the
just, too, involves at least four terms, and the ratio between one
pair is the same as that between the other pair; for there is a
similar distinction between the persons and between the
things. As the term A, then, is to B, so will C be to D, and
therefore, alternando, as A is to C, B will be to D. Therefore also
the whole is in the same ratio to the whole; and this coupling
the distribution effects, and, if the terms are so combined,
effects justly. The conjunction, then, of the term A with C and of
B with D is what is just in distribution, and this species of the
just is intermediate, and the unjust is what violates the
proportion; for the proportional is intermediate, and the just is
proportional. (Mathematicians call this kind of proportion
geometrical; for it is in geometrical proportion that it follows
that the whole is to the whole as either part is to the
corresponding part.) This proportion is not continuous; for we
cannot get a single term standing for a person and a thing.
This, then, is what the just is - the proportional; the unjust is
what violates the proportion. Hence one term becomes too
great, the other too small, as indeed happens in practice; for the
man who acts unjustly has too much, and the man who is
unjustly treated too little, of what is good. In the case of evil the
reverse is true; for the lesser evil is reckoned a good in
comparison with the greater evil, since the lesser evil is rather
to be chosen than the greater, and what is worthy of choice is
good, and what is worthier of choice a greater good.
This, then, is one species of the just.
2639
(B) The remaining one is the rectificatory, which arises in
connexion with transactions both voluntary and involuntary.
This form of the just has a different specific character from the
former. For the justice which distributes common possessions is
always in accordance with the kind of proportion mentioned
above (for in the case also in which the distribution is made
from the common funds of a partnership it will be according to
the same ratio which the funds put into the business by the
partners bear to one another); and the injustice opposed to this
kind of justice is that which violates the proportion. But the
justice in transactions between man and man is a sort of
equality indeed, and the injustice a sort of inequality; not
according to that kind of proportion, however, but according to
arithmetical proportion. For it makes no difference whether a
good man has defrauded a bad man or a bad man a good one,
nor whether it is a good or a bad man that has committed
adultery; the law looks only to the distinctive character of the
injury, and treats the parties as equal, if one is in the wrong and
the other is being wronged, and if one inflicted injury and the
other has received it. Therefore, this kind of injustice being an
inequality, the judge tries to equalize it; for in the case also in
which one has received and the other has inflicted a wound, or
one has slain and the other been slain, the suffering and the
action have been unequally distributed; but the judge tries to
equalize by means of the penalty, taking away from the gain of
the assailant. For the term 'gain' is applied generally to such
cases, even if it be not a term appropriate to certain cases, e.g. to
the person who inflicts a woundand 'loss' to the sufferer; at all
events when the suffering has been estimated, the one is called
2640
loss and the other gain. Therefore the equal is intermediate
between the greater and the less, but the gain and the loss are
respectively greater and less in contrary ways; more of the good
and less of the evil are gain, and the contrary is loss;
intermediate between them is, as we saw, equal, which we say
is just; therefore corrective justice will be the intermediate
between loss and gain. This is why, when people dispute, they
take refuge in the judge; and to go to the judge is to go to
justice; for the nature of the judge is to be a sort of animate
justice; and they seek the judge as an intermediate, and in some
states they call judges mediators, on the assumption that if they
get what is intermediate they will get what is just. The just,
then, is an intermediate, since the judge is so. Now the judge
restores equality; it is as though there were a line divided into
unequal parts, and he took away that by which the greater
segment exceeds the half, and added it to the smaller segment.
And when the whole has been equally divided, then they say
they have 'their own' - i.e. when they have got what is equal.
The equal is intermediate between the greater and the lesser
line according to arithmetical proportion. It is for this reason
also that it is called just (sikaion), because it is a division into
two equal parts (sicha), just as if one were to call it sichaion;
and the judge (sikastes) is one who bisects (sichastes). For when
something is subtracted from one of two equals and added to
the other, the other is in excess by these two; since if what was
taken from the one had not been added to the other, the latter
would have been in excess by one only. It therefore exceeds the
intermediate by one, and the intermediate exceeds by one that
from which something was taken. By this, then, we shall
recognize both what we must subtract from that which has
more, and what we must add to that which has less; we must
add to the latter that by which the intermediate exceeds it, and
subtract from the greatest that by which it exceeds the
intermediate. Let the lines AA', BB', CC be equal to one another;
2641
from the line AA' let the segment AE have been subtracted, and
to the line CC let the segment CD have been added, so that the
whole line DCC exceeds the line EA' by the segment CD and the
segment CF; therefore it exceeds the line BB' by the segment CD.
(See diagram.)
These names, both loss and gain, have come from voluntary
exchange; for to have more than one's own is called gaining,
and to have less than one's original share is called losing, e.g. in
buying and selling and in all other matters in which the law has
left people free to make their own terms; but when they get
neither more nor less but just what belongs to themselves, they
say that they have their own and that they neither lose nor
gain.
Therefore the just is intermediate between a sort of gain and a
sort of loss, viz. those which are involuntary; it consists in
having an equal amount before and after the transaction.
Some think that reciprocity is without qualification just, as the
Pythagoreans said; for they defined justice without qualification
as reciprocity. Now 'reciprocity' fits neither distributive nor
rectificatory justice - yet people want even the justice of
Rhadamanthus to mean this:
Should a man suffer what he did, right justice would be done -
for in many cases reciprocity and rectificatory justice are not in
accord; e.g. (1) if an official has inflicted a wound, he should not
be wounded in return, and if some one has wounded an official,
he ought not to be wounded only but punished in addition.
Further (2) there is a great difference between a voluntary and
2642
an involuntary act. But in associations for exchange this sort of
justice does hold men together - reciprocity in accordance with
a proportion and not on the basis of precisely equal return. For
it is by proportionate requital that the city holds together. Men
seek to return either evil for evil - and if they cannot do so,
think their position mere slavery - or good for good - and if they
cannot do so there is no exchange, but it is by exchange that
they hold together. This is why they give a prominent place to
the temple of the Graces - to promote the requital of services;
for this is characteristic of grace - we should serve in return one
who has shown grace to us, and should another time take the
initiative in showing it.
Now proportionate return is secured by cross-conjunction. Let A
be a builder, B a shoemaker, C a house, D a shoe. The builder,
then, must get from the shoemaker the latter's work, and must
himself give him in return his own. If, then, first there is
proportionate equality of goods, and then reciprocal action
takes place, the result we mention will be effected. If not, the
bargain is not equal, and does not hold; for there is nothing to
prevent the work of the one being better than that of the other;
they must therefore be equated. (And this is true of the other
arts also; for they would have been destroyed if what the
patient suffered had not been just what the agent did, and of
the same amount and kind.) For it is not two doctors that
associate for exchange, but a doctor and a farmer, or in general
people who are different and unequal; but these must be
equated. This is why all things that are exchanged must be
somehow comparable. It is for this end that money has been
introduced, and it becomes in a sense an intermediate; for it
measures all things, and therefore the excess and the defect -
how many shoes are equal to a house or to a given amount of
food. The number of shoes exchanged for a house (or for a given
amount of food) must therefore correspond to the ratio of
builder to shoemaker. For if this be not so, there will be no
2643
exchange and no intercourse. And this proportion will not be
effected unless the goods are somehow equal. All goods must
therefore be measured by some one thing, as we said before.
Now this unit is in truth demand, which holds all things
together (for if men did not need one another's goods at all, or
did not need them equally, there would be either no exchange
or not the same exchange); but money has become by
convention a sort of representative of demand; and this is why
it has the name 'money' (nomisma) - because it exists not by
nature but by law (nomos) and it is in our power to change it
and make it useless. There will, then, be reciprocity when the
terms have been equated so that as farmer is to shoemaker, the
amount of the shoemaker's work is to that of the farmer's work
for which it exchanges. But we must not bring them into a
figure of proportion when they have already exchanged
(otherwise one extreme will have both excesses), but when they
still have their own goods. Thus they are equals and associates
just because this equality can be effected in their case. Let A be
a farmer, C food, B a shoemaker, D his product equated to C. If it
had not been possible for reciprocity to be thus effected, there
would have been no association of the parties. That demand
holds things together as a single unit is shown by the fact that
when men do not need one another, i.e. when neither needs the
other or one does not need the other, they do not exchange, as
we do when some one wants what one has oneself, e.g. when
people permit the exportation of corn in exchange for wine.
This equation therefore must be established. And for the future
exchange - that if we do not need a thing now we shall have it if
ever we do need it - money is as it were our surety; for it must
be possible for us to get what we want by bringing the money.
Now the same thing happens to money itself as to goods - it is
not always worth the same; yet it tends to be steadier. This is
why all goods must have a price set on them; for then there will
always be exchange, and if so, association of man with man.
2644
Money, then, acting as a measure, makes goods commensurate
and equates them; for neither would there have been
association if there were not exchange, nor exchange if there
were not equality, nor equality if there were not
commensurability. Now in truth it is impossible that things
differing so much should become commensurate, but with
reference to demand they may become so sufficiently. There
must, then, be a unit, and that fixed by agreement (for which
reason it is called money); for it is this that makes all things
commensurate, since all things are measured by money. Let A
be a house, B ten minae, C a bed. A is half of B, if the house is
worth five minae or equal to them; the bed, C, is a tenth of B; it
is plain, then, how many beds are equal to a house, viz. five.
That exchange took place thus before there was money is plain;
for it makes no difference whether it is five beds that exchange
for a house, or the money value of five beds.
We have now defined the unjust and the just. These having
been marked off from each other, it is plain that just action is
intermediate between acting unjustly and being unjustly
treated; for the one is to have too much and the other to have
too little. Justice is a kind of mean, but not in the same way as
the other virtues, but because it relates to an intermediate
amount, while injustice relates to the extremes. And justice is
that in virtue of which the just man is said to be a doer, by
choice, of that which is just, and one who will distribute either
between himself and another or between two others not so as
to give more of what is desirable to himself and less to his
neighbour (and conversely with what is harmful), but so as to
give what is equal in accordance with proportion; and similarly
in distributing between two other persons. Injustice on the
other hand is similarly related to the unjust, which is excess
and defect, contrary to proportion, of the useful or hurtful. For
which reason injustice is excess and defect, viz. because it is
productive of excess and defect - in one's own case excess of
2645
what is in its own nature useful and defect of what is hurtful,
while in the case of others it is as a whole like what it is in one's
own case, but proportion may be violated in either direction. In
the unjust act to have too little is to be unjustly treated; to have
too much is to act unjustly.
Let this be taken as our account of the nature of justice and
injustice, and similarly of the just and the unjust in general.
Since acting unjustly does not necessarily imply being unjust,
we must ask what sort of unjust acts imply that the doer is
unjust with respect to each type of injustice, e.g. a thief, an
adulterer, or a brigand. Surely the answer does not turn on the
difference between these types. For a man might even lie with a
woman knowing who she was, but the origin of his might be not
deliberate choice but passion. He acts unjustly, then, but is not
unjust; e.g. a man is not a thief, yet he stole, nor an adulterer,
yet he committed adultery; and similarly in all other cases.
Now we have previously stated how the reciprocal is related to
the just; but we must not forget that what we are looking for is
not only what is just without qualification but also political
justice. This is found among men who share their life with a
view to selfsufficiency, men who are free and either
proportionately or arithmetically equal, so that between those
who do not fulfil this condition there is no political justice but
justice in a special sense and by analogy. For justice exists only
between men whose mutual relations are governed by law; and
law exists for men between whom there is injustice; for legal
justice is the discrimination of the just and the unjust. And
between men between whom there is injustice there is also
2646
unjust action (though there is not injustice between all between
whom there is unjust action), and this is assigning too much to
oneself of things good in themselves and too little of things evil
in themselves. This is why we do not allow a man to rule, but
rational principle, because a man behaves thus in his own
interests and becomes a tyrant. The magistrate on the other
hand is the guardian of justice, and, if of justice, then of equality
also. And since he is assumed to have no more than his share, if
he is just (for he does not assign to himself more of what is
good in itself, unless such a share is proportional to his merits -
so that it is for others that he labours, and it is for this reason
that men, as we stated previously, say that justice is 'another's
good'), therefore a reward must be given him, and this is honour
and privilege; but those for whom such things are not enough
become tyrants.
The justice of a master and that of a father are not the same as
the justice of citizens, though they are like it; for there can be
no injustice in the unqualified sense towards thing that are
one's own, but a man's chattel, and his child until it reaches a
certain age and sets up for itself, are as it were part of himself,
and no one chooses to hurt himself (for which reason there can
be no injustice towards oneself). Therefore the justice or
injustice of citizens is not manifested in these relations; for it
was as we saw according to law, and between people naturally
subject to law, and these as we saw' are people who have an
equal share in ruling and being ruled. Hence justice can more
truly be manifested towards a wife than towards children and
chattels, for the former is household justice; but even this is
different from political justice.
2647
Of political justice part is natural, part legal, natural, that which
everywhere has the same force and does not exist by people's
thinking this or that; legal, that which is originally indifferent,
but when it has been laid down is not indifferent, e.g. that a
prisoner's ransom shall be a mina, or that a goat and not two
sheep shall be sacrificed, and again all the laws that are passed
for particular cases, e.g. that sacrifice shall be made in honour
of Brasidas, and the provisions of decrees. Now some think that
all justice is of this sort, because that which is by nature is
unchangeable and has everywhere the same force (as fire burns
both here and in Persia), while they see change in the things
recognized as just. This, however, is not true in this unqualified
way, but is true in a sense; or rather, with the gods it is perhaps
not true at all, while with us there is something that is just even
by nature, yet all of it is changeable; but still some is by nature,
some not by nature. It is evident which sort of thing, among
things capable of being otherwise, is by nature, and which is not
but is legal and conventional, assuming that both are equally
changeable. And in all other things the same distinction will
apply; by nature the right hand is stronger, yet it is possible that
all men should come to be ambidextrous. The things which are
just by virtue of convention and expediency are like measures;
for wine and corn measures are not everywhere equal, but
larger in wholesale and smaller in retail markets. Similarly, the
things which are just not by nature but by human enactment
are not everywhere the same, since constitutions also are not
the same, though there is but one which is everywhere by
nature the best. Of things just and lawful each is related as the
universal to its particulars; for the things that are done are
many, but of them each is one, since it is universal.
There is a difference between the act of injustice and what is
unjust, and between the act of justice and what is just; for a
2648
thing is unjust by nature or by enactment; and this very thing,
when it has been done, is an act of injustice, but before it is
done is not yet that but is unjust. So, too, with an act of justice
(though the general term is rather 'just action', and 'act of
justice' is applied to the correction of the act of injustice).
Each of these must later be examined separately with regard to
the nature and number of its species and the nature of the
things with which it is concerned.
8
Acts just and unjust being as we have described them, a man
acts unjustly or justly whenever he does such acts voluntarily;
when involuntarily, he acts neither unjustly nor justly except in
an incidental way; for he does things which happen to be just or
unjust. Whether an act is or is not one of injustice (or of justice)
is determined by its voluntariness or involuntariness; for when
it is voluntary it is blamed, and at the same time is then an act
of injustice; so that there will be things that are unjust but not
yet acts of injustice, if voluntariness be not present as well. By
the voluntary I mean, as has been said before, any of the things
in a man's own power which he does with knowledge, i.e. not in
ignorance either of the person acted on or of the instrument
used or of the end that will be attained (e.g. whom he is striking,
with what, and to what end), each such act being done not
incidentally nor under compulsion (e.g. if A takes B's hand and
therewith strikes C, B does not act voluntarily; for the act was
not in his own power). The person struck may be the striker's
father, and the striker may know that it is a man or one of the
persons present, but not know that it is his father; a similar
distinction may be made in the case of the end, and with regard
2649
to the whole action. Therefore that which is done in ignorance,
or though not done in ignorance is not in the agent's power, or
is done under compulsion, is involuntary (for many natural
processes, even, we knowingly both perform and experience,
none of which is either voluntary or involuntary; e.g. growing
old or dying). But in the case of unjust and just acts alike the
injustice or justice may be only incidental; for a man might
return a deposit unwillingly and from fear, and then he must
not be said either to do what is just or to act justly, except in an
incidental way. Similarly the man who under compulsion and
unwillingly fails to return the deposit must be said to act
unjustly, and to do what is unjust, only incidentally. Of
voluntary acts we do some by choice, others not by choice; by
choice those which we do after deliberation, not by choice those
which we do without previous deliberation. Thus there are three
kinds of injury in transactions between man and man; those
done in ignorance are mistakes when the person acted on, the
act, the instrument, or the end that will be attained is other
than the agent supposed; the agent thought either that he was
not hiting any one or that he was not hitting with this missile or
not hitting this person or to this end, but a result followed other
than that which he thought likely (e.g. he threw not with intent
to wound but only to prick), or the person hit or the missile was
other than he supposed. Now when (1) the injury takes place
contrary to reasonable expectation, it is a misadventure. When
(2) it is not contrary to reasonable expectation, but does not
imply vice, it is a mistake (for a man makes a mistake when the
fault originates in him, but is the victim of accident when the
origin lies outside him). When (3) he acts with knowledge but
not after deliberation, it is an act of injustice - e.g. the acts due
to anger or to other passions necessary or natural to man; for
when men do such harmful and mistaken acts they act
unjustly, and the acts are acts of injustice, but this does not
imply that the doers are unjust or wicked; for the injury is not
2650
due to vice. But when (4) a man acts from choice, he is an unjust
man and a vicious man.
Hence acts proceeding from anger are rightly judged not to be
done of malice aforethought; for it is not the man who acts in
anger but he who enraged him that starts the mischief. Again,
the matter in dispute is not whether the thing happened or not,
but its justice; for it is apparent injustice that occasions rage.
For they do not dispute about the occurrence of the act - as in
commercial transactions where one of the two parties must be
vicious - unless they do so owing to forgetfulness; but, agreeing
about the fact, they dispute on which side justice lies (whereas
a man who has deliberately injured another cannot help
knowing that he has done so), so that the one thinks he is being
treated unjustly and the other disagrees.
But if a man harms another by choice, he acts unjustly; and
these are the acts of injustice which imply that the doer is an
unjust man, provided that the act violates proportion or
equality. Similarly, a man is just when he acts justly by choice;
but he acts justly if he merely acts voluntarily.
Of involuntary acts some are excusable, others not. For the
mistakes which men make not only in ignorance but also from
ignorance are excusable, while those which men do not from
ignorance but (though they do them in ignorance) owing to a
passion which is neither natural nor such as man is liable to,
are not excusable.
2651
Assuming that we have sufficiently defined the suffering and
doing of injustice, it may be asked (1) whether the truth in
expressed in Euripides' paradoxical words:
I slew my mother, that's my tale in brief.
Were you both willing, or unwilling both?
Is it truly possible to be willingly treated unjustly, or is all
suffering of injustice the contrary involuntary, as all unjust
action is voluntary? And is all suffering of injustice of the latter
kind or else all of the former, or is it sometimes voluntary,
sometimes involuntary? So, too, with the case of being justly
treated; all just action is voluntary, so that it is reasonable that
there should be a similar opposition in either case - that both
being unjustly and being justly treated should be either alike
voluntary or alike involuntary. But it would be thought
paradoxical even in the case of being justly treated, if it were
always voluntary; for some are unwillingly treated justly. (2) One
might raise this question also, whether every one who has
suffered what is unjust is being unjustly treated, or on the other
hand it is with suffering as with acting. In action and in
passivity alike it is possible to partake of justice incidentally,
and similarly (it is plain) of injustice; for to do what is unjust is
not the same as to act unjustly, nor to suffer what is unjust as
to be treated unjustly, and similarly in the case of acting justly
and being justly treated; for it is impossible to be unjustly
treated if the other does not act unjustly, or justly treated unless
he acts justly. Now if to act unjustly is simply to harm some one
voluntarily, and 'voluntarily' means 'knowing the person acted
on, the instrument, and the manner of one's acting', and the
incontinent man voluntarily harms himself, not only will he
voluntarily be unjustly treated but it will be possible to treat
oneself unjustly. (This also is one of the questions in doubt,
2652
whether a man can treat himself unjustly.) Again, a man may
voluntarily, owing to incontinence, be harmed by another who
acts voluntarily, so that it would be possible to be voluntarily
treated unjustly. Or is our definition incorrect; must we to
'harming another, with knowledge both of the person acted on,
of the instrument, and of the manner' add 'contrary to the wish
of the person acted on? Then a man may be voluntarily harmed
and voluntarily suffer what is unjust, but no one is voluntarily
treated unjustly; for no one wishes to be unjustly treated, not
even the incontinent man. He acts contrary to his wish; for no
one wishes for what he does not think to be good, but the
incontinent man does do things that he does not think he ought
to do. Again, one who gives what is his own, as Homer says
Glaucus gave Diomede Armour of gold for brazen, the price of a
hundred beeves for nine, is not unjustly treated; for though to
give is in his power, to be unjustly treated is not, but there must
be some one to treat him unjustly. It is plain, then, that being
unjustly treated is not voluntary.
Of the questions we intended to discuss two still remain for
discussion; (3) whether it is the man who has assigned to
another more than his share that acts unjustly, or he who has
the excessive share, and (4) whether it is possible to treat
oneself unjustly. The questions are connected; for if the former
alternative is possible and the distributor acts unjustly and not
the man who has the excessive share, then if a man assigns
more to another than to himself, knowingly and voluntarily, he
treats himself unjustly; which is what modest people seem to
do, since the virtuous man tends to take less than his share. Or
does this statement too need qualification? For (a) he perhaps
gets more than his share of some other good, e.g. of honour or
of intrinsic nobility, (b) The question is solved by applying the
distinction we applied to unjust action; for he suffers nothing
contrary to his own wish, so that he is not unjustly treated as
far as this goes, but at most only suffers harm.
2653
It is plain too that the distributor acts unjustly, but not always
the man who has the excessive share; for it is not he to whom
what is unjust appertains that acts unjustly, but he to whom it
appertains to do the unjust act voluntarily, i.e. the person in
whom lies the origin of the action, and this lies in the
distributor, not in the receiver. Again, since the word 'do' is
ambiguous, and there is a sense in which lifeless things, or a
hand, or a servant who obeys an order, may be said to slay, he
who gets an excessive share does not act unjustly, though he
'does' what is unjust.
Again, if the distributor gave his judgement in ignorance, he
does not act unjustly in respect of legal justice, and his
judgement is not unjust in this sense, but in a sense it is unjust
(for legal justice and primordial justice are different); but if with
knowledge he judged unjustly, he is himself aiming at an
excessive share either of gratitude or of revenge. As much, then,
as if he were to share in the plunder, the man who has judged
unjustly for these reasons has got too much; the fact that what
he gets is different from what he distributes makes no
difference, for even if he awards land with a view to sharing in
the plunder he gets not land but money.
Men think that acting unjustly is in their power, and therefore
that being just is easy. But it is not; to lie with one's neighbour's
wife, to wound another, to deliver a bribe, is easy and in our
power, but to do these things as a result of a certain state of
character is neither easy nor in our power. Similarly to know
what is just and what is unjust requires, men think, no great
wisdom, because it is not hard to understand the matters dealt
with by the laws (though these are not the things that are just,
except incidentally); but how actions must be done and
distributions effected in order to be just, to know this is a
greater achievement than knowing what is good for the health;
though even there, while it is easy to know that honey, wine,
2654
hellebore, cautery, and the use of the knife are so, to know how,
to whom, and when these should be applied with a view to
producing health, is no less an achievement than that of being a
physician. Again, for this very reason men think that acting
unjustly is characteristic of the just man no less than of the
unjust, because he would be not less but even more capable of
doing each of these unjust acts; for he could lie with a woman
or wound a neighbour; and the brave man could throw away his
shield and turn to flight in this direction or in that. But to play
the coward or to act unjustly consists not in doing these things,
except incidentally, but in doing them as the result of a certain
state of character, just as to practise medicine and healing
consists not in applying or not applying the knife, in using or
not using medicines, but in doing so in a certain way.
Just acts occur between people who participate in things good
in themselves and can have too much or too little of them; for
some beings (e.g. presumably the gods) cannot have too much
of them, and to others, those who are incurably bad, not even
the smallest share in them is beneficial but all such goods are
harmful, while to others they are beneficial up to a point;
therefore justice is essentially something human.
10
Our next subject is equity and the equitable (to epiekes), and
their respective relations to justice and the just. For on
examination they appear to be neither absolutely the same nor
generically different; and while we sometime praise what is
equitable and the equitable man (so that we apply the name by
way of praise even to instances of the other virtues, instead of
'good' meaning by epieikestebon that a thing is better), at other
2655
times, when we reason it out, it seems strange if the equitable,
being something different from the just, is yet praiseworthy; for
either the just or the equitable is not good, if they are different;
or, if both are good, they are the same.
These, then, are pretty much the considerations that give rise to
the problem about the equitable; they are all in a sense correct
and not opposed to one another; for the equitable, though it is
better than one kind of justice, yet is just, and it is not as being
a different class of thing that it is better than the just. The same
thing, then, is just and equitable, and while both are good the
equitable is superior. What creates the problem is that the
equitable is just, but not the legally just but a correction of legal
justice. The reason is that all law is universal but about some
things it is not possible to make a universal statement which
shall be correct. In those cases, then, in which it is necessary to
speak universally, but not possible to do so correctly, the law
takes the usual case, though it is not ignorant of the possibility
of error. And it is none the less correct; for the error is in the law
nor in the legislator but in the nature of the thing, since the
matter of practical affairs is of this kind from the start. When
the law speaks universally, then, and a case arises on it which is
not covered by the universal statement, then it is right, where
the legislator fails us and has erred by oversimplicity, to correct
the omission - to say what the legislator himself would have
said had he been present, and would have put into his law if he
had known. Hence the equitable is just, and better than one
kind of justice - not better than absolute justice but better than
the error that arises from the absoluteness of the statement.
And this is the nature of the equitable, a correction of law
where it is defective owing to its universality. In fact this is the
reason why all things are not determined by law, that about
some things it is impossible to lay down a law, so that a decree
is needed. For when the thing is indefinite the rule also is
indefinite, like the leaden rule used in making the Lesbian
2656
moulding; the rule adapts itself to the shape of the stone and is
not rigid, and so too the decree is adapted to the facts.
It is plain, then, what the equitable is, and that it is just and is
better than one kind of justice. It is evident also from this who
the equitable man is; the man who chooses and does such acts,
and is no stickler for his rights in a bad sense but tends to take
less than his share though he has the law oft his side, is
equitable, and this state of character is equity, which is a sort of
justice and not a different state of character.
11
Whether a man can treat himself unjustly or not, is evident
from what has been said. For (a) one class of just acts are those
acts in accordance with any virtue which are prescribed by the
law; e.g. the law does not expressly permit suicide, and what it
does not expressly permit it forbids. Again, when a man in
violation of the law harms another (otherwise than in
retaliation) voluntarily, he acts unjustly, and a voluntary agent is
one who knows both the person he is affecting by his action
and the instrument he is using; and he who through anger
voluntarily stabs himself does this contrary to the right rule of
life, and this the law does not allow; therefore he is acting
unjustly. But towards whom? Surely towards the state, not
towards himself. For he suffers voluntarily, but no one is
voluntarily treated unjustly. This is also the reason why the
state punishes; a certain loss of civil rights attaches to the man
who destroys himself, on the ground that he is treating the
state unjustly.
Further (b) in that sense of 'acting unjustly' in which the man
who 'acts unjustly' is unjust only and not bad all round, it is not
2657
possible to treat oneself unjustly (this is different from the
former sense; the unjust man in one sense of the term is
wicked in a particularized way just as the coward is, not in the
sense of being wicked all round, so that his 'unjust act' does not
manifest wickedness in general). For (i) that would imply the
possibility of the same thing's having been subtracted from and
added to the same thing at the same time; but this is impossible
- the just and the unjust always involve more than one person.
Further, (ii) unjust action is voluntary and done by choice, and
takes the initiative (for the man who because he has suffered
does the same in return is not thought to act unjustly); but if a
man harms himself he suffers and does the same things at the
same time. Further, (iii) if a man could treat himself unjustly, he
could be voluntarily treated unjustly. Besides, (iv) no one acts
unjustly without committing particular acts of injustice; but no
one can commit adultery with his own wife or housebreaking
on his own house or theft on his own property,
In general, the question 'can a man treat himself unjustly?' is
solved also by the distinction we applied to the question 'can a
man be voluntarily treated unjustly?'
(It is evident too that both are bad, being unjustly treated and
acting unjustly; for the one means having less and the other
having more than the intermediate amount, which plays the
part here that the healthy does in the medical art, and that good
condition does in the art of bodily training. But still acting
unjustly is the worse, for it involves vice and is blameworthy -
involves vice which is either of the complete and unqualified
kind or almost so (we must admit the latter alternative, because
not all voluntary unjust action implies injustice as a state of
character), while being unjustly treated does not involve vice
and injustice in oneself. In itself, then, being unjustly treated is
less bad, but there is nothing to prevent its being incidentally a
greater evil. But theory cares nothing for this; it calls pleurisy a
2658
more serious mischief than a stumble; yet the latter may
become incidentally the more serious, if the fall due to it leads
to your being taken prisoner or put to death the enemy.)
Metaphorically and in virtue of a certain resemblance there is a
justice, not indeed between a man and himself, but between
certain parts of him; yet not every kind of justice but that of
master and servant or that of husband and wife. For these are
the ratios in which the part of the soul that has a rational
principle stands to the irrational part; and it is with a view to
these parts that people also think a man can be unjust to
himself, viz. because these parts are liable to suffer something
contrary to their respective desires; there is therefore thought to
be a mutual justice between them as between ruler and ruled.
Let this be taken as our account of justice and the other, i.e. the
other moral, virtues.
Book VI
Since we have previously said that one ought to choose that
which is intermediate, not the excess nor the defect, and that
the intermediate is determined by the dictates of the right rule,
let us discuss the nature of these dictates. In all the states of
character we have mentioned, as in all other matters, there is a
mark to which the man who has the rule looks, and heightens
2659
or relaxes his activity accordingly, and there is a standard which
determines the mean states which we say are intermediate
between excess and defect, being in accordance with the right
rule. But such a statement, though true, is by no means clear;
for not only here but in all other pursuits which are objects of
knowledge it is indeed true to say that we must not exert
ourselves nor relax our efforts too much nor too little, but to an
intermediate extent and as the right rule dictates; but if a man
had only this knowledge he would be none the wiser e.g. we
should not know what sort of medicines to apply to our body if
some one were to say 'all those which the medical art
prescribes, and which agree with the practice of one who
possesses the art'. Hence it is necessary with regard to the
states of the soul also not only that this true statement should
be made, but also that it should be determined what is the right
rule and what is the standard that fixes it.
We divided the virtues of the soul and a said that some are
virtues of character and others of intellect. Now we have
discussed in detail the moral virtues; with regard to the others
let us express our view as follows, beginning with some remarks
about the soul. We said before that there are two parts of the
soul - that which grasps a rule or rational principle, and the
irrational; let us now draw a similar distinction within the part
which grasps a rational principle. And let it be assumed that
there are two parts which grasp a rational principle - one by
which we contemplate the kind of things whose originative
causes are invariable, and one by which we contemplate
variable things; for where objects differ in kind the part of the
soul answering to each of the two is different in kind, since it is
in virtue of a certain likeness and kinship with their objects that
they have the knowledge they have. Let one of these parts be
called the scientific and the other the calculative; for to
deliberate and to calculate are the same thing, but no one
deliberates about the invariable. Therefore the calculative is one
2660
part of the faculty which grasps a rational principle. We must,
then, learn what is the best state of each of these two parts; for
this is the virtue of each.
The virtue of a thing is relative to its proper work. Now there are
three things in the soul which control action and truth -
sensation, reason, desire.
Of these sensation originates no action; this is plain from the
fact that the lower animals have sensation but no share in
action.
What affirmation and negation are in thinking, pursuit and
avoidance are in desire; so that since moral virtue is a state of
character concerned with choice, and choice is deliberate desire,
therefore both the reasoning must be true and the desire right,
if the choice is to be good, and the latter must pursue just what
the former asserts. Now this kind of intellect and of truth is
practical; of the intellect which is contemplative, not practical
nor productive, the good and the bad state are truth and falsity
respectively (for this is the work of everything intellectual);
while of the part which is practical and intellectual the good
state is truth in agreement with right desire.
The origin of action - its efficient, not its final cause - is choice,
and that of choice is desire and reasoning with a view to an end.
This is why choice cannot exist either without reason and
intellect or without a moral state; for good action and its
opposite cannot exist without a combination of intellect and
character. Intellect itself, however, moves nothing, but only the
intellect which aims at an end and is practical; for this rules the
2661
productive intellect, as well, since every one who makes makes
for an end, and that which is made is not an end in the
unqualified sense (but only an end in a particular relation, and
the end of a particular operation) - only that which is done is
that; for good action is an end, and desire aims at this. Hence
choice is either desiderative reason or ratiocinative desire, and
such an origin of action is a man. (It is to be noted that nothing
that is past is an object of choice, e.g. no one chooses to have
sacked Troy; for no one deliberates about the past, but about
what is future and capable of being otherwise, while what is
past is not capable of not having taken place; hence Agathon is
right in saying
For this alone is lacking even to God,
To make undone things thathave once been done.)
The work of both the intellectual parts, then, is truth. Therefore
the states that are most strictly those in respect of which each
of these parts will reach truth are the virtues of the two parts.
Let us begin, then, from the beginning, and discuss these states
once more. Let it be assumed that the states by virtue of which
the soul possesses truth by way of affirmation or denial are five
in number, i.e. art, scientific knowledge, practical wisdom,
philosophic wisdom, intuitive reason; we do not include
judgement and opinion because in these we may be mistaken.
Now what scientific knowledge is, if we are to speak exactly and
not follow mere similarities, is plain from what follows. We all
suppose that what we know is not even capable of being
2662
otherwise; of things capable of being otherwise we do not know,
when they have passed outside our observation, whether they
exist or not. Therefore the object of scientific knowledge is of
necessity. Therefore it is eternal; for things that are of necessity
in the unqualified sense are all eternal; and things that are
eternal are ungenerated and imperishable. Again, every science
is thought to be capable of being taught, and its object of being
learned. And all teaching starts from what is already known, as
we maintain in the Analytics also; for it proceeds sometimes
through induction and sometimes by syllogism. Now induction
is the starting-point which knowledge even of the universal
presupposes, while syllogism proceeds from universals. There
are therefore starting-points from which syllogism proceeds,
which are not reached by syllogism; it is therefore by induction
that they are acquired. Scientific knowledge is, then, a state of
capacity to demonstrate, and has the other limiting
characteristics which we specify in the Analytics, for it is when
a man believes in a certain way and the starting-points are
known to him that he has scientific knowledge, since if they are
not better known to him than the conclusion, he will have his
knowledge only incidentally.
Let this, then, be taken as our account of scientific knowledge.
In the variable are included both things made and things done;
making and acting are different (for their nature we treat even
the discussions outside our school as reliable); so that the
reasoned state of capacity to act is different from the reasoned
state of capacity to make. Hence too they are not included one
in the other; for neither is acting making nor is making acting.
2663
Now since architecture is an art and is essentially a reasoned
state of capacity to make, and there is neither any art that is not
such a state nor any such state that is not an art, art is identical
with a state of capacity to make, involving a true course of
reasoning. All art is concerned with coming into being, i.e. with
contriving and considering how something may come into
being which is capable of either being or not being, and whose
origin is in the maker and not in the thing made; for art is
concerned neither with things that are, or come into being, by
necessity, nor with things that do so in accordance with nature
(since these have their origin in themselves). Making and acting
being different, art must be a matter of making, not of acting.
And in a sense chance and art are concerned with the same
objects; as Agathon says, 'art loves chance and chance loves art'.
Art, then, as has been is a state concerned with making,
involving a true course of reasoning, and lack of art on the
contrary is a state concerned with making, involving a false
course of reasoning; both are concerned with the variable.
Regarding practical wisdom we shall get at the truth by
considering who are the persons we credit with it. Now it is
thought to be the mark of a man of practical wisdom to be able
to deliberate well about what is good and expedient for himself,
not in some particular respect, e.g. about what sorts of thing
conduce to health or to strength, but about what sorts of thing
conduce to the good life in general. This is shown by the fact
that we credit men with practical wisdom in some particular
respect when they have calculated well with a view to some
good end which is one of those that are not the object of any
art. It follows that in the general sense also the man who is
2664
capable of deliberating has practical wisdom. Now no one
deliberates about things that are invariable, nor about things
that it is impossible for him to do. Therefore, since scientific
knowledge involves demonstration, but there is no
demonstration of things whose first principles are variable (for
all such things might actually be otherwise), and since it is
impossible to deliberate about things that are of necessity,
practical wisdom cannot be scientific knowledge nor art; not
science because that which can be done is capable of being
otherwise, not art because action and making are different
kinds of thing. The remaining alternative, then, is that it is a
true and reasoned state of capacity to act with regard to the
things that are good or bad for man. For while making has an
end other than itself, action cannot; for good action itself is its
end. It is for this reason that we think Pericles and men like him
have practical wisdom, viz. because they can see what is good
for themselves and what is good for men in general; we
consider that those can do this who are good at managing
households or states. (This is why we call temperance
(sophrosune) by this name; we imply that it preserves one's
practical wisdom (sozousa tan phronsin). Now what it preserves
is a judgement of the kind we have described. For it is not any
and every judgement that pleasant and painful objects destroy
and pervert, e.g. the judgement that the triangle has or has not
its angles equal to two right angles, but only judgements about
what is to be done. For the originating causes of the things that
are done consist in the end at which they are aimed; but the
man who has been ruined by pleasure or pain forthwith fails to
see any such originating cause - to see that for the sake of this
or because of this he ought to choose and do whatever he
chooses and does; for vice is destructive of the originating cause
of action.) Practical wisdom, then, must be a reasoned and true
state of capacity to act with regard to human goods. But further,
while there is such a thing as excellence in art, there is no such
2665
thing as excellence in practical wisdom; and in art he who errs
willingly is preferable, but in practical wisdom, as in the virtues,
he is the reverse. Plainly, then, practical wisdom is a virtue and
not an art. There being two parts of the soul that can follow a
course of reasoning, it must be the virtue of one of the two, i.e.
of that part which forms opinions; for opinion is about the
variable and so is practical wisdom. But yet it is not only a
reasoned state; this is shown by the fact that a state of that sort
may forgotten but practical wisdom cannot.
Scientific knowledge is judgement about things that are
universal and necessary, and the conclusions of demonstration,
and all scientific knowledge, follow from first principles (for
scientific knowledge involves apprehension of a rational
ground). This being so, the first principle from which what is
scientifically known follows cannot be an object of scientific
knowledge, of art, or of practical wisdom; for that which can be
scientifically known can be demonstrated, and art and practical
wisdom deal with things that are variable. Nor are these first
principles the objects of philosophic wisdom, for it is a mark of
the philosopher to have demonstration about some things. If,
then, the states of mind by which we have truth and are never
deceived about things invariable or even variable are scientific
knowlededge, practical wisdom, philosophic wisdom, and
intuitive reason, and it cannot be any of the three (i.e. practical
wisdom, scientific knowledge, or philosophic wisdom), the
remaining alternative is that it is intuitive reason that grasps
the first principles.
2666
Wisdom (1) in the arts we ascribe to their most finished
exponents, e.g. to Phidias as a sculptor and to Polyclitus as a
maker of portrait-statues, and here we mean nothing by
wisdom except excellence in art; but (2) we think that some
people are wise in general, not in some particular field or in any
other limited respect, as Homer says in the Margites,
Him did the gods make neither a digger nor yet a ploughman
Nor wise in anything else. Therefore wisdom must plainly be
the most finished of the forms of knowledge. It follows that the
wise man must not only know what follows from the first
principles, but must also possess truth about the first principles.
Therefore wisdom must be intuitive reason combined with
scientific knowledge - scientific knowledge of the highest
objects which has received as it were its proper completion.
Of the highest objects, we say; for it would be strange to think
that the art of politics, or practical wisdom, is the best
knowledge, since man is not the best thing in the world. Now if
what is healthy or good is different for men and for fishes, but
what is white or straight is always the same, any one would say
that what is wise is the same but what is practically wise is
different; for it is to that which observes well the various
matters concerning itself that one ascribes practical wisdom,
and it is to this that one will entrust such matters. This is why
we say that some even of the lower animals have practical
wisdom, viz. those which are found to have a power of foresight
with regard to their own life. It is evident also that philosophic
wisdom and the art of politics cannot be the same; for if the
state of mind concerned with a man's own interests is to be
called philosophic wisdom, there will be many philosophic
2667
wisdoms; there will not be one concerned with the good of all
animals (any more than there is one art of medicine for all
existing things), but a different philosophic wisdom about the
good of each species.
But if the argument be that man is the best of the animals, this
makes no difference; for there are other things much more
divine in their nature even than man, e.g., most conspicuously,
the bodies of which the heavens are framed. From what has
been said it is plain, then, that philosophic wisdom is scientific
knowledge, combined with intuitive reason, of the things that
are highest by nature. This is why we say Anaxagoras, Thales,
and men like them have philosophic but not practical wisdom,
when we see them ignorant of what is to their own advantage,
and why we say that they know things that are remarkable,
admirable, difficult, and divine, but useless; viz. because it is not
human goods that they seek.
Practical wisdom on the other hand is concerned with things
human and things about which it is possible to deliberate; for
we say this is above all the work of the man of practical
wisdom, to deliberate well, but no one deliberates about things
invariable, nor about things which have not an end, and that a
good that can be brought about by action. The man who is
without qualification good at deliberating is the man who is
capable of aiming in accordance with calculation at the best for
man of things attainable by action. Nor is practical wisdom
concerned with universals only - it must also recognize the
particulars; for it is practical, and practice is concerned with
particulars. This is why some who do not know, and especially
those who have experience, are more practical than others who
know; for if a man knew that light meats are digestible and
wholesome, but did not know which sorts of meat are light, he
would not produce health, but the man who knows that chicken
is wholesome is more likely to produce health.
2668
Now practical wisdom is concerned with action; therefore one
should have both forms of it, or the latter in preference to the
former. But of practical as of philosophic wisdom there must be
a controlling kind.
8
Political wisdom and practical wisdom are the same state of
mind, but their essence is not the same. Of the wisdom
concerned with the city, the practical wisdom which plays a
controlling part is legislative wisdom, while that which is
related to this as particulars to their universal is known by the
general name 'political wisdom'; this has to do with action and
deliberation, for a decree is a thing to be carried out in the form
of an individual act. This is why the exponents of this art are
alone said to 'take part in polities'; for these alone 'do things' as
manual labourers 'do things'.
Practical wisdom also is identified especially with that form of it
which is concerned with a man himself - with the individual;
and this is known by the general name 'practical wisdom'; of
the other kinds one is called household management, another
legislation, the third politics, and of the latter one part is called
deliberative and the other judicial. Now knowing what is good
for oneself will be one kind of knowledge, but it is very different
from the other kinds; and the man who knows and concerns
himself with his own interests is thought to have practical
wisdom, while politicians are thought to be busybodies; hence
the word of Euripides,
But how could I be wise, who might at ease,
Numbered among the army's multitude,
2669
Have had an equal share?
For those who aim too high and do too much. Those who think
thus seek their own good, and consider that one ought to do so.
From this opinion, then, has come the view that such men have
practical wisdom; yet perhaps one's own good cannot exist
without household management, nor without a form of
government. Further, how one should order one's own affairs is
not clear and needs inquiry.
What has been said is confirmed by the fact that while young
men become geometricians and mathematicians and wise in
matters like these, it is thought that a young man of practical
wisdom cannot be found. The cause is that such wisdom is
concerned not only with universals but with particulars, which
become familiar from experience, but a young man has no
experience, for it is length of time that gives experience; indeed
one might ask this question too, why a boy may become a
mathematician, but not a philosopher or a physicist. It is
because the objects of mathematics exist by abstraction, while
the first principles of these other subjects come from
experience, and because young men have no conviction about
the latter but merely use the proper language, while the essence
of mathematical objects is plain enough to them?
Further, error in deliberation may be either about the universal
or about the particular; we may fall to know either that all water
that weighs heavy is bad, or that this particular water weighs
heavy.
That practical wisdom is not scientific knowledge is evident; for
it is, as has been said, concerned with the ultimate particular
fact, since the thing to be done is of this nature. It is opposed,
then, to intuitive reason; for intuitive reason is of the limiting
premisses, for which no reason can be given, while practical
wisdom is concerned with the ultimate particular, which is the
2670
object not of scientific knowledge but of perception - not the
perception of qualities peculiar to one sense but a perception
akin to that by which we perceive that the particular figure
before us is a triangle; for in that direction as well as in that of
the major premiss there will be a limit. But this is rather
perception than practical wisdom, though it is another kind of
perception than that of the qualities peculiar to each sense.
There is a difference between inquiry and deliberation; for
deliberation is inquiry into a particular kind of thing. We must
grasp the nature of excellence in deliberation as well whether it
is a form of scientific knowledge, or opinion, or skill in
conjecture, or some other kind of thing. Scientific knowledge it
is not; for men do not inquire about the things they know about,
but good deliberation is a kind of deliberation, and he who
deliberates inquires and calculates. Nor is it skill in conjecture;
for this both involves no reasoning and is something that is
quick in its operation, while men deliberate a long time, and
they say that one should carry out quickly the conclusions of
one's deliberation, but should deliberate slowly. Again, readiness
of mind is different from excellence in deliberation; it is a sort
of skill in conjecture. Nor again is excellence in deliberation
opinion of any sort. But since the man who deliberates badly
makes a mistake, while he who deliberates well does so
correctly, excellence in deliberation is clearly a kind of
correctness, but neither of knowledge nor of opinion; for there
is no such thing as correctness of knowledge (since there is no
such thing as error of knowledge), and correctness of opinion is
truth; and at the same time everything that is an object of
opinion is already determined. But again excellence in
2671
deliberation involves reasoning. The remaining alternative,
then, is that it is correctness of thinking; for this is not yet
assertion, since, while even opinion is not inquiry but has
reached the stage of assertion, the man who is deliberating,
whether he does so well or ill, is searching for something and
calculating.
But excellence in deliberation is a certain correctness of
deliberation; hence we must first inquire what deliberation is
and what it is about. And, there being more than one kind of
correctness, plainly excellence in deliberation is not any and
every kind; for (1) the incontinent man and the bad man, if he is
clever, will reach as a result of his calculation what he sets
before himself, so that he will have deliberated correctly, but he
will have got for himself a great evil. Now to have deliberated
well is thought to be a good thing; for it is this kind of
correctness of deliberation that is excellence in deliberation, viz.
that which tends to attain what is good. But (2) it is possible to
attain even good by a false syllogism, and to attain what one
ought to do but not by the right means, the middle term being
false; so that this too is not yet excellence in deliberation this
state in virtue of which one attains what one ought but not by
the right means. Again (3) it is possible to attain it by long
deliberation while another man attains it quickly. Therefore in
the former case we have not yet got excellence in deliberation,
which is Tightness with regard to the expedient - Tightness in
respect both of the end, the manner, and the time. (4) Further it
is possible to have deliberated well either in the unqualified
sense or with reference to a particular end. Excellence in
deliberation in the unqualified sense, then, is that which
succeeds with reference to what is the end in the unqualified
sense, and excellence in deliberation in a particular sense is
that which succeeds relatively to a particular end. If, then, it is
characteristic of men of practical wisdom to have deliberated
well, excellence in deliberation will be correctness with regard
2672
to what conduces to the end of which practical wisdom is the
true apprehension.
10
Understanding, also, and goodness of understanding, in virtue
of which men are said to be men of understanding or of good
understanding, are neither entirely the same as opinion or
scientific knowledge (for at that rate all men would have been
men of understanding), nor are they one of the particular
sciences, such as medicine, the science of things connected
with health, or geometry, the science of spatial magnitudes. For
understanding is neither about things that are always and are
unchangeable, nor about any and every one of the things that
come into being, but about things which may become subjects
of questioning and deliberation. Hence it is about the same
objects as practical wisdom; but understanding and practical
wisdom are not the same. For practical wisdom issues
commands, since its end is what ought to be done or not to be
done; but understanding only judges. (Understanding is
identical with goodness of understanding, men of
understanding with men of good understanding.) Now
understanding is neither the having nor the acquiring of
practical wisdom; but as learning is called understanding when
it means the exercise of the faculty of knowledge, so
'understanding' is applicable to the exercise of the faculty of
opinion for the purpose of judging of what some one else says
about matters with which practical wisdom is concerned - and
of judging soundly; for 'well' and 'soundly' are the same thing.
And from this has come the use of the name 'understanding' in
virtue of which men are said to be 'of good understanding', viz.
2673
from the application of the word to the grasping of scientific
truth; for we often call such grasping understanding.
11
What is called judgement, in virtue of which men are said to 'be
sympathetic judges' and to 'have judgement', is the right
discrimination of the equitable. This is shown by the fact that
we say the equitable man is above all others a man of
sympathetic judgement, and identify equity with sympathetic
judgement about certain facts. And sympathetic judgement is
judgement which discriminates what is equitable and does so
correctly; and correct judgement is that which judges what is
true.
Now all the states we have considered converge, as might be
expected, to the same point; for when we speak of judgement
and understanding and practical wisdom and intuitive reason
we credit the same people with possessing judgement and
having reached years of reason and with having practical
wisdom and understanding. For all these faculties deal with
ultimates, i.e. with particulars; and being a man of
understanding and of good or sympathetic judgement consists
in being able judge about the things with which practical
wisdom is concerned; for the equities are common to all good
men in relation to other men. Now all things which have to be
done are included among particulars or ultimates; for not only
must the man of practical wisdom know particular facts, but
understanding and judgement are also concerned with things
to be done, and these are ultimates. And intuitive reason is
concerned with the ultimates in both directions; for both the
first terms and the last are objects of intuitive reason and not of
2674
argument, and the intuitive reason which is presupposed by
demonstrations grasps the unchangeable and first terms, while
the intuitive reason involved in practical reasonings grasps the
last and variable fact, i.e. the minor premiss. For these variable
facts are the starting-points for the apprehension of the end,
since the universals are reached from the particulars; of these
therefore we must have perception, and this perception is
intuitive reason.
This is why these states are thought to be natural endowments
- why, while no one is thought to be a philosopher by nature,
people are thought to have by nature judgement,
understanding, and intuitive reason. This is shown by the fact
that we think our powers correspond to our time of life, and
that a particular age brings with it intuitive reason and
judgement; this implies that nature is the cause. (Hence
intuitive reason is both beginning and end; for demonstrations
are from these and about these.) Therefore we ought to attend
to the undemonstrated sayings and opinions of experienced
and older people or of people of practical wisdom not less than
to demonstrations; for because experience has given them an
eye they see aright.
We have stated, then, what practical and philosophic wisdom
are, and with what each of them is concerned, and we have said
that each is the virtue of a different part of the soul.
12
Difficulties might be raised as to the utility of these qualities of
mind. For (1) philosophic wisdom will contemplate none of the
things that will make a man happy (for it is not concerned with
any coming into being), and though practical wisdom has this
2675
merit, for what purpose do we need it? Practical wisdom is the
quality of mind concerned with things just and noble and good
for man, but these are the things which it is the mark of a good
man to do, and we are none the more able to act for knowing
them if the virtues are states of character, just as we are none
the better able to act for knowing the things that are healthy
and sound, in the sense not of producing but of issuing from the
state of health; for we are none the more able to act for having
the art of medicine or of gymnastics. But (2) if we are to say that
a man should have practical wisdom not for the sake of
knowing moral truths but for the sake of becoming good,
practical wisdom will be of no use to those who are good; again
it is of no use to those who have not virtue; for it will make no
difference whether they have practical wisdom themselves or
obey others who have it, and it would be enough for us to do
what we do in the case of health; though we wish to become
healthy, yet we do not learn the art of medicine. (3) Besides this,
it would be thought strange if practical wisdom, being inferior
to philosophic wisdom, is to be put in authority over it, as
seems to be implied by the fact that the art which produces
anything rules and issues commands about that thing.
These, then, are the questions we must discuss; so far we have
only stated the difficulties.
(1) Now first let us say that in themselves these states must be
worthy of choice because they are the virtues of the two parts of
the soul respectively, even if neither of them produce anything.
(2) Secondly, they do produce something, not as the art of
medicine produces health, however, but as health produces
health; so does philosophic wisdom produce happiness; for,
being a part of virtue entire, by being possessed and by
actualizing itself it makes a man happy.
2676
(3) Again, the work of man is achieved only in accordance with
practical wisdom as well as with moral virtue; for virtue makes
us aim at the right mark, and practical wisdom makes us take
the right means. (Of the fourth part of the soul - the nutritive -
there is no such virtue; for there is nothing which it is in its
power to do or not to do.)
(4) With regard to our being none the more able to do because of
our practical wisdom what is noble and just, let us begin a little
further back, starting with the following principle. As we say
that some people who do just acts are not necessarily just, i.e.
those who do the acts ordained by the laws either unwillingly or
owing to ignorance or for some other reason and not for the
sake of the acts themselves (though, to be sure, they do what
they should and all the things that the good man ought), so is it,
it seems, that in order to be good one must be in a certain state
when one does the several acts, i.e. one must do them as a
result of choice and for the sake of the acts themselves. Now
virtue makes the choice right, but the question of the things
which should naturally be done to carry out our choice belongs
not to virtue but to another faculty. We must devote our
attention to these matters and give a clearer statement about
them. There is a faculty which is called cleverness; and this is
such as to be able to do the things that tend towards the mark
we have set before ourselves, and to hit it. Now if the mark be
noble, the cleverness is laudable, but if the mark be bad, the
cleverness is mere smartness; hence we call even men of
practical wisdom clever or smart. Practical wisdom is not the
faculty, but it does not exist without this faculty. And this eye of
the soul acquires its formed state not without the aid of virtue,
as has been said and is plain; for the syllogisms which deal with
acts to be done are things which involve a starting-point, viz.
'since the end, i.e. what is best, is of such and such a nature',
whatever it may be (let it for the sake of argument be what we
please); and this is not evident except to the good man; for
2677
wickedness perverts us and causes us to be deceived about the
starting-points of action. Therefore it is evident that it is
impossible to be practically wise without being good.
13
We must therefore consider virtue also once more; for virtue too
is similarly related; as practical wisdom is to cleverness - not
the same, but like it - so is natural virtue to virtue in the strict
sense. For all men think that each type of character belongs to
its possessors in some sense by nature; for from the very
moment of birth we are just or fitted for selfcontrol or brave or
have the other moral qualities; but yet we seek something else
as that which is good in the strict sense - we seek for the
presence of such qualities in another way. For both children and
brutes have the natural dispositions to these qualities, but
without reason these are evidently hurtful. Only we seem to see
this much, that, while one may be led astray by them, as a
strong body which moves without sight may stumble badly
because of its lack of sight, still, if a man once acquires reason,
that makes a difference in action; and his state, while still like
what it was, will then be virtue in the strict sense. Therefore, as
in the part of us which forms opinions there are two types,
cleverness and practical wisdom, so too in the moral part there
are two types, natural virtue and virtue in the strict sense, and
of these the latter involves practical wisdom. This is why some
say that all the virtues are forms of practical wisdom, and why
Socrates in one respect was on the right track while in another
he went astray; in thinking that all the virtues were forms of
practical wisdom he was wrong, but in saying they implied
practical wisdom he was right. This is confirmed by the fact that
even now all men, when they define virtue, after naming the
2678
state of character and its objects add 'that (state) which is in
accordance with the right rule'; now the right rule is that which
is in accordance with practical wisdom. All men, then, seem
somehow to divine that this kind of state is virtue, viz. that
which is in accordance with practical wisdom. But we must go a
little further. For it is not merely the state in accordance with
the right rule, but the state that implies the presence of the
right rule, that is virtue; and practical wisdom is a right rule
about such matters. Socrates, then, thought the virtues were
rules or rational principles (for he thought they were, all of
them, forms of scientific knowledge), while we think they
involve a rational principle.
It is clear, then, from what has been said, that it is not possible
to be good in the strict sense without practical wisdom, nor
practically wise without moral virtue. But in this way we may
also refute the dialectical argument whereby it might be
contended that the virtues exist in separation from each other;
the same man, it might be said, is not best equipped by nature
for all the virtues, so that he will have already acquired one
when he has not yet acquired another. This is possible in
respect of the natural virtues, but not in respect of those in
respect of which a man is called without qualification good; for
with the presence of the one quality, practical wisdom, will be
given all the virtues. And it is plain that, even if it were of no
practical value, we should have needed it because it is the virtue
of the part of us in question; plain too that the choice will not
be right without practical wisdom any more than without
virtue; for the one deter, mines the end and the other makes us
do the things that lead to the end.
But again it is not supreme over philosophic wisdom, i.e. over
the superior part of us, any more than the art of medicine is
over health; for it does not use it but provides for its coming
into being; it issues orders, then, for its sake, but not to it.
2679
Further, to maintain its supremacy would be like saying that the
art of politics rules the gods because it issues orders about all
the affairs of the state.
Book VII
Let us now make a fresh beginning and point out that of moral
states to be avoided there are three kinds - vice, incontinence,
brutishness. The contraries of two of these are evident, - one we
call virtue, the other continence; to brutishness it would be
most fitting to oppose superhuman virtue, a heroic and divine
kind of virtue, as Homer has represented Priam saying of Hector
that he was very good,
For he seemed not, he,
The child of a mortal man, but as one that of God's seed came.
Therefore if, as they say, men become gods by excess of virtue,
of this kind must evidently be the state opposed to the brutish
state; for as a brute has no vice or virtue, so neither has a god;
his state is higher than virtue, and that of a brute is a different
kind of state from vice.
Now, since it is rarely that a godlike man is found - to use the
epithet of the Spartans, who when they admire any one highly
call him a 'godlike man' - so too the brutish type is rarely found
2680
among men; it is found chiefly among barbarians, but some
brutish qualities are also produced by disease or deformity; and
we also call by this evil name those men who go beyond all
ordinary standards by reason of vice. Of this kind of disposition,
however, we must later make some mention, while we have
discussed vice before we must now discuss incontinence and
softness (or effeminacy), and continence and endurance; for we
must treat each of the two neither as identical with virtue or
wickedness, nor as a different genus. We must, as in all other
cases, set the observed facts before us and, after first discussing
the difficulties, go on to prove, if possible, the truth of all the
common opinions about these affections of the mind, or, failing
this, of the greater number and the most authoritative; for if we
both refute the objections and leave the common opinions
undisturbed, we shall have proved the case sufficiently.
Now (1) both continence and endurance are thought to be
included among things good and praiseworthy, and both
incontinence and soft, ness among things bad and
blameworthy; and the same man is thought to be continent and
ready to abide by the result of his calculations, or incontinent
and ready to abandon them. And (2) the incontinent man,
knowing that what he does is bad, does it as a result of passion,
while the continent man, knowing that his appetites are bad,
refuses on account of his rational principle to follow them (3)
The temperate man all men call continent and disposed to
endurance, while the continent man some maintain to be
always temperate but others do not; and some call the self-
indulgent man incontinent and the incontinent man
selfindulgent indiscriminately, while others distinguish them.
(4) The man of practical wisdom, they sometimes say, cannot be
incontinent, while sometimes they say that some who are
practically wise and clever are incontinent. Again (5) men are
said to be incontinent even with respect to anger, honour, and
gain. -These, then, are the things that are said.
2681
Now we may ask (1) how a man who judges rightly can behave
incontinently. That he should behave so when he has
knowledge, some say is impossible; for it would be strange - so
Socrates thought - if when knowledge was in a man something
else could master it and drag it about like a slave. For Socrates
was entirely opposed to the view in question, holding that there
is no such thing as incontinence; no one, he said, when he
judges acts against what he judges best-people act so only by
reason of ignorance. Now this view plainly contradicts the
observed facts, and we must inquire about what happens to
such a man; if he acts by reason of ignorance, what is the
manner of his ignorance? For that the man who behaves
incontinently does not, before he gets into this state, think he
ought to act so, is evident. But there are some who concede
certain of Socrates' contentions but not others; that nothing is
stronger than knowledge they admit, but not that on one acts
contrary to what has seemed to him the better course, and
therefore they say that the incontinent man has not knowledge
when he is mastered by his pleasures, but opinion. But if it is
opinion and not knowledge, if it is not a strong conviction that
resists but a weak one, as in men who hesitate, we sympathize
with their failure to stand by such convictions against strong
appetites; but we do not sympathize with wickedness, nor with
any of the other blameworthy states. Is it then practical wisdom
whose resistance is mastered? That is the strongest of all states.
But this is absurd; the same man will be at once practically wise
and incontinent, but no one would say that it is the part of a
practically wise man to do willingly the basest acts. Besides, it
has been shown before that the man of practical wisdom is one
2682
who will act (for he is a man concerned with the individual
facts) and who has the other virtues.
(2) Further, if continence involves having strong and bad
appetites, the temperate man will not be continent nor the
continent man temperate; for a temperate man will have
neither excessive nor bad appetites. But the continent man
must; for if the appetites are good, the state of character that
restrains us from following them is bad, so that not all
continence will be good; while if they are weak and not bad,
there is nothing admirable in resisting them, and if they are
weak and bad, there is nothing great in resisting these either.
(3) Further, if continence makes a man ready to stand by any
and every opinion, it is bad, i.e. if it mak 
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